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1// SPDX-License-Identifier: GPL-2.0+
2// Copyright 2017 IBM Corp.
3#include <linux/fs.h>
4#include <linux/poll.h>
5#include <linux/sched/signal.h>
6#include <linux/eventfd.h>
7#include <linux/uaccess.h>
8#include <uapi/misc/ocxl.h>
9#include <asm/reg.h>
10#include <asm/switch_to.h>
11#include "ocxl_internal.h"
12
13
14#define OCXL_NUM_MINORS 256 /* Total to reserve */
15
16static dev_t ocxl_dev;
17static DEFINE_MUTEX(minors_idr_lock);
18static struct idr minors_idr;
19
20static struct ocxl_file_info *find_and_get_file_info(dev_t devno)
21{
22 struct ocxl_file_info *info;
23
24 mutex_lock(&minors_idr_lock);
25 info = idr_find(&minors_idr, MINOR(devno));
26 if (info)
27 get_device(&info->dev);
28 mutex_unlock(&minors_idr_lock);
29 return info;
30}
31
32static int allocate_minor(struct ocxl_file_info *info)
33{
34 int minor;
35
36 mutex_lock(&minors_idr_lock);
37 minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL);
38 mutex_unlock(&minors_idr_lock);
39 return minor;
40}
41
42static void free_minor(struct ocxl_file_info *info)
43{
44 mutex_lock(&minors_idr_lock);
45 idr_remove(&minors_idr, MINOR(info->dev.devt));
46 mutex_unlock(&minors_idr_lock);
47}
48
49static int afu_open(struct inode *inode, struct file *file)
50{
51 struct ocxl_file_info *info;
52 struct ocxl_context *ctx;
53 int rc;
54
55 pr_debug("%s for device %x\n", __func__, inode->i_rdev);
56
57 info = find_and_get_file_info(inode->i_rdev);
58 if (!info)
59 return -ENODEV;
60
61 rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping);
62 if (rc) {
63 put_device(&info->dev);
64 return rc;
65 }
66 put_device(&info->dev);
67 file->private_data = ctx;
68 return 0;
69}
70
71static long afu_ioctl_attach(struct ocxl_context *ctx,
72 struct ocxl_ioctl_attach __user *uarg)
73{
74 struct ocxl_ioctl_attach arg;
75 u64 amr = 0;
76
77 pr_debug("%s for context %d\n", __func__, ctx->pasid);
78
79 if (copy_from_user(&arg, uarg, sizeof(arg)))
80 return -EFAULT;
81
82 /* Make sure reserved fields are not set for forward compatibility */
83 if (arg.reserved1 || arg.reserved2 || arg.reserved3)
84 return -EINVAL;
85
86 amr = arg.amr & mfspr(SPRN_UAMOR);
87 return ocxl_context_attach(ctx, amr, current->mm);
88}
89
90static long afu_ioctl_get_metadata(struct ocxl_context *ctx,
91 struct ocxl_ioctl_metadata __user *uarg)
92{
93 struct ocxl_ioctl_metadata arg;
94
95 memset(&arg, 0, sizeof(arg));
96
97 arg.version = 0;
98
99 arg.afu_version_major = ctx->afu->config.version_major;
100 arg.afu_version_minor = ctx->afu->config.version_minor;
101 arg.pasid = ctx->pasid;
102 arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride;
103 arg.global_mmio_size = ctx->afu->config.global_mmio_size;
104
105 if (copy_to_user(uarg, &arg, sizeof(arg)))
106 return -EFAULT;
107
108 return 0;
109}
110
111#ifdef CONFIG_PPC64
112static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,
113 struct ocxl_ioctl_p9_wait __user *uarg)
114{
115 struct ocxl_ioctl_p9_wait arg;
116
117 memset(&arg, 0, sizeof(arg));
118
119 if (cpu_has_feature(CPU_FTR_P9_TIDR)) {
120 enum ocxl_context_status status;
121
122 // Locks both status & tidr
123 mutex_lock(&ctx->status_mutex);
124 if (!ctx->tidr) {
125 if (set_thread_tidr(current)) {
126 mutex_unlock(&ctx->status_mutex);
127 return -ENOENT;
128 }
129
130 ctx->tidr = current->thread.tidr;
131 }
132
133 status = ctx->status;
134 mutex_unlock(&ctx->status_mutex);
135
136 if (status == ATTACHED) {
137 int rc = ocxl_link_update_pe(ctx->afu->fn->link,
138 ctx->pasid, ctx->tidr);
139
140 if (rc)
141 return rc;
142 }
143
144 arg.thread_id = ctx->tidr;
145 } else
146 return -ENOENT;
147
148 if (copy_to_user(uarg, &arg, sizeof(arg)))
149 return -EFAULT;
150
151 return 0;
152}
153#endif
154
155
