1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright 2014 IBM Corp.
6 #include <linux/spinlock.h>
7 #include <linux/module.h>
8 #include <linux/export.h>
9 #include <linux/kernel.h>
10 #include <linux/bitmap.h>
11 #include <linux/sched/signal.h>
12 #include <linux/poll.h>
13 #include <linux/pid.h>
16 #include <linux/slab.h>
17 #include <linux/sched/mm.h>
18 #include <linux/mmu_context.h>
19 #include <asm/cputable.h>
20 #include <asm/current.h>
21 #include <asm/copro.h>
26 #define CXL_NUM_MINORS 256 /* Total to reserve */
28 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
29 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
30 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
31 #define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
32 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
33 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
35 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
37 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
41 static struct class *cxl_class;
43 static int __afu_open(struct inode *inode, struct file *file, bool master)
47 struct cxl_context *ctx;
48 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
49 int slice = CXL_DEVT_AFU(inode->i_rdev);
52 pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
54 if (!(adapter = get_cxl_adapter(adapter_num)))
57 if (slice > adapter->slices)
60 spin_lock(&adapter->afu_list_lock);
61 if (!(afu = adapter->afu[slice])) {
62 spin_unlock(&adapter->afu_list_lock);
67 * taking a ref to the afu so that it doesn't go away
68 * for rest of the function. This ref is released before
72 spin_unlock(&adapter->afu_list_lock);
74 if (!afu->current_mode)
77 if (!cxl_ops->link_ok(adapter, afu)) {
82 if (!(ctx = cxl_context_alloc())) {
87 rc = cxl_context_init(ctx, afu, master);
91 cxl_context_set_mapping(ctx, inode->i_mapping);
93 pr_devel("afu_open pe: %i\n", ctx->pe);
94 file->private_data = ctx;
96 /* indicate success */
100 /* release the ref taken earlier */
103 put_device(&adapter->dev);
107 int afu_open(struct inode *inode, struct file *file)
109 return __afu_open(inode, file, false);
112 static int afu_master_open(struct inode *inode, struct file *file)
114 return __afu_open(inode, file, true);
117 int afu_release(struct inode *inode, struct file *file)
119 struct cxl_context *ctx = file->private_data;
121 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
123 cxl_context_detach(ctx);
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()
130 if (!ctx->kernelapi) {
131 mutex_lock(&ctx->mapping_lock);
133 mutex_unlock(&ctx->mapping_lock);
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
142 cxl_context_free(ctx);
147 static long afu_ioctl_start_work(struct cxl_context *ctx,
148 struct cxl_ioctl_start_work __user *uwork)
150 struct cxl_ioctl_start_work work;
154 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
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, sizeof(work)))
161 mutex_lock(&ctx->status_mutex);
162 if (ctx->status != OPENED) {
168 * if any of the reserved fields are set or any of the unused
169 * flags are set it's invalid
171 if (work.reserved1 || work.reserved2 || work.reserved3 ||
172 work.reserved4 || work.reserved5 ||
173 (work.flags & ~CXL_START_WORK_ALL)) {
178 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
179 work.num_interrupts = ctx->afu->pp_irqs;
180 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
181 (work.num_interrupts > ctx->afu->irqs_max)) {
186 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
189 if (work.flags & CXL_START_WORK_AMR)
190 amr = work.amr & mfspr(SPRN_UAMOR);
192 if (work.flags & CXL_START_WORK_TID)
193 ctx->assign_tidr = true;
195 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
198 * Increment the mapped context count for adapter. This also checks
199 * if adapter_context_lock is taken.
201 rc = cxl_adapter_context_get(ctx->afu->adapter);
203 afu_release_irqs(ctx, ctx);
208 * We grab the PID here and not in the file open to allow for the case
209 * where a process (master, some daemon, etc) has opened the chardev on
210 * behalf of another process, so the AFU's mm gets bound to the process
211 * that performs this ioctl and not the process that opened the file.
212 * Also we grab the PID of the group leader so that if the task that
213 * has performed the attach operation exits the mm context of the
214 * process is still accessible.
216 ctx->pid = get_task_pid(current, PIDTYPE_PID);
218 /* acquire a reference to the task's mm */
219 ctx->mm = get_task_mm(current);
221 /* ensure this mm_struct can't be freed */
222 cxl_context_mm_count_get(ctx);
225 /* decrement the use count from above */
227 /* make TLBIs for this context global */
228 mm_context_add_copro(ctx->mm);
232 * Increment driver use count. Enables global TLBIs for hash
233 * and callbacks to handle the segment table
238 * A barrier is needed to make sure all TLBIs are global
239 * before we attach and the context starts being used by the
242 * Needed after mm_context_add_copro() for radix and
243 * cxl_ctx_get() for hash/p8.
