Loading...
Note: File does not exist in v3.1.
1/*
2 * Copyright 2014 IBM Corp.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10#include <linux/spinlock.h>
11#include <linux/module.h>
12#include <linux/export.h>
13#include <linux/kernel.h>
14#include <linux/bitmap.h>
15#include <linux/sched.h>
16#include <linux/poll.h>
17#include <linux/pid.h>
18#include <linux/fs.h>
19#include <linux/mm.h>
20#include <linux/slab.h>
21#include <asm/cputable.h>
22#include <asm/current.h>
23#include <asm/copro.h>
24
25#include "cxl.h"
26#include "trace.h"
27
28#define CXL_NUM_MINORS 256 /* Total to reserve */
29
30#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
31#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
32#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
33#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
34#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
35#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
36
37#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
38
39#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
40
41static dev_t cxl_dev;
42
43static struct class *cxl_class;
44
45static int __afu_open(struct inode *inode, struct file *file, bool master)
46{
47 struct cxl *adapter;
48 struct cxl_afu *afu;
49 struct cxl_context *ctx;
50 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
51 int slice = CXL_DEVT_AFU(inode->i_rdev);
52 int rc = -ENODEV;
53
54 pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
55
56 if (!(adapter = get_cxl_adapter(adapter_num)))
57 return -ENODEV;
58
59 if (slice > adapter->slices)
60 goto err_put_adapter;
61
62 spin_lock(&adapter->afu_list_lock);
63 if (!(afu = adapter->afu[slice])) {
64 spin_unlock(&adapter->afu_list_lock);
65 goto err_put_adapter;
66 }
67
68 /*
69 * taking a ref to the afu so that it doesn't go away
70 * for rest of the function. This ref is released before
71 * we return.
72 */
73 cxl_afu_get(afu);
74 spin_unlock(&adapter->afu_list_lock);
75
76 if (!afu->current_mode)
77 goto err_put_afu;
78
79 if (!cxl_ops->link_ok(adapter, afu)) {
80 rc = -EIO;
81 goto err_put_afu;
82 }
83
84 if (!(ctx = cxl_context_alloc())) {
85 rc = -ENOMEM;
86 goto err_put_afu;
87 }
88
89 if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
90 goto err_put_afu;
91
92 pr_devel("afu_open pe: %i\n", ctx->pe);
93 file->private_data = ctx;
94 cxl_ctx_get();
95
96 /* indicate success */
97 rc = 0;
98
99err_put_afu:
100 /* release the ref taken earlier */
101 cxl_afu_put(afu);
102err_put_adapter:
103 put_device(&adapter->dev);
104 return rc;
105}
106
107int afu_open(struct inode *inode, struct file *file)
108{
109 return __afu_open(inode, file, false);
110}
111
112static int afu_master_open(struct inode *inode, struct file *file)
113{
114 return __afu_open(inode, file, true);
115}
116
117int afu_release(struct inode *inode, struct file *file)
118{
119 struct cxl_context *ctx = file->private_data;
120
121 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
122 __func__, ctx->pe);
123 cxl_context_detach(ctx);
124
125
126 /*
127 * Delete the context's mapping pointer, unless it's created by the
128 * kernel API, in which case leave it so it can be freed by reclaim_ctx()
129 */
130 if (!ctx->kernelapi) {
131 mutex_lock(&ctx->mapping_lock);
132 ctx->mapping = NULL;
133 mutex_unlock(&ctx->mapping_lock);
134 }
135
136 /*
137 * At this this point all bottom halfs have finished and we should be
138 * getting no more IRQs from the hardware for this context. Once it's
139 * removed from the IDR (and RCU synchronised) it's safe to free the
140 * sstp and context.
