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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
4 * Copyright (C) 2014 Red Hat, Inc.
5 * Copyright (C) 2015 Arrikto, Inc.
6 * Copyright (C) 2017 Chinamobile, Inc.
7 */
8
9#include <linux/spinlock.h>
10#include <linux/module.h>
11#include <linux/idr.h>
12#include <linux/kernel.h>
13#include <linux/timer.h>
14#include <linux/parser.h>
15#include <linux/vmalloc.h>
16#include <linux/uio_driver.h>
17#include <linux/radix-tree.h>
18#include <linux/stringify.h>
19#include <linux/bitops.h>
20#include <linux/highmem.h>
21#include <linux/configfs.h>
22#include <linux/mutex.h>
23#include <linux/workqueue.h>
24#include <net/genetlink.h>
25#include <scsi/scsi_common.h>
26#include <scsi/scsi_proto.h>
27#include <target/target_core_base.h>
28#include <target/target_core_fabric.h>
29#include <target/target_core_backend.h>
30
31#include <linux/target_core_user.h>
32
33/**
34 * DOC: Userspace I/O
35 * Userspace I/O
36 * -------------
37 *
38 * Define a shared-memory interface for LIO to pass SCSI commands and
39 * data to userspace for processing. This is to allow backends that
40 * are too complex for in-kernel support to be possible.
41 *
42 * It uses the UIO framework to do a lot of the device-creation and
43 * introspection work for us.
44 *
45 * See the .h file for how the ring is laid out. Note that while the
46 * command ring is defined, the particulars of the data area are
47 * not. Offset values in the command entry point to other locations
48 * internal to the mmap-ed area. There is separate space outside the
49 * command ring for data buffers. This leaves maximum flexibility for
50 * moving buffer allocations, or even page flipping or other
51 * allocation techniques, without altering the command ring layout.
52 *
53 * SECURITY:
54 * The user process must be assumed to be malicious. There's no way to
55 * prevent it breaking the command ring protocol if it wants, but in
56 * order to prevent other issues we must only ever read *data* from
57 * the shared memory area, not offsets or sizes. This applies to
58 * command ring entries as well as the mailbox. Extra code needed for
59 * this may have a 'UAM' comment.
60 */
61
62#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
63
64/* For cmd area, the size is fixed 8MB */
65#define CMDR_SIZE (8 * 1024 * 1024)
66
67/*
68 * For data area, the block size is PAGE_SIZE and
69 * the total size is 256K * PAGE_SIZE.
70 */
71#define DATA_BLOCK_SIZE PAGE_SIZE
72#define DATA_BLOCK_SHIFT PAGE_SHIFT
73#define DATA_BLOCK_BITS_DEF (256 * 1024)
74
75#define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
76#define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
77
78/*
79 * Default number of global data blocks(512K * PAGE_SIZE)
80 * when the unmap thread will be started.
81 */
82#define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)
83
84static u8 tcmu_kern_cmd_reply_supported;
85static u8 tcmu_netlink_blocked;
86
87static struct device *tcmu_root_device;
88
89struct tcmu_hba {
90 u32 host_id;
91};
92
93#define TCMU_CONFIG_LEN 256
94
95static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
96static LIST_HEAD(tcmu_nl_cmd_list);
97
98struct tcmu_dev;
99
100struct tcmu_nl_cmd {
101 /* wake up thread waiting for reply */
102 struct completion complete;
103 struct list_head nl_list;
104 struct tcmu_dev *udev;
105 int cmd;
106 int status;
107};
108
109struct tcmu_dev {
110 struct list_head node;
111 struct kref kref;
112
113 struct se_device se_dev;
114
115 char *name;
116 struct se_hba *hba;
117
118#define TCMU_DEV_BIT_OPEN 0
119#define TCMU_DEV_BIT_BROKEN 1
120#define TCMU_DEV_BIT_BLOCKED 2
121#define TCMU_DEV_BIT_TMR_NOTIFY 3
122 unsigned long flags;
123
124 struct uio_info uio_info;
125
126 struct inode *inode;
127
128 struct tcmu_mailbox *mb_addr;
129 uint64_t dev_size;
130 u32 cmdr_size;
131 u32 cmdr_last_cleaned;
132 /* Offset of data area from start of mb */
133 /* Must add data_off and mb_addr to get the address */
134 size_t data_off;
135 size_t data_size;
136 uint32_t max_blocks;
137 size_t ring_size;
138
139 struct mutex cmdr_lock;
140 struct list_head qfull_queue;
141 struct list_head tmr_queue;
142
143 uint32_t dbi_max;
144 uint32_t dbi_thresh;
145 unsigned long *data_bitmap;
146 struct radix_tree_root data_blocks;
147
148 struct idr commands;
149
150 struct timer_list cmd_timer;
151 unsigned int cmd_time_out;
152 struct list_head inflight_queue;
153
154 struct timer_list qfull_timer;
155 int qfull_time_out;
156
157 struct list_head timedout_entry;
158
159 struct tcmu_nl_cmd curr_nl_cmd;
160
161 char dev_config[TCMU_CONFIG_LEN];
162
163 int nl_reply_supported;
164};
165
166#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
167
168#define CMDR_OFF sizeof(struct tcmu_mailbox)
169
170struct tcmu_cmd {
171 struct se_cmd *se_cmd;
172 struct tcmu_dev *tcmu_dev;
173 struct list_head queue_entry;
174
175 uint16_t cmd_id;
176
177 /* Can't use se_cmd when cleaning up expired cmds, because if
178 cmd has been completed then accessing se_cmd is off limits */
179 uint32_t dbi_cnt;
180 uint32_t dbi_cur;
181 uint32_t *dbi;
182
183 unsigned long deadline;
184
185#define TCMU_CMD_BIT_EXPIRED 0
186 unsigned long flags;
187};
188
189struct tcmu_tmr {
190 struct list_head queue_entry;
191
192 uint8_t tmr_type;
193 uint32_t tmr_cmd_cnt;
194 int16_t tmr_cmd_ids[0];
195};
196
197/*
198 * To avoid dead lock the mutex lock order should always be:
199 *
200 * mutex_lock(&root_udev_mutex);
201 * ...
202 * mutex_lock(&tcmu_dev->cmdr_lock);
203 * mutex_unlock(&tcmu_dev->cmdr_lock);
204 * ...
205 * mutex_unlock(&root_udev_mutex);
206 */
207static DEFINE_MUTEX(root_udev_mutex);
208static LIST_HEAD(root_udev);
209
210static DEFINE_SPINLOCK(timed_out_udevs_lock);
211static LIST_HEAD(timed_out_udevs);
212
213static struct kmem_cache *tcmu_cmd_cache;
214
215static atomic_t global_db_count = ATOMIC_INIT(0);
216static struct delayed_work tcmu_unmap_work;
217static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
218
219static int tcmu_set_global_max_data_area(const char *str,
220 const struct kernel_param *kp)
221{
222 int ret, max_area_mb;
223
224 ret = kstrtoint(str, 10, &max_area_mb);
225 if (ret)
226 return -EINVAL;
227
228 if (max_area_mb <= 0) {
229 pr_err("global_max_data_area must be larger than 0.\n");
230 return -EINVAL;
231 }
232
233 tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
234 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
235 schedule_delayed_work(&tcmu_unmap_work, 0);
236 else
237 cancel_delayed_work_sync(&tcmu_unmap_work);
238
239 return 0;
240}
241
242static int tcmu_get_global_max_data_area(char *buffer,
243 const struct kernel_param *kp)
244{
245 return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
246}
247
248static const struct kernel_param_ops tcmu_global_max_data_area_op = {
249 .set = tcmu_set_global_max_data_area,
250 .get = tcmu_get_global_max_data_area,
251};
252
253module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
254 S_IWUSR | S_IRUGO);
255MODULE_PARM_DESC(global_max_data_area_mb,
256 "Max MBs allowed to be allocated to all the tcmu device's "
257 "data areas.");
258
259static int tcmu_get_block_netlink(char *buffer,
260 const struct kernel_param *kp)
261{
262 return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
263 "blocked" : "unblocked");
264}
265
266static int tcmu_set_block_netlink(const char *str,
267 const struct kernel_param *kp)
268{
269 int ret;
270 u8 val;
271
272 ret = kstrtou8(str, 0, &val);
273 if (ret < 0)
274 return ret;
275
276 if (val > 1) {
277 pr_err("Invalid block netlink value %u\n", val);
278 return -EINVAL;
279 }
280
281 tcmu_netlink_blocked = val;
282 return 0;
283}
284
285static const struct kernel_param_ops tcmu_block_netlink_op = {
286 .set = tcmu_set_block_netlink,
287 .get = tcmu_get_block_netlink,
288};
289
290module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
291MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
292
293static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
294{
295 struct tcmu_dev *udev = nl_cmd->udev;
296
297 if (!tcmu_netlink_blocked) {
298 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
299 return -EBUSY;
300 }
301
302 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
303 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
304 nl_cmd->status = -EINTR;
305 list_del(&nl_cmd->nl_list);
306 complete(&nl_cmd->complete);
307 }
308 return 0;
309}
310
311static int tcmu_set_reset_netlink(const char *str,
312 const struct kernel_param *kp)
313{
314 struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
315 int ret;
316 u8 val;
317
318 ret = kstrtou8(str, 0, &val);
319 if (ret < 0)
320 return ret;
321
322 if (val != 1) {
323 pr_err("Invalid reset netlink value %u\n", val);
324 return -EINVAL;
325 }
326
327 mutex_lock(&tcmu_nl_cmd_mutex);
328 list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
329 ret = tcmu_fail_netlink_cmd(nl_cmd);
330 if (ret)
331 break;
332 }
333 mutex_unlock(&tcmu_nl_cmd_mutex);
334
335 return ret;
336}
337
338static const struct kernel_param_ops tcmu_reset_netlink_op = {
339 .set = tcmu_set_reset_netlink,
340};
341
342module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
343MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
344
345/* multicast group */
346enum tcmu_multicast_groups {
347 TCMU_MCGRP_CONFIG,
348};
349
350static const struct genl_multicast_group tcmu_mcgrps[] = {
351 [TCMU_MCGRP_CONFIG] = { .name = "config", },
352};
353
354static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
355 [TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
356 [TCMU_ATTR_MINOR] = { .type = NLA_U32 },
357 [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
358 [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
359 [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
360};
361
362static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
363{
364 struct tcmu_dev *udev = NULL;
365 struct tcmu_nl_cmd *nl_cmd;
366 int dev_id, rc, ret = 0;
367
368 if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
369 !info->attrs[TCMU_ATTR_DEVICE_ID]) {
370 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
371 return -EINVAL;
372 }
373
374 dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
375 rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
376
377 mutex_lock(&tcmu_nl_cmd_mutex);
378 list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
379 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
380 udev = nl_cmd->udev;
381 break;
382 }
383 }
384
385 if (!udev) {
386 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
387 completed_cmd, rc, dev_id);
388 ret = -ENODEV;
389 goto unlock;
390 }
391 list_del(&nl_cmd->nl_list);
392
393 pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
394 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
395 nl_cmd->status);
396
397 if (nl_cmd->cmd != completed_cmd) {
398 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
399 udev->name, completed_cmd, nl_cmd->cmd);
400 ret = -EINVAL;
401 goto unlock;
402 }
403
404 nl_cmd->status = rc;
405 complete(&nl_cmd->complete);
406unlock:
407 mutex_unlock(&tcmu_nl_cmd_mutex);
408 return ret;
409}
410
411static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
412{
413 return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
414}
415
416static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
417{
418 return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
419}
420
421static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
422 struct genl_info *info)
423{
424 return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
425}
426
427static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
428{
429 if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
430 tcmu_kern_cmd_reply_supported =
431 nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
432 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
433 tcmu_kern_cmd_reply_supported);
434 }
435
436 return 0;
437}
438
439static const struct genl_ops tcmu_genl_ops[] = {
440 {
441 .cmd = TCMU_CMD_SET_FEATURES,
442 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
443 .flags = GENL_ADMIN_PERM,
444 .doit = tcmu_genl_set_features,
445 },
446 {
447 .cmd = TCMU_CMD_ADDED_DEVICE_DONE,
448 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
449 .flags = GENL_ADMIN_PERM,
450 .doit = tcmu_genl_add_dev_done,
451 },
452 {
453 .cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
454 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
455 .flags = GENL_ADMIN_PERM,
456 .doit = tcmu_genl_rm_dev_done,
457 },
458 {
459 .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
460 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
461 .flags = GENL_ADMIN_PERM,
462 .doit = tcmu_genl_reconfig_dev_done,
463 },
464};
465
466/* Our generic netlink family */
467static struct genl_family tcmu_genl_family __ro_after_init = {
468 .module = THIS_MODULE,
469 .hdrsize = 0,
470 .name = "TCM-USER",
471 .version = 2,
472 .maxattr = TCMU_ATTR_MAX,
473 .policy = tcmu_attr_policy,
474 .mcgrps = tcmu_mcgrps,
475 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
476 .netnsok = true,
477 .ops = tcmu_genl_ops,
478 .n_ops = ARRAY_SIZE(tcmu_genl_ops),
479};
480
481#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
482#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
483#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
484#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
485
486static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
487{
488 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
489 uint32_t i;
490
491 for (i = 0; i < len; i++)
492 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
493}
494
495static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
496 struct tcmu_cmd *tcmu_cmd)
497{
498 struct page *page;
499 int ret, dbi;
500
501 dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
502 if (dbi == udev->dbi_thresh)
503 return false;
504
505 page = radix_tree_lookup(&udev->data_blocks, dbi);
506 if (!page) {
507 if (atomic_add_return(1, &global_db_count) >
508 tcmu_global_max_blocks)
509 schedule_delayed_work(&tcmu_unmap_work, 0);
510
511 /* try to get new page from the mm */
512 page = alloc_page(GFP_NOIO);
513 if (!page)
514 goto err_alloc;
515
516 ret = radix_tree_insert(&udev->data_blocks, dbi, page);
517 if (ret)
518 goto err_insert;
519 }
520
521 if (dbi > udev->dbi_max)
522 udev->dbi_max = dbi;
523
524 set_bit(dbi, udev->data_bitmap);
525 tcmu_cmd_set_dbi(tcmu_cmd, dbi);
526
527 return true;
528err_insert:
529 __free_page(page);
530err_alloc:
531 atomic_dec(&global_db_count);
532 return false;
533}
534
535static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
536 struct tcmu_cmd *tcmu_cmd)
537{
538 int i;
539
540 for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
541 if (!tcmu_get_empty_block(udev, tcmu_cmd))
542 return false;
543 }
544 return true;
545}
546
547static inline struct page *
548tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
549{
550 return radix_tree_lookup(&udev->data_blocks, dbi);
551}
552
553static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
554{
555 if (tcmu_cmd->se_cmd)
556 tcmu_cmd->se_cmd->priv = NULL;
557 kfree(tcmu_cmd->dbi);
558 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
559}
560
561static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
562{
563 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
564 size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
565
566 if (se_cmd->se_cmd_flags & SCF_BIDI) {
567 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
568 data_length += round_up(se_cmd->t_bidi_data_sg->length,
569 DATA_BLOCK_SIZE);
570 }
571
572 return data_length;
573}
574
575static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
576{
577 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
578
579 return data_length / DATA_BLOCK_SIZE;
580}
581
582static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
583{
584 struct se_device *se_dev = se_cmd->se_dev;
585 struct tcmu_dev *udev = TCMU_DEV(se_dev);
586 struct tcmu_cmd *tcmu_cmd;
587
588 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
589 if (!tcmu_cmd)
590 return NULL;
591
592 INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
593 tcmu_cmd->se_cmd = se_cmd;
594 tcmu_cmd->tcmu_dev = udev;
595
596 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
597 tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
598 tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
599 GFP_NOIO);
600 if (!tcmu_cmd->dbi) {
601 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
602 return NULL;
603 }
604
605 return tcmu_cmd;
606}
607
608static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
609{
610 unsigned long offset = offset_in_page(vaddr);
611 void *start = vaddr - offset;
612
613 size = round_up(size+offset, PAGE_SIZE);
614
615 while (size) {
616 flush_dcache_page(vmalloc_to_page(start));
617 start += PAGE_SIZE;
618 size -= PAGE_SIZE;
619 }
620}
621
622/*
623 * Some ring helper functions. We don't assume size is a power of 2 so
624 * we can't use circ_buf.h.
625 */
626static inline size_t spc_used(size_t head, size_t tail, size_t size)
627{
628 int diff = head - tail;
629
630 if (diff >= 0)
631 return diff;
632 else
633 return size + diff;
634}
635
636static inline size_t spc_free(size_t head, size_t tail, size_t size)
637{
638 /* Keep 1 byte unused or we can't tell full from empty */
639 return (size - spc_used(head, tail, size) - 1);
640}
641
642static inline size_t head_to_end(size_t head, size_t size)
643{
644 return size - head;
645}
646
647static inline void new_iov(struct iovec **iov, int *iov_cnt)
648{
649 struct iovec *iovec;
650
651 if (*iov_cnt != 0)
652 (*iov)++;
653 (*iov_cnt)++;
654
655 iovec = *iov;
656 memset(iovec, 0, sizeof(struct iovec));
657}
658
659#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
660
661/* offset is relative to mb_addr */
662static inline size_t get_block_offset_user(struct tcmu_dev *dev,
663 int dbi, int remaining)
664{
665 return dev->data_off + dbi * DATA_BLOCK_SIZE +
666 DATA_BLOCK_SIZE - remaining;
667}
668
669static inline size_t iov_tail(struct iovec *iov)
670{
671 return (size_t)iov->iov_base + iov->iov_len;
672}
673
674static void scatter_data_area(struct tcmu_dev *udev,
675 struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
676 unsigned int data_nents, struct iovec **iov,
677 int *iov_cnt, bool copy_data)
678{
679 int i, dbi;
680 int block_remaining = 0;
681 void *from, *to = NULL;
682 size_t copy_bytes, to_offset, offset;
683 struct scatterlist *sg;
684 struct page *page;
685
686 for_each_sg(data_sg, sg, data_nents, i) {
687 int sg_remaining = sg->length;
688 from = kmap_atomic(sg_page(sg)) + sg->offset;
689 while (sg_remaining > 0) {
690 if (block_remaining == 0) {
691 if (to) {
692 flush_dcache_page(page);
693 kunmap_atomic(to);
694 }
695
696 block_remaining = DATA_BLOCK_SIZE;
697 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
698 page = tcmu_get_block_page(udev, dbi);
699 to = kmap_atomic(page);
700 }
701
702 /*
703 * Covert to virtual offset of the ring data area.
704 */
705 to_offset = get_block_offset_user(udev, dbi,
706 block_remaining);
707
708 /*
709 * The following code will gather and map the blocks
710 * to the same iovec when the blocks are all next to
711 * each other.
712 */
713 copy_bytes = min_t(size_t, sg_remaining,
714 block_remaining);
715 if (*iov_cnt != 0 &&
716 to_offset == iov_tail(*iov)) {
717 /*
718 * Will append to the current iovec, because
719 * the current block page is next to the
720 * previous one.
721 */
722 (*iov)->iov_len += copy_bytes;
723 } else {
724 /*
725 * Will allocate a new iovec because we are
726 * first time here or the current block page
727 * is not next to the previous one.
728 */
729 new_iov(iov, iov_cnt);
730 (*iov)->iov_base = (void __user *)to_offset;
731 (*iov)->iov_len = copy_bytes;
732 }
733
734 if (copy_data) {
735 offset = DATA_BLOCK_SIZE - block_remaining;
736 memcpy(to + offset,
737 from + sg->length - sg_remaining,
738 copy_bytes);
739 }
740
741 sg_remaining -= copy_bytes;
742 block_remaining -= copy_bytes;
743 }
744 kunmap_atomic(from - sg->offset);
745 }
746
747 if (to) {
748 flush_dcache_page(page);
749 kunmap_atomic(to);
750 }
751}
752
753static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
754 bool bidi, uint32_t read_len)
755{
756 struct se_cmd *se_cmd = cmd->se_cmd;
757 int i, dbi;
758 int block_remaining = 0;
759 void *from = NULL, *to;
760 size_t copy_bytes, offset;
761 struct scatterlist *sg, *data_sg;
762 struct page *page;
763 unsigned int data_nents;
764 uint32_t count = 0;
765
766 if (!bidi) {
767 data_sg = se_cmd->t_data_sg;
768 data_nents = se_cmd->t_data_nents;
769 } else {
770
771 /*
772 * For bidi case, the first count blocks are for Data-Out
773 * buffer blocks, and before gathering the Data-In buffer
774 * the Data-Out buffer blocks should be discarded.
775 */
776 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
777
778 data_sg = se_cmd->t_bidi_data_sg;
779 data_nents = se_cmd->t_bidi_data_nents;
780 }
781
782 tcmu_cmd_set_dbi_cur(cmd, count);
783
784 for_each_sg(data_sg, sg, data_nents, i) {
785 int sg_remaining = sg->length;
786 to = kmap_atomic(sg_page(sg)) + sg->offset;
787 while (sg_remaining > 0 && read_len > 0) {
788 if (block_remaining == 0) {
789 if (from)
790 kunmap_atomic(from);
791
792 block_remaining = DATA_BLOCK_SIZE;
793 dbi = tcmu_cmd_get_dbi(cmd);
794 page = tcmu_get_block_page(udev, dbi);
795 from = kmap_atomic(page);
796 flush_dcache_page(page);
797 }
798 copy_bytes = min_t(size_t, sg_remaining,
799 block_remaining);
800 if (read_len < copy_bytes)
801 copy_bytes = read_len;
802 offset = DATA_BLOCK_SIZE - block_remaining;
803 memcpy(to + sg->length - sg_remaining, from + offset,
804 copy_bytes);
805
806 sg_remaining -= copy_bytes;
807 block_remaining -= copy_bytes;
808 read_len -= copy_bytes;
809 }
810 kunmap_atomic(to - sg->offset);
811 if (read_len == 0)
812 break;
813 }
814 if (from)
815 kunmap_atomic(from);
816}
817
818static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
819{
820 return thresh - bitmap_weight(bitmap, thresh);
821}
822
823/*
824 * We can't queue a command until we have space available on the cmd ring *and*
825 * space available on the data area.
826 *
827 * Called with ring lock held.