245 * The barrier should really be mb(), since it involves a
246 * device. However, it's only useful when we have local
247 * vs. global TLBIs, i.e SMP=y. So keep smp_mb().
251 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
253 if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
255 afu_release_irqs(ctx, ctx);
256 cxl_adapter_context_put(ctx->afu->adapter);
260 cxl_context_mm_count_put(ctx);
262 mm_context_remove_copro(ctx->mm);
267 if (work.flags & CXL_START_WORK_TID) {
268 work.tid = ctx->tidr;
269 if (copy_to_user(uwork, &work, sizeof(work)))
273 ctx->status = STARTED;
276 mutex_unlock(&ctx->status_mutex);
280 static long afu_ioctl_process_element(struct cxl_context *ctx,
283 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
285 if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
291 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
292 struct cxl_afu_id __user *upafuid)
294 struct cxl_afu_id afuid = { 0 };
296 afuid.card_id = ctx->afu->adapter->adapter_num;
297 afuid.afu_offset = ctx->afu->slice;
298 afuid.afu_mode = ctx->afu->current_mode;
300 /* set the flag bit in case the afu is a slave */
301 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
302 afuid.flags |= CXL_AFUID_FLAG_SLAVE;
304 if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
310 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
312 struct cxl_context *ctx = file->private_data;
314 if (ctx->status == CLOSED)
317 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
320 pr_devel("afu_ioctl\n");
322 case CXL_IOCTL_START_WORK:
323 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
324 case CXL_IOCTL_GET_PROCESS_ELEMENT:
325 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
326 case CXL_IOCTL_GET_AFU_ID:
327 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
333 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
336 return afu_ioctl(file, cmd, arg);
339 int afu_mmap(struct file *file, struct vm_area_struct *vm)
341 struct cxl_context *ctx = file->private_data;
343 /* AFU must be started before we can MMIO */
344 if (ctx->status != STARTED)
347 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
350 return cxl_context_iomap(ctx, vm);
353 static inline bool ctx_event_pending(struct cxl_context *ctx)
355 if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)
358 if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
364 __poll_t afu_poll(struct file *file, struct poll_table_struct *poll)
366 struct cxl_context *ctx = file->private_data;
371 poll_wait(file, &ctx->wq, poll);
373 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
375 spin_lock_irqsave(&ctx->lock, flags);
376 if (ctx_event_pending(ctx))
377 mask |= EPOLLIN | EPOLLRDNORM;
378 else if (ctx->status == CLOSED)
379 /* Only error on closed when there are no futher events pending
382 spin_unlock_irqrestore(&ctx->lock, flags);
384 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
389 static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
391 struct cxl_event *event,
392 struct cxl_event_afu_driver_reserved *pl)
396 ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
400 /* Check event size */
401 event->header.size += pl->data_size;
402 if (event->header.size > CXL_READ_MIN_SIZE) {
403 ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
407 /* Copy event header */
408 if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
409 ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
413 /* Copy event data */
414 buf += sizeof(struct cxl_event_header);
415 if (copy_to_user(buf, &pl->data, pl->data_size)) {
416 ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
420 ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
421 return event->header.size;
424 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
427 struct cxl_context *ctx = file->private_data;
428 struct cxl_event_afu_driver_reserved *pl = NULL;
429 struct cxl_event event;
434 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
437 if (count < CXL_READ_MIN_SIZE)
440 spin_lock_irqsave(&ctx->lock, flags);
443 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
444 if (ctx_event_pending(ctx) || (ctx->status == CLOSED))
447 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
452 if (file->f_flags & O_NONBLOCK) {
457 if (signal_pending(current)) {
462 spin_unlock_irqrestore(&ctx->lock, flags);
463 pr_devel("afu_read going to sleep...\n");
465 pr_devel("afu_read woken up\n");
466 spin_lock_irqsave(&ctx->lock, flags);
469 finish_wait(&ctx->wq, &wait);
471 memset(&event, 0, sizeof(event));
472 event.header.process_element = ctx->pe;
473 event.header.size = sizeof(struct cxl_event_header);
474 if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
475 pr_devel("afu_read delivering AFU driver specific event\n");
476 pl = ctx->afu_driver_ops->fetch_event(ctx);
477 atomic_dec(&ctx->afu_driver_events);
478 event.header.type = CXL_EVENT_AFU_DRIVER;
479 } else if (ctx->pending_irq) {
480 pr_devel("afu_read delivering AFU interrupt\n");
481 event.header.size += sizeof(struct cxl_event_afu_interrupt);
