Loading...
Note: File does not exist in v3.1.
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 unsigned long flags;
122
123 struct uio_info uio_info;
124
125 struct inode *inode;
126
127 struct tcmu_mailbox *mb_addr;
128 uint64_t dev_size;
129 u32 cmdr_size;
130 u32 cmdr_last_cleaned;
131 /* Offset of data area from start of mb */
132 /* Must add data_off and mb_addr to get the address */
133 size_t data_off;
134 size_t data_size;
135 uint32_t max_blocks;
136 size_t ring_size;
137
138 struct mutex cmdr_lock;
139 struct list_head qfull_queue;
140
141 uint32_t dbi_max;
142 uint32_t dbi_thresh;
143 unsigned long *data_bitmap;
144 struct radix_tree_root data_blocks;
145
146 struct idr commands;
147
148 struct timer_list cmd_timer;
149 unsigned int cmd_time_out;
150 struct list_head inflight_queue;
151
152 struct timer_list qfull_timer;
153 int qfull_time_out;
154
155 struct list_head timedout_entry;
156
157 struct tcmu_nl_cmd curr_nl_cmd;
158
159 char dev_config[TCMU_CONFIG_LEN];
160
161 int nl_reply_supported;
162};
163
164#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
165
166#define CMDR_OFF sizeof(struct tcmu_mailbox)
167
168struct tcmu_cmd {
169 struct se_cmd *se_cmd;
170 struct tcmu_dev *tcmu_dev;
171 struct list_head queue_entry;
172
173 uint16_t cmd_id;
174
175 /* Can't use se_cmd when cleaning up expired cmds, because if
176 cmd has been completed then accessing se_cmd is off limits */
177 uint32_t dbi_cnt;
178 uint32_t dbi_cur;
179 uint32_t *dbi;
180
181 unsigned long deadline;
182
183#define TCMU_CMD_BIT_EXPIRED 0
184#define TCMU_CMD_BIT_INFLIGHT 1
185 unsigned long flags;
186};
187/*
188 * To avoid dead lock the mutex lock order should always be:
189 *
190 * mutex_lock(&root_udev_mutex);
191 * ...
192 * mutex_lock(&tcmu_dev->cmdr_lock);
193 * mutex_unlock(&tcmu_dev->cmdr_lock);
194 * ...
195 * mutex_unlock(&root_udev_mutex);
196 */
197static DEFINE_MUTEX(root_udev_mutex);
198static LIST_HEAD(root_udev);
199
200static DEFINE_SPINLOCK(timed_out_udevs_lock);
201static LIST_HEAD(timed_out_udevs);
202
203static struct kmem_cache *tcmu_cmd_cache;
204
205static atomic_t global_db_count = ATOMIC_INIT(0);
206static struct delayed_work tcmu_unmap_work;
207static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
208
209static int tcmu_set_global_max_data_area(const char *str,
210 const struct kernel_param *kp)
211{
212 int ret, max_area_mb;
213
214 ret = kstrtoint(str, 10, &max_area_mb);
215 if (ret)
216 return -EINVAL;
217
218 if (max_area_mb <= 0) {
219 pr_err("global_max_data_area must be larger than 0.\n");
220 return -EINVAL;
221 }
222
223 tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
224 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
225 schedule_delayed_work(&tcmu_unmap_work, 0);
226 else
227 cancel_delayed_work_sync(&tcmu_unmap_work);
228
229 return 0;
230}
231
232static int tcmu_get_global_max_data_area(char *buffer,
233 const struct kernel_param *kp)
234{
235 return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
236}
237
238static const struct kernel_param_ops tcmu_global_max_data_area_op = {
239 .set = tcmu_set_global_max_data_area,
240 .get = tcmu_get_global_max_data_area,
241};
242
243module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
244 S_IWUSR | S_IRUGO);
245MODULE_PARM_DESC(global_max_data_area_mb,
246 "Max MBs allowed to be allocated to all the tcmu device's "
247 "data areas.");
248
249static int tcmu_get_block_netlink(char *buffer,
250 const struct kernel_param *kp)
251{
252 return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
253 "blocked" : "unblocked");
254}
255
256static int tcmu_set_block_netlink(const char *str,
257 const struct kernel_param *kp)
258{
259 int ret;
260 u8 val;
261
262 ret = kstrtou8(str, 0, &val);
263 if (ret < 0)
264 return ret;
265
266 if (val > 1) {
267 pr_err("Invalid block netlink value %u\n", val);
268 return -EINVAL;
269 }
270
271 tcmu_netlink_blocked = val;
272 return 0;
273}
274
275static const struct kernel_param_ops tcmu_block_netlink_op = {
276 .set = tcmu_set_block_netlink,
277 .get = tcmu_get_block_netlink,
278};
279
280module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
281MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
282
283static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
284{
285 struct tcmu_dev *udev = nl_cmd->udev;
286
287 if (!tcmu_netlink_blocked) {
288 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
289 return -EBUSY;
290 }
291
292 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
293 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
294 nl_cmd->status = -EINTR;
295 list_del(&nl_cmd->nl_list);
296 complete(&nl_cmd->complete);
297 }
298 return 0;
299}
300
301static int tcmu_set_reset_netlink(const char *str,
302 const struct kernel_param *kp)
303{
304 struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
305 int ret;
306 u8 val;
307
308 ret = kstrtou8(str, 0, &val);
309 if (ret < 0)
310 return ret;
311
312 if (val != 1) {
313 pr_err("Invalid reset netlink value %u\n", val);
314 return -EINVAL;
315 }
316
317 mutex_lock(&tcmu_nl_cmd_mutex);
318 list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
319 ret = tcmu_fail_netlink_cmd(nl_cmd);
320 if (ret)
321 break;
322 }
323 mutex_unlock(&tcmu_nl_cmd_mutex);
324
325 return ret;
326}
327
328static const struct kernel_param_ops tcmu_reset_netlink_op = {
329 .set = tcmu_set_reset_netlink,
330};
331
332module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
333MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
334
335/* multicast group */
336enum tcmu_multicast_groups {
337 TCMU_MCGRP_CONFIG,
338};
339
340static const struct genl_multicast_group tcmu_mcgrps[] = {
341 [TCMU_MCGRP_CONFIG] = { .name = "config", },
342};
343
344static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
345 [TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
346 [TCMU_ATTR_MINOR] = { .type = NLA_U32 },
347 [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
348 [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
349 [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
350};
351
352static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
353{
354 struct tcmu_dev *udev = NULL;
355 struct tcmu_nl_cmd *nl_cmd;
356 int dev_id, rc, ret = 0;
357
358 if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
359 !info->attrs[TCMU_ATTR_DEVICE_ID]) {
360 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
361 return -EINVAL;
362 }
363
364 dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
365 rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
366
367 mutex_lock(&tcmu_nl_cmd_mutex);
368 list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
369 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
370 udev = nl_cmd->udev;
371 break;
372 }
373 }
374
375 if (!udev) {
376 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
377 completed_cmd, rc, dev_id);
378 ret = -ENODEV;
379 goto unlock;
380 }
381 list_del(&nl_cmd->nl_list);
382
383 pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
384 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
385 nl_cmd->status);
386
387 if (nl_cmd->cmd != completed_cmd) {
388 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
389 udev->name, completed_cmd, nl_cmd->cmd);
390 ret = -EINVAL;
391 goto unlock;
392 }
393
394 nl_cmd->status = rc;
395 complete(&nl_cmd->complete);
396unlock:
397 mutex_unlock(&tcmu_nl_cmd_mutex);
398 return ret;
399}
400
401static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
402{
403 return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
404}
405
406static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
407{
408 return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
409}
410
411static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
412 struct genl_info *info)
413{
414 return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
415}
416
417static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
418{
419 if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
420 tcmu_kern_cmd_reply_supported =
421 nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
422 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
423 tcmu_kern_cmd_reply_supported);
424 }
425
426 return 0;
427}
428
429static const struct genl_ops tcmu_genl_ops[] = {
430 {
431 .cmd = TCMU_CMD_SET_FEATURES,
432 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
433 .flags = GENL_ADMIN_PERM,
434 .doit = tcmu_genl_set_features,
435 },
436 {
437 .cmd = TCMU_CMD_ADDED_DEVICE_DONE,
438 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
439 .flags = GENL_ADMIN_PERM,
440 .doit = tcmu_genl_add_dev_done,
441 },
442 {
443 .cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
444 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
445 .flags = GENL_ADMIN_PERM,
446 .doit = tcmu_genl_rm_dev_done,
447 },
448 {
449 .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
450 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
451 .flags = GENL_ADMIN_PERM,
452 .doit = tcmu_genl_reconfig_dev_done,
453 },
454};
455
456/* Our generic netlink family */
457static struct genl_family tcmu_genl_family __ro_after_init = {
458 .module = THIS_MODULE,
459 .hdrsize = 0,
460 .name = "TCM-USER",
461 .version = 2,
462 .maxattr = TCMU_ATTR_MAX,