828 */
829static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
830 size_t cmd_size, size_t data_needed)
831{
832 struct tcmu_mailbox *mb = udev->mb_addr;
833 uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
834 / DATA_BLOCK_SIZE;
835 size_t space, cmd_needed;
836 u32 cmd_head;
837
838 tcmu_flush_dcache_range(mb, sizeof(*mb));
839
840 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
841
842 /*
843 * If cmd end-of-ring space is too small then we need space for a NOP plus
844 * original cmd - cmds are internally contiguous.
845 */
846 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
847 cmd_needed = cmd_size;
848 else
849 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
850
851 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
852 if (space < cmd_needed) {
853 pr_debug("no cmd space: %u %u %u\n", cmd_head,
854 udev->cmdr_last_cleaned, udev->cmdr_size);
855 return false;
856 }
857
858 if (!data_needed)
859 return true;
860
861 /* try to check and get the data blocks as needed */
862 space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
863 if ((space * DATA_BLOCK_SIZE) < data_needed) {
864 unsigned long blocks_left =
865 (udev->max_blocks - udev->dbi_thresh) + space;
866
867 if (blocks_left < blocks_needed) {
868 pr_debug("no data space: only %lu available, but ask for %zu\n",
869 blocks_left * DATA_BLOCK_SIZE,
870 data_needed);
871 return false;
872 }
873
874 udev->dbi_thresh += blocks_needed;
875 if (udev->dbi_thresh > udev->max_blocks)
876 udev->dbi_thresh = udev->max_blocks;
877 }
878
879 return tcmu_get_empty_blocks(udev, cmd);
880}
881
882static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
883{
884 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
885 sizeof(struct tcmu_cmd_entry));
886}
887
888static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
889 size_t base_command_size)
890{
891 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
892 size_t command_size;
893
894 command_size = base_command_size +
895 round_up(scsi_command_size(se_cmd->t_task_cdb),
896 TCMU_OP_ALIGN_SIZE);
897
898 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
899
900 return command_size;
901}
902
903static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
904 struct timer_list *timer)
905{
906 if (!tmo)
907 return;
908
909 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
910 if (!timer_pending(timer))
911 mod_timer(timer, tcmu_cmd->deadline);
912
913 pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
914 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
915}
916
917static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
918{
919 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
920 unsigned int tmo;
921
922 /*
923 * For backwards compat if qfull_time_out is not set use
924 * cmd_time_out and if that's not set use the default time out.
925 */
926 if (!udev->qfull_time_out)
927 return -ETIMEDOUT;
928 else if (udev->qfull_time_out > 0)
929 tmo = udev->qfull_time_out;
930 else if (udev->cmd_time_out)
931 tmo = udev->cmd_time_out;
932 else
933 tmo = TCMU_TIME_OUT;
934
935 tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
936
937 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
938 pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
939 tcmu_cmd, udev->name);
940 return 0;
941}
942
943static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
944{
945 struct tcmu_cmd_entry_hdr *hdr;
946 struct tcmu_mailbox *mb = udev->mb_addr;
947 uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
948
949 /* Insert a PAD if end-of-ring space is too small */
950 if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
951 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
952
953 hdr = (void *) mb + CMDR_OFF + cmd_head;
954 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
955 tcmu_hdr_set_len(&hdr->len_op, pad_size);
956 hdr->cmd_id = 0; /* not used for PAD */
957 hdr->kflags = 0;
958 hdr->uflags = 0;
959 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
960
961 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
962 tcmu_flush_dcache_range(mb, sizeof(*mb));
963
964 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
965 WARN_ON(cmd_head != 0);
966 }
967
968 return cmd_head;
969}
970
971/**
972 * queue_cmd_ring - queue cmd to ring or internally
973 * @tcmu_cmd: cmd to queue
974 * @scsi_err: TCM error code if failure (-1) returned.
975 *
976 * Returns:
977 * -1 we cannot queue internally or to the ring.
978 * 0 success
979 * 1 internally queued to wait for ring memory to free.
980 */
981static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
982{
983 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
984 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
985 size_t base_command_size, command_size;
986 struct tcmu_mailbox *mb = udev->mb_addr;
987 struct tcmu_cmd_entry *entry;
988 struct iovec *iov;
989 int iov_cnt, cmd_id;
990 uint32_t cmd_head;
991 uint64_t cdb_off;
992 bool copy_to_data_area;
993 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
994
995 *scsi_err = TCM_NO_SENSE;
996
997 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
998 *scsi_err = TCM_LUN_BUSY;
999 return -1;
1000 }
1001
1002 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1003 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1004 return -1;
1005 }
1006
1007 /*
1008 * Must be a certain minimum size for response sense info, but
1009 * also may be larger if the iov array is large.
1010 *
1011 * We prepare as many iovs as possbile for potential uses here,
1012 * because it's expensive to tell how many regions are freed in
1013 * the bitmap & global data pool, as the size calculated here
1014 * will only be used to do the checks.
1015 *
1016 * The size will be recalculated later as actually needed to save
1017 * cmd area memories.
1018 */
1019 base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
1020 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1021
1022 if (!list_empty(&udev->qfull_queue))
1023 goto queue;
1024
1025 if ((command_size > (udev->cmdr_size / 2)) ||
1026 data_length > udev->data_size) {
1027 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
1028 "cmd ring/data area\n", command_size, data_length,
1029 udev->cmdr_size, udev->data_size);
1030 *scsi_err = TCM_INVALID_CDB_FIELD;
1031 return -1;
1032 }
1033
1034 if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
1035 /*
1036 * Don't leave commands partially setup because the unmap
1037 * thread might need the blocks to make forward progress.
1038 */
1039 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1040 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1041 goto queue;
1042 }
1043
1044 cmd_head = ring_insert_padding(udev, command_size);
1045
1046 entry = (void *) mb + CMDR_OFF + cmd_head;
1047 memset(entry, 0, command_size);
1048 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1049
1050 /* Handle allocating space from the data area */
1051 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1052 iov = &entry->req.iov[0];
1053 iov_cnt = 0;
1054 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
1055 || se_cmd->se_cmd_flags & SCF_BIDI);
1056 scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
1057 se_cmd->t_data_nents, &iov, &iov_cnt,
1058 copy_to_data_area);
1059 entry->req.iov_cnt = iov_cnt;
1060
1061 /* Handle BIDI commands */
1062 iov_cnt = 0;
1063 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1064 iov++;
1065 scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
1066 se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
1067 false);
1068 }
1069 entry->req.iov_bidi_cnt = iov_cnt;
1070
1071 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
1072 if (cmd_id < 0) {
1073 pr_err("tcmu: Could not allocate cmd id.\n");
1074
1075 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1076 *scsi_err = TCM_OUT_OF_RESOURCES;
1077 return -1;
1078 }
1079 tcmu_cmd->cmd_id = cmd_id;
1080
1081 pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1082 tcmu_cmd, udev->name);
1083
1084 tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1085
1086 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1087
1088 /*
1089 * Recalaulate the command's base size and size according
1090 * to the actual needs
1091 */
1092 base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
1093 entry->req.iov_bidi_cnt);
1094 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1095
1096 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1097
1098 /* All offsets relative to mb_addr, not start of entry! */
1099 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1100 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1101 entry->req.cdb_off = cdb_off;
1102 tcmu_flush_dcache_range(entry, command_size);
1103
1104 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1105 tcmu_flush_dcache_range(mb, sizeof(*mb));
1106
1107 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1108
1109 /* TODO: only if FLUSH and FUA? */
1110 uio_event_notify(&udev->uio_info);
1111
1112 return 0;
1113
1114queue:
1115 if (add_to_qfull_queue(tcmu_cmd)) {
1116 *scsi_err = TCM_OUT_OF_RESOURCES;
1117 return -1;
1118 }
1119
1120 return 1;
1121}
1122
1123/**
1124 * queue_tmr_ring - queue tmr info to ring or internally
1125 * @udev: related tcmu_dev
1126 * @tmr: tcmu_tmr containing tmr info to queue
1127 *
1128 * Returns:
1129 * 0 success
1130 * 1 internally queued to wait for ring memory to free.
1131 */
1132static int
1133queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1134{
1135 struct tcmu_tmr_entry *entry;
1136 int cmd_size;
1137 int id_list_sz;
1138 struct tcmu_mailbox *mb = udev->mb_addr;
1139 uint32_t cmd_head;
1140
1141 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1142 goto out_free;
1143
1144 id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1145 cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1146
1147 if (!list_empty(&udev->tmr_queue) ||
1148 !is_ring_space_avail(udev, NULL, cmd_size, 0)) {
1149 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1150 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1151 tmr, udev->name);
1152 return 1;
1153 }
1154
1155 cmd_head = ring_insert_padding(udev, cmd_size);
1156
1157 entry = (void *)mb + CMDR_OFF + cmd_head;
1158 memset(entry, 0, cmd_size);
1159 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1160 tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1161 entry->tmr_type = tmr->tmr_type;
1162 entry->cmd_cnt = tmr->tmr_cmd_cnt;
1163 memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1164 tcmu_flush_dcache_range(entry, cmd_size);
1165
1166 UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1167 tcmu_flush_dcache_range(mb, sizeof(*mb));
1168
1169 uio_event_notify(&udev->uio_info);
1170
1171out_free:
1172 kfree(tmr);
1173
1174 return 0;
1175}
1176
1177static sense_reason_t
1178tcmu_queue_cmd(struct se_cmd *se_cmd)
1179{
1180 struct se_device *se_dev = se_cmd->se_dev;
1181 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1182 struct tcmu_cmd *tcmu_cmd;
1183 sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1184 int ret = -1;
1185
1186 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1187 if (!tcmu_cmd)
1188 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1189
1190 mutex_lock(&udev->cmdr_lock);
1191 se_cmd->priv = tcmu_cmd;
1192 if (!(se_cmd->transport_state & CMD_T_ABORTED))
1193 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1194 if (ret < 0)
1195 tcmu_free_cmd(tcmu_cmd);
1196 mutex_unlock(&udev->cmdr_lock);
1197 return scsi_ret;
1198}
1199
1200static void tcmu_set_next_deadline(struct list_head *queue,
1201 struct timer_list *timer)
1202{
1203 struct tcmu_cmd *cmd;
1204
1205 if (!list_empty(queue)) {
1206 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1207 mod_timer(timer, cmd->deadline);
1208 } else
1209 del_timer(timer);
1210}
1211
1212static int
1213tcmu_tmr_type(enum tcm_tmreq_table tmf)
1214{
1215 switch (tmf) {
1216 case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
1217 case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
1218 case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
1219 case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
1220 case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
1221 case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
1222 case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
1223 case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
1224 default: return TCMU_TMR_UNKNOWN;
1225 }
1226}
1227
1228static void
1229tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1230 struct list_head *cmd_list)
1231{
1232 int i = 0, cmd_cnt = 0;
1233 bool unqueued = false;
1234 uint16_t *cmd_ids = NULL;
1235 struct tcmu_cmd *cmd;
1236 struct se_cmd *se_cmd;
1237 struct tcmu_tmr *tmr;
1238 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1239
1240 mutex_lock(&udev->cmdr_lock);
1241
1242 /* First we check for aborted commands in qfull_queue */
1243 list_for_each_entry(se_cmd, cmd_list, state_list) {
1244 i++;
1245 if (!se_cmd->priv)
1246 continue;
1247 cmd = se_cmd->priv;
1248 /* Commands on qfull queue have no id yet */
1249 if (cmd->cmd_id) {
1250 cmd_cnt++;
1251 continue;
1252 }
1253 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1254 cmd, udev->name);
1255
1256 list_del_init(&cmd->queue_entry);
1257 tcmu_free_cmd(cmd);
1258 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1259 unqueued = true;
1260 }
1261 if (unqueued)
1262 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1263
1264 if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1265 goto unlock;
1266
1267 pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1268 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1269
1270 tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL);
1271 if (!tmr)
1272 goto unlock;
1273
1274 tmr->tmr_type = tcmu_tmr_type(tmf);
1275 tmr->tmr_cmd_cnt = cmd_cnt;
1276
1277 if (cmd_cnt != 0) {
1278 cmd_cnt = 0;
1279 list_for_each_entry(se_cmd, cmd_list, state_list) {
1280 if (!se_cmd->priv)
1281 continue;
1282 cmd = se_cmd->priv;
1283 if (cmd->cmd_id)
1284 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1285 }
1286 }
1287
1288 queue_tmr_ring(udev, tmr);
1289
1290unlock:
1291 mutex_unlock(&udev->cmdr_lock);
1292}
1293
1294static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1295{
1296 struct se_cmd *se_cmd = cmd->se_cmd;
1297 struct tcmu_dev *udev = cmd->tcmu_dev;
1298 bool read_len_valid = false;
1299 uint32_t read_len;
1300
1301 /*
1302 * cmd has been completed already from timeout, just reclaim
1303 * data area space and free cmd
1304 */
1305 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1306 WARN_ON_ONCE(se_cmd);
1307 goto out;
1308 }
1309
1310 list_del_init(&cmd->queue_entry);
1311
1312 tcmu_cmd_reset_dbi_cur(cmd);
1313
1314 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1315 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1316 cmd->se_cmd);
1317 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1318 goto done;
1319 }
1320
1321 read_len = se_cmd->data_length;
1322 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1323 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1324 read_len_valid = true;
1325 if (entry->rsp.read_len < read_len)
1326 read_len = entry->rsp.read_len;
1327 }
1328
1329 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1330 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1331 if (!read_len_valid )
1332 goto done;
1333 else
1334 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1335 }
1336 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1337 /* Get Data-In buffer before clean up */
1338 gather_data_area(udev, cmd, true, read_len);
1339 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1340 gather_data_area(udev, cmd, false, read_len);
1341 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1342 /* TODO: */
1343 } else if (se_cmd->data_direction != DMA_NONE) {
1344 pr_warn("TCMU: data direction was %d!\n",
1345 se_cmd->data_direction);
1346 }
1347
1348done:
1349 if (read_len_valid) {
1350 pr_debug("read_len = %d\n", read_len);
1351 target_complete_cmd_with_length(cmd->se_cmd,
1352 entry->rsp.scsi_status, read_len);
1353 } else
1354 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1355
1356out:
1357 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1358 tcmu_free_cmd(cmd);
1359}
1360
1361static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1362{
1363 struct tcmu_tmr *tmr, *tmp;
1364 LIST_HEAD(tmrs);
1365
1366 if (list_empty(&udev->tmr_queue))
1367 return 1;
1368
1369 pr_debug("running %s's tmr queue\n", udev->name);
1370
1371 list_splice_init(&udev->tmr_queue, &tmrs);
1372
1373 list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1374 list_del_init(&tmr->queue_entry);
1375
1376 pr_debug("removing tmr %p on dev %s from queue\n",
1377 tmr, udev->name);
1378
1379 if (queue_tmr_ring(udev, tmr)) {
1380 pr_debug("ran out of space during tmr queue run\n");
1381 /*
1382 * tmr was requeued, so just put all tmrs back in
1383 * the queue
1384 */
1385 list_splice_tail(&tmrs, &udev->tmr_queue);
1386 return 0;
1387 }
1388 }
1389
1390 return 1;
1391}
1392
1393static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1394{
1395 struct tcmu_mailbox *mb;
1396 struct tcmu_cmd *cmd;
1397 bool free_space = false;
1398
1399 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1400 pr_err("ring broken, not handling completions\n");
1401 return 0;
1402 }
1403
1404 mb = udev->mb_addr;
1405 tcmu_flush_dcache_range(mb, sizeof(*mb));
1406
1407 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1408
1409 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1410
1411 /*
1412 * Flush max. up to end of cmd ring since current entry might
1413 * be a padding that is shorter than sizeof(*entry)
1414 */
1415 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1416 udev->cmdr_size);
1417 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1418 ring_left : sizeof(*entry));
1419
1420 free_space = true;
1421
1422 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1423 tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1424 UPDATE_HEAD(udev->cmdr_last_cleaned,
1425 tcmu_hdr_get_len(entry->hdr.len_op),
1426 udev->cmdr_size);
1427 continue;
1428 }
1429 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1430
1431 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1432 if (!cmd) {
1433 pr_err("cmd_id %u not found, ring is broken\n",
1434 entry->hdr.cmd_id);
1435 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1436 break;
1437 }
1438
1439 tcmu_handle_completion(cmd, entry);
1440
1441 UPDATE_HEAD(udev->cmdr_last_cleaned,
1442 tcmu_hdr_get_len(entry->hdr.len_op),
1443 udev->cmdr_size);
1444 }
1445 if (free_space)
1446 free_space = tcmu_run_tmr_queue(udev);
1447
1448 if (atomic_read(&global_db_count) > tcmu_global_max_blocks &&
1449 idr_is_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1450 /*
1451 * Allocated blocks exceeded global block limit, currently no
1452 * more pending or waiting commands so try to reclaim blocks.
1453 */
1454 schedule_delayed_work(&tcmu_unmap_work, 0);
1455 }
1456 if (udev->cmd_time_out)
1457 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1458
1459 return free_space;
1460}
1461
1462static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1463{
1464 struct se_cmd *se_cmd;
1465
1466 if (!time_after_eq(jiffies, cmd->deadline))
1467 return;
1468
1469 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1470 list_del_init(&cmd->queue_entry);
1471 se_cmd = cmd->se_cmd;
1472 se_cmd->priv = NULL;
1473 cmd->se_cmd = NULL;
1474
1475 pr_debug("Timing out inflight cmd %u on dev %s.\n",
1476 cmd->cmd_id, cmd->tcmu_dev->name);
1477
1478 target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1479}
1480
1481static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1482{
1483 struct se_cmd *se_cmd;
1484
1485 if (!time_after_eq(jiffies, cmd->deadline))
1486 return;
1487
1488 pr_debug("Timing out queued cmd %p on dev %s.\n",
1489 cmd, cmd->tcmu_dev->name);
1490
1491 list_del_init(&cmd->queue_entry);
1492 se_cmd = cmd->se_cmd;
1493 tcmu_free_cmd(cmd);
1494
1495 target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1496}
1497
1498static void tcmu_device_timedout(struct tcmu_dev *udev)
1499{
1500 spin_lock(&timed_out_udevs_lock);
1501 if (list_empty(&udev->timedout_entry))
1502 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1503 spin_unlock(&timed_out_udevs_lock);
1504
1505 schedule_delayed_work(&tcmu_unmap_work, 0);
1506}
1507
1508static void tcmu_cmd_timedout(struct timer_list *t)
1509{
1510 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1511
1512 pr_debug("%s cmd timeout has expired\n", udev->name);
1513 tcmu_device_timedout(udev);
1514}
1515
1516static void tcmu_qfull_timedout(struct timer_list *t)
1517{
1518 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1519
1520 pr_debug("%s qfull timeout has expired\n", udev->name);
1521 tcmu_device_timedout(udev);
1522}
1523
1524static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1525{
1526 struct tcmu_hba *tcmu_hba;
1527
1528 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1529 if (!tcmu_hba)
1530 return -ENOMEM;
1531
1532 tcmu_hba->host_id = host_id;
1533 hba->hba_ptr = tcmu_hba;
1534
1535 return 0;
1536}
1537
1538static void tcmu_detach_hba(struct se_hba *hba)
1539{
1540 kfree(hba->hba_ptr);
1541 hba->hba_ptr = NULL;
1542}
1543
1544static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1545{
1546 struct tcmu_dev *udev;
1547
1548 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1549 if (!udev)
1550 return NULL;
1551 kref_init(&udev->kref);
1552
1553 udev->name = kstrdup(name, GFP_KERNEL);
1554 if (!udev->name) {
1555 kfree(udev);
1556 return NULL;
1557 }
1558
1559 udev->hba = hba;
1560 udev->cmd_time_out = TCMU_TIME_OUT;
1561 udev->qfull_time_out = -1;
1562
1563 udev->max_blocks = DATA_BLOCK_BITS_DEF;
1564 mutex_init(&udev->cmdr_lock);
1565
1566 INIT_LIST_HEAD(&udev->node);
1567 INIT_LIST_HEAD(&udev->timedout_entry);
1568 INIT_LIST_HEAD(&udev->qfull_queue);
1569 INIT_LIST_HEAD(&udev->tmr_queue);
1570 INIT_LIST_HEAD(&udev->inflight_queue);
1571 idr_init(&udev->commands);
1572
1573 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1574 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1575
1576 INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1577
1578 return &udev->se_dev;
1579}
1580
1581static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1582{
1583 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1584 LIST_HEAD(cmds);
1585 sense_reason_t scsi_ret;
1586 int ret;
1587
1588 if (list_empty(&udev->qfull_queue))
1589 return;
1590
1591 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1592
1593 list_splice_init(&udev->qfull_queue, &cmds);
1594
1595 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1596 list_del_init(&tcmu_cmd->queue_entry);
1597
1598 pr_debug("removing cmd %p on dev %s from queue\n",
1599 tcmu_cmd, udev->name);
1600
1601 if (fail) {
1602 /*
1603 * We were not able to even start the command, so
1604 * fail with busy to allow a retry in case runner
1605 * was only temporarily down. If the device is being
1606 * removed then LIO core will do the right thing and
1607 * fail the retry.
1608 */
1609 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1610 tcmu_free_cmd(tcmu_cmd);
1611 continue;
1612 }
1613
1614 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1615 if (ret < 0) {
1616 pr_debug("cmd %p on dev %s failed with %u\n",
1617 tcmu_cmd, udev->name, scsi_ret);
1618 /*
1619 * Ignore scsi_ret for now. target_complete_cmd
1620 * drops it.
1621 */
1622 target_complete_cmd(tcmu_cmd->se_cmd,
1623 SAM_STAT_CHECK_CONDITION);
1624 tcmu_free_cmd(tcmu_cmd);
1625 } else if (ret > 0) {
1626 pr_debug("ran out of space during cmdr queue run\n");
1627 /*
1628 * cmd was requeued, so just put all cmds back in
1629 * the queue
1630 */
1631 list_splice_tail(&cmds, &udev->qfull_queue);
1632 break;
1633 }
1634 }
1635
1636 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1637}
1638
1639static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1640{
1641 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1642
1643 mutex_lock(&udev->cmdr_lock);
1644 if (tcmu_handle_completions(udev))
1645 run_qfull_queue(udev, false);
1646 mutex_unlock(&udev->cmdr_lock);
1647
1648 return 0;
1649}
1650
1651/*
1652 * mmap code from uio.c. Copied here because we want to hook mmap()
1653 * and this stuff must come along.