482 event.header.type = CXL_EVENT_AFU_INTERRUPT;
483 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
484 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
485 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
486 ctx->pending_irq = false;
487 } else if (ctx->pending_fault) {
488 pr_devel("afu_read delivering data storage fault\n");
489 event.header.size += sizeof(struct cxl_event_data_storage);
490 event.header.type = CXL_EVENT_DATA_STORAGE;
491 event.fault.addr = ctx->fault_addr;
492 event.fault.dsisr = ctx->fault_dsisr;
493 ctx->pending_fault = false;
494 } else if (ctx->pending_afu_err) {
495 pr_devel("afu_read delivering afu error\n");
496 event.header.size += sizeof(struct cxl_event_afu_error);
497 event.header.type = CXL_EVENT_AFU_ERROR;
498 event.afu_error.error = ctx->afu_err;
499 ctx->pending_afu_err = false;
500 } else if (ctx->status == CLOSED) {
501 pr_devel("afu_read fatal error\n");
502 spin_unlock_irqrestore(&ctx->lock, flags);
505 WARN(1, "afu_read must be buggy\n");
507 spin_unlock_irqrestore(&ctx->lock, flags);
509 if (event.header.type == CXL_EVENT_AFU_DRIVER)
510 return afu_driver_event_copy(ctx, buf, &event, pl);
512 if (copy_to_user(buf, &event, event.header.size))
514 return event.header.size;
517 finish_wait(&ctx->wq, &wait);
518 spin_unlock_irqrestore(&ctx->lock, flags);
523 * Note: if this is updated, we need to update api.c to patch the new ones in
526 const struct file_operations afu_fops = {
527 .owner = THIS_MODULE,
531 .release = afu_release,
532 .unlocked_ioctl = afu_ioctl,
533 .compat_ioctl = afu_compat_ioctl,
537 static const struct file_operations afu_master_fops = {
538 .owner = THIS_MODULE,
539 .open = afu_master_open,
542 .release = afu_release,
543 .unlocked_ioctl = afu_ioctl,
544 .compat_ioctl = afu_compat_ioctl,
549 static char *cxl_devnode(struct device *dev, umode_t *mode)
551 if (cpu_has_feature(CPU_FTR_HVMODE) &&
552 CXL_DEVT_IS_CARD(dev->devt)) {
554 * These minor numbers will eventually be used to program the
555 * PSL and AFUs once we have dynamic reprogramming support
559 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
562 extern struct class *cxl_class;
564 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
565 struct device **chardev, char *postfix, char *desc,
566 const struct file_operations *fops)
571 cdev_init(cdev, fops);
572 if ((rc = cdev_add(cdev, devt, 1))) {
573 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
577 dev = device_create(cxl_class, &afu->dev, devt, afu,
578 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
580 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
593 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
595 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
596 &afu->chardev_d, "d", "dedicated",
597 &afu_master_fops); /* Uses master fops */
600 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
602 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
603 &afu->chardev_m, "m", "master",
607 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
609 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
610 &afu->chardev_s, "s", "shared",
614 void cxl_chardev_afu_remove(struct cxl_afu *afu)
616 if (afu->chardev_d) {
617 cdev_del(&afu->afu_cdev_d);
618 device_unregister(afu->chardev_d);
619 afu->chardev_d = NULL;
621 if (afu->chardev_m) {
622 cdev_del(&afu->afu_cdev_m);
623 device_unregister(afu->chardev_m);
624 afu->chardev_m = NULL;
626 if (afu->chardev_s) {
627 cdev_del(&afu->afu_cdev_s);
628 device_unregister(afu->chardev_s);
629 afu->chardev_s = NULL;
633 int cxl_register_afu(struct cxl_afu *afu)
635 afu->dev.class = cxl_class;
637 return device_register(&afu->dev);
640 int cxl_register_adapter(struct cxl *adapter)
642 adapter->dev.class = cxl_class;
645 * Future: When we support dynamically reprogramming the PSL & AFU we
646 * will expose the interface to do that via a chardev:
647 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
650 return device_register(&adapter->dev);
653 dev_t cxl_get_dev(void)
658 int __init cxl_file_init(void)
663 * If these change we really need to update API. Either change some
664 * flags or update API version number CXL_API_VERSION.
666 BUILD_BUG_ON(CXL_API_VERSION != 3);
667 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
668 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
669 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
670 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
671 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
673 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
674 pr_err("Unable to allocate CXL major number: %i\n", rc);
678 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
680 cxl_class = class_create(THIS_MODULE, "cxl");
681 if (IS_ERR(cxl_class)) {
682 pr_err("Unable to create CXL class\n");
683 rc = PTR_ERR(cxl_class);
686 cxl_class->devnode = cxl_devnode;
691 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
695 void cxl_file_exit(void)
697 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
698 class_destroy(cxl_class);