156static long afu_ioctl_get_features(struct ocxl_context *ctx,
157 struct ocxl_ioctl_features __user *uarg)
158{
159 struct ocxl_ioctl_features arg;
160
161 memset(&arg, 0, sizeof(arg));
162
163#ifdef CONFIG_PPC64
164 if (cpu_has_feature(CPU_FTR_P9_TIDR))
165 arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT;
166#endif
167
168 if (copy_to_user(uarg, &arg, sizeof(arg)))
169 return -EFAULT;
170
171 return 0;
172}
173
174#define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \
175 x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \
176 x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \
177 x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \
178 x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" : \
179 x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" : \
180 x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \
181 "UNKNOWN")
182
183static irqreturn_t irq_handler(void *private)
184{
185 struct eventfd_ctx *ev_ctx = private;
186
187 eventfd_signal(ev_ctx);
188 return IRQ_HANDLED;
189}
190
191static void irq_free(void *private)
192{
193 struct eventfd_ctx *ev_ctx = private;
194
195 eventfd_ctx_put(ev_ctx);
196}
197
198static long afu_ioctl(struct file *file, unsigned int cmd,
199 unsigned long args)
200{
201 struct ocxl_context *ctx = file->private_data;
202 struct ocxl_ioctl_irq_fd irq_fd;
203 struct eventfd_ctx *ev_ctx;
204 int irq_id;
205 u64 irq_offset;
206 long rc;
207 bool closed;
208
209 pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid,
210 CMD_STR(cmd));
211
212 mutex_lock(&ctx->status_mutex);
213 closed = (ctx->status == CLOSED);
214 mutex_unlock(&ctx->status_mutex);
215
216 if (closed)
217 return -EIO;
218
219 switch (cmd) {
220 case OCXL_IOCTL_ATTACH:
221 rc = afu_ioctl_attach(ctx,
222 (struct ocxl_ioctl_attach __user *) args);
223 break;
224
225 case OCXL_IOCTL_IRQ_ALLOC:
226 rc = ocxl_afu_irq_alloc(ctx, &irq_id);
227 if (!rc) {
228 irq_offset = ocxl_irq_id_to_offset(ctx, irq_id);
229 rc = copy_to_user((u64 __user *) args, &irq_offset,
230 sizeof(irq_offset));
231 if (rc) {
232 ocxl_afu_irq_free(ctx, irq_id);
233 return -EFAULT;
234 }
235 }
236 break;
237
238 case OCXL_IOCTL_IRQ_FREE:
239 rc = copy_from_user(&irq_offset, (u64 __user *) args,
240 sizeof(irq_offset));
241 if (rc)
242 return -EFAULT;
243 irq_id = ocxl_irq_offset_to_id(ctx, irq_offset);
244 rc = ocxl_afu_irq_free(ctx, irq_id);
245 break;
246
247 case OCXL_IOCTL_IRQ_SET_FD:
248 rc = copy_from_user(&irq_fd, (u64 __user *) args,
249 sizeof(irq_fd));
250 if (rc)
251 return -EFAULT;
252 if (irq_fd.reserved)
253 return -EINVAL;
254 irq_id = ocxl_irq_offset_to_id(ctx, irq_fd.irq_offset);
255 ev_ctx = eventfd_ctx_fdget(irq_fd.eventfd);
256 if (IS_ERR(ev_ctx))
257 return PTR_ERR(ev_ctx);
258 rc = ocxl_irq_set_handler(ctx, irq_id, irq_handler, irq_free, ev_ctx);
259 if (rc)
260 eventfd_ctx_put(ev_ctx);
261 break;
262
263 case OCXL_IOCTL_GET_METADATA:
264 rc = afu_ioctl_get_metadata(ctx,
265 (struct ocxl_ioctl_metadata __user *) args);
266 break;
267
268#ifdef CONFIG_PPC64
269 case OCXL_IOCTL_ENABLE_P9_WAIT:
270 rc = afu_ioctl_enable_p9_wait(ctx,
271 (struct ocxl_ioctl_p9_wait __user *) args);
272 break;
273#endif
274
275 case OCXL_IOCTL_GET_FEATURES:
276 rc = afu_ioctl_get_features(ctx,
277 (struct ocxl_ioctl_features __user *) args);
278 break;
279
280 default:
281 rc = -EINVAL;
282 }
283 return rc;
284}
285
286static long afu_compat_ioctl(struct file *file, unsigned int cmd,
287 unsigned long args)
288{
289 return afu_ioctl(file, cmd, args);
290}
291
292static int afu_mmap(struct file *file, struct vm_area_struct *vma)
293{
294 struct ocxl_context *ctx = file->private_data;
295
296 pr_debug("%s for context %d\n", __func__, ctx->pasid);
297 return ocxl_context_mmap(ctx, vma);
298}
299
300static bool has_xsl_error(struct ocxl_context *ctx)
301{