1654 */
1655static int tcmu_find_mem_index(struct vm_area_struct *vma)
1656{
1657 struct tcmu_dev *udev = vma->vm_private_data;
1658 struct uio_info *info = &udev->uio_info;
1659
1660 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1661 if (info->mem[vma->vm_pgoff].size == 0)
1662 return -1;
1663 return (int)vma->vm_pgoff;
1664 }
1665 return -1;
1666}
1667
1668static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1669{
1670 struct page *page;
1671
1672 mutex_lock(&udev->cmdr_lock);
1673 page = tcmu_get_block_page(udev, dbi);
1674 if (likely(page)) {
1675 mutex_unlock(&udev->cmdr_lock);
1676 return page;
1677 }
1678
1679 /*
1680 * Userspace messed up and passed in a address not in the
1681 * data iov passed to it.
1682 */
1683 pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
1684 dbi, udev->name);
1685 page = NULL;
1686 mutex_unlock(&udev->cmdr_lock);
1687
1688 return page;
1689}
1690
1691static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1692{
1693 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1694 struct uio_info *info = &udev->uio_info;
1695 struct page *page;
1696 unsigned long offset;
1697 void *addr;
1698
1699 int mi = tcmu_find_mem_index(vmf->vma);
1700 if (mi < 0)
1701 return VM_FAULT_SIGBUS;
1702
1703 /*
1704 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1705 * to use mem[N].
1706 */
1707 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1708
1709 if (offset < udev->data_off) {
1710 /* For the vmalloc()ed cmd area pages */
1711 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1712 page = vmalloc_to_page(addr);
1713 } else {
1714 uint32_t dbi;
1715
1716 /* For the dynamically growing data area pages */
1717 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1718 page = tcmu_try_get_block_page(udev, dbi);
1719 if (!page)
1720 return VM_FAULT_SIGBUS;
1721 }
1722
1723 get_page(page);
1724 vmf->page = page;
1725 return 0;
1726}
1727
1728static const struct vm_operations_struct tcmu_vm_ops = {
1729 .fault = tcmu_vma_fault,
1730};
1731
1732static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1733{
1734 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1735
1736 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1737 vma->vm_ops = &tcmu_vm_ops;
1738
1739 vma->vm_private_data = udev;
1740
1741 /* Ensure the mmap is exactly the right size */
1742 if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1743 return -EINVAL;
1744
1745 return 0;
1746}
1747
1748static int tcmu_open(struct uio_info *info, struct inode *inode)
1749{
1750 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1751
1752 /* O_EXCL not supported for char devs, so fake it? */
1753 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1754 return -EBUSY;
1755
1756 udev->inode = inode;
1757 kref_get(&udev->kref);
1758
1759 pr_debug("open\n");
1760
1761 return 0;
1762}
1763
1764static void tcmu_dev_call_rcu(struct rcu_head *p)
1765{
1766 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1767 struct tcmu_dev *udev = TCMU_DEV(dev);
1768
1769 kfree(udev->uio_info.name);
1770 kfree(udev->name);
1771 kfree(udev);
1772}
1773
1774static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1775{
1776 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1777 kmem_cache_free(tcmu_cmd_cache, cmd);
1778 return 0;
1779 }
1780 return -EINVAL;
1781}
1782
1783static void tcmu_blocks_release(struct radix_tree_root *blocks,
1784 int start, int end)
1785{
1786 int i;
1787 struct page *page;
1788
1789 for (i = start; i < end; i++) {
1790 page = radix_tree_delete(blocks, i);
1791 if (page) {
1792 __free_page(page);
1793 atomic_dec(&global_db_count);
1794 }
1795 }
1796}
1797
1798static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1799{
1800 struct tcmu_tmr *tmr, *tmp;
1801
1802 list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1803 list_del_init(&tmr->queue_entry);
1804 kfree(tmr);
1805 }
1806}
1807
1808static void tcmu_dev_kref_release(struct kref *kref)
1809{
1810 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1811 struct se_device *dev = &udev->se_dev;
1812 struct tcmu_cmd *cmd;
1813 bool all_expired = true;
1814 int i;
1815
1816 vfree(udev->mb_addr);
1817 udev->mb_addr = NULL;
1818
1819 spin_lock_bh(&timed_out_udevs_lock);
1820 if (!list_empty(&udev->timedout_entry))
1821 list_del(&udev->timedout_entry);
1822 spin_unlock_bh(&timed_out_udevs_lock);
1823
1824 /* Upper layer should drain all requests before calling this */
1825 mutex_lock(&udev->cmdr_lock);
1826 idr_for_each_entry(&udev->commands, cmd, i) {
1827 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1828 all_expired = false;
1829 }
1830 /* There can be left over TMR cmds. Remove them. */
1831 tcmu_remove_all_queued_tmr(udev);
1832 if (!list_empty(&udev->qfull_queue))
1833 all_expired = false;
1834 idr_destroy(&udev->commands);
1835 WARN_ON(!all_expired);
1836
1837 tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1838 bitmap_free(udev->data_bitmap);
1839 mutex_unlock(&udev->cmdr_lock);
1840
1841 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1842}
1843
1844static int tcmu_release(struct uio_info *info, struct inode *inode)
1845{
1846 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1847
1848 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1849
1850 pr_debug("close\n");
1851 /* release ref from open */
1852 kref_put(&udev->kref, tcmu_dev_kref_release);
1853 return 0;
1854}
1855
1856static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1857{
1858 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1859
1860 if (!tcmu_kern_cmd_reply_supported)
1861 return 0;
1862
1863 if (udev->nl_reply_supported <= 0)
1864 return 0;
1865
1866 mutex_lock(&tcmu_nl_cmd_mutex);
1867
1868 if (tcmu_netlink_blocked) {
1869 mutex_unlock(&tcmu_nl_cmd_mutex);
1870 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1871 udev->name);
1872 return -EAGAIN;
1873 }
1874
1875 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1876 mutex_unlock(&tcmu_nl_cmd_mutex);
1877 pr_warn("netlink cmd %d already executing on %s\n",
1878 nl_cmd->cmd, udev->name);
1879 return -EBUSY;
1880 }
1881
1882 memset(nl_cmd, 0, sizeof(*nl_cmd));
1883 nl_cmd->cmd = cmd;
1884 nl_cmd->udev = udev;
1885 init_completion(&nl_cmd->complete);
1886 INIT_LIST_HEAD(&nl_cmd->nl_list);
1887
1888 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1889
1890 mutex_unlock(&tcmu_nl_cmd_mutex);
1891 return 0;
1892}
1893
1894static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1895{
1896 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1897
1898 if (!tcmu_kern_cmd_reply_supported)
1899 return;
1900
1901 if (udev->nl_reply_supported <= 0)
1902 return;
1903
1904 mutex_lock(&tcmu_nl_cmd_mutex);
1905
1906 list_del(&nl_cmd->nl_list);
1907 memset(nl_cmd, 0, sizeof(*nl_cmd));
1908
1909 mutex_unlock(&tcmu_nl_cmd_mutex);
1910}
1911
1912static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1913{
1914 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1915 int ret;
1916
1917 if (!tcmu_kern_cmd_reply_supported)
1918 return 0;
1919
1920 if (udev->nl_reply_supported <= 0)
1921 return 0;
1922
1923 pr_debug("sleeping for nl reply\n");
1924 wait_for_completion(&nl_cmd->complete);
1925
1926 mutex_lock(&tcmu_nl_cmd_mutex);
1927 nl_cmd->cmd = TCMU_CMD_UNSPEC;
1928 ret = nl_cmd->status;
1929 mutex_unlock(&tcmu_nl_cmd_mutex);
1930
1931 return ret;
1932}
1933
1934static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1935 enum tcmu_genl_cmd cmd,
1936 struct sk_buff **buf, void **hdr)
1937{
1938 struct sk_buff *skb;
1939 void *msg_header;
1940 int ret = -ENOMEM;
1941
1942 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1943 if (!skb)
1944 return ret;
1945
1946 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1947 if (!msg_header)
1948 goto free_skb;
1949
1950 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1951 if (ret < 0)
1952 goto free_skb;
1953
1954 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1955 if (ret < 0)
1956 goto free_skb;
1957
1958 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1959 if (ret < 0)
1960 goto free_skb;
1961
1962 *buf = skb;
1963 *hdr = msg_header;
1964 return ret;
1965
1966free_skb:
1967 nlmsg_free(skb);
1968 return ret;
1969}
1970
1971static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1972 enum tcmu_genl_cmd cmd,
1973 struct sk_buff *skb, void *msg_header)
1974{
1975 int ret;
1976
1977 genlmsg_end(skb, msg_header);
1978
1979 ret = tcmu_init_genl_cmd_reply(udev, cmd);
1980 if (ret) {
1981 nlmsg_free(skb);
1982 return ret;
1983 }
1984
1985 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1986 TCMU_MCGRP_CONFIG, GFP_KERNEL);
1987
1988 /* Wait during an add as the listener may not be up yet */
1989 if (ret == 0 ||
1990 (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
1991 return tcmu_wait_genl_cmd_reply(udev);
1992 else
1993 tcmu_destroy_genl_cmd_reply(udev);
1994
1995 return ret;
1996}
1997
1998static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
1999{
2000 struct sk_buff *skb = NULL;
2001 void *msg_header = NULL;
2002 int ret = 0;
2003
2004 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2005 &msg_header);
2006 if (ret < 0)
2007 return ret;
2008 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2009 msg_header);
2010}
2011
2012static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2013{
2014 struct sk_buff *skb = NULL;
2015 void *msg_header = NULL;
2016 int ret = 0;
2017
2018 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2019 &skb, &msg_header);
2020 if (ret < 0)
2021 return ret;
2022 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2023 skb, msg_header);
2024}
2025
2026static int tcmu_update_uio_info(struct tcmu_dev *udev)
2027{
2028 struct tcmu_hba *hba = udev->hba->hba_ptr;
2029 struct uio_info *info;
2030 char *str;
2031
2032 info = &udev->uio_info;
2033
2034 if (udev->dev_config[0])
2035 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2036 udev->name, udev->dev_config);
2037 else
2038 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2039 udev->name);
2040 if (!str)
2041 return -ENOMEM;
2042
2043 /* If the old string exists, free it */
2044 kfree(info->name);
2045 info->name = str;
2046
2047 return 0;
2048}
2049
2050static int tcmu_configure_device(struct se_device *dev)
2051{
2052 struct tcmu_dev *udev = TCMU_DEV(dev);
2053 struct uio_info *info;
2054 struct tcmu_mailbox *mb;
2055 int ret = 0;
2056
2057 ret = tcmu_update_uio_info(udev);
2058 if (ret)
2059 return ret;
2060
2061 info = &udev->uio_info;
2062
2063 mutex_lock(&udev->cmdr_lock);
2064 udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2065 mutex_unlock(&udev->cmdr_lock);
2066 if (!udev->data_bitmap) {
2067 ret = -ENOMEM;
2068 goto err_bitmap_alloc;
2069 }
2070
2071 udev->mb_addr = vzalloc(CMDR_SIZE);
2072 if (!udev->mb_addr) {
2073 ret = -ENOMEM;
2074 goto err_vzalloc;
2075 }
2076
2077 /* mailbox fits in first part of CMDR space */
2078 udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
2079 udev->data_off = CMDR_SIZE;
2080 udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
2081 udev->dbi_thresh = 0; /* Default in Idle state */
2082
2083 /* Initialise the mailbox of the ring buffer */
2084 mb = udev->mb_addr;
2085 mb->version = TCMU_MAILBOX_VERSION;
2086 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2087 TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2088 TCMU_MAILBOX_FLAG_CAP_TMR;
2089 mb->cmdr_off = CMDR_OFF;
2090 mb->cmdr_size = udev->cmdr_size;
2091
2092 WARN_ON(!PAGE_ALIGNED(udev->data_off));
2093 WARN_ON(udev->data_size % PAGE_SIZE);
2094 WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
2095
2096 info->version = __stringify(TCMU_MAILBOX_VERSION);
2097
2098 info->mem[0].name = "tcm-user command & data buffer";
2099 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2100 info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
2101 info->mem[0].memtype = UIO_MEM_NONE;
2102
2103 info->irqcontrol = tcmu_irqcontrol;
2104 info->irq = UIO_IRQ_CUSTOM;
2105
2106 info->mmap = tcmu_mmap;
2107 info->open = tcmu_open;
2108 info->release = tcmu_release;
2109
2110 ret = uio_register_device(tcmu_root_device, info);
2111 if (ret)
2112 goto err_register;
2113
2114 /* User can set hw_block_size before enable the device */
2115 if (dev->dev_attrib.hw_block_size == 0)
2116 dev->dev_attrib.hw_block_size = 512;
2117 /* Other attributes can be configured in userspace */
2118 if (!dev->dev_attrib.hw_max_sectors)
2119 dev->dev_attrib.hw_max_sectors = 128;
2120 if (!dev->dev_attrib.emulate_write_cache)
2121 dev->dev_attrib.emulate_write_cache = 0;
2122 dev->dev_attrib.hw_queue_depth = 128;
2123
2124 /* If user didn't explicitly disable netlink reply support, use
2125 * module scope setting.
2126 */
2127 if (udev->nl_reply_supported >= 0)
2128 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2129
2130 /*
2131 * Get a ref incase userspace does a close on the uio device before
2132 * LIO has initiated tcmu_free_device.
2133 */
2134 kref_get(&udev->kref);
2135
2136 ret = tcmu_send_dev_add_event(udev);
2137 if (ret)
2138 goto err_netlink;
2139
2140 mutex_lock(&root_udev_mutex);
2141 list_add(&udev->node, &root_udev);
2142 mutex_unlock(&root_udev_mutex);
2143
2144 return 0;
2145
2146err_netlink:
2147 kref_put(&udev->kref, tcmu_dev_kref_release);
2148 uio_unregister_device(&udev->uio_info);
2149err_register:
2150 vfree(udev->mb_addr);
2151 udev->mb_addr = NULL;
2152err_vzalloc:
2153 bitmap_free(udev->data_bitmap);
2154 udev->data_bitmap = NULL;
2155err_bitmap_alloc:
2156 kfree(info->name);
2157 info->name = NULL;
2158
2159 return ret;
2160}
2161
2162static void tcmu_free_device(struct se_device *dev)
2163{
2164 struct tcmu_dev *udev = TCMU_DEV(dev);
2165
2166 /* release ref from init */
2167 kref_put(&udev->kref, tcmu_dev_kref_release);
2168}
2169
2170static void tcmu_destroy_device(struct se_device *dev)
2171{
2172 struct tcmu_dev *udev = TCMU_DEV(dev);
2173
2174 del_timer_sync(&udev->cmd_timer);
2175 del_timer_sync(&udev->qfull_timer);
2176
2177 mutex_lock(&root_udev_mutex);
2178 list_del(&udev->node);
2179 mutex_unlock(&root_udev_mutex);
2180
2181 tcmu_send_dev_remove_event(udev);
2182
2183 uio_unregister_device(&udev->uio_info);
2184
2185 /* release ref from configure */
2186 kref_put(&udev->kref, tcmu_dev_kref_release);
2187}
2188
2189static void tcmu_unblock_dev(struct tcmu_dev *udev)
2190{
2191 mutex_lock(&udev->cmdr_lock);
2192 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2193 mutex_unlock(&udev->cmdr_lock);
2194}
2195
2196static void tcmu_block_dev(struct tcmu_dev *udev)
2197{
2198 mutex_lock(&udev->cmdr_lock);
2199
2200 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2201 goto unlock;
2202
2203 /* complete IO that has executed successfully */
2204 tcmu_handle_completions(udev);
2205 /* fail IO waiting to be queued */
2206 run_qfull_queue(udev, true);
2207
2208unlock:
2209 mutex_unlock(&udev->cmdr_lock);
2210}
2211
2212static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2213{
2214 struct tcmu_mailbox *mb;
2215 struct tcmu_cmd *cmd;
2216 int i;
2217
2218 mutex_lock(&udev->cmdr_lock);
2219
2220 idr_for_each_entry(&udev->commands, cmd, i) {
2221 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2222 cmd->cmd_id, udev->name,
2223 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2224
2225 idr_remove(&udev->commands, i);
2226 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2227 WARN_ON(!cmd->se_cmd);
2228 list_del_init(&cmd->queue_entry);
2229 if (err_level == 1) {
2230 /*
2231 * Userspace was not able to start the
2232 * command or it is retryable.
2233 */
2234 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2235 } else {
2236 /* hard failure */
2237 target_complete_cmd(cmd->se_cmd,
2238 SAM_STAT_CHECK_CONDITION);
2239 }
2240 }
2241 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2242 tcmu_free_cmd(cmd);
2243 }
2244
2245 mb = udev->mb_addr;
2246 tcmu_flush_dcache_range(mb, sizeof(*mb));
2247 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2248 mb->cmd_tail, mb->cmd_head);
2249
2250 udev->cmdr_last_cleaned = 0;
2251 mb->cmd_tail = 0;
2252 mb->cmd_head = 0;
2253 tcmu_flush_dcache_range(mb, sizeof(*mb));
2254 clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2255
2256 del_timer(&udev->cmd_timer);
2257
2258 /*
2259 * ring is empty and qfull queue never contains aborted commands.
2260 * So TMRs in tmr queue do not contain relevant cmd_ids.
2261 * After a ring reset userspace should do a fresh start, so
2262 * even LUN RESET message is no longer relevant.