463 .policy = tcmu_attr_policy,
464 .mcgrps = tcmu_mcgrps,
465 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
466 .netnsok = true,
467 .ops = tcmu_genl_ops,
468 .n_ops = ARRAY_SIZE(tcmu_genl_ops),
469};
470
471#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
472#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
473#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
474#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
475
476static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
477{
478 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
479 uint32_t i;
480
481 for (i = 0; i < len; i++)
482 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
483}
484
485static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
486 struct tcmu_cmd *tcmu_cmd)
487{
488 struct page *page;
489 int ret, dbi;
490
491 dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
492 if (dbi == udev->dbi_thresh)
493 return false;
494
495 page = radix_tree_lookup(&udev->data_blocks, dbi);
496 if (!page) {
497 if (atomic_add_return(1, &global_db_count) >
498 tcmu_global_max_blocks)
499 schedule_delayed_work(&tcmu_unmap_work, 0);
500
501 /* try to get new page from the mm */
502 page = alloc_page(GFP_KERNEL);
503 if (!page)
504 goto err_alloc;
505
506 ret = radix_tree_insert(&udev->data_blocks, dbi, page);
507 if (ret)
508 goto err_insert;
509 }
510
511 if (dbi > udev->dbi_max)
512 udev->dbi_max = dbi;
513
514 set_bit(dbi, udev->data_bitmap);
515 tcmu_cmd_set_dbi(tcmu_cmd, dbi);
516
517 return true;
518err_insert:
519 __free_page(page);
520err_alloc:
521 atomic_dec(&global_db_count);
522 return false;
523}
524
525static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
526 struct tcmu_cmd *tcmu_cmd)
527{
528 int i;
529
530 for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
531 if (!tcmu_get_empty_block(udev, tcmu_cmd))
532 return false;
533 }
534 return true;
535}
536
537static inline struct page *
538tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
539{
540 return radix_tree_lookup(&udev->data_blocks, dbi);
541}
542
543static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
544{
545 kfree(tcmu_cmd->dbi);
546 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
547}
548
549static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
550{
551 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
552 size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
553
554 if (se_cmd->se_cmd_flags & SCF_BIDI) {
555 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
556 data_length += round_up(se_cmd->t_bidi_data_sg->length,
557 DATA_BLOCK_SIZE);
558 }
559
560 return data_length;
561}
562
563static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
564{
565 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
566
567 return data_length / DATA_BLOCK_SIZE;
568}
569
570static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
571{
572 struct se_device *se_dev = se_cmd->se_dev;
573 struct tcmu_dev *udev = TCMU_DEV(se_dev);
574 struct tcmu_cmd *tcmu_cmd;
575
576 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
577 if (!tcmu_cmd)
578 return NULL;
579
580 INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
581 tcmu_cmd->se_cmd = se_cmd;
582 tcmu_cmd->tcmu_dev = udev;
583
584 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
585 tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
586 tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
587 GFP_KERNEL);
588 if (!tcmu_cmd->dbi) {
589 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
590 return NULL;
591 }
592
593 return tcmu_cmd;
594}
595
596static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
597{
598 unsigned long offset = offset_in_page(vaddr);
599 void *start = vaddr - offset;
600
601 size = round_up(size+offset, PAGE_SIZE);
602
603 while (size) {
604 flush_dcache_page(virt_to_page(start));
605 start += PAGE_SIZE;
606 size -= PAGE_SIZE;
607 }
608}
609
610/*
611 * Some ring helper functions. We don't assume size is a power of 2 so
612 * we can't use circ_buf.h.
613 */
614static inline size_t spc_used(size_t head, size_t tail, size_t size)
615{
616 int diff = head - tail;
617
618 if (diff >= 0)
619 return diff;
620 else
621 return size + diff;
622}
623
624static inline size_t spc_free(size_t head, size_t tail, size_t size)
625{
626 /* Keep 1 byte unused or we can't tell full from empty */
627 return (size - spc_used(head, tail, size) - 1);
628}
629
630static inline size_t head_to_end(size_t head, size_t size)
631{
632 return size - head;
633}
634
635static inline void new_iov(struct iovec **iov, int *iov_cnt)
636{
637 struct iovec *iovec;
638
639 if (*iov_cnt != 0)
640 (*iov)++;
641 (*iov_cnt)++;
642
643 iovec = *iov;
644 memset(iovec, 0, sizeof(struct iovec));
645}
646
647#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
648
649/* offset is relative to mb_addr */
650static inline size_t get_block_offset_user(struct tcmu_dev *dev,
651 int dbi, int remaining)
652{
653 return dev->data_off + dbi * DATA_BLOCK_SIZE +
654 DATA_BLOCK_SIZE - remaining;
655}
656
657static inline size_t iov_tail(struct iovec *iov)
658{
659 return (size_t)iov->iov_base + iov->iov_len;
660}
661
662static void scatter_data_area(struct tcmu_dev *udev,
663 struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
664 unsigned int data_nents, struct iovec **iov,
665 int *iov_cnt, bool copy_data)
666{
667 int i, dbi;
668 int block_remaining = 0;
669 void *from, *to = NULL;
670 size_t copy_bytes, to_offset, offset;
671 struct scatterlist *sg;
672 struct page *page;
673
674 for_each_sg(data_sg, sg, data_nents, i) {
675 int sg_remaining = sg->length;
676 from = kmap_atomic(sg_page(sg)) + sg->offset;
677 while (sg_remaining > 0) {
678 if (block_remaining == 0) {
679 if (to)
680 kunmap_atomic(to);
681
682 block_remaining = DATA_BLOCK_SIZE;
683 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
684 page = tcmu_get_block_page(udev, dbi);
685 to = kmap_atomic(page);
686 }
687
688 /*
689 * Covert to virtual offset of the ring data area.
690 */
691 to_offset = get_block_offset_user(udev, dbi,
692 block_remaining);
693
694 /*
695 * The following code will gather and map the blocks
696 * to the same iovec when the blocks are all next to
697 * each other.
698 */
699 copy_bytes = min_t(size_t, sg_remaining,
700 block_remaining);
701 if (*iov_cnt != 0 &&
702 to_offset == iov_tail(*iov)) {
703 /*
704 * Will append to the current iovec, because
705 * the current block page is next to the
706 * previous one.
707 */
708 (*iov)->iov_len += copy_bytes;
709 } else {
710 /*
711 * Will allocate a new iovec because we are
712 * first time here or the current block page
713 * is not next to the previous one.
714 */
715 new_iov(iov, iov_cnt);
716 (*iov)->iov_base = (void __user *)to_offset;
717 (*iov)->iov_len = copy_bytes;
718 }
719
720 if (copy_data) {
721 offset = DATA_BLOCK_SIZE - block_remaining;
722 memcpy(to + offset,
723 from + sg->length - sg_remaining,
724 copy_bytes);
725 tcmu_flush_dcache_range(to, copy_bytes);
726 }
727
728 sg_remaining -= copy_bytes;
729 block_remaining -= copy_bytes;
730 }
731 kunmap_atomic(from - sg->offset);
732 }
733
734 if (to)
735 kunmap_atomic(to);
736}
737
738static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
739 bool bidi, uint32_t read_len)
740{
741 struct se_cmd *se_cmd = cmd->se_cmd;
742 int i, dbi;
743 int block_remaining = 0;
744 void *from = NULL, *to;
745 size_t copy_bytes, offset;
746 struct scatterlist *sg, *data_sg;
747 struct page *page;
748 unsigned int data_nents;
749 uint32_t count = 0;
750
751 if (!bidi) {
752 data_sg = se_cmd->t_data_sg;
753 data_nents = se_cmd->t_data_nents;
754 } else {
755
756 /*
757 * For bidi case, the first count blocks are for Data-Out
758 * buffer blocks, and before gathering the Data-In buffer
759 * the Data-Out buffer blocks should be discarded.
760 */
761 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
762
763 data_sg = se_cmd->t_bidi_data_sg;
764 data_nents = se_cmd->t_bidi_data_nents;
765 }
766
767 tcmu_cmd_set_dbi_cur(cmd, count);
768
769 for_each_sg(data_sg, sg, data_nents, i) {
770 int sg_remaining = sg->length;
771 to = kmap_atomic(sg_page(sg)) + sg->offset;
772 while (sg_remaining > 0 && read_len > 0) {
773 if (block_remaining == 0) {
774 if (from)
775 kunmap_atomic(from);
776
777 block_remaining = DATA_BLOCK_SIZE;
778 dbi = tcmu_cmd_get_dbi(cmd);
779 page = tcmu_get_block_page(udev, dbi);
780 from = kmap_atomic(page);
781 }
782 copy_bytes = min_t(size_t, sg_remaining,
783 block_remaining);
784 if (read_len < copy_bytes)
785 copy_bytes = read_len;
786 offset = DATA_BLOCK_SIZE - block_remaining;
787 tcmu_flush_dcache_range(from, copy_bytes);
788 memcpy(to + sg->length - sg_remaining, from + offset,
789 copy_bytes);
790
791 sg_remaining -= copy_bytes;
792 block_remaining -= copy_bytes;
793 read_len -= copy_bytes;
794 }
795 kunmap_atomic(to - sg->offset);
796 if (read_len == 0)
797 break;
798 }
799 if (from)
800 kunmap_atomic(from);
801}
802
803static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
804{
805 return thresh - bitmap_weight(bitmap, thresh);
806}
807
808/*
809 * We can't queue a command until we have space available on the cmd ring *and*
810 * space available on the data area.
811 *
812 * Called with ring lock held.
