1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
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>
10 #include <asm/switch_to.h>
11 #include "ocxl_internal.h"
14 #define OCXL_NUM_MINORS 256 /* Total to reserve */
16 static dev_t ocxl_dev;
17 static struct class *ocxl_class;
18 static DEFINE_MUTEX(minors_idr_lock);
19 static struct idr minors_idr;
21 static struct ocxl_file_info *find_and_get_file_info(dev_t devno)
23 struct ocxl_file_info *info;
25 mutex_lock(&minors_idr_lock);
26 info = idr_find(&minors_idr, MINOR(devno));
28 get_device(&info->dev);
29 mutex_unlock(&minors_idr_lock);
33 static int allocate_minor(struct ocxl_file_info *info)
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);
43 static void free_minor(struct ocxl_file_info *info)
45 mutex_lock(&minors_idr_lock);
46 idr_remove(&minors_idr, MINOR(info->dev.devt));
47 mutex_unlock(&minors_idr_lock);
50 static int afu_open(struct inode *inode, struct file *file)
52 struct ocxl_file_info *info;
53 struct ocxl_context *ctx;
56 pr_debug("%s for device %x\n", __func__, inode->i_rdev);
58 info = find_and_get_file_info(inode->i_rdev);
62 rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping);
64 put_device(&info->dev);
67 put_device(&info->dev);
68 file->private_data = ctx;
72 static long afu_ioctl_attach(struct ocxl_context *ctx,
73 struct ocxl_ioctl_attach __user *uarg)
75 struct ocxl_ioctl_attach arg;
79 pr_debug("%s for context %d\n", __func__, ctx->pasid);
81 if (copy_from_user(&arg, uarg, sizeof(arg)))
84 /* Make sure reserved fields are not set for forward compatibility */
85 if (arg.reserved1 || arg.reserved2 || arg.reserved3)
88 amr = arg.amr & mfspr(SPRN_UAMOR);
89 rc = ocxl_context_attach(ctx, amr, current->mm);
93 static long afu_ioctl_get_metadata(struct ocxl_context *ctx,
94 struct ocxl_ioctl_metadata __user *uarg)
96 struct ocxl_ioctl_metadata arg;
98 memset(&arg, 0, sizeof(arg));
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;
108 if (copy_to_user(uarg, &arg, sizeof(arg)))
115 static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx,
116 struct ocxl_ioctl_p9_wait __user *uarg)
118 struct ocxl_ioctl_p9_wait arg;
120 memset(&arg, 0, sizeof(arg));
122 if (cpu_has_feature(CPU_FTR_P9_TIDR)) {
123 enum ocxl_context_status status;
125 // Locks both status & tidr
126 mutex_lock(&ctx->status_mutex);
128 if (set_thread_tidr(current)) {
129 mutex_unlock(&ctx->status_mutex);
133 ctx->tidr = current->thread.tidr;
136 status = ctx->status;
137 mutex_unlock(&ctx->status_mutex);
139 if (status == ATTACHED) {
140 int rc = ocxl_link_update_pe(ctx->afu->fn->link,
141 ctx->pasid, ctx->tidr);
147 arg.thread_id = ctx->tidr;
151 if (copy_to_user(uarg, &arg, sizeof(arg)))
159 static long afu_ioctl_get_features(struct ocxl_context *ctx,
160 struct ocxl_ioctl_features __user *uarg)
162 struct ocxl_ioctl_features arg;
164 memset(&arg, 0, sizeof(arg));
167 if (cpu_has_feature(CPU_FTR_P9_TIDR))
168 arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT;
171 if (copy_to_user(uarg, &arg, sizeof(arg)))
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" : \
186 static irqreturn_t irq_handler(void *private)
188 struct eventfd_ctx *ev_ctx = private;
190 eventfd_signal(ev_ctx, 1);
194 static void irq_free(void *private)
196 struct eventfd_ctx *ev_ctx = private;
198 eventfd_ctx_put(ev_ctx);
201 static long afu_ioctl(struct file *file, unsigned int cmd,
204 struct ocxl_context *ctx = file->private_data;
205 struct ocxl_ioctl_irq_fd irq_fd;