2263 * Therefore remove all TMRs from qfull queue
2264 */
2265 tcmu_remove_all_queued_tmr(udev);
2266
2267 run_qfull_queue(udev, false);
2268
2269 mutex_unlock(&udev->cmdr_lock);
2270}
2271
2272enum {
2273 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2274 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2275};
2276
2277static match_table_t tokens = {
2278 {Opt_dev_config, "dev_config=%s"},
2279 {Opt_dev_size, "dev_size=%s"},
2280 {Opt_hw_block_size, "hw_block_size=%d"},
2281 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2282 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2283 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2284 {Opt_err, NULL}
2285};
2286
2287static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2288{
2289 int val, ret;
2290
2291 ret = match_int(arg, &val);
2292 if (ret < 0) {
2293 pr_err("match_int() failed for dev attrib. Error %d.\n",
2294 ret);
2295 return ret;
2296 }
2297
2298 if (val <= 0) {
2299 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2300 val);
2301 return -EINVAL;
2302 }
2303 *dev_attrib = val;
2304 return 0;
2305}
2306
2307static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2308{
2309 int val, ret;
2310
2311 ret = match_int(arg, &val);
2312 if (ret < 0) {
2313 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2314 ret);
2315 return ret;
2316 }
2317
2318 if (val <= 0) {
2319 pr_err("Invalid max_data_area %d.\n", val);
2320 return -EINVAL;
2321 }
2322
2323 mutex_lock(&udev->cmdr_lock);
2324 if (udev->data_bitmap) {
2325 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2326 ret = -EINVAL;
2327 goto unlock;
2328 }
2329
2330 udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2331 if (udev->max_blocks > tcmu_global_max_blocks) {
2332 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2333 val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2334 udev->max_blocks = tcmu_global_max_blocks;
2335 }
2336
2337unlock:
2338 mutex_unlock(&udev->cmdr_lock);
2339 return ret;
2340}
2341
2342static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2343 const char *page, ssize_t count)
2344{
2345 struct tcmu_dev *udev = TCMU_DEV(dev);
2346 char *orig, *ptr, *opts;
2347 substring_t args[MAX_OPT_ARGS];
2348 int ret = 0, token;
2349
2350 opts = kstrdup(page, GFP_KERNEL);
2351 if (!opts)
2352 return -ENOMEM;
2353
2354 orig = opts;
2355
2356 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2357 if (!*ptr)
2358 continue;
2359
2360 token = match_token(ptr, tokens, args);
2361 switch (token) {
2362 case Opt_dev_config:
2363 if (match_strlcpy(udev->dev_config, &args[0],
2364 TCMU_CONFIG_LEN) == 0) {
2365 ret = -EINVAL;
2366 break;
2367 }
2368 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2369 break;
2370 case Opt_dev_size:
2371 ret = match_u64(&args[0], &udev->dev_size);
2372 if (ret < 0)
2373 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2374 ret);
2375 break;
2376 case Opt_hw_block_size:
2377 ret = tcmu_set_dev_attrib(&args[0],
2378 &(dev->dev_attrib.hw_block_size));
2379 break;
2380 case Opt_hw_max_sectors:
2381 ret = tcmu_set_dev_attrib(&args[0],
2382 &(dev->dev_attrib.hw_max_sectors));
2383 break;
2384 case Opt_nl_reply_supported:
2385 ret = match_int(&args[0], &udev->nl_reply_supported);
2386 if (ret < 0)
2387 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2388 ret);
2389 break;
2390 case Opt_max_data_area_mb:
2391 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2392 break;
2393 default:
2394 break;
2395 }
2396
2397 if (ret)
2398 break;
2399 }
2400
2401 kfree(orig);
2402 return (!ret) ? count : ret;
2403}
2404
2405static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2406{
2407 struct tcmu_dev *udev = TCMU_DEV(dev);
2408 ssize_t bl = 0;
2409
2410 bl = sprintf(b + bl, "Config: %s ",
2411 udev->dev_config[0] ? udev->dev_config : "NULL");
2412 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2413 bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2414 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2415
2416 return bl;
2417}
2418
2419static sector_t tcmu_get_blocks(struct se_device *dev)
2420{
2421 struct tcmu_dev *udev = TCMU_DEV(dev);
2422
2423 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2424 dev->dev_attrib.block_size);
2425}
2426
2427static sense_reason_t
2428tcmu_parse_cdb(struct se_cmd *cmd)
2429{
2430 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2431}
2432
2433static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2434{
2435 struct se_dev_attrib *da = container_of(to_config_group(item),
2436 struct se_dev_attrib, da_group);
2437 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2438
2439 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2440}
2441
2442static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2443 size_t count)
2444{
2445 struct se_dev_attrib *da = container_of(to_config_group(item),
2446 struct se_dev_attrib, da_group);
2447 struct tcmu_dev *udev = container_of(da->da_dev,
2448 struct tcmu_dev, se_dev);
2449 u32 val;
2450 int ret;
2451
2452 if (da->da_dev->export_count) {
2453 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2454 return -EINVAL;
2455 }
2456
2457 ret = kstrtou32(page, 0, &val);
2458 if (ret < 0)
2459 return ret;
2460
2461 udev->cmd_time_out = val * MSEC_PER_SEC;
2462 return count;
2463}
2464CONFIGFS_ATTR(tcmu_, cmd_time_out);
2465
2466static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2467{
2468 struct se_dev_attrib *da = container_of(to_config_group(item),
2469 struct se_dev_attrib, da_group);
2470 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2471
2472 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2473 udev->qfull_time_out :
2474 udev->qfull_time_out / MSEC_PER_SEC);
2475}
2476
2477static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2478 const char *page, size_t count)
2479{
2480 struct se_dev_attrib *da = container_of(to_config_group(item),
2481 struct se_dev_attrib, da_group);
2482 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2483 s32 val;
2484 int ret;
2485
2486 ret = kstrtos32(page, 0, &val);
2487 if (ret < 0)
2488 return ret;
2489
2490 if (val >= 0) {
2491 udev->qfull_time_out = val * MSEC_PER_SEC;
2492 } else if (val == -1) {
2493 udev->qfull_time_out = val;
2494 } else {
2495 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2496 return -EINVAL;
2497 }
2498 return count;
2499}
2500CONFIGFS_ATTR(tcmu_, qfull_time_out);
2501
2502static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2503{
2504 struct se_dev_attrib *da = container_of(to_config_group(item),
2505 struct se_dev_attrib, da_group);
2506 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2507
2508 return snprintf(page, PAGE_SIZE, "%u\n",
2509 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2510}
2511CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2512
2513static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2514{
2515 struct se_dev_attrib *da = container_of(to_config_group(item),
2516 struct se_dev_attrib, da_group);
2517 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2518
2519 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2520}
2521
2522static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2523 const char *reconfig_data)
2524{
2525 struct sk_buff *skb = NULL;
2526 void *msg_header = NULL;
2527 int ret = 0;
2528
2529 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2530 &skb, &msg_header);
2531 if (ret < 0)
2532 return ret;
2533 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2534 if (ret < 0) {
2535 nlmsg_free(skb);
2536 return ret;
2537 }
2538 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2539 skb, msg_header);
2540}
2541
2542
2543static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2544 size_t count)
2545{
2546 struct se_dev_attrib *da = container_of(to_config_group(item),
2547 struct se_dev_attrib, da_group);
2548 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2549 int ret, len;
2550
2551 len = strlen(page);
2552 if (!len || len > TCMU_CONFIG_LEN - 1)
2553 return -EINVAL;
2554
2555 /* Check if device has been configured before */
2556 if (target_dev_configured(&udev->se_dev)) {
2557 ret = tcmu_send_dev_config_event(udev, page);
2558 if (ret) {
2559 pr_err("Unable to reconfigure device\n");
2560 return ret;
2561 }
2562 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2563
2564 ret = tcmu_update_uio_info(udev);
2565 if (ret)
2566 return ret;
2567 return count;
2568 }
2569 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2570
2571 return count;
2572}
2573CONFIGFS_ATTR(tcmu_, dev_config);
2574
2575static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2576{
2577 struct se_dev_attrib *da = container_of(to_config_group(item),
2578 struct se_dev_attrib, da_group);
2579 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2580
2581 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2582}
2583
2584static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2585{
2586 struct sk_buff *skb = NULL;
2587 void *msg_header = NULL;
2588 int ret = 0;
2589
2590 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2591 &skb, &msg_header);
2592 if (ret < 0)
2593 return ret;
2594 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2595 size, TCMU_ATTR_PAD);
2596 if (ret < 0) {
2597 nlmsg_free(skb);
2598 return ret;
2599 }
2600 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2601 skb, msg_header);
2602}
2603
2604static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2605 size_t count)
2606{
2607 struct se_dev_attrib *da = container_of(to_config_group(item),
2608 struct se_dev_attrib, da_group);
2609 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2610 u64 val;
2611 int ret;
2612
2613 ret = kstrtou64(page, 0, &val);
2614 if (ret < 0)
2615 return ret;
2616
2617 /* Check if device has been configured before */
2618 if (target_dev_configured(&udev->se_dev)) {
2619 ret = tcmu_send_dev_size_event(udev, val);
2620 if (ret) {
2621 pr_err("Unable to reconfigure device\n");
2622 return ret;
2623 }
2624 }
2625 udev->dev_size = val;
2626 return count;
2627}
2628CONFIGFS_ATTR(tcmu_, dev_size);
2629
2630static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2631 char *page)
2632{
2633 struct se_dev_attrib *da = container_of(to_config_group(item),
2634 struct se_dev_attrib, da_group);
2635 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2636
2637 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2638}
2639
2640static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2641 const char *page, size_t count)
2642{
2643 struct se_dev_attrib *da = container_of(to_config_group(item),
2644 struct se_dev_attrib, da_group);
2645 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2646 s8 val;
2647 int ret;
2648
2649 ret = kstrtos8(page, 0, &val);
2650 if (ret < 0)
2651 return ret;
2652
2653 udev->nl_reply_supported = val;
2654 return count;
2655}
2656CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2657
2658static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2659 char *page)
2660{
2661 struct se_dev_attrib *da = container_of(to_config_group(item),
2662 struct se_dev_attrib, da_group);
2663
2664 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2665}
2666
2667static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2668{
2669 struct sk_buff *skb = NULL;
2670 void *msg_header = NULL;
2671 int ret = 0;
2672
2673 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2674 &skb, &msg_header);
2675 if (ret < 0)
2676 return ret;
2677 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2678 if (ret < 0) {
2679 nlmsg_free(skb);
2680 return ret;
2681 }
2682 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2683 skb, msg_header);
2684}
2685
2686static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2687 const char *page, size_t count)
2688{
2689 struct se_dev_attrib *da = container_of(to_config_group(item),
2690 struct se_dev_attrib, da_group);
2691 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2692 u8 val;
2693 int ret;
2694
2695 ret = kstrtou8(page, 0, &val);
2696 if (ret < 0)
2697 return ret;
2698
2699 /* Check if device has been configured before */
2700 if (target_dev_configured(&udev->se_dev)) {
2701 ret = tcmu_send_emulate_write_cache(udev, val);
2702 if (ret) {
2703 pr_err("Unable to reconfigure device\n");
2704 return ret;
2705 }
2706 }
2707
2708 da->emulate_write_cache = val;
2709 return count;
2710}
2711CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2712
2713static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2714{
2715 struct se_dev_attrib *da = container_of(to_config_group(item),
2716 struct se_dev_attrib, da_group);
2717 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2718
2719 return snprintf(page, PAGE_SIZE, "%i\n",
2720 test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2721}
2722
2723static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2724 const char *page, size_t count)
2725{
2726 struct se_dev_attrib *da = container_of(to_config_group(item),
2727 struct se_dev_attrib, da_group);
2728 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2729 u8 val;
2730 int ret;
2731
2732 ret = kstrtou8(page, 0, &val);
2733 if (ret < 0)
2734 return ret;
2735 if (val > 1)
2736 return -EINVAL;
2737
2738 if (val)
2739 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2740 else
2741 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2742 return count;
2743}
2744CONFIGFS_ATTR(tcmu_, tmr_notification);
2745
2746static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2747{
2748 struct se_device *se_dev = container_of(to_config_group(item),
2749 struct se_device,
2750 dev_action_group);
2751 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2752
2753 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2754 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2755 else
2756 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2757}
2758
2759static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2760 size_t count)
2761{
2762 struct se_device *se_dev = container_of(to_config_group(item),
2763 struct se_device,
2764 dev_action_group);
2765 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2766 u8 val;
2767 int ret;
2768
2769 if (!target_dev_configured(&udev->se_dev)) {
2770 pr_err("Device is not configured.\n");
2771 return -EINVAL;
2772 }
2773
2774 ret = kstrtou8(page, 0, &val);
2775 if (ret < 0)
2776 return ret;
2777
2778 if (val > 1) {
2779 pr_err("Invalid block value %d\n", val);
2780 return -EINVAL;
2781 }
2782
2783 if (!val)
2784 tcmu_unblock_dev(udev);
2785 else
2786 tcmu_block_dev(udev);
2787 return count;
2788}
2789CONFIGFS_ATTR(tcmu_, block_dev);
2790
2791static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2792 size_t count)
2793{
2794 struct se_device *se_dev = container_of(to_config_group(item),
2795 struct se_device,
2796 dev_action_group);
2797 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2798 u8 val;
2799 int ret;
2800
2801 if (!target_dev_configured(&udev->se_dev)) {
2802 pr_err("Device is not configured.\n");
2803 return -EINVAL;
2804 }
2805
2806 ret = kstrtou8(page, 0, &val);
2807 if (ret < 0)
2808 return ret;
2809
2810 if (val != 1 && val != 2) {
2811 pr_err("Invalid reset ring value %d\n", val);
2812 return -EINVAL;
2813 }
2814
2815 tcmu_reset_ring(udev, val);
2816 return count;
2817}
2818CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2819
2820static struct configfs_attribute *tcmu_attrib_attrs[] = {
2821 &tcmu_attr_cmd_time_out,
2822 &tcmu_attr_qfull_time_out,
2823 &tcmu_attr_max_data_area_mb,
2824 &tcmu_attr_dev_config,
2825 &tcmu_attr_dev_size,
2826 &tcmu_attr_emulate_write_cache,
2827 &tcmu_attr_tmr_notification,
2828 &tcmu_attr_nl_reply_supported,
2829 NULL,
2830};
2831
2832static struct configfs_attribute **tcmu_attrs;
2833
2834static struct configfs_attribute *tcmu_action_attrs[] = {
2835 &tcmu_attr_block_dev,
2836 &tcmu_attr_reset_ring,
2837 NULL,
2838};
2839
2840static struct target_backend_ops tcmu_ops = {
2841 .name = "user",
2842 .owner = THIS_MODULE,
2843 .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
2844 .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
2845 TRANSPORT_FLAG_PASSTHROUGH_ALUA,
2846 .attach_hba = tcmu_attach_hba,
2847 .detach_hba = tcmu_detach_hba,
2848 .alloc_device = tcmu_alloc_device,
2849 .configure_device = tcmu_configure_device,
2850 .destroy_device = tcmu_destroy_device,
2851 .free_device = tcmu_free_device,
2852 .parse_cdb = tcmu_parse_cdb,
2853 .tmr_notify = tcmu_tmr_notify,
2854 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2855 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2856 .get_device_type = sbc_get_device_type,
2857 .get_blocks = tcmu_get_blocks,
2858 .tb_dev_action_attrs = tcmu_action_attrs,
2859};
2860
2861static void find_free_blocks(void)
2862{
2863 struct tcmu_dev *udev;
2864 loff_t off;
2865 u32 start, end, block, total_freed = 0;
2866
2867 if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2868 return;
2869
2870 mutex_lock(&root_udev_mutex);
2871 list_for_each_entry(udev, &root_udev, node) {
2872 mutex_lock(&udev->cmdr_lock);
2873
2874 if (!target_dev_configured(&udev->se_dev)) {
2875 mutex_unlock(&udev->cmdr_lock);
2876 continue;
2877 }
2878
2879 /* Try to complete the finished commands first */
2880 if (tcmu_handle_completions(udev))
2881 run_qfull_queue(udev, false);
2882
2883 /* Skip the udevs in idle */
2884 if (!udev->dbi_thresh) {
2885 mutex_unlock(&udev->cmdr_lock);
2886 continue;
2887 }
2888
2889 end = udev->dbi_max + 1;
2890 block = find_last_bit(udev->data_bitmap, end);
2891 if (block == udev->dbi_max) {
2892 /*
2893 * The last bit is dbi_max, so it is not possible
2894 * reclaim any blocks.
2895 */
2896 mutex_unlock(&udev->cmdr_lock);
2897 continue;
2898 } else if (block == end) {
2899 /* The current udev will goto idle state */
2900 udev->dbi_thresh = start = 0;
2901 udev->dbi_max = 0;
2902 } else {
2903 udev->dbi_thresh = start = block + 1;
2904 udev->dbi_max = block;
2905 }
2906
2907 /* Here will truncate the data area from off */
2908 off = udev->data_off + start * DATA_BLOCK_SIZE;
2909 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2910
2911 /* Release the block pages */
2912 tcmu_blocks_release(&udev->data_blocks, start, end);
2913 mutex_unlock(&udev->cmdr_lock);
2914
2915 total_freed += end - start;
2916 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2917 total_freed, udev->name);
2918 }
2919 mutex_unlock(&root_udev_mutex);
2920
2921 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2922 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2923}
2924
2925static void check_timedout_devices(void)
2926{
2927 struct tcmu_dev *udev, *tmp_dev;
2928 struct tcmu_cmd *cmd, *tmp_cmd;
2929 LIST_HEAD(devs);
2930
2931 spin_lock_bh(&timed_out_udevs_lock);
2932 list_splice_init(&timed_out_udevs, &devs);
2933
2934 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2935 list_del_init(&udev->timedout_entry);
2936 spin_unlock_bh(&timed_out_udevs_lock);
2937
2938 mutex_lock(&udev->cmdr_lock);
2939
2940 /*
2941 * If cmd_time_out is disabled but qfull is set deadline
2942 * will only reflect the qfull timeout. Ignore it.
2943 */
2944 if (udev->cmd_time_out) {
2945 list_for_each_entry_safe(cmd, tmp_cmd,
2946 &udev->inflight_queue,
2947 queue_entry) {
2948 tcmu_check_expired_ring_cmd(cmd);
2949 }
2950 tcmu_set_next_deadline(&udev->inflight_queue,
2951 &udev->cmd_timer);
2952 }
2953 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
2954 queue_entry) {
2955 tcmu_check_expired_queue_cmd(cmd);
2956 }
2957 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2958
2959 mutex_unlock(&udev->cmdr_lock);
2960
2961 spin_lock_bh(&timed_out_udevs_lock);
2962 }
2963
2964 spin_unlock_bh(&timed_out_udevs_lock);
2965}
2966
2967static void tcmu_unmap_work_fn(struct work_struct *work)
2968{
2969 check_timedout_devices();
2970 find_free_blocks();
2971}
2972
2973static int __init tcmu_module_init(void)
2974{
2975 int ret, i, k, len = 0;
2976
2977 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2978
2979 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2980
2981 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2982 sizeof(struct tcmu_cmd),
2983 __alignof__(struct tcmu_cmd),
2984 0, NULL);
2985 if (!tcmu_cmd_cache)
2986 return -ENOMEM;
2987
2988 tcmu_root_device = root_device_register("tcm_user");
2989 if (IS_ERR(tcmu_root_device)) {
2990 ret = PTR_ERR(tcmu_root_device);
2991 goto out_free_cache;
2992 }
2993
2994 ret = genl_register_family(&tcmu_genl_family);
2995 if (ret < 0) {
2996 goto out_unreg_device;
2997 }
2998
2999 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3000 len += sizeof(struct configfs_attribute *);
3001 for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3002 len += sizeof(struct configfs_attribute *);
3003 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3004 len += sizeof(struct configfs_attribute *);
3005 len += sizeof(struct configfs_attribute *);
3006
3007 tcmu_attrs = kzalloc(len, GFP_KERNEL);
3008 if (!tcmu_attrs) {
3009 ret = -ENOMEM;
3010 goto out_unreg_genl;
3011 }
3012
3013 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3014 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3015 for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3016 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3017 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3018 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3019 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3020
3021 ret = transport_backend_register(&tcmu_ops);
3022 if (ret)
3023 goto out_attrs;
3024
3025 return 0;
3026
3027out_attrs:
3028 kfree(tcmu_attrs);
3029out_unreg_genl:
3030 genl_unregister_family(&tcmu_genl_family);
3031out_unreg_device:
3032 root_device_unregister(tcmu_root_device);
3033out_free_cache:
3034 kmem_cache_destroy(tcmu_cmd_cache);
3035
3036 return ret;
3037}
3038
3039static void __exit tcmu_module_exit(void)
3040{
3041 cancel_delayed_work_sync(&tcmu_unmap_work);
3042 target_backend_unregister(&tcmu_ops);
3043 kfree(tcmu_attrs);
3044 genl_unregister_family(&tcmu_genl_family);
3045 root_device_unregister(tcmu_root_device);
3046 kmem_cache_destroy(tcmu_cmd_cache);
3047}
3048
3049MODULE_DESCRIPTION("TCM USER subsystem plugin");
3050MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3051MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3052MODULE_LICENSE("GPL");
3053
3054module_init(tcmu_module_init);
3055module_exit(tcmu_module_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
4 * Copyright (C) 2014 Red Hat, Inc.
5 * Copyright (C) 2015 Arrikto, Inc.
6 * Copyright (C) 2017 Chinamobile, Inc.
7 */
8
9#include <linux/spinlock.h>
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/timer.h>
13#include <linux/parser.h>
14#include <linux/vmalloc.h>
15#include <linux/uio_driver.h>
16#include <linux/xarray.h>
17#include <linux/stringify.h>
18#include <linux/bitops.h>
19#include <linux/highmem.h>
20#include <linux/configfs.h>
21#include <linux/mutex.h>
22#include <linux/workqueue.h>
23#include <linux/pagemap.h>
24#include <net/genetlink.h>
25#include <scsi/scsi_common.h>
26#include <scsi/scsi_proto.h>
27#include <target/target_core_base.h>
28#include <target/target_core_fabric.h>
29#include <target/target_core_backend.h>
30
31#include <linux/target_core_user.h>
32
33/**
34 * DOC: Userspace I/O
35 * Userspace I/O
36 * -------------
37 *
38 * Define a shared-memory interface for LIO to pass SCSI commands and
39 * data to userspace for processing. This is to allow backends that
40 * are too complex for in-kernel support to be possible.
41 *
42 * It uses the UIO framework to do a lot of the device-creation and
43 * introspection work for us.
44 *
45 * See the .h file for how the ring is laid out. Note that while the
46 * command ring is defined, the particulars of the data area are
47 * not. Offset values in the command entry point to other locations
48 * internal to the mmap-ed area. There is separate space outside the
49 * command ring for data buffers. This leaves maximum flexibility for
50 * moving buffer allocations, or even page flipping or other
51 * allocation techniques, without altering the command ring layout.
52 *
53 * SECURITY:
54 * The user process must be assumed to be malicious. There's no way to
55 * prevent it breaking the command ring protocol if it wants, but in
56 * order to prevent other issues we must only ever read *data* from
57 * the shared memory area, not offsets or sizes. This applies to
58 * command ring entries as well as the mailbox. Extra code needed for
59 * this may have a 'UAM' comment.
60 */
61
62#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
63
64/* For mailbox plus cmd ring, the size is fixed 8MB */
65#define MB_CMDR_SIZE_DEF (8 * 1024 * 1024)
66/* Offset of cmd ring is size of mailbox */
67#define CMDR_OFF ((__u32)sizeof(struct tcmu_mailbox))
68#define CMDR_SIZE_DEF (MB_CMDR_SIZE_DEF - CMDR_OFF)
69
70/*
71 * For data area, the default block size is PAGE_SIZE and
72 * the default total size is 256K * PAGE_SIZE.
73 */
74#define DATA_PAGES_PER_BLK_DEF 1
75#define DATA_AREA_PAGES_DEF (256 * 1024)
76
77#define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
78#define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
79
80/*
81 * Default number of global data blocks(512K * PAGE_SIZE)
82 * when the unmap thread will be started.
83 */
84#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
85
86static u8 tcmu_kern_cmd_reply_supported;
87static u8 tcmu_netlink_blocked;
88
89static struct device *tcmu_root_device;
90
91struct tcmu_hba {
92 u32 host_id;
93};
94
95#define TCMU_CONFIG_LEN 256
96
97static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
98static LIST_HEAD(tcmu_nl_cmd_list);
99
100struct tcmu_dev;
101
102struct tcmu_nl_cmd {
103 /* wake up thread waiting for reply */
104 struct completion complete;
105 struct list_head nl_list;
106 struct tcmu_dev *udev;
107 int cmd;
108 int status;
109};
110
111struct tcmu_dev {
112 struct list_head node;
113 struct kref kref;
114
115 struct se_device se_dev;
116 struct se_dev_plug se_plug;
117
118 char *name;
119 struct se_hba *hba;
120
121#define TCMU_DEV_BIT_OPEN 0
122#define TCMU_DEV_BIT_BROKEN 1
123#define TCMU_DEV_BIT_BLOCKED 2
124#define TCMU_DEV_BIT_TMR_NOTIFY 3
125#define TCMU_DEV_BIT_PLUGGED 4
126 unsigned long flags;
127
128 struct uio_info uio_info;
129
130 struct inode *inode;
131
132 uint64_t dev_size;
133
134 struct tcmu_mailbox *mb_addr;
135 void *cmdr;
136 u32 cmdr_size;
137 u32 cmdr_last_cleaned;
138 /* Offset of data area from start of mb */
139 /* Must add data_off and mb_addr to get the address */
140 size_t data_off;
141 int data_area_mb;
142 uint32_t max_blocks;
143 size_t mmap_pages;
144
145 struct mutex cmdr_lock;
146 struct list_head qfull_queue;
147 struct list_head tmr_queue;
148
149 uint32_t dbi_max;
150 uint32_t dbi_thresh;
151 unsigned long *data_bitmap;
152 struct xarray data_pages;
153 uint32_t data_pages_per_blk;
154 uint32_t data_blk_size;
155
156 struct xarray commands;
157
158 struct timer_list cmd_timer;
159 unsigned int cmd_time_out;
160 struct list_head inflight_queue;
161
162 struct timer_list qfull_timer;
163 int qfull_time_out;
164
165 struct list_head timedout_entry;
166
167 struct tcmu_nl_cmd curr_nl_cmd;
168
169 char dev_config[TCMU_CONFIG_LEN];
170
171 int nl_reply_supported;
172};
173
174#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
175
176struct tcmu_cmd {
177 struct se_cmd *se_cmd;
178 struct tcmu_dev *tcmu_dev;
179 struct list_head queue_entry;
180
181 uint16_t cmd_id;
182
183 /* Can't use se_cmd when cleaning up expired cmds, because if
184 cmd has been completed then accessing se_cmd is off limits */
185 uint32_t dbi_cnt;
186 uint32_t dbi_bidi_cnt;
187 uint32_t dbi_cur;
188 uint32_t *dbi;
189
190 uint32_t data_len_bidi;
191
192 unsigned long deadline;
193
194#define TCMU_CMD_BIT_EXPIRED 0
195#define TCMU_CMD_BIT_KEEP_BUF 1
196 unsigned long flags;
197};
198
199struct tcmu_tmr {
200 struct list_head queue_entry;
201
202 uint8_t tmr_type;
203 uint32_t tmr_cmd_cnt;
204 int16_t tmr_cmd_ids[];
205};
206
207/*
208 * To avoid dead lock the mutex lock order should always be:
209 *
210 * mutex_lock(&root_udev_mutex);
211 * ...