141 */
142 cxl_context_free(ctx);
143
144 return 0;
145}
146
147static long afu_ioctl_start_work(struct cxl_context *ctx,
148 struct cxl_ioctl_start_work __user *uwork)
149{
150 struct cxl_ioctl_start_work work;
151 u64 amr = 0;
152 int rc;
153
154 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
155
156 /* Do this outside the status_mutex to avoid a circular dependency with
157 * the locking in cxl_mmap_fault() */
158 if (copy_from_user(&work, uwork,
159 sizeof(struct cxl_ioctl_start_work))) {
160 rc = -EFAULT;
161 goto out;
162 }
163
164 mutex_lock(&ctx->status_mutex);
165 if (ctx->status != OPENED) {
166 rc = -EIO;
167 goto out;
168 }
169
170 /*
171 * if any of the reserved fields are set or any of the unused
172 * flags are set it's invalid
173 */
174 if (work.reserved1 || work.reserved2 || work.reserved3 ||
175 work.reserved4 || work.reserved5 || work.reserved6 ||
176 (work.flags & ~CXL_START_WORK_ALL)) {
177 rc = -EINVAL;
178 goto out;
179 }
180
181 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
182 work.num_interrupts = ctx->afu->pp_irqs;
183 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
184 (work.num_interrupts > ctx->afu->irqs_max)) {
185 rc = -EINVAL;
186 goto out;
187 }
188 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
189 goto out;
190
191 if (work.flags & CXL_START_WORK_AMR)
192 amr = work.amr & mfspr(SPRN_UAMOR);
193
194 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
195
196 /*
197 * We grab the PID here and not in the file open to allow for the case
198 * where a process (master, some daemon, etc) has opened the chardev on
199 * behalf of another process, so the AFU's mm gets bound to the process
200 * that performs this ioctl and not the process that opened the file.
201 * Also we grab the PID of the group leader so that if the task that
202 * has performed the attach operation exits the mm context of the
203 * process is still accessible.
204 */
205 ctx->pid = get_task_pid(current, PIDTYPE_PID);
206 ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
207
208 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
209
210 if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
211 amr))) {
212 afu_release_irqs(ctx, ctx);
213 goto out;
214 }
215
216 ctx->status = STARTED;
217 rc = 0;
218out:
219 mutex_unlock(&ctx->status_mutex);
220 return rc;
221}
222
223static long afu_ioctl_process_element(struct cxl_context *ctx,
224 int __user *upe)
225{
226 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
227
228 if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
229 return -EFAULT;
230
231 return 0;
232}
233
234static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
235 struct cxl_afu_id __user *upafuid)
236{
237 struct cxl_afu_id afuid = { 0 };
238
239 afuid.card_id = ctx->afu->adapter->adapter_num;
240 afuid.afu_offset = ctx->afu->slice;
241 afuid.afu_mode = ctx->afu->current_mode;
242
243 /* set the flag bit in case the afu is a slave */
244 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
245 afuid.flags |= CXL_AFUID_FLAG_SLAVE;
246
247 if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
248 return -EFAULT;
249
250 return 0;
251}
252
253long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
254{
255 struct cxl_context *ctx = file->private_data;
256
257 if (ctx->status == CLOSED)
258 return -EIO;
259
260 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
261 return -EIO;
262
263 pr_devel("afu_ioctl\n");
264 switch (cmd) {
265 case CXL_IOCTL_START_WORK:
266 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
267 case CXL_IOCTL_GET_PROCESS_ELEMENT:
268 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
269 case CXL_IOCTL_GET_AFU_ID:
270 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
271 arg);
272 }
273 return -EINVAL;
274}
275
276static long afu_compat_ioctl(struct file *file, unsigned int cmd,
277 unsigned long arg)
278{
279 return afu_ioctl(file, cmd, arg);
280}
281
282int afu_mmap(struct file *file, struct vm_area_struct *vm)
283{
284 struct cxl_context *ctx = file->private_data;
285
286 /* AFU must be started before we can MMIO */