206 struct eventfd_ctx *ev_ctx;
212 pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid,
215 mutex_lock(&ctx->status_mutex);
216 closed = (ctx->status == CLOSED);
217 mutex_unlock(&ctx->status_mutex);
223 case OCXL_IOCTL_ATTACH:
224 rc = afu_ioctl_attach(ctx,
225 (struct ocxl_ioctl_attach __user *) args);
228 case OCXL_IOCTL_IRQ_ALLOC:
229 rc = ocxl_afu_irq_alloc(ctx, &irq_id);
231 irq_offset = ocxl_irq_id_to_offset(ctx, irq_id);
232 rc = copy_to_user((u64 __user *) args, &irq_offset,
235 ocxl_afu_irq_free(ctx, irq_id);
241 case OCXL_IOCTL_IRQ_FREE:
242 rc = copy_from_user(&irq_offset, (u64 __user *) args,
246 irq_id = ocxl_irq_offset_to_id(ctx, irq_offset);
247 rc = ocxl_afu_irq_free(ctx, irq_id);
250 case OCXL_IOCTL_IRQ_SET_FD:
251 rc = copy_from_user(&irq_fd, (u64 __user *) args,
257 irq_id = ocxl_irq_offset_to_id(ctx, irq_fd.irq_offset);
258 ev_ctx = eventfd_ctx_fdget(irq_fd.eventfd);
260 return PTR_ERR(ev_ctx);
261 rc = ocxl_irq_set_handler(ctx, irq_id, irq_handler, irq_free, ev_ctx);
264 case OCXL_IOCTL_GET_METADATA:
265 rc = afu_ioctl_get_metadata(ctx,
266 (struct ocxl_ioctl_metadata __user *) args);
270 case OCXL_IOCTL_ENABLE_P9_WAIT:
271 rc = afu_ioctl_enable_p9_wait(ctx,
272 (struct ocxl_ioctl_p9_wait __user *) args);
276 case OCXL_IOCTL_GET_FEATURES:
277 rc = afu_ioctl_get_features(ctx,
278 (struct ocxl_ioctl_features __user *) args);
287 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
290 return afu_ioctl(file, cmd, args);
293 static int afu_mmap(struct file *file, struct vm_area_struct *vma)
295 struct ocxl_context *ctx = file->private_data;
297 pr_debug("%s for context %d\n", __func__, ctx->pasid);
298 return ocxl_context_mmap(ctx, vma);
301 static bool has_xsl_error(struct ocxl_context *ctx)
305 mutex_lock(&ctx->xsl_error_lock);
306 ret = !!ctx->xsl_error.addr;
307 mutex_unlock(&ctx->xsl_error_lock);
313 * Are there any events pending on the AFU
314 * ctx: The AFU context
315 * Returns: true if there are events pending
317 static bool afu_events_pending(struct ocxl_context *ctx)
319 if (has_xsl_error(ctx))
324 static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait)
326 struct ocxl_context *ctx = file->private_data;
327 unsigned int mask = 0;
330 pr_debug("%s for context %d\n", __func__, ctx->pasid);
332 poll_wait(file, &ctx->events_wq, wait);
334 mutex_lock(&ctx->status_mutex);
335 closed = (ctx->status == CLOSED);
336 mutex_unlock(&ctx->status_mutex);
338 if (afu_events_pending(ctx))
339 mask = EPOLLIN | EPOLLRDNORM;
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
354 static ssize_t append_xsl_error(struct ocxl_context *ctx,
355 struct ocxl_kernel_event_header *header,
358 struct ocxl_kernel_event_xsl_fault_error body;
360 memset(&body, 0, sizeof(body));
362 mutex_lock(&ctx->xsl_error_lock);
363 if (!ctx->xsl_error.addr) {
364 mutex_unlock(&ctx->xsl_error_lock);
368 body.addr = ctx->xsl_error.addr;
369 body.dsisr = ctx->xsl_error.dsisr;
370 body.count = ctx->xsl_error.count;
372 ctx->xsl_error.addr = 0;
373 ctx->xsl_error.dsisr = 0;
374 ctx->xsl_error.count = 0;
376 mutex_unlock(&ctx->xsl_error_lock);
378 header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR;
380 if (copy_to_user(buf, &body, sizeof(body)))
386 #define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error)
389 * Reports events on the AFU
391 * Header (struct ocxl_kernel_event_header)
392 * Body (struct ocxl_kernel_event_*)
395 static ssize_t afu_read(struct file *file, char __user *buf, size_t count,