212 * mutex_lock(&tcmu_dev->cmdr_lock);
213 * mutex_unlock(&tcmu_dev->cmdr_lock);
214 * ...
215 * mutex_unlock(&root_udev_mutex);
216 */
217static DEFINE_MUTEX(root_udev_mutex);
218static LIST_HEAD(root_udev);
219
220static DEFINE_SPINLOCK(timed_out_udevs_lock);
221static LIST_HEAD(timed_out_udevs);
222
223static struct kmem_cache *tcmu_cmd_cache;
224
225static atomic_t global_page_count = ATOMIC_INIT(0);
226static struct delayed_work tcmu_unmap_work;
227static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
228
229static int tcmu_set_global_max_data_area(const char *str,
230 const struct kernel_param *kp)
231{
232 int ret, max_area_mb;
233
234 ret = kstrtoint(str, 10, &max_area_mb);
235 if (ret)
236 return -EINVAL;
237
238 if (max_area_mb <= 0) {
239 pr_err("global_max_data_area must be larger than 0.\n");
240 return -EINVAL;
241 }
242
243 tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
244 if (atomic_read(&global_page_count) > tcmu_global_max_pages)
245 schedule_delayed_work(&tcmu_unmap_work, 0);
246 else
247 cancel_delayed_work_sync(&tcmu_unmap_work);
248
249 return 0;
250}
251
252static int tcmu_get_global_max_data_area(char *buffer,
253 const struct kernel_param *kp)
254{
255 return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
256}
257
258static const struct kernel_param_ops tcmu_global_max_data_area_op = {
259 .set = tcmu_set_global_max_data_area,
260 .get = tcmu_get_global_max_data_area,
261};
262
263module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
264 S_IWUSR | S_IRUGO);
265MODULE_PARM_DESC(global_max_data_area_mb,
266 "Max MBs allowed to be allocated to all the tcmu device's "
267 "data areas.");
268
269static int tcmu_get_block_netlink(char *buffer,
270 const struct kernel_param *kp)
271{
272 return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
273 "blocked" : "unblocked");
274}
275
276static int tcmu_set_block_netlink(const char *str,
277 const struct kernel_param *kp)
278{
279 int ret;
280 u8 val;
281
282 ret = kstrtou8(str, 0, &val);
283 if (ret < 0)
284 return ret;
285
286 if (val > 1) {
287 pr_err("Invalid block netlink value %u\n", val);
288 return -EINVAL;
289 }
290
291 tcmu_netlink_blocked = val;
292 return 0;
293}
294
295static const struct kernel_param_ops tcmu_block_netlink_op = {
296 .set = tcmu_set_block_netlink,
297 .get = tcmu_get_block_netlink,
298};
299
300module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
301MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
302
303static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
304{
305 struct tcmu_dev *udev = nl_cmd->udev;
306
307 if (!tcmu_netlink_blocked) {
308 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
309 return -EBUSY;
310 }
311
312 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
313 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
314 nl_cmd->status = -EINTR;
315 list_del(&nl_cmd->nl_list);
316 complete(&nl_cmd->complete);
317 }
318 return 0;
319}
320
321static int tcmu_set_reset_netlink(const char *str,
322 const struct kernel_param *kp)
323{
324 struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
325 int ret;
326 u8 val;
327
328 ret = kstrtou8(str, 0, &val);
329 if (ret < 0)
330 return ret;
331
332 if (val != 1) {
333 pr_err("Invalid reset netlink value %u\n", val);
334 return -EINVAL;
335 }
336
337 mutex_lock(&tcmu_nl_cmd_mutex);
338 list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
339 ret = tcmu_fail_netlink_cmd(nl_cmd);
340 if (ret)
341 break;
342 }
343 mutex_unlock(&tcmu_nl_cmd_mutex);
344
345 return ret;
346}
347
348static const struct kernel_param_ops tcmu_reset_netlink_op = {
349 .set = tcmu_set_reset_netlink,
350};
351
352module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
353MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
354
355/* multicast group */
356enum tcmu_multicast_groups {
357 TCMU_MCGRP_CONFIG,
358};
359
360static const struct genl_multicast_group tcmu_mcgrps[] = {
361 [TCMU_MCGRP_CONFIG] = { .name = "config", },
362};
363
364static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
365 [TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
366 [TCMU_ATTR_MINOR] = { .type = NLA_U32 },
367 [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
368 [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
369 [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
370};
371
372static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
373{
374 struct tcmu_dev *udev = NULL;
375 struct tcmu_nl_cmd *nl_cmd;
376 int dev_id, rc, ret = 0;
377
378 if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
379 !info->attrs[TCMU_ATTR_DEVICE_ID]) {
380 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
381 return -EINVAL;
382 }
383
384 dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
385 rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
386
387 mutex_lock(&tcmu_nl_cmd_mutex);
388 list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
389 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
390 udev = nl_cmd->udev;
391 break;
392 }
393 }
394
395 if (!udev) {
396 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
397 completed_cmd, rc, dev_id);
398 ret = -ENODEV;
399 goto unlock;
400 }
401 list_del(&nl_cmd->nl_list);
402
403 pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
404 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
405 nl_cmd->status);
406
407 if (nl_cmd->cmd != completed_cmd) {
408 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
409 udev->name, completed_cmd, nl_cmd->cmd);
410 ret = -EINVAL;
411 goto unlock;
412 }
413
414 nl_cmd->status = rc;
415 complete(&nl_cmd->complete);
416unlock:
417 mutex_unlock(&tcmu_nl_cmd_mutex);
418 return ret;
419}
420
421static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
422{
423 return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
424}
425
426static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
427{
428 return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
429}
430
431static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
432 struct genl_info *info)
433{
434 return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
435}
436
437static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
438{
439 if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
440 tcmu_kern_cmd_reply_supported =
441 nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
442 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
443 tcmu_kern_cmd_reply_supported);
444 }
445
446 return 0;
447}
448
449static const struct genl_small_ops tcmu_genl_ops[] = {
450 {
451 .cmd = TCMU_CMD_SET_FEATURES,
452 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
453 .flags = GENL_ADMIN_PERM,
454 .doit = tcmu_genl_set_features,
455 },
456 {
457 .cmd = TCMU_CMD_ADDED_DEVICE_DONE,
458 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
459 .flags = GENL_ADMIN_PERM,
460 .doit = tcmu_genl_add_dev_done,
461 },
462 {
463 .cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
464 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
465 .flags = GENL_ADMIN_PERM,
466 .doit = tcmu_genl_rm_dev_done,
467 },
468 {
469 .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
470 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
471 .flags = GENL_ADMIN_PERM,
472 .doit = tcmu_genl_reconfig_dev_done,
473 },
474};
475
476/* Our generic netlink family */
477static struct genl_family tcmu_genl_family __ro_after_init = {
478 .module = THIS_MODULE,
479 .hdrsize = 0,
480 .name = "TCM-USER",
481 .version = 2,
482 .maxattr = TCMU_ATTR_MAX,
483 .policy = tcmu_attr_policy,
484 .mcgrps = tcmu_mcgrps,
485 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
486 .netnsok = true,
487 .small_ops = tcmu_genl_ops,
488 .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
489 .resv_start_op = TCMU_CMD_SET_FEATURES + 1,
490};
491
492#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
493#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
494#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
495#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
496
497static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
498{
499 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
500 uint32_t i;
501
502 for (i = 0; i < len; i++)
503 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
504}
505
506static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
507 struct tcmu_cmd *tcmu_cmd,
508 int prev_dbi, int length, int *iov_cnt)
509{
510 XA_STATE(xas, &udev->data_pages, 0);
511 struct page *page;
512 int i, cnt, dbi, dpi;
513 int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
514
515 dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
516 if (dbi == udev->dbi_thresh)
517 return -1;
518
519 dpi = dbi * udev->data_pages_per_blk;
520 /* Count the number of already allocated pages */
521 xas_set(&xas, dpi);
522 rcu_read_lock();
523 for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
524 cnt++;
525 rcu_read_unlock();
526
527 for (i = cnt; i < page_cnt; i++) {
528 /* try to get new zeroed page from the mm */
529 page = alloc_page(GFP_NOIO | __GFP_ZERO);
530 if (!page)
531 break;
532
533 if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
534 __free_page(page);
535 break;
536 }
537 }
538 if (atomic_add_return(i - cnt, &global_page_count) >
539 tcmu_global_max_pages)
540 schedule_delayed_work(&tcmu_unmap_work, 0);
541
542 if (i && dbi > udev->dbi_max)
543 udev->dbi_max = dbi;
544
545 set_bit(dbi, udev->data_bitmap);
546 tcmu_cmd_set_dbi(tcmu_cmd, dbi);
547
548 if (dbi != prev_dbi + 1)
549 *iov_cnt += 1;
550
551 return i == page_cnt ? dbi : -1;
552}
553
554static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
555 struct tcmu_cmd *tcmu_cmd, int length)
556{
557 /* start value of dbi + 1 must not be a valid dbi */
558 int dbi = -2;
559 int blk_data_len, iov_cnt = 0;
560 uint32_t blk_size = udev->data_blk_size;
561
562 for (; length > 0; length -= blk_size) {
563 blk_data_len = min_t(uint32_t, length, blk_size);
564 dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
565 &iov_cnt);
566 if (dbi < 0)
567 return -1;
568 }
569 return iov_cnt;
570}
571
572static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
573{
574 kfree(tcmu_cmd->dbi);
575 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
576}
577
578static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
579{
580 int i, len;
581 struct se_cmd *se_cmd = cmd->se_cmd;
582 uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
583
584 cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
585
586 if (se_cmd->se_cmd_flags & SCF_BIDI) {
587 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
588 for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
589 len += se_cmd->t_bidi_data_sg[i].length;
590 cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
591 cmd->dbi_cnt += cmd->dbi_bidi_cnt;
592 cmd->data_len_bidi = len;
593 }
594}
595
596static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
597 struct iovec **iov, int prev_dbi, int len)
598{
599 /* Get the next dbi */
600 int dbi = tcmu_cmd_get_dbi(cmd);
601
602 /* Do not add more than udev->data_blk_size to iov */
603 len = min_t(int, len, udev->data_blk_size);
604
605 /*
606 * The following code will gather and map the blocks to the same iovec
607 * when the blocks are all next to each other.
608 */
609 if (dbi != prev_dbi + 1) {
610 /* dbi is not next to previous dbi, so start new iov */
611 if (prev_dbi >= 0)
612 (*iov)++;
613 /* write offset relative to mb_addr */
614 (*iov)->iov_base = (void __user *)
615 (udev->data_off + dbi * udev->data_blk_size);
616 }
617 (*iov)->iov_len += len;
618
619 return dbi;
620}
621
622static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
623 struct iovec **iov, int data_length)
624{
625 /* start value of dbi + 1 must not be a valid dbi */
626 int dbi = -2;
627
628 /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
629 for (; data_length > 0; data_length -= udev->data_blk_size)
630 dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
631}
632
633static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
634{
635 struct se_device *se_dev = se_cmd->se_dev;
636 struct tcmu_dev *udev = TCMU_DEV(se_dev);
637 struct tcmu_cmd *tcmu_cmd;
638
639 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
640 if (!tcmu_cmd)
641 return NULL;
642
643 INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
644 tcmu_cmd->se_cmd = se_cmd;
645 tcmu_cmd->tcmu_dev = udev;
646
647 tcmu_cmd_set_block_cnts(tcmu_cmd);
648 tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
649 GFP_NOIO);
650 if (!tcmu_cmd->dbi) {
651 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
652 return NULL;
653 }
654
655 return tcmu_cmd;
656}
657
658static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
659{
660 unsigned long offset = offset_in_page(vaddr);
661 void *start = vaddr - offset;
662
663 size = round_up(size+offset, PAGE_SIZE);
664
665 while (size) {
666 flush_dcache_page(vmalloc_to_page(start));
667 start += PAGE_SIZE;
668 size -= PAGE_SIZE;
669 }
670}
671
672/*
673 * Some ring helper functions. We don't assume size is a power of 2 so
674 * we can't use circ_buf.h.
675 */
676static inline size_t spc_used(size_t head, size_t tail, size_t size)
677{
678 int diff = head - tail;
679
680 if (diff >= 0)
681 return diff;
682 else
683 return size + diff;
684}
685
686static inline size_t spc_free(size_t head, size_t tail, size_t size)
687{
688 /* Keep 1 byte unused or we can't tell full from empty */
689 return (size - spc_used(head, tail, size) - 1);
690}
691
692static inline size_t head_to_end(size_t head, size_t size)
693{
694 return size - head;
695}
696
697#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
698
699#define TCMU_SG_TO_DATA_AREA 1
700#define TCMU_DATA_AREA_TO_SG 2
701
702static inline void tcmu_copy_data(struct tcmu_dev *udev,
703 struct tcmu_cmd *tcmu_cmd, uint32_t direction,
704 struct scatterlist *sg, unsigned int sg_nents,
705 struct iovec **iov, size_t data_len)
706{
707 /* start value of dbi + 1 must not be a valid dbi */
708 int dbi = -2;
709 size_t page_remaining, cp_len;
710 int page_cnt, page_inx, dpi;
711 struct sg_mapping_iter sg_iter;
712 unsigned int sg_flags;
713 struct page *page;
714 void *data_page_start, *data_addr;
715
716 if (direction == TCMU_SG_TO_DATA_AREA)
717 sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
718 else
719 sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
720 sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
721
722 while (data_len) {
723 if (direction == TCMU_SG_TO_DATA_AREA)
724 dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
725 data_len);
726 else
727 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
728
729 page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
730 if (page_cnt > udev->data_pages_per_blk)
731 page_cnt = udev->data_pages_per_blk;
732
733 dpi = dbi * udev->data_pages_per_blk;
734 for (page_inx = 0; page_inx < page_cnt && data_len;
735 page_inx++, dpi++) {
736 page = xa_load(&udev->data_pages, dpi);
737
738 if (direction == TCMU_DATA_AREA_TO_SG)
739 flush_dcache_page(page);
740 data_page_start = kmap_atomic(page);
741 page_remaining = PAGE_SIZE;
742
743 while (page_remaining && data_len) {
744 if (!sg_miter_next(&sg_iter)) {
745 /* set length to 0 to abort outer loop */
746 data_len = 0;
747 pr_debug("%s: aborting data copy due to exhausted sg_list\n",
748 __func__);
749 break;
750 }
751 cp_len = min3(sg_iter.length, page_remaining,
752 data_len);
753
754 data_addr = data_page_start +
755 PAGE_SIZE - page_remaining;
756 if (direction == TCMU_SG_TO_DATA_AREA)
757 memcpy(data_addr, sg_iter.addr, cp_len);
758 else
759 memcpy(sg_iter.addr, data_addr, cp_len);
760
761 data_len -= cp_len;
762 page_remaining -= cp_len;
763 sg_iter.consumed = cp_len;
764 }
765 sg_miter_stop(&sg_iter);
766
767 kunmap_atomic(data_page_start);
768 if (direction == TCMU_SG_TO_DATA_AREA)
769 flush_dcache_page(page);
770 }
771 }
772}
773
774static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
775 struct iovec **iov)
776{
777 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
778
779 tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
780 se_cmd->t_data_nents, iov, se_cmd->data_length);
781}
782
783static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
784 bool bidi, uint32_t read_len)
785{
786 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
787 struct scatterlist *data_sg;
788 unsigned int data_nents;
789
790 if (!bidi) {
791 data_sg = se_cmd->t_data_sg;
792 data_nents = se_cmd->t_data_nents;
793 } else {
794 /*
795 * For bidi case, the first count blocks are for Data-Out
796 * buffer blocks, and before gathering the Data-In buffer
797 * the Data-Out buffer blocks should be skipped.
798 */
799 tcmu_cmd_set_dbi_cur(tcmu_cmd,
800 tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
801
802 data_sg = se_cmd->t_bidi_data_sg;
803 data_nents = se_cmd->t_bidi_data_nents;
804 }
805
806 tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
807 data_nents, NULL, read_len);
808}
809
810static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
811{
812 return thresh - bitmap_weight(bitmap, thresh);
813}
814
815/*
816 * We can't queue a command until we have space available on the cmd ring.
817 *
818 * Called with ring lock held.
819 */
820static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
821{
822 struct tcmu_mailbox *mb = udev->mb_addr;
823 size_t space, cmd_needed;
824 u32 cmd_head;
825
826 tcmu_flush_dcache_range(mb, sizeof(*mb));
827
828 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
829
830 /*
831 * If cmd end-of-ring space is too small then we need space for a NOP plus
832 * original cmd - cmds are internally contiguous.
833 */
834 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
835 cmd_needed = cmd_size;
836 else
837 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
838
839 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
840 if (space < cmd_needed) {
841 pr_debug("no cmd space: %u %u %u\n", cmd_head,
842 udev->cmdr_last_cleaned, udev->cmdr_size);
843 return false;
844 }
845 return true;
846}
847
848/*
849 * We have to allocate data buffers before we can queue a command.
850 * Returns -1 on error (not enough space) or number of needed iovs on success
851 *
852 * Called with ring lock held.
853 */
854static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
855 int *iov_bidi_cnt)
856{
857 int space, iov_cnt = 0, ret = 0;
858
859 if (!cmd->dbi_cnt)
860 goto wr_iov_cnts;
861
862 /* try to check and get the data blocks as needed */
863 space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
864 if (space < cmd->dbi_cnt) {
865 unsigned long blocks_left =
866 (udev->max_blocks - udev->dbi_thresh) + space;
867
868 if (blocks_left < cmd->dbi_cnt) {
869 pr_debug("no data space: only %lu available, but ask for %u\n",
870 blocks_left * udev->data_blk_size,
871 cmd->dbi_cnt * udev->data_blk_size);
872 return -1;
873 }
874
875 udev->dbi_thresh += cmd->dbi_cnt;
876 if (udev->dbi_thresh > udev->max_blocks)
877 udev->dbi_thresh = udev->max_blocks;
878 }
879
880 iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
881 if (iov_cnt < 0)
882 return -1;
883
884 if (cmd->dbi_bidi_cnt) {
885 ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
886 if (ret < 0)
887 return -1;
888 }
889wr_iov_cnts:
890 *iov_bidi_cnt = ret;
891 return iov_cnt + ret;
892}
893
894static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
895{
896 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
897 sizeof(struct tcmu_cmd_entry));
898}
899
900static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
901 size_t base_command_size)
902{
903 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
904 size_t command_size;
905
906 command_size = base_command_size +
907 round_up(scsi_command_size(se_cmd->t_task_cdb),
908 TCMU_OP_ALIGN_SIZE);
909
910 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
911
912 return command_size;
913}
914
915static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
916 struct timer_list *timer)
917{
918 if (!tmo)
919 return;
920
921 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
922 if (!timer_pending(timer))
923 mod_timer(timer, tcmu_cmd->deadline);
924
925 pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
926 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
927}
928
929static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
930{
931 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
932 unsigned int tmo;
933
934 /*
935 * For backwards compat if qfull_time_out is not set use
936 * cmd_time_out and if that's not set use the default time out.
937 */
938 if (!udev->qfull_time_out)
939 return -ETIMEDOUT;
940 else if (udev->qfull_time_out > 0)
941 tmo = udev->qfull_time_out;
942 else if (udev->cmd_time_out)
943 tmo = udev->cmd_time_out;
944 else
945 tmo = TCMU_TIME_OUT;
946
947 tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
948
949 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
950 pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
951 tcmu_cmd, udev->name);
952 return 0;
953}
954
955static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
956{
957 struct tcmu_cmd_entry_hdr *hdr;
958 struct tcmu_mailbox *mb = udev->mb_addr;
959 uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
960
961 /* Insert a PAD if end-of-ring space is too small */
962 if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
963 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
964
965 hdr = udev->cmdr + cmd_head;
966 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
967 tcmu_hdr_set_len(&hdr->len_op, pad_size);
968 hdr->cmd_id = 0; /* not used for PAD */
969 hdr->kflags = 0;
970 hdr->uflags = 0;
971 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
972
973 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
974 tcmu_flush_dcache_range(mb, sizeof(*mb));
975
976 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
977 WARN_ON(cmd_head != 0);
978 }
979
980 return cmd_head;
981}
982
983static void tcmu_unplug_device(struct se_dev_plug *se_plug)
984{
985 struct se_device *se_dev = se_plug->se_dev;
986 struct tcmu_dev *udev = TCMU_DEV(se_dev);
987
988 clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags);
989 uio_event_notify(&udev->uio_info);
990}
991
992static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
993{
994 struct tcmu_dev *udev = TCMU_DEV(se_dev);
995
996 if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
997 return &udev->se_plug;
998
999 return NULL;
1000}
1001
1002/**
1003 * queue_cmd_ring - queue cmd to ring or internally
1004 * @tcmu_cmd: cmd to queue
1005 * @scsi_err: TCM error code if failure (-1) returned.
1006 *
1007 * Returns:
1008 * -1 we cannot queue internally or to the ring.
1009 * 0 success
1010 * 1 internally queued to wait for ring memory to free.
1011 */
1012static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1013{
1014 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1015 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1016 size_t base_command_size, command_size;
1017 struct tcmu_mailbox *mb = udev->mb_addr;
1018 struct tcmu_cmd_entry *entry;
1019 struct iovec *iov;
1020 int iov_cnt, iov_bidi_cnt;
1021 uint32_t cmd_id, cmd_head;
1022 uint64_t cdb_off;
1023 uint32_t blk_size = udev->data_blk_size;
1024 /* size of data buffer needed */
1025 size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1026
1027 *scsi_err = TCM_NO_SENSE;
1028
1029 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1030 *scsi_err = TCM_LUN_BUSY;
1031 return -1;
1032 }
1033
1034 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1035 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1036 return -1;
1037 }
1038
1039 if (!list_empty(&udev->qfull_queue))
1040 goto queue;
1041
1042 if (data_length > (size_t)udev->max_blocks * blk_size) {
1043 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1044 data_length, (size_t)udev->max_blocks * blk_size);
1045 *scsi_err = TCM_INVALID_CDB_FIELD;
1046 return -1;
1047 }
1048
1049 iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1050 if (iov_cnt < 0)
1051 goto free_and_queue;
1052
1053 /*
1054 * Must be a certain minimum size for response sense info, but
1055 * also may be larger if the iov array is large.