813 */
814static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
815 size_t cmd_size, size_t data_needed)
816{
817 struct tcmu_mailbox *mb = udev->mb_addr;
818 uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
819 / DATA_BLOCK_SIZE;
820 size_t space, cmd_needed;
821 u32 cmd_head;
822
823 tcmu_flush_dcache_range(mb, sizeof(*mb));
824
825 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
826
827 /*
828 * If cmd end-of-ring space is too small then we need space for a NOP plus
829 * original cmd - cmds are internally contiguous.
830 */
831 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
832 cmd_needed = cmd_size;
833 else
834 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
835
836 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
837 if (space < cmd_needed) {
838 pr_debug("no cmd space: %u %u %u\n", cmd_head,
839 udev->cmdr_last_cleaned, udev->cmdr_size);
840 return false;
841 }
842
843 /* try to check and get the data blocks as needed */
844 space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
845 if ((space * DATA_BLOCK_SIZE) < data_needed) {
846 unsigned long blocks_left =
847 (udev->max_blocks - udev->dbi_thresh) + space;
848
849 if (blocks_left < blocks_needed) {
850 pr_debug("no data space: only %lu available, but ask for %zu\n",
851 blocks_left * DATA_BLOCK_SIZE,
852 data_needed);
853 return false;
854 }
855
856 udev->dbi_thresh += blocks_needed;
857 if (udev->dbi_thresh > udev->max_blocks)
858 udev->dbi_thresh = udev->max_blocks;
859 }
860
861 return tcmu_get_empty_blocks(udev, cmd);
862}
863
864static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
865{
866 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
867 sizeof(struct tcmu_cmd_entry));
868}
869
870static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
871 size_t base_command_size)
872{
873 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
874 size_t command_size;
875
876 command_size = base_command_size +
877 round_up(scsi_command_size(se_cmd->t_task_cdb),
878 TCMU_OP_ALIGN_SIZE);
879
880 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
881
882 return command_size;
883}
884
885static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
886 struct timer_list *timer)
887{
888 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
889 int cmd_id;
890
891 if (tcmu_cmd->cmd_id)
892 goto setup_timer;
893
894 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
895 if (cmd_id < 0) {
896 pr_err("tcmu: Could not allocate cmd id.\n");
897 return cmd_id;
898 }
899 tcmu_cmd->cmd_id = cmd_id;
900
901 pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id,
902 udev->name, tmo / MSEC_PER_SEC);
903
904setup_timer:
905 if (!tmo)
906 return 0;
907
908 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
909 if (!timer_pending(timer))
910 mod_timer(timer, tcmu_cmd->deadline);
911
912 return 0;
913}
914
915static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
916{
917 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
918 unsigned int tmo;
919 int ret;
920
921 /*
922 * For backwards compat if qfull_time_out is not set use
923 * cmd_time_out and if that's not set use the default time out.
924 */
925 if (!udev->qfull_time_out)
926 return -ETIMEDOUT;
927 else if (udev->qfull_time_out > 0)
928 tmo = udev->qfull_time_out;
929 else if (udev->cmd_time_out)
930 tmo = udev->cmd_time_out;
931 else
932 tmo = TCMU_TIME_OUT;
933
934 ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
935 if (ret)
936 return ret;
937
938 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
939 pr_debug("adding cmd %u on dev %s to ring space wait queue\n",
940 tcmu_cmd->cmd_id, udev->name);
941 return 0;
942}
943
944/**
945 * queue_cmd_ring - queue cmd to ring or internally
946 * @tcmu_cmd: cmd to queue
947 * @scsi_err: TCM error code if failure (-1) returned.
948 *
949 * Returns:
950 * -1 we cannot queue internally or to the ring.
951 * 0 success
952 * 1 internally queued to wait for ring memory to free.
953 */
954static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
955{
956 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
957 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
958 size_t base_command_size, command_size;
959 struct tcmu_mailbox *mb;
960 struct tcmu_cmd_entry *entry;
961 struct iovec *iov;
962 int iov_cnt, ret;
963 uint32_t cmd_head;
964 uint64_t cdb_off;
965 bool copy_to_data_area;
966 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
967
968 *scsi_err = TCM_NO_SENSE;
969
970 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
971 *scsi_err = TCM_LUN_BUSY;
972 return -1;
973 }
974
975 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
976 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
977 return -1;
978 }
979
980 /*
981 * Must be a certain minimum size for response sense info, but
982 * also may be larger if the iov array is large.
983 *
984 * We prepare as many iovs as possbile for potential uses here,
985 * because it's expensive to tell how many regions are freed in
986 * the bitmap & global data pool, as the size calculated here
987 * will only be used to do the checks.
988 *
989 * The size will be recalculated later as actually needed to save
990 * cmd area memories.
991 */
992 base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
993 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
994
995 if (!list_empty(&udev->qfull_queue))
996 goto queue;
997
998 mb = udev->mb_addr;
999 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
1000 if ((command_size > (udev->cmdr_size / 2)) ||
1001 data_length > udev->data_size) {
1002 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
1003 "cmd ring/data area\n", command_size, data_length,
1004 udev->cmdr_size, udev->data_size);
1005 *scsi_err = TCM_INVALID_CDB_FIELD;
1006 return -1;
1007 }
1008
1009 if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
1010 /*
1011 * Don't leave commands partially setup because the unmap
1012 * thread might need the blocks to make forward progress.
1013 */
1014 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1015 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1016 goto queue;
1017 }
1018
1019 /* Insert a PAD if end-of-ring space is too small */
1020 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
1021 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
1022
1023 entry = (void *) mb + CMDR_OFF + cmd_head;
1024 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
1025 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
1026 entry->hdr.cmd_id = 0; /* not used for PAD */
1027 entry->hdr.kflags = 0;
1028 entry->hdr.uflags = 0;
1029 tcmu_flush_dcache_range(entry, sizeof(*entry));
1030
1031 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
1032 tcmu_flush_dcache_range(mb, sizeof(*mb));
1033
1034 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
1035 WARN_ON(cmd_head != 0);
1036 }
1037
1038 entry = (void *) mb + CMDR_OFF + cmd_head;
1039 memset(entry, 0, command_size);
1040 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1041
1042 /* Handle allocating space from the data area */
1043 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1044 iov = &entry->req.iov[0];
1045 iov_cnt = 0;
1046 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
1047 || se_cmd->se_cmd_flags & SCF_BIDI);
1048 scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
1049 se_cmd->t_data_nents, &iov, &iov_cnt,
1050 copy_to_data_area);
1051 entry->req.iov_cnt = iov_cnt;
1052
1053 /* Handle BIDI commands */
1054 iov_cnt = 0;
1055 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1056 iov++;
1057 scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
1058 se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
1059 false);
1060 }
1061 entry->req.iov_bidi_cnt = iov_cnt;
1062
1063 ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out,
1064 &udev->cmd_timer);
1065 if (ret) {
1066 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1067
1068 *scsi_err = TCM_OUT_OF_RESOURCES;
1069 return -1;
1070 }
1071 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1072
1073 /*
1074 * Recalaulate the command's base size and size according
1075 * to the actual needs
1076 */
1077 base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
1078 entry->req.iov_bidi_cnt);
1079 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1080
1081 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1082
1083 /* All offsets relative to mb_addr, not start of entry! */
1084 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1085 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1086 entry->req.cdb_off = cdb_off;
1087 tcmu_flush_dcache_range(entry, sizeof(*entry));
1088
1089 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1090 tcmu_flush_dcache_range(mb, sizeof(*mb));
1091
1092 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1093 set_bit(TCMU_CMD_BIT_INFLIGHT, &tcmu_cmd->flags);
1094
1095 /* TODO: only if FLUSH and FUA? */
1096 uio_event_notify(&udev->uio_info);
1097
1098 return 0;
1099
1100queue:
1101 if (add_to_qfull_queue(tcmu_cmd)) {
1102 *scsi_err = TCM_OUT_OF_RESOURCES;
1103 return -1;
1104 }
1105
1106 return 1;
1107}
1108
1109static sense_reason_t
1110tcmu_queue_cmd(struct se_cmd *se_cmd)
1111{
1112 struct se_device *se_dev = se_cmd->se_dev;
1113 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1114 struct tcmu_cmd *tcmu_cmd;
1115 sense_reason_t scsi_ret;
1116 int ret;
1117
1118 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1119 if (!tcmu_cmd)
1120 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1121
1122 mutex_lock(&udev->cmdr_lock);
1123 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1124 mutex_unlock(&udev->cmdr_lock);
1125 if (ret < 0)
1126 tcmu_free_cmd(tcmu_cmd);
1127 return scsi_ret;
1128}
1129
1130static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1131{
1132 struct se_cmd *se_cmd = cmd->se_cmd;
1133 struct tcmu_dev *udev = cmd->tcmu_dev;
1134 bool read_len_valid = false;