287 if (ctx->status != STARTED)
288 return -EIO;
289
290 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
291 return -EIO;
292
293 return cxl_context_iomap(ctx, vm);
294}
295
296unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
297{
298 struct cxl_context *ctx = file->private_data;
299 int mask = 0;
300 unsigned long flags;
301
302
303 poll_wait(file, &ctx->wq, poll);
304
305 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
306
307 spin_lock_irqsave(&ctx->lock, flags);
308 if (ctx->pending_irq || ctx->pending_fault ||
309 ctx->pending_afu_err)
310 mask |= POLLIN | POLLRDNORM;
311 else if (ctx->status == CLOSED)
312 /* Only error on closed when there are no futher events pending
313 */
314 mask |= POLLERR;
315 spin_unlock_irqrestore(&ctx->lock, flags);
316
317 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
318
319 return mask;
320}
321
322static inline int ctx_event_pending(struct cxl_context *ctx)
323{
324 return (ctx->pending_irq || ctx->pending_fault ||
325 ctx->pending_afu_err || (ctx->status == CLOSED));
326}
327
328ssize_t afu_read(struct file *file, char __user *buf, size_t count,
329 loff_t *off)
330{
331 struct cxl_context *ctx = file->private_data;
332 struct cxl_event event;
333 unsigned long flags;
334 int rc;
335 DEFINE_WAIT(wait);
336
337 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
338 return -EIO;
339
340 if (count < CXL_READ_MIN_SIZE)
341 return -EINVAL;
342
343 spin_lock_irqsave(&ctx->lock, flags);
344
345 for (;;) {
346 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
347 if (ctx_event_pending(ctx))
348 break;
349
350 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
351 rc = -EIO;
352 goto out;
353 }
354
355 if (file->f_flags & O_NONBLOCK) {
356 rc = -EAGAIN;
357 goto out;
358 }
359
360 if (signal_pending(current)) {
361 rc = -ERESTARTSYS;
362 goto out;
363 }
364
365 spin_unlock_irqrestore(&ctx->lock, flags);
366 pr_devel("afu_read going to sleep...\n");
367 schedule();
368 pr_devel("afu_read woken up\n");
369 spin_lock_irqsave(&ctx->lock, flags);
370 }
371
372 finish_wait(&ctx->wq, &wait);
373
374 memset(&event, 0, sizeof(event));
375 event.header.process_element = ctx->pe;
376 event.header.size = sizeof(struct cxl_event_header);
377 if (ctx->pending_irq) {
378 pr_devel("afu_read delivering AFU interrupt\n");
379 event.header.size += sizeof(struct cxl_event_afu_interrupt);
380 event.header.type = CXL_EVENT_AFU_INTERRUPT;
381 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
382 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
383 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
384 ctx->pending_irq = false;
385 } else if (ctx->pending_fault) {
386 pr_devel("afu_read delivering data storage fault\n");
387 event.header.size += sizeof(struct cxl_event_data_storage);
388 event.header.type = CXL_EVENT_DATA_STORAGE;
389 event.fault.addr = ctx->fault_addr;
390 event.fault.dsisr = ctx->fault_dsisr;
391 ctx->pending_fault = false;
392 } else if (ctx->pending_afu_err) {
393 pr_devel("afu_read delivering afu error\n");
394 event.header.size += sizeof(struct cxl_event_afu_error);
395 event.header.type = CXL_EVENT_AFU_ERROR;
396 event.afu_error.error = ctx->afu_err;
397 ctx->pending_afu_err = false;
398 } else if (ctx->status == CLOSED) {
399 pr_devel("afu_read fatal error\n");
400 spin_unlock_irqrestore(&ctx->lock, flags);
401 return -EIO;
402 } else
403 WARN(1, "afu_read must be buggy\n");
404
405 spin_unlock_irqrestore(&ctx->lock, flags);
406
407 if (copy_to_user(buf, &event, event.header.size))
408 return -EFAULT;
409 return event.header.size;
410
411out:
412 finish_wait(&ctx->wq, &wait);
413 spin_unlock_irqrestore(&ctx->lock, flags);
414 return rc;
415}
416
417/*
418 * Note: if this is updated, we need to update api.c to patch the new ones in
419 * too
420 */
421const struct file_operations afu_fops = {
422 .owner = THIS_MODULE,
423 .open = afu_open,
424 .poll = afu_poll,
425 .read = afu_read,
426 .release = afu_release,
427 .unlocked_ioctl = afu_ioctl,
428 .compat_ioctl = afu_compat_ioctl,
429 .mmap = afu_mmap,
430};
431
432static const struct file_operations afu_master_fops = {
