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