1135 uint32_t read_len;
1136
1137 /*
1138 * cmd has been completed already from timeout, just reclaim
1139 * data area space and free cmd
1140 */
1141 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1142 WARN_ON_ONCE(se_cmd);
1143 goto out;
1144 }
1145
1146 list_del_init(&cmd->queue_entry);
1147
1148 tcmu_cmd_reset_dbi_cur(cmd);
1149
1150 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1151 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1152 cmd->se_cmd);
1153 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1154 goto done;
1155 }
1156
1157 read_len = se_cmd->data_length;
1158 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1159 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1160 read_len_valid = true;
1161 if (entry->rsp.read_len < read_len)
1162 read_len = entry->rsp.read_len;
1163 }
1164
1165 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1166 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1167 if (!read_len_valid )
1168 goto done;
1169 else
1170 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1171 }
1172 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1173 /* Get Data-In buffer before clean up */
1174 gather_data_area(udev, cmd, true, read_len);
1175 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1176 gather_data_area(udev, cmd, false, read_len);
1177 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1178 /* TODO: */
1179 } else if (se_cmd->data_direction != DMA_NONE) {
1180 pr_warn("TCMU: data direction was %d!\n",
1181 se_cmd->data_direction);
1182 }
1183
1184done:
1185 if (read_len_valid) {
1186 pr_debug("read_len = %d\n", read_len);
1187 target_complete_cmd_with_length(cmd->se_cmd,
1188 entry->rsp.scsi_status, read_len);
1189 } else
1190 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1191
1192out:
1193 cmd->se_cmd = NULL;
1194 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1195 tcmu_free_cmd(cmd);
1196}
1197
1198static void tcmu_set_next_deadline(struct list_head *queue,
1199 struct timer_list *timer)
1200{
1201 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1202 unsigned long deadline = 0;
1203
1204 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, queue, queue_entry) {
1205 if (!time_after(jiffies, tcmu_cmd->deadline)) {
1206 deadline = tcmu_cmd->deadline;
1207 break;
1208 }
1209 }
1210
1211 if (deadline)
1212 mod_timer(timer, deadline);
1213 else
1214 del_timer(timer);
1215}
1216
1217static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1218{
1219 struct tcmu_mailbox *mb;
1220 struct tcmu_cmd *cmd;
1221 int handled = 0;
1222
1223 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1224 pr_err("ring broken, not handling completions\n");
1225 return 0;
1226 }
1227
1228 mb = udev->mb_addr;
1229 tcmu_flush_dcache_range(mb, sizeof(*mb));
1230
1231 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1232
1233 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1234
1235 tcmu_flush_dcache_range(entry, sizeof(*entry));
1236
1237 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
1238 UPDATE_HEAD(udev->cmdr_last_cleaned,
1239 tcmu_hdr_get_len(entry->hdr.len_op),
1240 udev->cmdr_size);
1241 continue;
1242 }
1243 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1244
1245 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1246 if (!cmd) {
1247 pr_err("cmd_id %u not found, ring is broken\n",
1248 entry->hdr.cmd_id);
1249 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1250 break;
1251 }
1252
1253 tcmu_handle_completion(cmd, entry);
1254
1255 UPDATE_HEAD(udev->cmdr_last_cleaned,
1256 tcmu_hdr_get_len(entry->hdr.len_op),
1257 udev->cmdr_size);
1258
1259 handled++;
1260 }
1261
1262 if (mb->cmd_tail == mb->cmd_head) {
1263 /* no more pending commands */
1264 del_timer(&udev->cmd_timer);
1265
1266 if (list_empty(&udev->qfull_queue)) {
1267 /*
1268 * no more pending or waiting commands so try to
1269 * reclaim blocks if needed.
1270 */
1271 if (atomic_read(&global_db_count) >
1272 tcmu_global_max_blocks)
1273 schedule_delayed_work(&tcmu_unmap_work, 0);
1274 }
1275 } else if (udev->cmd_time_out) {
1276 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1277 }
1278
1279 return handled;
1280}
1281
1282static int tcmu_check_expired_cmd(int id, void *p, void *data)
1283{
1284 struct tcmu_cmd *cmd = p;
1285 struct tcmu_dev *udev = cmd->tcmu_dev;
1286 u8 scsi_status;
1287 struct se_cmd *se_cmd;
1288 bool is_running;
1289
1290 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
1291 return 0;
1292
1293 if (!time_after(jiffies, cmd->deadline))
1294 return 0;
1295
1296 is_running = test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags);
1297 se_cmd = cmd->se_cmd;
1298
1299 if (is_running) {
1300 /*
1301 * If cmd_time_out is disabled but qfull is set deadline
1302 * will only reflect the qfull timeout. Ignore it.
1303 */
1304 if (!udev->cmd_time_out)
1305 return 0;
1306
1307 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1308 /*
1309 * target_complete_cmd will translate this to LUN COMM FAILURE
1310 */
1311 scsi_status = SAM_STAT_CHECK_CONDITION;
1312 list_del_init(&cmd->queue_entry);
1313 cmd->se_cmd = NULL;
1314 } else {
1315 list_del_init(&cmd->queue_entry);
1316 idr_remove(&udev->commands, id);
1317 tcmu_free_cmd(cmd);
1318 scsi_status = SAM_STAT_TASK_SET_FULL;
1319 }
1320
1321 pr_debug("Timing out cmd %u on dev %s that is %s.\n",
1322 id, udev->name, is_running ? "inflight" : "queued");
1323
1324 target_complete_cmd(se_cmd, scsi_status);
1325 return 0;
1326}
1327
1328static void tcmu_device_timedout(struct tcmu_dev *udev)
1329{
1330 spin_lock(&timed_out_udevs_lock);
1331 if (list_empty(&udev->timedout_entry))
1332 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1333 spin_unlock(&timed_out_udevs_lock);
1334
1335 schedule_delayed_work(&tcmu_unmap_work, 0);
1336}
1337
1338static void tcmu_cmd_timedout(struct timer_list *t)
1339{
1340 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1341
1342 pr_debug("%s cmd timeout has expired\n", udev->name);
1343 tcmu_device_timedout(udev);
1344}
1345
1346static void tcmu_qfull_timedout(struct timer_list *t)
1347{
1348 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1349
1350 pr_debug("%s qfull timeout has expired\n", udev->name);
1351 tcmu_device_timedout(udev);
1352}
1353
1354static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1355{
1356 struct tcmu_hba *tcmu_hba;
1357
1358 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1359 if (!tcmu_hba)
1360 return -ENOMEM;
1361
1362 tcmu_hba->host_id = host_id;
1363 hba->hba_ptr = tcmu_hba;
1364
1365 return 0;
1366}
1367
1368static void tcmu_detach_hba(struct se_hba *hba)
1369{
1370 kfree(hba->hba_ptr);
1371 hba->hba_ptr = NULL;
1372}
1373
1374static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1375{
1376 struct tcmu_dev *udev;
1377
1378 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1379 if (!udev)
1380 return NULL;
1381 kref_init(&udev->kref);
1382
1383 udev->name = kstrdup(name, GFP_KERNEL);
1384 if (!udev->name) {
1385 kfree(udev);
1386 return NULL;
1387 }
1388
1389 udev->hba = hba;
1390 udev->cmd_time_out = TCMU_TIME_OUT;
1391 udev->qfull_time_out = -1;
1392
1393 udev->max_blocks = DATA_BLOCK_BITS_DEF;
1394 mutex_init(&udev->cmdr_lock);
1395
1396 INIT_LIST_HEAD(&udev->node);
1397 INIT_LIST_HEAD(&udev->timedout_entry);
1398 INIT_LIST_HEAD(&udev->qfull_queue);
1399 INIT_LIST_HEAD(&udev->inflight_queue);
1400 idr_init(&udev->commands);
1401
1402 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1403 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1404
1405 INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1406
1407 return &udev->se_dev;
1408}
1409
1410static bool run_qfull_queue(struct tcmu_dev *udev, bool fail)
1411{
1412 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1413 LIST_HEAD(cmds);
1414 bool drained = true;
1415 sense_reason_t scsi_ret;
1416 int ret;
1417
1418 if (list_empty(&udev->qfull_queue))
1419 return true;
1420
1421 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1422
1423 list_splice_init(&udev->qfull_queue, &cmds);
1424
1425 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1426 list_del_init(&tcmu_cmd->queue_entry);
1427
1428 pr_debug("removing cmd %u on dev %s from queue\n",
1429 tcmu_cmd->cmd_id, udev->name);
1430
1431 if (fail) {
1432 idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1433 /*
1434 * We were not able to even start the command, so
1435 * fail with busy to allow a retry in case runner
1436 * was only temporarily down. If the device is being
1437 * removed then LIO core will do the right thing and
1438 * fail the retry.
1439 */
1440 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1441 tcmu_free_cmd(tcmu_cmd);
1442 continue;
1443 }
1444
1445 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1446 if (ret < 0) {
1447 pr_debug("cmd %u on dev %s failed with %u\n",
1448 tcmu_cmd->cmd_id, udev->name, scsi_ret);
1449
1450 idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1451 /*
1452 * Ignore scsi_ret for now. target_complete_cmd
1453 * drops it.
1454 */
1455 target_complete_cmd(tcmu_cmd->se_cmd,
1456 SAM_STAT_CHECK_CONDITION);
1457 tcmu_free_cmd(tcmu_cmd);
1458 } else if (ret > 0) {
1459 pr_debug("ran out of space during cmdr queue run\n");
1460 /*
1461 * cmd was requeued, so just put all cmds back in
1462 * the queue
1463 */
1464 list_splice_tail(&cmds, &udev->qfull_queue);
1465 drained = false;
1466 break;
1467 }
1468 }
1469
1470 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1471 return drained;
1472}
1473
1474static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1475{
1476 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1477
1478 mutex_lock(&udev->cmdr_lock);
1479 tcmu_handle_completions(udev);
1480 run_qfull_queue(udev, false);
1481 mutex_unlock(&udev->cmdr_lock);
1482
1483 return 0;
1484}
1485
1486/*
1487 * mmap code from uio.c. Copied here because we want to hook mmap()
1488 * and this stuff must come along.