302 bool ret;
303
304 mutex_lock(&ctx->xsl_error_lock);
305 ret = !!ctx->xsl_error.addr;
306 mutex_unlock(&ctx->xsl_error_lock);
307
308 return ret;
309}
310
311/*
312 * Are there any events pending on the AFU
313 * ctx: The AFU context
314 * Returns: true if there are events pending
315 */
316static bool afu_events_pending(struct ocxl_context *ctx)
317{
318 if (has_xsl_error(ctx))
319 return true;
320 return false;
321}
322
323static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait)
324{
325 struct ocxl_context *ctx = file->private_data;
326 unsigned int mask = 0;
327 bool closed;
328
329 pr_debug("%s for context %d\n", __func__, ctx->pasid);
330
331 poll_wait(file, &ctx->events_wq, wait);
332
333 mutex_lock(&ctx->status_mutex);
334 closed = (ctx->status == CLOSED);
335 mutex_unlock(&ctx->status_mutex);
336
337 if (afu_events_pending(ctx))
338 mask = EPOLLIN | EPOLLRDNORM;
339 else if (closed)
340 mask = EPOLLERR;
341
342 return mask;
343}
344
345/*
346 * Populate the supplied buffer with a single XSL error
347 * ctx: The AFU context to report the error from
348 * header: the event header to populate
349 * buf: The buffer to write the body into (should be at least
350 * AFU_EVENT_BODY_XSL_ERROR_SIZE)
351 * Return: the amount of buffer that was populated
352 */
353static ssize_t append_xsl_error(struct ocxl_context *ctx,
354 struct ocxl_kernel_event_header *header,
355 char __user *buf)
356{
357 struct ocxl_kernel_event_xsl_fault_error body;
358
359 memset(&body, 0, sizeof(body));
360
361 mutex_lock(&ctx->xsl_error_lock);
362 if (!ctx->xsl_error.addr) {
363 mutex_unlock(&ctx->xsl_error_lock);
364 return 0;
365 }
366
367 body.addr = ctx->xsl_error.addr;
368 body.dsisr = ctx->xsl_error.dsisr;
369 body.count = ctx->xsl_error.count;
370
371 ctx->xsl_error.addr = 0;
372 ctx->xsl_error.dsisr = 0;
373 ctx->xsl_error.count = 0;
374
375 mutex_unlock(&ctx->xsl_error_lock);
376
377 header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR;
378
379 if (copy_to_user(buf, &body, sizeof(body)))
380 return -EFAULT;
381
382 return sizeof(body);
383}
384
385#define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error)
386
387/*
388 * Reports events on the AFU
389 * Format:
390 * Header (struct ocxl_kernel_event_header)
391 * Body (struct ocxl_kernel_event_*)
392 * Header...
393 */
394static ssize_t afu_read(struct file *file, char __user *buf, size_t count,
395 loff_t *off)
396{
397 struct ocxl_context *ctx = file->private_data;
398 struct ocxl_kernel_event_header header;
399 ssize_t rc;
400 ssize_t used = 0;
401 DEFINE_WAIT(event_wait);
402
403 memset(&header, 0, sizeof(header));
404
405 /* Require offset to be 0 */
406 if (*off != 0)
407 return -EINVAL;
408
409 if (count < (sizeof(struct ocxl_kernel_event_header) +
410 AFU_EVENT_BODY_MAX_SIZE))
411 return -EINVAL;
412
413 for (;;) {
414 prepare_to_wait(&ctx->events_wq, &event_wait,
415 TASK_INTERRUPTIBLE);
416
417 if (afu_events_pending(ctx))
418 break;
419
420 if (ctx->status == CLOSED)
421 break;
422
423 if (file->f_flags & O_NONBLOCK) {
424 finish_wait(&ctx->events_wq, &event_wait);
425 return -EAGAIN;
426 }
427
428 if (signal_pending(current)) {
429 finish_wait(&ctx->events_wq, &event_wait);
430 return -ERESTARTSYS;
431 }
432
433 schedule();
434 }
435
436 finish_wait(&ctx->events_wq, &event_wait);
437
438 if (has_xsl_error(ctx)) {
439 used = append_xsl_error(ctx, &header, buf + sizeof(header));
440 if (used < 0)
441 return used;
442 }
443
444 if (!afu_events_pending(ctx))
445 header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST;
446
447 if (copy_to_user(buf, &header, sizeof(header)))
448 return -EFAULT;
449
450 used += sizeof(header);
451
452 rc = used;
453 return rc;
454}
455
456static int afu_release(struct inode *inode, struct file *file)
457{