433 .owner = THIS_MODULE,
434 .open = afu_master_open,
435 .poll = afu_poll,
436 .read = afu_read,
437 .release = afu_release,
438 .unlocked_ioctl = afu_ioctl,
439 .compat_ioctl = afu_compat_ioctl,
440 .mmap = afu_mmap,
441};
442
443
444static char *cxl_devnode(struct device *dev, umode_t *mode)
445{
446 if (cpu_has_feature(CPU_FTR_HVMODE) &&
447 CXL_DEVT_IS_CARD(dev->devt)) {
448 /*
449 * These minor numbers will eventually be used to program the
450 * PSL and AFUs once we have dynamic reprogramming support
451 */
452 return NULL;
453 }
454 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
455}
456
457extern struct class *cxl_class;
458
459static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
460 struct device **chardev, char *postfix, char *desc,
461 const struct file_operations *fops)
462{
463 struct device *dev;
464 int rc;
465
466 cdev_init(cdev, fops);
467 if ((rc = cdev_add(cdev, devt, 1))) {
468 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
469 return rc;
470 }
471
472 dev = device_create(cxl_class, &afu->dev, devt, afu,
473 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
474 if (IS_ERR(dev)) {
475 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
476 rc = PTR_ERR(dev);
477 goto err;
478 }
479
480 *chardev = dev;
481
482 return 0;
483err:
484 cdev_del(cdev);
485 return rc;
486}
487
488int cxl_chardev_d_afu_add(struct cxl_afu *afu)
489{
490 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
491 &afu->chardev_d, "d", "dedicated",
492 &afu_master_fops); /* Uses master fops */
493}
494
495int cxl_chardev_m_afu_add(struct cxl_afu *afu)
496{
497 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
498 &afu->chardev_m, "m", "master",
499 &afu_master_fops);
500}
501
502int cxl_chardev_s_afu_add(struct cxl_afu *afu)
503{
504 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
505 &afu->chardev_s, "s", "shared",
506 &afu_fops);
507}
508
509void cxl_chardev_afu_remove(struct cxl_afu *afu)
510{
511 if (afu->chardev_d) {
512 cdev_del(&afu->afu_cdev_d);
513 device_unregister(afu->chardev_d);
514 afu->chardev_d = NULL;
515 }
516 if (afu->chardev_m) {
517 cdev_del(&afu->afu_cdev_m);
518 device_unregister(afu->chardev_m);
519 afu->chardev_m = NULL;
520 }
521 if (afu->chardev_s) {
522 cdev_del(&afu->afu_cdev_s);
523 device_unregister(afu->chardev_s);
524 afu->chardev_s = NULL;
525 }
526}
527
528int cxl_register_afu(struct cxl_afu *afu)
529{
530 afu->dev.class = cxl_class;
531
532 return device_register(&afu->dev);
533}
534
535int cxl_register_adapter(struct cxl *adapter)
536{
537 adapter->dev.class = cxl_class;
538
539 /*
540 * Future: When we support dynamically reprogramming the PSL & AFU we
541 * will expose the interface to do that via a chardev:
542 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
543 */
544
545 return device_register(&adapter->dev);
546}
547
548dev_t cxl_get_dev(void)
549{
550 return cxl_dev;
551}
552
553int __init cxl_file_init(void)
554{
555 int rc;
556
557 /*
558 * If these change we really need to update API. Either change some
559 * flags or update API version number CXL_API_VERSION.
560 */
561 BUILD_BUG_ON(CXL_API_VERSION != 2);
562 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
563 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
564 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
565 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
566 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
567
568 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
569 pr_err("Unable to allocate CXL major number: %i\n", rc);
570 return rc;
571 }
572
573 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
574
575 cxl_class = class_create(THIS_MODULE, "cxl");
576 if (IS_ERR(cxl_class)) {
577 pr_err("Unable to create CXL class\n");
578 rc = PTR_ERR(cxl_class);
579 goto err;
580 }
581 cxl_class->devnode = cxl_devnode;
582
583 return 0;
584
585err:
586 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
587 return rc;
588}
589
590void cxl_file_exit(void)
591{
592 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
593 class_destroy(cxl_class);
594}