398 struct ocxl_context *ctx = file->private_data;
399 struct ocxl_kernel_event_header header;
402 DEFINE_WAIT(event_wait);
404 memset(&header, 0, sizeof(header));
406 /* Require offset to be 0 */
410 if (count < (sizeof(struct ocxl_kernel_event_header) +
411 AFU_EVENT_BODY_MAX_SIZE))
415 prepare_to_wait(&ctx->events_wq, &event_wait,
418 if (afu_events_pending(ctx))
421 if (ctx->status == CLOSED)
424 if (file->f_flags & O_NONBLOCK) {
425 finish_wait(&ctx->events_wq, &event_wait);
429 if (signal_pending(current)) {
430 finish_wait(&ctx->events_wq, &event_wait);
437 finish_wait(&ctx->events_wq, &event_wait);
439 if (has_xsl_error(ctx)) {
440 used = append_xsl_error(ctx, &header, buf + sizeof(header));
445 if (!afu_events_pending(ctx))
446 header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST;
448 if (copy_to_user(buf, &header, sizeof(header)))
451 used += sizeof(header);
457 static int afu_release(struct inode *inode, struct file *file)
459 struct ocxl_context *ctx = file->private_data;
462 pr_debug("%s for device %x\n", __func__, inode->i_rdev);
463 rc = ocxl_context_detach(ctx);
464 mutex_lock(&ctx->mapping_lock);
466 mutex_unlock(&ctx->mapping_lock);
467 wake_up_all(&ctx->events_wq);
469 ocxl_context_free(ctx);
473 static const struct file_operations ocxl_afu_fops = {
474 .owner = THIS_MODULE,
476 .unlocked_ioctl = afu_ioctl,
477 .compat_ioctl = afu_compat_ioctl,
481 .release = afu_release,
484 // Free the info struct
485 static void info_release(struct device *dev)
487 struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev);
489 ocxl_afu_put(info->afu);
493 static int ocxl_file_make_visible(struct ocxl_file_info *info)
497 cdev_init(&info->cdev, &ocxl_afu_fops);
498 rc = cdev_add(&info->cdev, info->dev.devt, 1);
500 dev_err(&info->dev, "Unable to add afu char device: %d\n", rc);
507 static void ocxl_file_make_invisible(struct ocxl_file_info *info)
509 cdev_del(&info->cdev);
512 int ocxl_file_register_afu(struct ocxl_afu *afu)
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);
520 info = kzalloc(sizeof(*info), GFP_KERNEL);
524 minor = allocate_minor(info);
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;
538 rc = dev_set_name(&info->dev, "%s.%s.%hhu",
539 afu->config.name, dev_name(&pci_dev->dev), afu->config.idx);
543 rc = device_register(&info->dev);
547 rc = ocxl_sysfs_register_afu(info);
551 rc = ocxl_file_make_visible(info);
555 ocxl_afu_set_private(afu, info);
560 ocxl_sysfs_unregister_afu(info); // safe to call even if register failed
561 device_unregister(&info->dev);
569 void ocxl_file_unregister_afu(struct ocxl_afu *afu)
571 struct ocxl_file_info *info = ocxl_afu_get_private(afu);
576 ocxl_file_make_invisible(info);
577 ocxl_sysfs_unregister_afu(info);
579 device_unregister(&info->dev);
582 static char *ocxl_devnode(struct device *dev, umode_t *mode)
584 return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev));
587 int ocxl_file_init(void)
591 idr_init(&minors_idr);
593 rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl");
595 pr_err("Unable to allocate ocxl major number: %d\n", rc);
599 ocxl_class = class_create(THIS_MODULE, "ocxl");
600 if (IS_ERR(ocxl_class)) {
601 pr_err("Unable to create ocxl class\n");
602 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
603 return PTR_ERR(ocxl_class);
606 ocxl_class->devnode = ocxl_devnode;
610 void ocxl_file_exit(void)
612 class_destroy(ocxl_class);
613 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
614 idr_destroy(&minors_idr);