1489 */
1490static int tcmu_find_mem_index(struct vm_area_struct *vma)
1491{
1492 struct tcmu_dev *udev = vma->vm_private_data;
1493 struct uio_info *info = &udev->uio_info;
1494
1495 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1496 if (info->mem[vma->vm_pgoff].size == 0)
1497 return -1;
1498 return (int)vma->vm_pgoff;
1499 }
1500 return -1;
1501}
1502
1503static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1504{
1505 struct page *page;
1506
1507 mutex_lock(&udev->cmdr_lock);
1508 page = tcmu_get_block_page(udev, dbi);
1509 if (likely(page)) {
1510 mutex_unlock(&udev->cmdr_lock);
1511 return page;
1512 }
1513
1514 /*
1515 * Userspace messed up and passed in a address not in the
1516 * data iov passed to it.
1517 */
1518 pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
1519 dbi, udev->name);
1520 page = NULL;
1521 mutex_unlock(&udev->cmdr_lock);
1522
1523 return page;
1524}
1525
1526static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1527{
1528 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1529 struct uio_info *info = &udev->uio_info;
1530 struct page *page;
1531 unsigned long offset;
1532 void *addr;
1533
1534 int mi = tcmu_find_mem_index(vmf->vma);
1535 if (mi < 0)
1536 return VM_FAULT_SIGBUS;
1537
1538 /*
1539 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1540 * to use mem[N].
1541 */
1542 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1543
1544 if (offset < udev->data_off) {
1545 /* For the vmalloc()ed cmd area pages */
1546 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1547 page = vmalloc_to_page(addr);
1548 } else {
1549 uint32_t dbi;
1550
1551 /* For the dynamically growing data area pages */
1552 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1553 page = tcmu_try_get_block_page(udev, dbi);
1554 if (!page)
1555 return VM_FAULT_SIGBUS;
1556 }
1557
1558 get_page(page);
1559 vmf->page = page;
1560 return 0;
1561}
1562
1563static const struct vm_operations_struct tcmu_vm_ops = {
1564 .fault = tcmu_vma_fault,
1565};
1566
1567static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1568{
1569 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1570
1571 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1572 vma->vm_ops = &tcmu_vm_ops;
1573
1574 vma->vm_private_data = udev;
1575
1576 /* Ensure the mmap is exactly the right size */
1577 if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1578 return -EINVAL;
1579
1580 return 0;
1581}
1582
1583static int tcmu_open(struct uio_info *info, struct inode *inode)
1584{
1585 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1586
1587 /* O_EXCL not supported for char devs, so fake it? */
1588 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1589 return -EBUSY;
1590
1591 udev->inode = inode;
1592 kref_get(&udev->kref);
1593
1594 pr_debug("open\n");
1595
1596 return 0;
1597}
1598
1599static void tcmu_dev_call_rcu(struct rcu_head *p)
1600{
1601 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1602 struct tcmu_dev *udev = TCMU_DEV(dev);
1603
1604 kfree(udev->uio_info.name);
1605 kfree(udev->name);
1606 kfree(udev);
1607}
1608
1609static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1610{
1611 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1612 kmem_cache_free(tcmu_cmd_cache, cmd);
1613 return 0;
1614 }
1615 return -EINVAL;
1616}
1617
1618static void tcmu_blocks_release(struct radix_tree_root *blocks,
1619 int start, int end)
1620{
1621 int i;
1622 struct page *page;
1623
1624 for (i = start; i < end; i++) {
1625 page = radix_tree_delete(blocks, i);
1626 if (page) {
1627 __free_page(page);
1628 atomic_dec(&global_db_count);
1629 }
1630 }
1631}
1632
1633static void tcmu_dev_kref_release(struct kref *kref)
1634{
1635 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1636 struct se_device *dev = &udev->se_dev;
1637 struct tcmu_cmd *cmd;
1638 bool all_expired = true;
1639 int i;
1640
1641 vfree(udev->mb_addr);
1642 udev->mb_addr = NULL;
1643
1644 spin_lock_bh(&timed_out_udevs_lock);
1645 if (!list_empty(&udev->timedout_entry))
1646 list_del(&udev->timedout_entry);
1647 spin_unlock_bh(&timed_out_udevs_lock);
1648
1649 /* Upper layer should drain all requests before calling this */
1650 mutex_lock(&udev->cmdr_lock);
1651 idr_for_each_entry(&udev->commands, cmd, i) {
1652 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1653 all_expired = false;
1654 }
1655 idr_destroy(&udev->commands);
1656 WARN_ON(!all_expired);
1657
1658 tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1659 bitmap_free(udev->data_bitmap);
1660 mutex_unlock(&udev->cmdr_lock);
1661
1662 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1663}
1664
1665static int tcmu_release(struct uio_info *info, struct inode *inode)
1666{
1667 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1668
1669 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1670
1671 pr_debug("close\n");
1672 /* release ref from open */
1673 kref_put(&udev->kref, tcmu_dev_kref_release);
1674 return 0;
1675}
1676
1677static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1678{
1679 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1680
1681 if (!tcmu_kern_cmd_reply_supported)
1682 return 0;
1683
1684 if (udev->nl_reply_supported <= 0)
1685 return 0;
1686
1687 mutex_lock(&tcmu_nl_cmd_mutex);
1688
1689 if (tcmu_netlink_blocked) {
1690 mutex_unlock(&tcmu_nl_cmd_mutex);
1691 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1692 udev->name);
1693 return -EAGAIN;
1694 }
1695
1696 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1697 mutex_unlock(&tcmu_nl_cmd_mutex);
1698 pr_warn("netlink cmd %d already executing on %s\n",
1699 nl_cmd->cmd, udev->name);
1700 return -EBUSY;
1701 }
1702
1703 memset(nl_cmd, 0, sizeof(*nl_cmd));
1704 nl_cmd->cmd = cmd;
1705 nl_cmd->udev = udev;
1706 init_completion(&nl_cmd->complete);
1707 INIT_LIST_HEAD(&nl_cmd->nl_list);
1708
1709 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1710
1711 mutex_unlock(&tcmu_nl_cmd_mutex);
1712 return 0;
1713}
1714
1715static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1716{
1717 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1718
1719 if (!tcmu_kern_cmd_reply_supported)
1720 return;
1721
1722 if (udev->nl_reply_supported <= 0)
1723 return;
1724
1725 mutex_lock(&tcmu_nl_cmd_mutex);
1726
1727 list_del(&nl_cmd->nl_list);
1728 memset(nl_cmd, 0, sizeof(*nl_cmd));
1729
1730 mutex_unlock(&tcmu_nl_cmd_mutex);
1731}
1732
1733static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1734{
1735 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1736 int ret;
1737
1738 if (!tcmu_kern_cmd_reply_supported)
1739 return 0;
1740
1741 if (udev->nl_reply_supported <= 0)
1742 return 0;
1743
1744 pr_debug("sleeping for nl reply\n");
1745 wait_for_completion(&nl_cmd->complete);
1746
1747 mutex_lock(&tcmu_nl_cmd_mutex);
1748 nl_cmd->cmd = TCMU_CMD_UNSPEC;
1749 ret = nl_cmd->status;
1750 mutex_unlock(&tcmu_nl_cmd_mutex);
1751
1752 return ret;
1753}
1754
1755static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1756 enum tcmu_genl_cmd cmd,
1757 struct sk_buff **buf, void **hdr)
1758{
1759 struct sk_buff *skb;
1760 void *msg_header;
1761 int ret = -ENOMEM;
1762
1763 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1764 if (!skb)
1765 return ret;
1766
1767 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1768 if (!msg_header)
1769 goto free_skb;
1770
1771 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1772 if (ret < 0)
1773 goto free_skb;
1774
1775 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1776 if (ret < 0)
1777 goto free_skb;
1778