458 struct ocxl_context *ctx = file->private_data;
459 int rc;
460
461 pr_debug("%s for device %x\n", __func__, inode->i_rdev);
462 rc = ocxl_context_detach(ctx);
463 mutex_lock(&ctx->mapping_lock);
464 ctx->mapping = NULL;
465 mutex_unlock(&ctx->mapping_lock);
466 wake_up_all(&ctx->events_wq);
467 if (rc != -EBUSY)
468 ocxl_context_free(ctx);
469 return 0;
470}
471
472static const struct file_operations ocxl_afu_fops = {
473 .owner = THIS_MODULE,
474 .open = afu_open,
475 .unlocked_ioctl = afu_ioctl,
476 .compat_ioctl = afu_compat_ioctl,
477 .mmap = afu_mmap,
478 .poll = afu_poll,
479 .read = afu_read,
480 .release = afu_release,
481};
482
483// Free the info struct
484static void info_release(struct device *dev)
485{
486 struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev);
487
488 ocxl_afu_put(info->afu);
489 kfree(info);
490}
491
492static int ocxl_file_make_visible(struct ocxl_file_info *info)
493{
494 int rc;
495
496 cdev_init(&info->cdev, &ocxl_afu_fops);
497 rc = cdev_add(&info->cdev, info->dev.devt, 1);
498 if (rc) {
499 dev_err(&info->dev, "Unable to add afu char device: %d\n", rc);
500 return rc;
501 }
502
503 return 0;
504}
505
506static void ocxl_file_make_invisible(struct ocxl_file_info *info)
507{
508 cdev_del(&info->cdev);
509}
510
511static char *ocxl_devnode(const struct device *dev, umode_t *mode)
512{
513 return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev));
514}
515
516static const struct class ocxl_class = {
517 .name = "ocxl",
518 .devnode = ocxl_devnode,
519};
520
521int ocxl_file_register_afu(struct ocxl_afu *afu)
522{
523 int minor;
524 int rc;
525 struct ocxl_file_info *info;
526 struct ocxl_fn *fn = afu->fn;
527 struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent);
528
529 info = kzalloc_obj(*info);
530 if (info == NULL)
531 return -ENOMEM;
532
533 minor = allocate_minor(info);
534 if (minor < 0) {
535 kfree(info);
536 return minor;
537 }
538
539 info->dev.parent = &fn->dev;
540 info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor);
541 info->dev.class = &ocxl_class;
542 info->dev.release = info_release;
543
544 info->afu = afu;
545 ocxl_afu_get(afu);
546
547 rc = dev_set_name(&info->dev, "%s.%s.%hhu",
548 afu->config.name, dev_name(&pci_dev->dev), afu->config.idx);
549 if (rc)
550 goto err_put;
551
552 rc = device_register(&info->dev);
553 if (rc) {
554 free_minor(info);
555 put_device(&info->dev);
556 return rc;
557 }
558
559 rc = ocxl_sysfs_register_afu(info);
560 if (rc)
561 goto err_unregister;
562
563 rc = ocxl_file_make_visible(info);
564 if (rc)
565 goto err_unregister;
566
567 ocxl_afu_set_private(afu, info);
568
569 return 0;
570
571err_unregister:
572 ocxl_sysfs_unregister_afu(info); // safe to call even if register failed
573 free_minor(info);
574 device_unregister(&info->dev);
575 return rc;
576err_put:
577 ocxl_afu_put(afu);
578 free_minor(info);
579 kfree(info);
580 return rc;
581}
582
583void ocxl_file_unregister_afu(struct ocxl_afu *afu)
584{
585 struct ocxl_file_info *info = ocxl_afu_get_private(afu);
586
587 if (!info)
588 return;
589
590 ocxl_file_make_invisible(info);
591 ocxl_sysfs_unregister_afu(info);
592 free_minor(info);
593 device_unregister(&info->dev);
594}
595
596int ocxl_file_init(void)
597{
598 int rc;
599
600 idr_init(&minors_idr);
601
602 rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl");
603 if (rc) {
604 pr_err("Unable to allocate ocxl major number: %d\n", rc);
605 return rc;
606 }
607
608 rc = class_register(&ocxl_class);
609 if (rc) {
610 pr_err("Unable to create ocxl class\n");
611 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
612 return rc;
613 }
614
615 return 0;
616}
617
618void ocxl_file_exit(void)
619{
620 class_unregister(&ocxl_class);
621 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
622 idr_destroy(&minors_idr);
623}