1056 */
1057 base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1058 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1059
1060 if (command_size > (udev->cmdr_size / 2)) {
1061 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1062 command_size, udev->cmdr_size);
1063 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1064 *scsi_err = TCM_INVALID_CDB_FIELD;
1065 return -1;
1066 }
1067
1068 if (!is_ring_space_avail(udev, command_size))
1069 /*
1070 * Don't leave commands partially setup because the unmap
1071 * thread might need the blocks to make forward progress.
1072 */
1073 goto free_and_queue;
1074
1075 if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1076 GFP_NOWAIT) < 0) {
1077 pr_err("tcmu: Could not allocate cmd id.\n");
1078
1079 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1080 *scsi_err = TCM_OUT_OF_RESOURCES;
1081 return -1;
1082 }
1083 tcmu_cmd->cmd_id = cmd_id;
1084
1085 pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1086 tcmu_cmd, udev->name);
1087
1088 cmd_head = ring_insert_padding(udev, command_size);
1089
1090 entry = udev->cmdr + cmd_head;
1091 memset(entry, 0, command_size);
1092 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1093
1094 /* prepare iov list and copy data to data area if necessary */
1095 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1096 iov = &entry->req.iov[0];
1097
1098 if (se_cmd->data_direction == DMA_TO_DEVICE ||
1099 se_cmd->se_cmd_flags & SCF_BIDI)
1100 scatter_data_area(udev, tcmu_cmd, &iov);
1101 else
1102 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1103
1104 entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1105
1106 /* Handle BIDI commands */
1107 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1108 iov++;
1109 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1110 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1111 }
1112
1113 tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1114
1115 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1116
1117 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1118
1119 /* All offsets relative to mb_addr, not start of entry! */
1120 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1121 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1122 entry->req.cdb_off = cdb_off;
1123 tcmu_flush_dcache_range(entry, command_size);
1124
1125 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1126 tcmu_flush_dcache_range(mb, sizeof(*mb));
1127
1128 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1129
1130 if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
1131 uio_event_notify(&udev->uio_info);
1132
1133 return 0;
1134
1135free_and_queue:
1136 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1137 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1138
1139queue:
1140 if (add_to_qfull_queue(tcmu_cmd)) {
1141 *scsi_err = TCM_OUT_OF_RESOURCES;
1142 return -1;
1143 }
1144
1145 return 1;
1146}
1147
1148/**
1149 * queue_tmr_ring - queue tmr info to ring or internally
1150 * @udev: related tcmu_dev
1151 * @tmr: tcmu_tmr containing tmr info to queue
1152 *
1153 * Returns:
1154 * 0 success
1155 * 1 internally queued to wait for ring memory to free.
1156 */
1157static int
1158queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1159{
1160 struct tcmu_tmr_entry *entry;
1161 int cmd_size;
1162 int id_list_sz;
1163 struct tcmu_mailbox *mb = udev->mb_addr;
1164 uint32_t cmd_head;
1165
1166 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1167 goto out_free;
1168
1169 id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1170 cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1171
1172 if (!list_empty(&udev->tmr_queue) ||
1173 !is_ring_space_avail(udev, cmd_size)) {
1174 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1175 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1176 tmr, udev->name);
1177 return 1;
1178 }
1179
1180 cmd_head = ring_insert_padding(udev, cmd_size);
1181
1182 entry = udev->cmdr + cmd_head;
1183 memset(entry, 0, cmd_size);
1184 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1185 tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1186 entry->tmr_type = tmr->tmr_type;
1187 entry->cmd_cnt = tmr->tmr_cmd_cnt;
1188 memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1189 tcmu_flush_dcache_range(entry, cmd_size);
1190
1191 UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1192 tcmu_flush_dcache_range(mb, sizeof(*mb));
1193
1194 uio_event_notify(&udev->uio_info);
1195
1196out_free:
1197 kfree(tmr);
1198
1199 return 0;
1200}
1201
1202static sense_reason_t
1203tcmu_queue_cmd(struct se_cmd *se_cmd)
1204{
1205 struct se_device *se_dev = se_cmd->se_dev;
1206 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1207 struct tcmu_cmd *tcmu_cmd;
1208 sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1209 int ret = -1;
1210
1211 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1212 if (!tcmu_cmd)
1213 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1214
1215 mutex_lock(&udev->cmdr_lock);
1216 if (!(se_cmd->transport_state & CMD_T_ABORTED))
1217 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1218 if (ret < 0)
1219 tcmu_free_cmd(tcmu_cmd);
1220 else
1221 se_cmd->priv = tcmu_cmd;
1222 mutex_unlock(&udev->cmdr_lock);
1223 return scsi_ret;
1224}
1225
1226static void tcmu_set_next_deadline(struct list_head *queue,
1227 struct timer_list *timer)
1228{
1229 struct tcmu_cmd *cmd;
1230
1231 if (!list_empty(queue)) {
1232 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1233 mod_timer(timer, cmd->deadline);
1234 } else
1235 del_timer(timer);
1236}
1237
1238static int
1239tcmu_tmr_type(enum tcm_tmreq_table tmf)
1240{
1241 switch (tmf) {
1242 case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
1243 case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
1244 case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
1245 case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
1246 case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
1247 case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
1248 case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
1249 case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
1250 default: return TCMU_TMR_UNKNOWN;
1251 }
1252}
1253
1254static void
1255tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1256 struct list_head *cmd_list)
1257{
1258 int i = 0, cmd_cnt = 0;
1259 bool unqueued = false;
1260 struct tcmu_cmd *cmd;
1261 struct se_cmd *se_cmd;
1262 struct tcmu_tmr *tmr;
1263 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1264
1265 mutex_lock(&udev->cmdr_lock);
1266
1267 /* First we check for aborted commands in qfull_queue */
1268 list_for_each_entry(se_cmd, cmd_list, state_list) {
1269 i++;
1270 if (!se_cmd->priv)
1271 continue;
1272 cmd = se_cmd->priv;
1273 /* Commands on qfull queue have no id yet */
1274 if (cmd->cmd_id) {
1275 cmd_cnt++;
1276 continue;
1277 }
1278 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1279 cmd, udev->name);
1280
1281 list_del_init(&cmd->queue_entry);
1282 tcmu_free_cmd(cmd);
1283 se_cmd->priv = NULL;
1284 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1285 unqueued = true;
1286 }
1287 if (unqueued)
1288 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1289
1290 if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1291 goto unlock;
1292
1293 pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1294 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1295
1296 tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
1297 if (!tmr)
1298 goto unlock;
1299
1300 tmr->tmr_type = tcmu_tmr_type(tmf);
1301 tmr->tmr_cmd_cnt = cmd_cnt;
1302
1303 if (cmd_cnt != 0) {
1304 cmd_cnt = 0;
1305 list_for_each_entry(se_cmd, cmd_list, state_list) {
1306 if (!se_cmd->priv)
1307 continue;
1308 cmd = se_cmd->priv;
1309 if (cmd->cmd_id)
1310 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1311 }
1312 }
1313
1314 queue_tmr_ring(udev, tmr);
1315
1316unlock:
1317 mutex_unlock(&udev->cmdr_lock);
1318}
1319
1320static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
1321 struct tcmu_cmd_entry *entry, bool keep_buf)
1322{
1323 struct se_cmd *se_cmd = cmd->se_cmd;
1324 struct tcmu_dev *udev = cmd->tcmu_dev;
1325 bool read_len_valid = false;
1326 bool ret = true;
1327 uint32_t read_len;
1328
1329 /*
1330 * cmd has been completed already from timeout, just reclaim
1331 * data area space and free cmd
1332 */
1333 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1334 WARN_ON_ONCE(se_cmd);
1335 goto out;
1336 }
1337 if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1338 pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
1339 entry->hdr.cmd_id);
1340 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1341 ret = false;
1342 goto out;
1343 }
1344
1345 list_del_init(&cmd->queue_entry);
1346
1347 tcmu_cmd_reset_dbi_cur(cmd);
1348
1349 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1350 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1351 cmd->se_cmd);
1352 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1353 goto done;
1354 }
1355
1356 read_len = se_cmd->data_length;
1357 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1358 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1359 read_len_valid = true;
1360 if (entry->rsp.read_len < read_len)
1361 read_len = entry->rsp.read_len;
1362 }
1363
1364 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1365 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1366 if (!read_len_valid )
1367 goto done;
1368 else
1369 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1370 }
1371 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1372 /* Get Data-In buffer before clean up */
1373 gather_data_area(udev, cmd, true, read_len);
1374 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1375 gather_data_area(udev, cmd, false, read_len);
1376 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1377 /* TODO: */
1378 } else if (se_cmd->data_direction != DMA_NONE) {
1379 pr_warn("TCMU: data direction was %d!\n",
1380 se_cmd->data_direction);
1381 }
1382
1383done:
1384 se_cmd->priv = NULL;
1385 if (read_len_valid) {
1386 pr_debug("read_len = %d\n", read_len);
1387 target_complete_cmd_with_length(cmd->se_cmd,
1388 entry->rsp.scsi_status, read_len);
1389 } else
1390 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1391
1392out:
1393 if (!keep_buf) {
1394 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1395 tcmu_free_cmd(cmd);
1396 } else {
1397 /*
1398 * Keep this command after completion, since userspace still
1399 * needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF
1400 * and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept
1401 * a second completion later.
1402 * Userspace can free the buffer later by writing the cmd_id
1403 * to new action attribute free_kept_buf.
1404 */
1405 clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1406 set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags);
1407 }
1408 return ret;
1409}
1410
1411static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1412{
1413 struct tcmu_tmr *tmr, *tmp;
1414 LIST_HEAD(tmrs);
1415
1416 if (list_empty(&udev->tmr_queue))
1417 return 1;
1418
1419 pr_debug("running %s's tmr queue\n", udev->name);
1420
1421 list_splice_init(&udev->tmr_queue, &tmrs);
1422
1423 list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1424 list_del_init(&tmr->queue_entry);
1425
1426 pr_debug("removing tmr %p on dev %s from queue\n",
1427 tmr, udev->name);
1428
1429 if (queue_tmr_ring(udev, tmr)) {
1430 pr_debug("ran out of space during tmr queue run\n");
1431 /*
1432 * tmr was requeued, so just put all tmrs back in
1433 * the queue
1434 */
1435 list_splice_tail(&tmrs, &udev->tmr_queue);
1436 return 0;
1437 }
1438 }
1439
1440 return 1;
1441}
1442
1443static bool tcmu_handle_completions(struct tcmu_dev *udev)
1444{
1445 struct tcmu_mailbox *mb;
1446 struct tcmu_cmd *cmd;
1447 bool free_space = false;
1448
1449 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1450 pr_err("ring broken, not handling completions\n");
1451 return false;
1452 }
1453
1454 mb = udev->mb_addr;
1455 tcmu_flush_dcache_range(mb, sizeof(*mb));
1456
1457 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1458
1459 struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1460 bool keep_buf;
1461
1462 /*
1463 * Flush max. up to end of cmd ring since current entry might
1464 * be a padding that is shorter than sizeof(*entry)
1465 */
1466 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1467 udev->cmdr_size);
1468 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1469 ring_left : sizeof(*entry));
1470
1471 free_space = true;
1472
1473 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1474 tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1475 UPDATE_HEAD(udev->cmdr_last_cleaned,
1476 tcmu_hdr_get_len(entry->hdr.len_op),
1477 udev->cmdr_size);
1478 continue;
1479 }
1480 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1481
1482 keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF);
1483 if (keep_buf)
1484 cmd = xa_load(&udev->commands, entry->hdr.cmd_id);
1485 else
1486 cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1487 if (!cmd) {
1488 pr_err("cmd_id %u not found, ring is broken\n",
1489 entry->hdr.cmd_id);
1490 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1491 return false;
1492 }
1493
1494 if (!tcmu_handle_completion(cmd, entry, keep_buf))
1495 break;
1496
1497 UPDATE_HEAD(udev->cmdr_last_cleaned,
1498 tcmu_hdr_get_len(entry->hdr.len_op),
1499 udev->cmdr_size);
1500 }
1501 if (free_space)
1502 free_space = tcmu_run_tmr_queue(udev);
1503
1504 if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1505 xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1506 /*
1507 * Allocated blocks exceeded global block limit, currently no
1508 * more pending or waiting commands so try to reclaim blocks.
1509 */
1510 schedule_delayed_work(&tcmu_unmap_work, 0);
1511 }
1512 if (udev->cmd_time_out)
1513 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1514
1515 return free_space;
1516}
1517
1518static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1519{
1520 struct se_cmd *se_cmd;
1521
1522 if (!time_after_eq(jiffies, cmd->deadline))
1523 return;
1524
1525 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1526 list_del_init(&cmd->queue_entry);
1527 se_cmd = cmd->se_cmd;
1528 se_cmd->priv = NULL;
1529 cmd->se_cmd = NULL;
1530
1531 pr_debug("Timing out inflight cmd %u on dev %s.\n",
1532 cmd->cmd_id, cmd->tcmu_dev->name);
1533
1534 target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1535}
1536
1537static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1538{
1539 struct se_cmd *se_cmd;
1540
1541 if (!time_after_eq(jiffies, cmd->deadline))
1542 return;
1543
1544 pr_debug("Timing out queued cmd %p on dev %s.\n",
1545 cmd, cmd->tcmu_dev->name);
1546
1547 list_del_init(&cmd->queue_entry);
1548 se_cmd = cmd->se_cmd;
1549 tcmu_free_cmd(cmd);
1550
1551 se_cmd->priv = NULL;
1552 target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1553}
1554
1555static void tcmu_device_timedout(struct tcmu_dev *udev)
1556{
1557 spin_lock(&timed_out_udevs_lock);
1558 if (list_empty(&udev->timedout_entry))
1559 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1560 spin_unlock(&timed_out_udevs_lock);
1561
1562 schedule_delayed_work(&tcmu_unmap_work, 0);
1563}
1564
1565static void tcmu_cmd_timedout(struct timer_list *t)
1566{
1567 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1568
1569 pr_debug("%s cmd timeout has expired\n", udev->name);
1570 tcmu_device_timedout(udev);
1571}
1572
1573static void tcmu_qfull_timedout(struct timer_list *t)
1574{
1575 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1576
1577 pr_debug("%s qfull timeout has expired\n", udev->name);
1578 tcmu_device_timedout(udev);
1579}
1580
1581static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1582{
1583 struct tcmu_hba *tcmu_hba;
1584
1585 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1586 if (!tcmu_hba)
1587 return -ENOMEM;
1588
1589 tcmu_hba->host_id = host_id;
1590 hba->hba_ptr = tcmu_hba;
1591
1592 return 0;
1593}
1594
1595static void tcmu_detach_hba(struct se_hba *hba)
1596{
1597 kfree(hba->hba_ptr);
1598 hba->hba_ptr = NULL;
1599}
1600
1601static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1602{
1603 struct tcmu_dev *udev;
1604
1605 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1606 if (!udev)
1607 return NULL;
1608 kref_init(&udev->kref);
1609
1610 udev->name = kstrdup(name, GFP_KERNEL);
1611 if (!udev->name) {
1612 kfree(udev);
1613 return NULL;
1614 }
1615
1616 udev->hba = hba;
1617 udev->cmd_time_out = TCMU_TIME_OUT;
1618 udev->qfull_time_out = -1;
1619
1620 udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1621 udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1622 udev->cmdr_size = CMDR_SIZE_DEF;
1623 udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1624
1625 mutex_init(&udev->cmdr_lock);
1626
1627 INIT_LIST_HEAD(&udev->node);
1628 INIT_LIST_HEAD(&udev->timedout_entry);
1629 INIT_LIST_HEAD(&udev->qfull_queue);
1630 INIT_LIST_HEAD(&udev->tmr_queue);
1631 INIT_LIST_HEAD(&udev->inflight_queue);
1632 xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1633
1634 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1635 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1636
1637 xa_init(&udev->data_pages);
1638
1639 return &udev->se_dev;
1640}
1641
1642static void tcmu_dev_call_rcu(struct rcu_head *p)
1643{
1644 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1645 struct tcmu_dev *udev = TCMU_DEV(dev);
1646
1647 kfree(udev->uio_info.name);
1648 kfree(udev->name);
1649 kfree(udev);
1650}
1651
1652static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1653{
1654 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
1655 test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1656 kmem_cache_free(tcmu_cmd_cache, cmd);
1657 return 0;
1658 }
1659 return -EINVAL;
1660}
1661
1662static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1663 unsigned long last)
1664{
1665 struct page *page;
1666 unsigned long dpi;
1667 u32 pages_freed = 0;
1668
1669 first = first * udev->data_pages_per_blk;
1670 last = (last + 1) * udev->data_pages_per_blk - 1;
1671 xa_for_each_range(&udev->data_pages, dpi, page, first, last) {
1672 xa_erase(&udev->data_pages, dpi);
1673 /*
1674 * While reaching here there may be page faults occurring on
1675 * the to-be-released pages. A race condition may occur if
1676 * unmap_mapping_range() is called before page faults on these
1677 * pages have completed; a valid but stale map is created.
1678 *
1679 * If another command subsequently runs and needs to extend
1680 * dbi_thresh, it may reuse the slot corresponding to the
1681 * previous page in data_bitmap. Though we will allocate a new
1682 * page for the slot in data_area, no page fault will happen
1683 * because we have a valid map. Therefore the command's data
1684 * will be lost.
1685 *
1686 * We lock and unlock pages that are to be released to ensure
1687 * all page faults have completed. This way
1688 * unmap_mapping_range() can ensure stale maps are cleanly
1689 * removed.
1690 */
1691 lock_page(page);
1692 unlock_page(page);
1693 __free_page(page);
1694 pages_freed++;
1695 }
1696
1697 atomic_sub(pages_freed, &global_page_count);
1698
1699 return pages_freed;
1700}
1701
1702static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1703{
1704 struct tcmu_tmr *tmr, *tmp;
1705
1706 list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1707 list_del_init(&tmr->queue_entry);
1708 kfree(tmr);
1709 }
1710}
1711
1712static void tcmu_dev_kref_release(struct kref *kref)
1713{
1714 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1715 struct se_device *dev = &udev->se_dev;
1716 struct tcmu_cmd *cmd;
1717 bool all_expired = true;
1718 unsigned long i;
1719
1720 vfree(udev->mb_addr);
1721 udev->mb_addr = NULL;
1722
1723 spin_lock_bh(&timed_out_udevs_lock);
1724 if (!list_empty(&udev->timedout_entry))
1725 list_del(&udev->timedout_entry);
1726 spin_unlock_bh(&timed_out_udevs_lock);
1727
1728 /* Upper layer should drain all requests before calling this */
1729 mutex_lock(&udev->cmdr_lock);
1730 xa_for_each(&udev->commands, i, cmd) {
1731 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1732 all_expired = false;
1733 }
1734 /* There can be left over TMR cmds. Remove them. */
1735 tcmu_remove_all_queued_tmr(udev);
1736 if (!list_empty(&udev->qfull_queue))
1737 all_expired = false;
1738 xa_destroy(&udev->commands);
1739 WARN_ON(!all_expired);
1740
1741 tcmu_blocks_release(udev, 0, udev->dbi_max);
1742 bitmap_free(udev->data_bitmap);
1743 mutex_unlock(&udev->cmdr_lock);
1744
1745 pr_debug("dev_kref_release\n");
1746
1747 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1748}
1749
1750static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1751{
1752 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1753 LIST_HEAD(cmds);
1754 sense_reason_t scsi_ret;
1755 int ret;
1756
1757 if (list_empty(&udev->qfull_queue))
1758 return;
1759
1760 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1761
1762 list_splice_init(&udev->qfull_queue, &cmds);
1763
1764 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1765 list_del_init(&tcmu_cmd->queue_entry);
1766
1767 pr_debug("removing cmd %p on dev %s from queue\n",
1768 tcmu_cmd, udev->name);
1769
1770 if (fail) {
1771 /*
1772 * We were not able to even start the command, so
1773 * fail with busy to allow a retry in case runner
1774 * was only temporarily down. If the device is being
1775 * removed then LIO core will do the right thing and
1776 * fail the retry.
1777 */
1778 tcmu_cmd->se_cmd->priv = NULL;
1779 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1780 tcmu_free_cmd(tcmu_cmd);
1781 continue;
1782 }
1783
1784 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1785 if (ret < 0) {
1786 pr_debug("cmd %p on dev %s failed with %u\n",
1787 tcmu_cmd, udev->name, scsi_ret);
1788 /*
1789 * Ignore scsi_ret for now. target_complete_cmd
1790 * drops it.
1791 */
1792 tcmu_cmd->se_cmd->priv = NULL;
1793 target_complete_cmd(tcmu_cmd->se_cmd,
1794 SAM_STAT_CHECK_CONDITION);
1795 tcmu_free_cmd(tcmu_cmd);
1796 } else if (ret > 0) {
1797 pr_debug("ran out of space during cmdr queue run\n");
1798 /*
1799 * cmd was requeued, so just put all cmds back in
1800 * the queue
1801 */
1802 list_splice_tail(&cmds, &udev->qfull_queue);
1803 break;
1804 }
1805 }
1806
1807 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1808}
1809
1810static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1811{
1812 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1813
1814 mutex_lock(&udev->cmdr_lock);
1815 if (tcmu_handle_completions(udev))
1816 run_qfull_queue(udev, false);
1817 mutex_unlock(&udev->cmdr_lock);
1818
1819 return 0;
1820}
1821
1822/*
1823 * mmap code from uio.c. Copied here because we want to hook mmap()
1824 * and this stuff must come along.
1825 */
1826static int tcmu_find_mem_index(struct vm_area_struct *vma)
1827{
1828 struct tcmu_dev *udev = vma->vm_private_data;
1829 struct uio_info *info = &udev->uio_info;
1830
1831 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1832 if (info->mem[vma->vm_pgoff].size == 0)
1833 return -1;
1834 return (int)vma->vm_pgoff;
1835 }
1836 return -1;
1837}
1838
1839static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1840{
1841 struct page *page;
1842
1843 mutex_lock(&udev->cmdr_lock);
1844 page = xa_load(&udev->data_pages, dpi);
1845 if (likely(page)) {
1846 get_page(page);
1847 lock_page(page);
1848 mutex_unlock(&udev->cmdr_lock);
1849 return page;
1850 }
1851
1852 /*
1853 * Userspace messed up and passed in a address not in the
1854 * data iov passed to it.