1779 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1780 if (ret < 0)
1781 goto free_skb;
1782
1783 *buf = skb;
1784 *hdr = msg_header;
1785 return ret;
1786
1787free_skb:
1788 nlmsg_free(skb);
1789 return ret;
1790}
1791
1792static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1793 enum tcmu_genl_cmd cmd,
1794 struct sk_buff *skb, void *msg_header)
1795{
1796 int ret;
1797
1798 genlmsg_end(skb, msg_header);
1799
1800 ret = tcmu_init_genl_cmd_reply(udev, cmd);
1801 if (ret) {
1802 nlmsg_free(skb);
1803 return ret;
1804 }
1805
1806 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1807 TCMU_MCGRP_CONFIG, GFP_KERNEL);
1808
1809 /* Wait during an add as the listener may not be up yet */
1810 if (ret == 0 ||
1811 (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
1812 return tcmu_wait_genl_cmd_reply(udev);
1813 else
1814 tcmu_destroy_genl_cmd_reply(udev);
1815
1816 return ret;
1817}
1818
1819static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
1820{
1821 struct sk_buff *skb = NULL;
1822 void *msg_header = NULL;
1823 int ret = 0;
1824
1825 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
1826 &msg_header);
1827 if (ret < 0)
1828 return ret;
1829 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
1830 msg_header);
1831}
1832
1833static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
1834{
1835 struct sk_buff *skb = NULL;
1836 void *msg_header = NULL;
1837 int ret = 0;
1838
1839 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
1840 &skb, &msg_header);
1841 if (ret < 0)
1842 return ret;
1843 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
1844 skb, msg_header);
1845}
1846
1847static int tcmu_update_uio_info(struct tcmu_dev *udev)
1848{
1849 struct tcmu_hba *hba = udev->hba->hba_ptr;
1850 struct uio_info *info;
1851 char *str;
1852
1853 info = &udev->uio_info;
1854
1855 if (udev->dev_config[0])
1856 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
1857 udev->name, udev->dev_config);
1858 else
1859 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
1860 udev->name);
1861 if (!str)
1862 return -ENOMEM;
1863
1864 /* If the old string exists, free it */
1865 kfree(info->name);
1866 info->name = str;
1867
1868 return 0;
1869}
1870
1871static int tcmu_configure_device(struct se_device *dev)
1872{
1873 struct tcmu_dev *udev = TCMU_DEV(dev);
1874 struct uio_info *info;
1875 struct tcmu_mailbox *mb;
1876 int ret = 0;
1877
1878 ret = tcmu_update_uio_info(udev);
1879 if (ret)
1880 return ret;
1881
1882 info = &udev->uio_info;
1883
1884 mutex_lock(&udev->cmdr_lock);
1885 udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
1886 mutex_unlock(&udev->cmdr_lock);
1887 if (!udev->data_bitmap) {
1888 ret = -ENOMEM;
1889 goto err_bitmap_alloc;
1890 }
1891
1892 udev->mb_addr = vzalloc(CMDR_SIZE);
1893 if (!udev->mb_addr) {
1894 ret = -ENOMEM;
1895 goto err_vzalloc;
1896 }
1897
1898 /* mailbox fits in first part of CMDR space */
1899 udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
1900 udev->data_off = CMDR_SIZE;
1901 udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
1902 udev->dbi_thresh = 0; /* Default in Idle state */
1903
1904 /* Initialise the mailbox of the ring buffer */
1905 mb = udev->mb_addr;
1906 mb->version = TCMU_MAILBOX_VERSION;
1907 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN;
1908 mb->cmdr_off = CMDR_OFF;
1909 mb->cmdr_size = udev->cmdr_size;
1910
1911 WARN_ON(!PAGE_ALIGNED(udev->data_off));
1912 WARN_ON(udev->data_size % PAGE_SIZE);
1913 WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
1914
1915 info->version = __stringify(TCMU_MAILBOX_VERSION);
1916
1917 info->mem[0].name = "tcm-user command & data buffer";
1918 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
1919 info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
1920 info->mem[0].memtype = UIO_MEM_NONE;
1921
1922 info->irqcontrol = tcmu_irqcontrol;
1923 info->irq = UIO_IRQ_CUSTOM;
1924
1925 info->mmap = tcmu_mmap;
1926 info->open = tcmu_open;
1927 info->release = tcmu_release;
1928
1929 ret = uio_register_device(tcmu_root_device, info);
1930 if (ret)
1931 goto err_register;
1932
1933 /* User can set hw_block_size before enable the device */
1934 if (dev->dev_attrib.hw_block_size == 0)
1935 dev->dev_attrib.hw_block_size = 512;
1936 /* Other attributes can be configured in userspace */
1937 if (!dev->dev_attrib.hw_max_sectors)
1938 dev->dev_attrib.hw_max_sectors = 128;
1939 if (!dev->dev_attrib.emulate_write_cache)
1940 dev->dev_attrib.emulate_write_cache = 0;
1941 dev->dev_attrib.hw_queue_depth = 128;
1942
1943 /* If user didn't explicitly disable netlink reply support, use
1944 * module scope setting.
1945 */
1946 if (udev->nl_reply_supported >= 0)
1947 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
1948
1949 /*
1950 * Get a ref incase userspace does a close on the uio device before
1951 * LIO has initiated tcmu_free_device.
1952 */
1953 kref_get(&udev->kref);
1954
1955 ret = tcmu_send_dev_add_event(udev);
1956 if (ret)
1957 goto err_netlink;
1958
1959 mutex_lock(&root_udev_mutex);
1960 list_add(&udev->node, &root_udev);
1961 mutex_unlock(&root_udev_mutex);
1962
1963 return 0;
1964
1965err_netlink:
1966 kref_put(&udev->kref, tcmu_dev_kref_release);
1967 uio_unregister_device(&udev->uio_info);
1968err_register:
1969 vfree(udev->mb_addr);
1970 udev->mb_addr = NULL;
1971err_vzalloc:
1972 bitmap_free(udev->data_bitmap);
1973 udev->data_bitmap = NULL;
1974err_bitmap_alloc:
1975 kfree(info->name);
1976 info->name = NULL;
1977
1978 return ret;
1979}
1980
1981static void tcmu_free_device(struct se_device *dev)
1982{
1983 struct tcmu_dev *udev = TCMU_DEV(dev);
1984
1985 /* release ref from init */
1986 kref_put(&udev->kref, tcmu_dev_kref_release);
1987}
1988
1989static void tcmu_destroy_device(struct se_device *dev)
1990{
1991 struct tcmu_dev *udev = TCMU_DEV(dev);
1992
1993 del_timer_sync(&udev->cmd_timer);
1994 del_timer_sync(&udev->qfull_timer);
1995
1996 mutex_lock(&root_udev_mutex);
1997 list_del(&udev->node);
1998 mutex_unlock(&root_udev_mutex);
1999
2000 tcmu_send_dev_remove_event(udev);
2001
2002 uio_unregister_device(&udev->uio_info);
2003
2004 /* release ref from configure */
2005 kref_put(&udev->kref, tcmu_dev_kref_release);
2006}
2007
2008static void tcmu_unblock_dev(struct tcmu_dev *udev)
2009{
2010 mutex_lock(&udev->cmdr_lock);
2011 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2012 mutex_unlock(&udev->cmdr_lock);
2013}
2014
2015static void tcmu_block_dev(struct tcmu_dev *udev)
2016{
2017 mutex_lock(&udev->cmdr_lock);
2018
2019 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2020 goto unlock;
2021
2022 /* complete IO that has executed successfully */
2023 tcmu_handle_completions(udev);
2024 /* fail IO waiting to be queued */
2025 run_qfull_queue(udev, true);
2026
2027unlock:
2028 mutex_unlock(&udev->cmdr_lock);
2029}
2030
2031static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2032{
2033 struct tcmu_mailbox *mb;
2034 struct tcmu_cmd *cmd;
2035 int i;
2036
2037 mutex_lock(&udev->cmdr_lock);
2038
2039 idr_for_each_entry(&udev->commands, cmd, i) {
2040 if (!test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags))
2041 continue;
2042
2043 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2044 cmd->cmd_id, udev->name,
2045 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2046
2047 idr_remove(&udev->commands, i);
2048 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2049 WARN_ON(!cmd->se_cmd);
2050 list_del_init(&cmd->queue_entry);
2051 if (err_level == 1) {
2052 /*
2053 * Userspace was not able to start the
2054 * command or it is retryable.
2055 */
2056 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2057 } else {
2058 /* hard failure */
2059 target_complete_cmd(cmd->se_cmd,
2060 SAM_STAT_CHECK_CONDITION);
2061 }
2062 }
2063 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2064 tcmu_free_cmd(cmd);
2065 }
2066
2067 mb = udev->mb_addr;
2068 tcmu_flush_dcache_range(mb, sizeof(*mb));
2069 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2070 mb->cmd_tail, mb->cmd_head);
2071
2072 udev->cmdr_last_cleaned = 0;
2073 mb->cmd_tail = 0;
2074 mb->cmd_head = 0;
2075 tcmu_flush_dcache_range(mb, sizeof(*mb));
2076
2077 del_timer(&udev->cmd_timer);
2078
2079 mutex_unlock(&udev->cmdr_lock);
2080}
2081
2082enum {
2083 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2084 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2085};
2086
2087static match_table_t tokens = {
2088 {Opt_dev_config, "dev_config=%s"},
2089 {Opt_dev_size, "dev_size=%s"},
2090 {Opt_hw_block_size, "hw_block_size=%d"},
2091 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2092 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2093 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2094 {Opt_err, NULL}
2095};
2096
2097static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2098{
2099 int val, ret;
2100
2101 ret = match_int(arg, &val);
2102 if (ret < 0) {
2103 pr_err("match_int() failed for dev attrib. Error %d.\n",
2104 ret);
2105 return ret;
2106 }
2107
2108 if (val <= 0) {
2109 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2110 val);
2111 return -EINVAL;
2112 }
2113 *dev_attrib = val;
2114 return 0;
2115}
2116
2117static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2118{
2119 int val, ret;
2120
2121 ret = match_int(arg, &val);
2122 if (ret < 0) {
2123 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2124 ret);
2125 return ret;
2126 }
2127
2128 if (val <= 0) {
2129 pr_err("Invalid max_data_area %d.\n", val);
2130 return -EINVAL;
2131 }
2132
2133 mutex_lock(&udev->cmdr_lock);
2134 if (udev->data_bitmap) {
2135 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2136 ret = -EINVAL;
2137 goto unlock;
2138 }
2139
2140 udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2141 if (udev->max_blocks > tcmu_global_max_blocks) {
2142 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2143 val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2144 udev->max_blocks = tcmu_global_max_blocks;
2145 }
2146
2147unlock:
2148 mutex_unlock(&udev->cmdr_lock);
2149 return ret;
2150}
2151
2152static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2153 const char *page, ssize_t count)
2154{
2155 struct tcmu_dev *udev = TCMU_DEV(dev);
2156 char *orig, *ptr, *opts;
2157 substring_t args[MAX_OPT_ARGS];
2158 int ret = 0, token;
2159
2160 opts = kstrdup(page, GFP_KERNEL);
2161 if (!opts)
2162 return -ENOMEM;
2163
2164 orig = opts;
2165
2166 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2167 if (!*ptr)
2168 continue;
2169
2170 token = match_token(ptr, tokens, args);
2171 switch (token) {
2172 case Opt_dev_config:
2173 if (match_strlcpy(udev->dev_config, &args[0],
2174 TCMU_CONFIG_LEN) == 0) {
2175 ret = -EINVAL;
2176 break;
2177 }
2178 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2179 break;
2180 case Opt_dev_size:
2181 ret = match_u64(&args[0], &udev->dev_size);
2182 if (ret < 0)
2183 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2184 ret);
2185 break;
2186 case Opt_hw_block_size:
2187 ret = tcmu_set_dev_attrib(&args[0],
2188 &(dev->dev_attrib.hw_block_size));
2189 break;
2190 case Opt_hw_max_sectors:
2191 ret = tcmu_set_dev_attrib(&args[0],
2192 &(dev->dev_attrib.hw_max_sectors));
2193 break;
2194 case Opt_nl_reply_supported:
2195 ret = match_int(&args[0], &udev->nl_reply_supported);
2196 if (ret < 0)
2197 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2198 ret);
2199 break;
2200 case Opt_max_data_area_mb:
2201 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2202 break;
2203 default:
2204 break;
2205 }
2206
2207 if (ret)
2208 break;
2209 }
2210
2211 kfree(orig);
2212 return (!ret) ? count : ret;
2213}
2214
2215static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2216{
2217 struct tcmu_dev *udev = TCMU_DEV(dev);
2218 ssize_t bl = 0;
2219
2220 bl = sprintf(b + bl, "Config: %s ",
2221 udev->dev_config[0] ? udev->dev_config : "NULL");
2222 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2223 bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2224 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2225
2226 return bl;
2227}
2228
2229static sector_t tcmu_get_blocks(struct se_device *dev)
2230{
2231 struct tcmu_dev *udev = TCMU_DEV(dev);
2232
2233 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2234 dev->dev_attrib.block_size);
2235}
2236
2237static sense_reason_t
2238tcmu_parse_cdb(struct se_cmd *cmd)
2239{
2240 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2241}
2242
2243static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2244{
2245 struct se_dev_attrib *da = container_of(to_config_group(item),
2246 struct se_dev_attrib, da_group);
2247 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2248
2249 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2250}
2251
2252static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2253 size_t count)
2254{
2255 struct se_dev_attrib *da = container_of(to_config_group(item),
2256 struct se_dev_attrib, da_group);
2257 struct tcmu_dev *udev = container_of(da->da_dev,
2258 struct tcmu_dev, se_dev);
2259 u32 val;
2260 int ret;
2261
2262 if (da->da_dev->export_count) {
2263 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2264 return -EINVAL;
2265 }
2266
2267 ret = kstrtou32(page, 0, &val);
2268 if (ret < 0)
2269 return ret;
2270
2271 udev->cmd_time_out = val * MSEC_PER_SEC;
2272 return count;
2273}
2274CONFIGFS_ATTR(tcmu_, cmd_time_out);
2275
2276static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2277{
2278 struct se_dev_attrib *da = container_of(to_config_group(item),
2279 struct se_dev_attrib, da_group);
2280 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2281
2282 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2283 udev->qfull_time_out :
2284 udev->qfull_time_out / MSEC_PER_SEC);
2285}
2286
2287static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2288 const char *page, size_t count)
2289{
2290 struct se_dev_attrib *da = container_of(to_config_group(item),
2291 struct se_dev_attrib, da_group);
2292 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2293 s32 val;
2294 int ret;
2295
2296 ret = kstrtos32(page, 0, &val);
2297 if (ret < 0)
2298 return ret;
2299
2300 if (val >= 0) {
2301 udev->qfull_time_out = val * MSEC_PER_SEC;
2302 } else if (val == -1) {
2303 udev->qfull_time_out = val;
2304 } else {
2305 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2306 return -EINVAL;
2307 }
2308 return count;
2309}
2310CONFIGFS_ATTR(tcmu_, qfull_time_out);
2311
2312static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2313{
2314 struct se_dev_attrib *da = container_of(to_config_group(item),
2315 struct se_dev_attrib, da_group);
2316 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2317
2318 return snprintf(page, PAGE_SIZE, "%u\n",
2319 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2320}
2321CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2322
2323static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2324{
2325 struct se_dev_attrib *da = container_of(to_config_group(item),
2326 struct se_dev_attrib, da_group);
2327 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2328
2329 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2330}
2331
2332static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2333 const char *reconfig_data)
2334{
2335 struct sk_buff *skb = NULL;
2336 void *msg_header = NULL;
2337 int ret = 0;
2338
2339 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2340 &skb, &msg_header);
2341 if (ret < 0)
2342 return ret;
2343 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2344 if (ret < 0) {
2345 nlmsg_free(skb);
2346 return ret;
2347 }
2348 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2349 skb, msg_header);
2350}
2351
2352
2353static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2354 size_t count)
2355{
2356 struct se_dev_attrib *da = container_of(to_config_group(item),
2357 struct se_dev_attrib, da_group);
2358 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2359 int ret, len;
2360
2361 len = strlen(page);
2362 if (!len || len > TCMU_CONFIG_LEN - 1)
2363 return -EINVAL;
2364
2365 /* Check if device has been configured before */
2366 if (target_dev_configured(&udev->se_dev)) {
2367 ret = tcmu_send_dev_config_event(udev, page);
2368 if (ret) {
2369 pr_err("Unable to reconfigure device\n");
2370 return ret;
2371 }
2372 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2373
2374 ret = tcmu_update_uio_info(udev);
2375 if (ret)
2376 return ret;
2377 return count;
2378 }
2379 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2380
2381 return count;
2382}
2383CONFIGFS_ATTR(tcmu_, dev_config);
2384
2385static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2386{
2387 struct se_dev_attrib *da = container_of(to_config_group(item),
2388 struct se_dev_attrib, da_group);
2389 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2390
2391 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2392}
2393
2394static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2395{
2396 struct sk_buff *skb = NULL;
2397 void *msg_header = NULL;
2398 int ret = 0;
2399
2400 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2401 &skb, &msg_header);
2402 if (ret < 0)
2403 return ret;
2404 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2405 size, TCMU_ATTR_PAD);
2406 if (ret < 0) {
2407 nlmsg_free(skb);
2408 return ret;
2409 }
2410 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2411 skb, msg_header);
2412}
2413
2414static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2415 size_t count)
2416{
2417 struct se_dev_attrib *da = container_of(to_config_group(item),
2418 struct se_dev_attrib, da_group);
2419 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2420 u64 val;
2421 int ret;
2422
2423 ret = kstrtou64(page, 0, &val);
2424 if (ret < 0)
2425 return ret;
2426
2427 /* Check if device has been configured before */
2428 if (target_dev_configured(&udev->se_dev)) {
2429 ret = tcmu_send_dev_size_event(udev, val);
2430 if (ret) {
2431 pr_err("Unable to reconfigure device\n");
2432 return ret;
2433 }
2434 }
2435 udev->dev_size = val;
2436 return count;
2437}