1855 */
1856 pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1857 dpi, udev->name);
1858 mutex_unlock(&udev->cmdr_lock);
1859
1860 return NULL;
1861}
1862
1863static void tcmu_vma_open(struct vm_area_struct *vma)
1864{
1865 struct tcmu_dev *udev = vma->vm_private_data;
1866
1867 pr_debug("vma_open\n");
1868
1869 kref_get(&udev->kref);
1870}
1871
1872static void tcmu_vma_close(struct vm_area_struct *vma)
1873{
1874 struct tcmu_dev *udev = vma->vm_private_data;
1875
1876 pr_debug("vma_close\n");
1877
1878 /* release ref from tcmu_vma_open */
1879 kref_put(&udev->kref, tcmu_dev_kref_release);
1880}
1881
1882static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1883{
1884 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1885 struct uio_info *info = &udev->uio_info;
1886 struct page *page;
1887 unsigned long offset;
1888 void *addr;
1889 vm_fault_t ret = 0;
1890
1891 int mi = tcmu_find_mem_index(vmf->vma);
1892 if (mi < 0)
1893 return VM_FAULT_SIGBUS;
1894
1895 /*
1896 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1897 * to use mem[N].
1898 */
1899 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1900
1901 if (offset < udev->data_off) {
1902 /* For the vmalloc()ed cmd area pages */
1903 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1904 page = vmalloc_to_page(addr);
1905 get_page(page);
1906 } else {
1907 uint32_t dpi;
1908
1909 /* For the dynamically growing data area pages */
1910 dpi = (offset - udev->data_off) / PAGE_SIZE;
1911 page = tcmu_try_get_data_page(udev, dpi);
1912 if (!page)
1913 return VM_FAULT_SIGBUS;
1914 ret = VM_FAULT_LOCKED;
1915 }
1916
1917 vmf->page = page;
1918 return ret;
1919}
1920
1921static const struct vm_operations_struct tcmu_vm_ops = {
1922 .open = tcmu_vma_open,
1923 .close = tcmu_vma_close,
1924 .fault = tcmu_vma_fault,
1925};
1926
1927static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1928{
1929 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1930
1931 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1932 vma->vm_ops = &tcmu_vm_ops;
1933
1934 vma->vm_private_data = udev;
1935
1936 /* Ensure the mmap is exactly the right size */
1937 if (vma_pages(vma) != udev->mmap_pages)
1938 return -EINVAL;
1939
1940 tcmu_vma_open(vma);
1941
1942 return 0;
1943}
1944
1945static int tcmu_open(struct uio_info *info, struct inode *inode)
1946{
1947 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1948
1949 /* O_EXCL not supported for char devs, so fake it? */
1950 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1951 return -EBUSY;
1952
1953 udev->inode = inode;
1954
1955 pr_debug("open\n");
1956
1957 return 0;
1958}
1959
1960static int tcmu_release(struct uio_info *info, struct inode *inode)
1961{
1962 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1963 struct tcmu_cmd *cmd;
1964 unsigned long i;
1965 bool freed = false;
1966
1967 mutex_lock(&udev->cmdr_lock);
1968
1969 xa_for_each(&udev->commands, i, cmd) {
1970 /* Cmds with KEEP_BUF set are no longer on the ring, but
1971 * userspace still holds the data buffer. If userspace closes
1972 * we implicitly free these cmds and buffers, since after new
1973 * open the (new ?) userspace cannot find the cmd in the ring
1974 * and thus never will release the buffer by writing cmd_id to
1975 * free_kept_buf action attribute.
1976 */
1977 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
1978 continue;
1979 pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
1980 cmd->cmd_id, udev->name);
1981 freed = true;
1982
1983 xa_erase(&udev->commands, i);
1984 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1985 tcmu_free_cmd(cmd);
1986 }
1987 /*
1988 * We only freed data space, not ring space. Therefore we dont call
1989 * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
1990 */
1991 if (freed && list_empty(&udev->tmr_queue))
1992 run_qfull_queue(udev, false);
1993
1994 mutex_unlock(&udev->cmdr_lock);
1995
1996 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1997
1998 pr_debug("close\n");
1999
2000 return 0;
2001}
2002
2003static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
2004{
2005 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2006
2007 if (!tcmu_kern_cmd_reply_supported)
2008 return 0;
2009
2010 if (udev->nl_reply_supported <= 0)
2011 return 0;
2012
2013 mutex_lock(&tcmu_nl_cmd_mutex);
2014
2015 if (tcmu_netlink_blocked) {
2016 mutex_unlock(&tcmu_nl_cmd_mutex);
2017 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
2018 udev->name);
2019 return -EAGAIN;
2020 }
2021
2022 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
2023 mutex_unlock(&tcmu_nl_cmd_mutex);
2024 pr_warn("netlink cmd %d already executing on %s\n",
2025 nl_cmd->cmd, udev->name);
2026 return -EBUSY;
2027 }
2028
2029 memset(nl_cmd, 0, sizeof(*nl_cmd));
2030 nl_cmd->cmd = cmd;
2031 nl_cmd->udev = udev;
2032 init_completion(&nl_cmd->complete);
2033 INIT_LIST_HEAD(&nl_cmd->nl_list);
2034
2035 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
2036
2037 mutex_unlock(&tcmu_nl_cmd_mutex);
2038 return 0;
2039}
2040
2041static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
2042{
2043 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2044
2045 if (!tcmu_kern_cmd_reply_supported)
2046 return;
2047
2048 if (udev->nl_reply_supported <= 0)
2049 return;
2050
2051 mutex_lock(&tcmu_nl_cmd_mutex);
2052
2053 list_del(&nl_cmd->nl_list);
2054 memset(nl_cmd, 0, sizeof(*nl_cmd));
2055
2056 mutex_unlock(&tcmu_nl_cmd_mutex);
2057}
2058
2059static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
2060{
2061 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2062 int ret;
2063
2064 if (!tcmu_kern_cmd_reply_supported)
2065 return 0;
2066
2067 if (udev->nl_reply_supported <= 0)
2068 return 0;
2069
2070 pr_debug("sleeping for nl reply\n");
2071 wait_for_completion(&nl_cmd->complete);
2072
2073 mutex_lock(&tcmu_nl_cmd_mutex);
2074 nl_cmd->cmd = TCMU_CMD_UNSPEC;
2075 ret = nl_cmd->status;
2076 mutex_unlock(&tcmu_nl_cmd_mutex);
2077
2078 return ret;
2079}
2080
2081static int tcmu_netlink_event_init(struct tcmu_dev *udev,
2082 enum tcmu_genl_cmd cmd,
2083 struct sk_buff **buf, void **hdr)
2084{
2085 struct sk_buff *skb;
2086 void *msg_header;
2087 int ret = -ENOMEM;
2088
2089 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2090 if (!skb)
2091 return ret;
2092
2093 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2094 if (!msg_header)
2095 goto free_skb;
2096
2097 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2098 if (ret < 0)
2099 goto free_skb;
2100
2101 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2102 if (ret < 0)
2103 goto free_skb;
2104
2105 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2106 if (ret < 0)
2107 goto free_skb;
2108
2109 *buf = skb;
2110 *hdr = msg_header;
2111 return ret;
2112
2113free_skb:
2114 nlmsg_free(skb);
2115 return ret;
2116}
2117
2118static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2119 enum tcmu_genl_cmd cmd,
2120 struct sk_buff *skb, void *msg_header)
2121{
2122 int ret;
2123
2124 genlmsg_end(skb, msg_header);
2125
2126 ret = tcmu_init_genl_cmd_reply(udev, cmd);
2127 if (ret) {
2128 nlmsg_free(skb);
2129 return ret;
2130 }
2131
2132 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2133 TCMU_MCGRP_CONFIG, GFP_KERNEL);
2134
2135 /* Wait during an add as the listener may not be up yet */
2136 if (ret == 0 ||
2137 (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2138 return tcmu_wait_genl_cmd_reply(udev);
2139 else
2140 tcmu_destroy_genl_cmd_reply(udev);
2141
2142 return ret;
2143}
2144
2145static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2146{
2147 struct sk_buff *skb = NULL;
2148 void *msg_header = NULL;
2149 int ret = 0;
2150
2151 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2152 &msg_header);
2153 if (ret < 0)
2154 return ret;
2155 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2156 msg_header);
2157}
2158
2159static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2160{
2161 struct sk_buff *skb = NULL;
2162 void *msg_header = NULL;
2163 int ret = 0;
2164
2165 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2166 &skb, &msg_header);
2167 if (ret < 0)
2168 return ret;
2169 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2170 skb, msg_header);
2171}
2172
2173static int tcmu_update_uio_info(struct tcmu_dev *udev)
2174{
2175 struct tcmu_hba *hba = udev->hba->hba_ptr;
2176 struct uio_info *info;
2177 char *str;
2178
2179 info = &udev->uio_info;
2180
2181 if (udev->dev_config[0])
2182 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2183 udev->name, udev->dev_config);
2184 else
2185 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2186 udev->name);
2187 if (!str)
2188 return -ENOMEM;
2189
2190 /* If the old string exists, free it */
2191 kfree(info->name);
2192 info->name = str;
2193
2194 return 0;
2195}
2196
2197static int tcmu_configure_device(struct se_device *dev)
2198{
2199 struct tcmu_dev *udev = TCMU_DEV(dev);
2200 struct uio_info *info;
2201 struct tcmu_mailbox *mb;
2202 size_t data_size;
2203 int ret = 0;
2204
2205 ret = tcmu_update_uio_info(udev);
2206 if (ret)
2207 return ret;
2208
2209 info = &udev->uio_info;
2210
2211 mutex_lock(&udev->cmdr_lock);
2212 udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2213 mutex_unlock(&udev->cmdr_lock);
2214 if (!udev->data_bitmap) {
2215 ret = -ENOMEM;
2216 goto err_bitmap_alloc;
2217 }
2218
2219 mb = vzalloc(udev->cmdr_size + CMDR_OFF);
2220 if (!mb) {
2221 ret = -ENOMEM;
2222 goto err_vzalloc;
2223 }
2224
2225 /* mailbox fits in first part of CMDR space */
2226 udev->mb_addr = mb;
2227 udev->cmdr = (void *)mb + CMDR_OFF;
2228 udev->data_off = udev->cmdr_size + CMDR_OFF;
2229 data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2230 udev->mmap_pages = (data_size + udev->cmdr_size + CMDR_OFF) >> PAGE_SHIFT;
2231 udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2232 udev->dbi_thresh = 0; /* Default in Idle state */
2233
2234 /* Initialise the mailbox of the ring buffer */
2235 mb->version = TCMU_MAILBOX_VERSION;
2236 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2237 TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2238 TCMU_MAILBOX_FLAG_CAP_TMR |
2239 TCMU_MAILBOX_FLAG_CAP_KEEP_BUF;
2240 mb->cmdr_off = CMDR_OFF;
2241 mb->cmdr_size = udev->cmdr_size;
2242
2243 WARN_ON(!PAGE_ALIGNED(udev->data_off));
2244 WARN_ON(data_size % PAGE_SIZE);
2245
2246 info->version = __stringify(TCMU_MAILBOX_VERSION);
2247
2248 info->mem[0].name = "tcm-user command & data buffer";
2249 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2250 info->mem[0].size = data_size + udev->cmdr_size + CMDR_OFF;
2251 info->mem[0].memtype = UIO_MEM_NONE;
2252
2253 info->irqcontrol = tcmu_irqcontrol;
2254 info->irq = UIO_IRQ_CUSTOM;
2255
2256 info->mmap = tcmu_mmap;
2257 info->open = tcmu_open;
2258 info->release = tcmu_release;
2259
2260 ret = uio_register_device(tcmu_root_device, info);
2261 if (ret)
2262 goto err_register;
2263
2264 /* User can set hw_block_size before enable the device */
2265 if (dev->dev_attrib.hw_block_size == 0)
2266 dev->dev_attrib.hw_block_size = 512;
2267 /* Other attributes can be configured in userspace */
2268 if (!dev->dev_attrib.hw_max_sectors)
2269 dev->dev_attrib.hw_max_sectors = 128;
2270 if (!dev->dev_attrib.emulate_write_cache)
2271 dev->dev_attrib.emulate_write_cache = 0;
2272 dev->dev_attrib.hw_queue_depth = 128;
2273
2274 /* If user didn't explicitly disable netlink reply support, use
2275 * module scope setting.
2276 */
2277 if (udev->nl_reply_supported >= 0)
2278 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2279
2280 /*
2281 * Get a ref incase userspace does a close on the uio device before
2282 * LIO has initiated tcmu_free_device.
2283 */
2284 kref_get(&udev->kref);
2285
2286 ret = tcmu_send_dev_add_event(udev);
2287 if (ret)
2288 goto err_netlink;
2289
2290 mutex_lock(&root_udev_mutex);
2291 list_add(&udev->node, &root_udev);
2292 mutex_unlock(&root_udev_mutex);
2293
2294 return 0;
2295
2296err_netlink:
2297 kref_put(&udev->kref, tcmu_dev_kref_release);
2298 uio_unregister_device(&udev->uio_info);
2299err_register:
2300 vfree(udev->mb_addr);
2301 udev->mb_addr = NULL;
2302err_vzalloc:
2303 bitmap_free(udev->data_bitmap);
2304 udev->data_bitmap = NULL;
2305err_bitmap_alloc:
2306 kfree(info->name);
2307 info->name = NULL;
2308
2309 return ret;
2310}
2311
2312static void tcmu_free_device(struct se_device *dev)
2313{
2314 struct tcmu_dev *udev = TCMU_DEV(dev);
2315
2316 /* release ref from init */
2317 kref_put(&udev->kref, tcmu_dev_kref_release);
2318}
2319
2320static void tcmu_destroy_device(struct se_device *dev)
2321{
2322 struct tcmu_dev *udev = TCMU_DEV(dev);
2323
2324 del_timer_sync(&udev->cmd_timer);
2325 del_timer_sync(&udev->qfull_timer);
2326
2327 mutex_lock(&root_udev_mutex);
2328 list_del(&udev->node);
2329 mutex_unlock(&root_udev_mutex);
2330
2331 tcmu_send_dev_remove_event(udev);
2332
2333 uio_unregister_device(&udev->uio_info);
2334
2335 /* release ref from configure */
2336 kref_put(&udev->kref, tcmu_dev_kref_release);
2337}
2338
2339static void tcmu_unblock_dev(struct tcmu_dev *udev)
2340{
2341 mutex_lock(&udev->cmdr_lock);
2342 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2343 mutex_unlock(&udev->cmdr_lock);
2344}
2345
2346static void tcmu_block_dev(struct tcmu_dev *udev)
2347{
2348 mutex_lock(&udev->cmdr_lock);
2349
2350 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2351 goto unlock;
2352
2353 /* complete IO that has executed successfully */
2354 tcmu_handle_completions(udev);
2355 /* fail IO waiting to be queued */
2356 run_qfull_queue(udev, true);
2357
2358unlock:
2359 mutex_unlock(&udev->cmdr_lock);
2360}
2361
2362static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2363{
2364 struct tcmu_mailbox *mb;
2365 struct tcmu_cmd *cmd;
2366 unsigned long i;
2367
2368 mutex_lock(&udev->cmdr_lock);
2369
2370 xa_for_each(&udev->commands, i, cmd) {
2371 pr_debug("removing cmd %u on dev %s from ring %s\n",
2372 cmd->cmd_id, udev->name,
2373 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
2374 "(is expired)" :
2375 (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
2376 "(is keep buffer)" : ""));
2377
2378 xa_erase(&udev->commands, i);
2379 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) &&
2380 !test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
2381 WARN_ON(!cmd->se_cmd);
2382 list_del_init(&cmd->queue_entry);
2383 cmd->se_cmd->priv = NULL;
2384 if (err_level == 1) {
2385 /*
2386 * Userspace was not able to start the
2387 * command or it is retryable.
2388 */
2389 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2390 } else {
2391 /* hard failure */
2392 target_complete_cmd(cmd->se_cmd,
2393 SAM_STAT_CHECK_CONDITION);
2394 }
2395 }
2396 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2397 tcmu_free_cmd(cmd);
2398 }
2399
2400 mb = udev->mb_addr;
2401 tcmu_flush_dcache_range(mb, sizeof(*mb));
2402 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2403 mb->cmd_tail, mb->cmd_head);
2404
2405 udev->cmdr_last_cleaned = 0;
2406 mb->cmd_tail = 0;
2407 mb->cmd_head = 0;
2408 tcmu_flush_dcache_range(mb, sizeof(*mb));
2409 clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2410
2411 del_timer(&udev->cmd_timer);
2412
2413 /*
2414 * ring is empty and qfull queue never contains aborted commands.
2415 * So TMRs in tmr queue do not contain relevant cmd_ids.
2416 * After a ring reset userspace should do a fresh start, so
2417 * even LUN RESET message is no longer relevant.
2418 * Therefore remove all TMRs from qfull queue
2419 */
2420 tcmu_remove_all_queued_tmr(udev);
2421
2422 run_qfull_queue(udev, false);
2423
2424 mutex_unlock(&udev->cmdr_lock);
2425}
2426
2427enum {
2428 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2429 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2430 Opt_cmd_ring_size_mb, Opt_err,
2431};
2432
2433static match_table_t tokens = {
2434 {Opt_dev_config, "dev_config=%s"},
2435 {Opt_dev_size, "dev_size=%s"},
2436 {Opt_hw_block_size, "hw_block_size=%d"},
2437 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2438 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2439 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2440 {Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2441 {Opt_cmd_ring_size_mb, "cmd_ring_size_mb=%d"},
2442 {Opt_err, NULL}
2443};
2444
2445static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2446{
2447 int val, ret;
2448
2449 ret = match_int(arg, &val);
2450 if (ret < 0) {
2451 pr_err("match_int() failed for dev attrib. Error %d.\n",
2452 ret);
2453 return ret;
2454 }
2455
2456 if (val <= 0) {
2457 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2458 val);
2459 return -EINVAL;
2460 }
2461 *dev_attrib = val;
2462 return 0;
2463}
2464
2465static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2466{
2467 int val, ret;
2468 uint32_t pages_per_blk = udev->data_pages_per_blk;
2469
2470 ret = match_int(arg, &val);
2471 if (ret < 0) {
2472 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2473 ret);
2474 return ret;
2475 }
2476 if (val <= 0) {
2477 pr_err("Invalid max_data_area %d.\n", val);
2478 return -EINVAL;
2479 }
2480 if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2481 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2482 val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2483 val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2484 }
2485 if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2486 pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2487 val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2488 return -EINVAL;
2489 }
2490
2491 mutex_lock(&udev->cmdr_lock);
2492 if (udev->data_bitmap) {
2493 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2494 ret = -EINVAL;
2495 goto unlock;
2496 }
2497
2498 udev->data_area_mb = val;
2499 udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2500
2501unlock:
2502 mutex_unlock(&udev->cmdr_lock);
2503 return ret;
2504}
2505
2506static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2507{
2508 int val, ret;
2509
2510 ret = match_int(arg, &val);
2511 if (ret < 0) {
2512 pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2513 ret);
2514 return ret;
2515 }
2516
2517 if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2518 pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2519 val, udev->data_area_mb,
2520 TCMU_MBS_TO_PAGES(udev->data_area_mb));
2521 return -EINVAL;
2522 }
2523
2524 mutex_lock(&udev->cmdr_lock);
2525 if (udev->data_bitmap) {
2526 pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2527 ret = -EINVAL;
2528 goto unlock;
2529 }
2530
2531 udev->data_pages_per_blk = val;
2532 udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2533
2534unlock:
2535 mutex_unlock(&udev->cmdr_lock);
2536 return ret;
2537}
2538
2539static int tcmu_set_cmd_ring_size(struct tcmu_dev *udev, substring_t *arg)
2540{
2541 int val, ret;
2542
2543 ret = match_int(arg, &val);
2544 if (ret < 0) {
2545 pr_err("match_int() failed for cmd_ring_size_mb=. Error %d.\n",
2546 ret);
2547 return ret;
2548 }
2549
2550 if (val <= 0) {
2551 pr_err("Invalid cmd_ring_size_mb %d.\n", val);
2552 return -EINVAL;
2553 }
2554
2555 mutex_lock(&udev->cmdr_lock);
2556 if (udev->data_bitmap) {
2557 pr_err("Cannot set cmd_ring_size_mb after it has been enabled.\n");
2558 ret = -EINVAL;
2559 goto unlock;
2560 }
2561
2562 udev->cmdr_size = (val << 20) - CMDR_OFF;
2563 if (val > (MB_CMDR_SIZE_DEF >> 20)) {
2564 pr_err("%d is too large. Adjusting cmd_ring_size_mb to global limit of %u\n",
2565 val, (MB_CMDR_SIZE_DEF >> 20));
2566 udev->cmdr_size = CMDR_SIZE_DEF;
2567 }
2568
2569unlock:
2570 mutex_unlock(&udev->cmdr_lock);
2571 return ret;
2572}
2573
2574static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2575 const char *page, ssize_t count)
2576{
2577 struct tcmu_dev *udev = TCMU_DEV(dev);
2578 char *orig, *ptr, *opts;
2579 substring_t args[MAX_OPT_ARGS];
2580 int ret = 0, token;
2581
2582 opts = kstrdup(page, GFP_KERNEL);
2583 if (!opts)
2584 return -ENOMEM;
2585
2586 orig = opts;
2587
2588 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2589 if (!*ptr)
2590 continue;
2591
2592 token = match_token(ptr, tokens, args);
2593 switch (token) {
2594 case Opt_dev_config:
2595 if (match_strlcpy(udev->dev_config, &args[0],
2596 TCMU_CONFIG_LEN) == 0) {
2597 ret = -EINVAL;
2598 break;
2599 }
2600 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2601 break;
2602 case Opt_dev_size:
2603 ret = match_u64(&args[0], &udev->dev_size);
2604 if (ret < 0)
2605 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2606 ret);
2607 break;
2608 case Opt_hw_block_size:
2609 ret = tcmu_set_dev_attrib(&args[0],
2610 &(dev->dev_attrib.hw_block_size));
2611 break;
2612 case Opt_hw_max_sectors:
2613 ret = tcmu_set_dev_attrib(&args[0],
2614 &(dev->dev_attrib.hw_max_sectors));
2615 break;
2616 case Opt_nl_reply_supported:
2617 ret = match_int(&args[0], &udev->nl_reply_supported);
2618 if (ret < 0)
2619 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2620 ret);
2621 break;
2622 case Opt_max_data_area_mb:
2623 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2624 break;
2625 case Opt_data_pages_per_blk:
2626 ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2627 break;
2628 case Opt_cmd_ring_size_mb:
2629 ret = tcmu_set_cmd_ring_size(udev, &args[0]);
2630 break;
2631 default:
2632 break;
2633 }
2634
2635 if (ret)
2636 break;
2637 }
2638
2639 kfree(orig);
2640 return (!ret) ? count : ret;
2641}
2642
2643static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2644{
2645 struct tcmu_dev *udev = TCMU_DEV(dev);
2646 ssize_t bl = 0;
2647
2648 bl = sprintf(b + bl, "Config: %s ",
2649 udev->dev_config[0] ? udev->dev_config : "NULL");
2650 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2651 bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2652 bl += sprintf(b + bl, "DataPagesPerBlk: %u ", udev->data_pages_per_blk);
2653 bl += sprintf(b + bl, "CmdRingSizeMB: %u\n",
2654 (udev->cmdr_size + CMDR_OFF) >> 20);
2655
2656 return bl;
2657}
2658
2659static sector_t tcmu_get_blocks(struct se_device *dev)
2660{
2661 struct tcmu_dev *udev = TCMU_DEV(dev);
2662
2663 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2664 dev->dev_attrib.block_size);
2665}
2666
2667static sense_reason_t
2668tcmu_parse_cdb(struct se_cmd *cmd)
2669{
2670 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2671}
2672
2673static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2674{
2675 struct se_dev_attrib *da = container_of(to_config_group(item),
2676 struct se_dev_attrib, da_group);
2677 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2678
2679 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2680}
2681
2682static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2683 size_t count)
2684{
2685 struct se_dev_attrib *da = container_of(to_config_group(item),
2686 struct se_dev_attrib, da_group);
2687 struct tcmu_dev *udev = container_of(da->da_dev,
2688 struct tcmu_dev, se_dev);
2689 u32 val;
2690 int ret;
2691
2692 if (da->da_dev->export_count) {
2693 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2694 return -EINVAL;
2695 }
2696
2697 ret = kstrtou32(page, 0, &val);
2698 if (ret < 0)
2699 return ret;
2700
2701 udev->cmd_time_out = val * MSEC_PER_SEC;
2702 return count;
2703}
2704CONFIGFS_ATTR(tcmu_, cmd_time_out);
2705
2706static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2707{
2708 struct se_dev_attrib *da = container_of(to_config_group(item),
2709 struct se_dev_attrib, da_group);
2710 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2711
2712 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2713 udev->qfull_time_out :
2714 udev->qfull_time_out / MSEC_PER_SEC);
2715}
2716
2717static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2718 const char *page, size_t count)
2719{
2720 struct se_dev_attrib *da = container_of(to_config_group(item),
2721 struct se_dev_attrib, da_group);
2722 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2723 s32 val;
2724 int ret;
2725
2726 ret = kstrtos32(page, 0, &val);
2727 if (ret < 0)
2728 return ret;
2729
2730 if (val >= 0) {
2731 udev->qfull_time_out = val * MSEC_PER_SEC;
2732 } else if (val == -1) {
2733 udev->qfull_time_out = val;
2734 } else {
2735 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2736 return -EINVAL;
2737 }
2738 return count;
2739}
2740CONFIGFS_ATTR(tcmu_, qfull_time_out);
2741
2742static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2743{
2744 struct se_dev_attrib *da = container_of(to_config_group(item),
2745 struct se_dev_attrib, da_group);
2746 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2747
2748 return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2749}
2750CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2751
2752static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2753 char *page)
2754{
2755 struct se_dev_attrib *da = container_of(to_config_group(item),
2756 struct se_dev_attrib, da_group);
2757 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2758
2759 return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2760}
2761CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2762
2763static ssize_t tcmu_cmd_ring_size_mb_show(struct config_item *item, char *page)
2764{
2765 struct se_dev_attrib *da = container_of(to_config_group(item),
2766 struct se_dev_attrib, da_group);
2767 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2768
2769 return snprintf(page, PAGE_SIZE, "%u\n",
2770 (udev->cmdr_size + CMDR_OFF) >> 20);
2771}
2772CONFIGFS_ATTR_RO(tcmu_, cmd_ring_size_mb);
2773
2774static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2775{
2776 struct se_dev_attrib *da = container_of(to_config_group(item),
2777 struct se_dev_attrib, da_group);
2778 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2779
2780 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2781}
2782
2783static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2784 const char *reconfig_data)
2785{
2786 struct sk_buff *skb = NULL;
2787 void *msg_header = NULL;
2788 int ret = 0;
2789
2790 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2791 &skb, &msg_header);
2792 if (ret < 0)
2793 return ret;
2794 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2795 if (ret < 0) {
2796 nlmsg_free(skb);
2797 return ret;
2798 }
2799 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2800 skb, msg_header);
2801}
2802
2803
2804static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2805 size_t count)
2806{
2807 struct se_dev_attrib *da = container_of(to_config_group(item),
2808 struct se_dev_attrib, da_group);
2809 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2810 int ret, len;
2811
2812 len = strlen(page);
2813 if (!len || len > TCMU_CONFIG_LEN - 1)
2814 return -EINVAL;
2815
2816 /* Check if device has been configured before */
2817 if (target_dev_configured(&udev->se_dev)) {
2818 ret = tcmu_send_dev_config_event(udev, page);
2819 if (ret) {
2820 pr_err("Unable to reconfigure device\n");
2821 return ret;
2822 }
2823 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2824
2825 ret = tcmu_update_uio_info(udev);
2826 if (ret)
2827 return ret;
2828 return count;
2829 }
2830 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2831
2832 return count;
2833}
2834CONFIGFS_ATTR(tcmu_, dev_config);
2835
2836static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2837{
2838 struct se_dev_attrib *da = container_of(to_config_group(item),
2839 struct se_dev_attrib, da_group);
2840 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2841
2842 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2843}
2844
2845static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2846{
2847 struct sk_buff *skb = NULL;
2848 void *msg_header = NULL;
2849 int ret = 0;
2850
2851 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2852 &skb, &msg_header);
2853 if (ret < 0)
2854 return ret;
2855 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2856 size, TCMU_ATTR_PAD);
2857 if (ret < 0) {
2858 nlmsg_free(skb);
2859 return ret;
2860 }
2861 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2862 skb, msg_header);
2863}
2864
2865static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2866 size_t count)
2867{
2868 struct se_dev_attrib *da = container_of(to_config_group(item),
2869 struct se_dev_attrib, da_group);
2870 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2871 u64 val;
2872 int ret;
2873
2874 ret = kstrtou64(page, 0, &val);
2875 if (ret < 0)
2876 return ret;
2877
2878 /* Check if device has been configured before */
2879 if (target_dev_configured(&udev->se_dev)) {
2880 ret = tcmu_send_dev_size_event(udev, val);
2881 if (ret) {
2882 pr_err("Unable to reconfigure device\n");
2883 return ret;
2884 }
2885 }
2886 udev->dev_size = val;
2887 return count;
2888}
2889CONFIGFS_ATTR(tcmu_, dev_size);
2890
2891static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2892 char *page)
2893{
2894 struct se_dev_attrib *da = container_of(to_config_group(item),
2895 struct se_dev_attrib, da_group);
2896 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2897
2898 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2899}
2900
2901static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2902 const char *page, size_t count)
2903{
2904 struct se_dev_attrib *da = container_of(to_config_group(item),
2905 struct se_dev_attrib, da_group);
2906 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2907 s8 val;
2908 int ret;
2909
2910 ret = kstrtos8(page, 0, &val);
2911 if (ret < 0)
2912 return ret;
2913
2914 udev->nl_reply_supported = val;
2915 return count;
2916}
2917CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2918
2919static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2920 char *page)
2921{
2922 struct se_dev_attrib *da = container_of(to_config_group(item),
2923 struct se_dev_attrib, da_group);
2924
2925 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2926}
2927
2928static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2929{
2930 struct sk_buff *skb = NULL;
2931 void *msg_header = NULL;
2932 int ret = 0;
2933
2934 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2935 &skb, &msg_header);
2936 if (ret < 0)
2937 return ret;
2938 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2939 if (ret < 0) {
2940 nlmsg_free(skb);
2941 return ret;
2942 }
2943 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2944 skb, msg_header);
2945}
2946
2947static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2948 const char *page, size_t count)
2949{
2950 struct se_dev_attrib *da = container_of(to_config_group(item),
2951 struct se_dev_attrib, da_group);
2952 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2953 u8 val;
2954 int ret;
2955
2956 ret = kstrtou8(page, 0, &val);
2957 if (ret < 0)
2958 return ret;
2959
2960 /* Check if device has been configured before */
2961 if (target_dev_configured(&udev->se_dev)) {
2962 ret = tcmu_send_emulate_write_cache(udev, val);
2963 if (ret) {
2964 pr_err("Unable to reconfigure device\n");
2965 return ret;
2966 }
2967 }
2968
2969 da->emulate_write_cache = val;
2970 return count;
2971}
2972CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2973
2974static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2975{
2976 struct se_dev_attrib *da = container_of(to_config_group(item),
2977 struct se_dev_attrib, da_group);
2978 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2979
2980 return snprintf(page, PAGE_SIZE, "%i\n",
2981 test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2982}
2983
2984static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2985 const char *page, size_t count)
2986{
2987 struct se_dev_attrib *da = container_of(to_config_group(item),
2988 struct se_dev_attrib, da_group);
2989 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2990 u8 val;
2991 int ret;
2992
2993 ret = kstrtou8(page, 0, &val);
2994 if (ret < 0)
2995 return ret;
2996 if (val > 1)
2997 return -EINVAL;
2998
2999 if (val)
3000 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3001 else
3002 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3003 return count;
3004}
3005CONFIGFS_ATTR(tcmu_, tmr_notification);
3006
3007static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
3008{
3009 struct se_device *se_dev = container_of(to_config_group(item),
3010 struct se_device,
3011 dev_action_group);
3012 struct tcmu_dev *udev = TCMU_DEV(se_dev);
3013
3014 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
3015 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
3016 else
3017 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
3018}
3019
3020static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
3021 size_t count)
3022{
3023 struct se_device *se_dev = container_of(to_config_group(item),
3024 struct se_device,
3025 dev_action_group);
3026 struct tcmu_dev *udev = TCMU_DEV(se_dev);
3027 u8 val;
3028 int ret;
3029
3030 if (!target_dev_configured(&udev->se_dev)) {
3031 pr_err("Device is not configured.\n");
3032 return -EINVAL;
3033 }
3034
3035 ret = kstrtou8(page, 0, &val);
3036 if (ret < 0)
3037 return ret;
3038
3039 if (val > 1) {
3040 pr_err("Invalid block value %d\n", val);
3041 return -EINVAL;
3042 }
3043
3044 if (!val)
3045 tcmu_unblock_dev(udev);
3046 else
3047 tcmu_block_dev(udev);
3048 return count;
3049}
3050CONFIGFS_ATTR(tcmu_, block_dev);
3051
3052static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
3053 size_t count)
3054{
3055 struct se_device *se_dev = container_of(to_config_group(item),
3056 struct se_device,
3057 dev_action_group);
3058 struct tcmu_dev *udev = TCMU_DEV(se_dev);
3059 u8 val;
3060 int ret;
3061
3062 if (!target_dev_configured(&udev->se_dev)) {
3063 pr_err("Device is not configured.\n");
3064 return -EINVAL;
3065 }
3066
3067 ret = kstrtou8(page, 0, &val);
3068 if (ret < 0)
3069 return ret;
3070
3071 if (val != 1 && val != 2) {
3072 pr_err("Invalid reset ring value %d\n", val);
3073 return -EINVAL;
3074 }
3075
3076 tcmu_reset_ring(udev, val);
3077 return count;
3078}
3079CONFIGFS_ATTR_WO(tcmu_, reset_ring);
3080
3081static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
3082 size_t count)
3083{
3084 struct se_device *se_dev = container_of(to_config_group(item),
3085 struct se_device,
3086 dev_action_group);
3087 struct tcmu_dev *udev = TCMU_DEV(se_dev);
3088 struct tcmu_cmd *cmd;
3089 u16 cmd_id;
3090 int ret;
3091
3092 if (!target_dev_configured(&udev->se_dev)) {
3093 pr_err("Device is not configured.\n");
3094 return -EINVAL;
3095 }
3096
3097 ret = kstrtou16(page, 0, &cmd_id);
3098 if (ret < 0)
3099 return ret;
3100
3101 mutex_lock(&udev->cmdr_lock);
3102
3103 {
3104 XA_STATE(xas, &udev->commands, cmd_id);
3105
3106 xas_lock(&xas);
3107 cmd = xas_load(&xas);
3108 if (!cmd) {
3109 pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id);
3110 count = -EINVAL;
3111 xas_unlock(&xas);
3112 goto out_unlock;
3113 }
3114 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
3115 pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n",
3116 cmd_id);
3117 count = -EINVAL;
3118 xas_unlock(&xas);
3119 goto out_unlock;
3120 }
3121 xas_store(&xas, NULL);
3122 xas_unlock(&xas);
3123 }
3124
3125 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
3126 tcmu_free_cmd(cmd);
3127 /*
3128 * We only freed data space, not ring space. Therefore we dont call
3129 * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
3130 */
3131 if (list_empty(&udev->tmr_queue))
3132 run_qfull_queue(udev, false);
3133
3134out_unlock:
3135 mutex_unlock(&udev->cmdr_lock);
3136 return count;
3137}
3138CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
3139
3140static struct configfs_attribute *tcmu_attrib_attrs[] = {
3141 &tcmu_attr_cmd_time_out,
3142 &tcmu_attr_qfull_time_out,
3143 &tcmu_attr_max_data_area_mb,
3144 &tcmu_attr_data_pages_per_blk,
3145 &tcmu_attr_cmd_ring_size_mb,
3146 &tcmu_attr_dev_config,
3147 &tcmu_attr_dev_size,
3148 &tcmu_attr_emulate_write_cache,
3149 &tcmu_attr_tmr_notification,
3150 &tcmu_attr_nl_reply_supported,
3151 NULL,
3152};
3153
3154static struct configfs_attribute **tcmu_attrs;
3155
3156static struct configfs_attribute *tcmu_action_attrs[] = {
3157 &tcmu_attr_block_dev,
3158 &tcmu_attr_reset_ring,
3159 &tcmu_attr_free_kept_buf,
3160 NULL,
3161};
3162
3163static struct target_backend_ops tcmu_ops = {
3164 .name = "user",
3165 .owner = THIS_MODULE,
3166 .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
3167 .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
3168 TRANSPORT_FLAG_PASSTHROUGH_ALUA,
3169 .attach_hba = tcmu_attach_hba,
3170 .detach_hba = tcmu_detach_hba,
3171 .alloc_device = tcmu_alloc_device,
3172 .configure_device = tcmu_configure_device,
3173 .destroy_device = tcmu_destroy_device,
3174 .free_device = tcmu_free_device,
3175 .unplug_device = tcmu_unplug_device,
3176 .plug_device = tcmu_plug_device,
3177 .parse_cdb = tcmu_parse_cdb,
3178 .tmr_notify = tcmu_tmr_notify,
3179 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
3180 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
3181 .get_device_type = sbc_get_device_type,
3182 .get_blocks = tcmu_get_blocks,
3183 .tb_dev_action_attrs = tcmu_action_attrs,
3184};
3185
3186static void find_free_blocks(void)
3187{
3188 struct tcmu_dev *udev;
3189 loff_t off;
3190 u32 pages_freed, total_pages_freed = 0;
3191 u32 start, end, block, total_blocks_freed = 0;
3192
3193 if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
3194 return;
3195
3196 mutex_lock(&root_udev_mutex);
3197 list_for_each_entry(udev, &root_udev, node) {
3198 mutex_lock(&udev->cmdr_lock);
3199
3200 if (!target_dev_configured(&udev->se_dev)) {
3201 mutex_unlock(&udev->cmdr_lock);
3202 continue;
3203 }
3204
3205 /* Try to complete the finished commands first */
3206 if (tcmu_handle_completions(udev))
3207 run_qfull_queue(udev, false);
3208
3209 /* Skip the udevs in idle */
3210 if (!udev->dbi_thresh) {
3211 mutex_unlock(&udev->cmdr_lock);
3212 continue;
3213 }
3214
3215 end = udev->dbi_max + 1;
3216 block = find_last_bit(udev->data_bitmap, end);
3217 if (block == udev->dbi_max) {
3218 /*
3219 * The last bit is dbi_max, so it is not possible
3220 * reclaim any blocks.
3221 */
3222 mutex_unlock(&udev->cmdr_lock);
3223 continue;
3224 } else if (block == end) {
3225 /* The current udev will goto idle state */
3226 udev->dbi_thresh = start = 0;
3227 udev->dbi_max = 0;
3228 } else {
3229 udev->dbi_thresh = start = block + 1;
3230 udev->dbi_max = block;
3231 }
3232
3233 /*
3234 * Release the block pages.
3235 *
3236 * Also note that since tcmu_vma_fault() gets an extra page
3237 * refcount, tcmu_blocks_release() won't free pages if pages
3238 * are mapped. This means it is safe to call
3239 * tcmu_blocks_release() before unmap_mapping_range() which
3240 * drops the refcount of any pages it unmaps and thus releases
3241 * them.
3242 */
3243 pages_freed = tcmu_blocks_release(udev, start, end - 1);
3244
3245 /* Here will truncate the data area from off */
3246 off = udev->data_off + (loff_t)start * udev->data_blk_size;
3247 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3248
3249 mutex_unlock(&udev->cmdr_lock);
3250
3251 total_pages_freed += pages_freed;
3252 total_blocks_freed += end - start;
3253 pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3254 pages_freed, total_pages_freed, end - start,
3255 total_blocks_freed, udev->name);
3256 }
3257 mutex_unlock(&root_udev_mutex);
3258
3259 if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3260 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3261}
3262
3263static void check_timedout_devices(void)
3264{
3265 struct tcmu_dev *udev, *tmp_dev;
3266 struct tcmu_cmd *cmd, *tmp_cmd;
3267 LIST_HEAD(devs);
3268
3269 spin_lock_bh(&timed_out_udevs_lock);
3270 list_splice_init(&timed_out_udevs, &devs);
3271
3272 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3273 list_del_init(&udev->timedout_entry);
3274 spin_unlock_bh(&timed_out_udevs_lock);
3275
3276 mutex_lock(&udev->cmdr_lock);
3277
3278 /*
3279 * If cmd_time_out is disabled but qfull is set deadline
3280 * will only reflect the qfull timeout. Ignore it.
3281 */
3282 if (udev->cmd_time_out) {
3283 list_for_each_entry_safe(cmd, tmp_cmd,
3284 &udev->inflight_queue,
3285 queue_entry) {
3286 tcmu_check_expired_ring_cmd(cmd);
3287 }
3288 tcmu_set_next_deadline(&udev->inflight_queue,
3289 &udev->cmd_timer);
3290 }
3291 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3292 queue_entry) {
3293 tcmu_check_expired_queue_cmd(cmd);
3294 }
3295 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3296
3297 mutex_unlock(&udev->cmdr_lock);
3298
3299 spin_lock_bh(&timed_out_udevs_lock);
3300 }
3301
3302 spin_unlock_bh(&timed_out_udevs_lock);
3303}
3304
3305static void tcmu_unmap_work_fn(struct work_struct *work)
3306{
3307 check_timedout_devices();
3308 find_free_blocks();
3309}
3310
3311static int __init tcmu_module_init(void)
3312{
3313 int ret, i, k, len = 0;
3314
3315 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3316
3317 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3318
3319 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3320 sizeof(struct tcmu_cmd),
3321 __alignof__(struct tcmu_cmd),
3322 0, NULL);
3323 if (!tcmu_cmd_cache)
3324 return -ENOMEM;
3325
3326 tcmu_root_device = root_device_register("tcm_user");
3327 if (IS_ERR(tcmu_root_device)) {
3328 ret = PTR_ERR(tcmu_root_device);
3329 goto out_free_cache;
3330 }
3331
3332 ret = genl_register_family(&tcmu_genl_family);
3333 if (ret < 0) {
3334 goto out_unreg_device;
3335 }
3336
3337 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3338 len += sizeof(struct configfs_attribute *);
3339 for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3340 len += sizeof(struct configfs_attribute *);
3341 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3342 len += sizeof(struct configfs_attribute *);
3343 len += sizeof(struct configfs_attribute *);
3344
3345 tcmu_attrs = kzalloc(len, GFP_KERNEL);
3346 if (!tcmu_attrs) {
3347 ret = -ENOMEM;
3348 goto out_unreg_genl;
3349 }
3350
3351 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3352 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3353 for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3354 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3355 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3356 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3357 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3358
3359 ret = transport_backend_register(&tcmu_ops);
3360 if (ret)
3361 goto out_attrs;
3362
3363 return 0;
3364
3365out_attrs:
3366 kfree(tcmu_attrs);
3367out_unreg_genl:
3368 genl_unregister_family(&tcmu_genl_family);
3369out_unreg_device:
3370 root_device_unregister(tcmu_root_device);
3371out_free_cache:
3372 kmem_cache_destroy(tcmu_cmd_cache);
3373
3374 return ret;
3375}
3376
3377static void __exit tcmu_module_exit(void)
3378{
3379 cancel_delayed_work_sync(&tcmu_unmap_work);
3380 target_backend_unregister(&tcmu_ops);
3381 kfree(tcmu_attrs);
3382 genl_unregister_family(&tcmu_genl_family);
3383 root_device_unregister(tcmu_root_device);
3384 kmem_cache_destroy(tcmu_cmd_cache);
3385}
3386
3387MODULE_DESCRIPTION("TCM USER subsystem plugin");
3388MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3389MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3390MODULE_LICENSE("GPL");
3391
3392module_init(tcmu_module_init);
3393module_exit(tcmu_module_exit);