2438CONFIGFS_ATTR(tcmu_, dev_size);
2439
2440static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2441 char *page)
2442{
2443 struct se_dev_attrib *da = container_of(to_config_group(item),
2444 struct se_dev_attrib, da_group);
2445 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2446
2447 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2448}
2449
2450static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2451 const char *page, size_t count)
2452{
2453 struct se_dev_attrib *da = container_of(to_config_group(item),
2454 struct se_dev_attrib, da_group);
2455 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2456 s8 val;
2457 int ret;
2458
2459 ret = kstrtos8(page, 0, &val);
2460 if (ret < 0)
2461 return ret;
2462
2463 udev->nl_reply_supported = val;
2464 return count;
2465}
2466CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2467
2468static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2469 char *page)
2470{
2471 struct se_dev_attrib *da = container_of(to_config_group(item),
2472 struct se_dev_attrib, da_group);
2473
2474 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2475}
2476
2477static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2478{
2479 struct sk_buff *skb = NULL;
2480 void *msg_header = NULL;
2481 int ret = 0;
2482
2483 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2484 &skb, &msg_header);
2485 if (ret < 0)
2486 return ret;
2487 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2488 if (ret < 0) {
2489 nlmsg_free(skb);
2490 return ret;
2491 }
2492 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2493 skb, msg_header);
2494}
2495
2496static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2497 const char *page, size_t count)
2498{
2499 struct se_dev_attrib *da = container_of(to_config_group(item),
2500 struct se_dev_attrib, da_group);
2501 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2502 u8 val;
2503 int ret;
2504
2505 ret = kstrtou8(page, 0, &val);
2506 if (ret < 0)
2507 return ret;
2508
2509 /* Check if device has been configured before */
2510 if (target_dev_configured(&udev->se_dev)) {
2511 ret = tcmu_send_emulate_write_cache(udev, val);
2512 if (ret) {
2513 pr_err("Unable to reconfigure device\n");
2514 return ret;
2515 }
2516 }
2517
2518 da->emulate_write_cache = val;
2519 return count;
2520}
2521CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2522
2523static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2524{
2525 struct se_device *se_dev = container_of(to_config_group(item),
2526 struct se_device,
2527 dev_action_group);
2528 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2529
2530 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2531 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2532 else
2533 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2534}
2535
2536static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2537 size_t count)
2538{
2539 struct se_device *se_dev = container_of(to_config_group(item),
2540 struct se_device,
2541 dev_action_group);
2542 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2543 u8 val;
2544 int ret;
2545
2546 if (!target_dev_configured(&udev->se_dev)) {
2547 pr_err("Device is not configured.\n");
2548 return -EINVAL;
2549 }
2550
2551 ret = kstrtou8(page, 0, &val);
2552 if (ret < 0)
2553 return ret;
2554
2555 if (val > 1) {
2556 pr_err("Invalid block value %d\n", val);
2557 return -EINVAL;
2558 }
2559
2560 if (!val)
2561 tcmu_unblock_dev(udev);
2562 else
2563 tcmu_block_dev(udev);
2564 return count;
2565}
2566CONFIGFS_ATTR(tcmu_, block_dev);
2567
2568static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2569 size_t count)
2570{
2571 struct se_device *se_dev = container_of(to_config_group(item),
2572 struct se_device,
2573 dev_action_group);
2574 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2575 u8 val;
2576 int ret;
2577
2578 if (!target_dev_configured(&udev->se_dev)) {
2579 pr_err("Device is not configured.\n");
2580 return -EINVAL;
2581 }
2582
2583 ret = kstrtou8(page, 0, &val);
2584 if (ret < 0)
2585 return ret;
2586
2587 if (val != 1 && val != 2) {
2588 pr_err("Invalid reset ring value %d\n", val);
2589 return -EINVAL;
2590 }
2591
2592 tcmu_reset_ring(udev, val);
2593 return count;
2594}
2595CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2596
2597static struct configfs_attribute *tcmu_attrib_attrs[] = {
2598 &tcmu_attr_cmd_time_out,
2599 &tcmu_attr_qfull_time_out,
2600 &tcmu_attr_max_data_area_mb,
2601 &tcmu_attr_dev_config,
2602 &tcmu_attr_dev_size,
2603 &tcmu_attr_emulate_write_cache,
2604 &tcmu_attr_nl_reply_supported,
2605 NULL,
2606};
2607
2608static struct configfs_attribute **tcmu_attrs;
2609
2610static struct configfs_attribute *tcmu_action_attrs[] = {
2611 &tcmu_attr_block_dev,
2612 &tcmu_attr_reset_ring,
2613 NULL,
2614};
2615
2616static struct target_backend_ops tcmu_ops = {
2617 .name = "user",
2618 .owner = THIS_MODULE,
2619 .transport_flags = TRANSPORT_FLAG_PASSTHROUGH,
2620 .attach_hba = tcmu_attach_hba,
2621 .detach_hba = tcmu_detach_hba,
2622 .alloc_device = tcmu_alloc_device,
2623 .configure_device = tcmu_configure_device,
2624 .destroy_device = tcmu_destroy_device,
2625 .free_device = tcmu_free_device,
2626 .parse_cdb = tcmu_parse_cdb,
2627 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2628 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2629 .get_device_type = sbc_get_device_type,
2630 .get_blocks = tcmu_get_blocks,
2631 .tb_dev_action_attrs = tcmu_action_attrs,
2632};
2633
2634static void find_free_blocks(void)
2635{
2636 struct tcmu_dev *udev;
2637 loff_t off;
2638 u32 start, end, block, total_freed = 0;
2639
2640 if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2641 return;
2642
2643 mutex_lock(&root_udev_mutex);
2644 list_for_each_entry(udev, &root_udev, node) {
2645 mutex_lock(&udev->cmdr_lock);
2646
2647 if (!target_dev_configured(&udev->se_dev)) {
2648 mutex_unlock(&udev->cmdr_lock);
2649 continue;
2650 }
2651
2652 /* Try to complete the finished commands first */
2653 tcmu_handle_completions(udev);
2654
2655 /* Skip the udevs in idle */
2656 if (!udev->dbi_thresh) {
2657 mutex_unlock(&udev->cmdr_lock);
2658 continue;
2659 }
2660
2661 end = udev->dbi_max + 1;
2662 block = find_last_bit(udev->data_bitmap, end);
2663 if (block == udev->dbi_max) {
2664 /*
2665 * The last bit is dbi_max, so it is not possible
2666 * reclaim any blocks.
2667 */
2668 mutex_unlock(&udev->cmdr_lock);
2669 continue;
2670 } else if (block == end) {
2671 /* The current udev will goto idle state */
2672 udev->dbi_thresh = start = 0;
2673 udev->dbi_max = 0;
2674 } else {
2675 udev->dbi_thresh = start = block + 1;
2676 udev->dbi_max = block;
2677 }
2678
2679 /* Here will truncate the data area from off */
2680 off = udev->data_off + start * DATA_BLOCK_SIZE;
2681 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2682
2683 /* Release the block pages */
2684 tcmu_blocks_release(&udev->data_blocks, start, end);
2685 mutex_unlock(&udev->cmdr_lock);
2686
2687 total_freed += end - start;
2688 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2689 total_freed, udev->name);
2690 }
2691 mutex_unlock(&root_udev_mutex);
2692
2693 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2694 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2695}
2696
2697static void check_timedout_devices(void)
2698{
2699 struct tcmu_dev *udev, *tmp_dev;
2700 LIST_HEAD(devs);
2701
2702 spin_lock_bh(&timed_out_udevs_lock);
2703 list_splice_init(&timed_out_udevs, &devs);
2704
2705 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2706 list_del_init(&udev->timedout_entry);
2707 spin_unlock_bh(&timed_out_udevs_lock);
2708
2709 mutex_lock(&udev->cmdr_lock);
2710 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
2711
2712 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
2713 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2714
2715 mutex_unlock(&udev->cmdr_lock);
2716
2717 spin_lock_bh(&timed_out_udevs_lock);
2718 }
2719
2720 spin_unlock_bh(&timed_out_udevs_lock);
2721}
2722
2723static void tcmu_unmap_work_fn(struct work_struct *work)
2724{
2725 check_timedout_devices();
2726 find_free_blocks();
2727}
2728
2729static int __init tcmu_module_init(void)
2730{
2731 int ret, i, k, len = 0;
2732
2733 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2734
2735 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2736
2737 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2738 sizeof(struct tcmu_cmd),
2739 __alignof__(struct tcmu_cmd),
2740 0, NULL);
2741 if (!tcmu_cmd_cache)
2742 return -ENOMEM;
2743
2744 tcmu_root_device = root_device_register("tcm_user");
2745 if (IS_ERR(tcmu_root_device)) {
2746 ret = PTR_ERR(tcmu_root_device);
2747 goto out_free_cache;
2748 }
2749
2750 ret = genl_register_family(&tcmu_genl_family);
2751 if (ret < 0) {
2752 goto out_unreg_device;
2753 }
2754
2755 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2756 len += sizeof(struct configfs_attribute *);
2757 }
2758 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
2759 len += sizeof(struct configfs_attribute *);
2760 }
2761 len += sizeof(struct configfs_attribute *);
2762
2763 tcmu_attrs = kzalloc(len, GFP_KERNEL);
2764 if (!tcmu_attrs) {
2765 ret = -ENOMEM;
2766 goto out_unreg_genl;
2767 }
2768
2769 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2770 tcmu_attrs[i] = passthrough_attrib_attrs[i];
2771 }
2772 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
2773 tcmu_attrs[i] = tcmu_attrib_attrs[k];
2774 i++;
2775 }
2776 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
2777
2778 ret = transport_backend_register(&tcmu_ops);
2779 if (ret)
2780 goto out_attrs;
2781
2782 return 0;
2783
2784out_attrs:
2785 kfree(tcmu_attrs);
2786out_unreg_genl:
2787 genl_unregister_family(&tcmu_genl_family);
2788out_unreg_device:
2789 root_device_unregister(tcmu_root_device);
2790out_free_cache:
2791 kmem_cache_destroy(tcmu_cmd_cache);
2792
2793 return ret;
2794}
2795
2796static void __exit tcmu_module_exit(void)
2797{
2798 cancel_delayed_work_sync(&tcmu_unmap_work);
2799 target_backend_unregister(&tcmu_ops);
2800 kfree(tcmu_attrs);
2801 genl_unregister_family(&tcmu_genl_family);
2802 root_device_unregister(tcmu_root_device);
2803 kmem_cache_destroy(tcmu_cmd_cache);
2804}
2805
2806MODULE_DESCRIPTION("TCM USER subsystem plugin");
2807MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
2808MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
2809MODULE_LICENSE("GPL");
2810
2811module_init(tcmu_module_init);
2812module_exit(tcmu_module_exit);