xref: /linux/drivers/misc/cxl/file.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2014 IBM Corp.
4  */
5 
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>
14 #include <linux/fs.h>
15 #include <linux/mm.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>
22 
23 #include "cxl.h"
24 #include "trace.h"
25 
26 #define CXL_NUM_MINORS 256 /* Total to reserve */
27 
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))
34 
35 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
36 
37 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
38 
39 static dev_t cxl_dev;
40 
__afu_open(struct inode * inode,struct file * file,bool master)41 static int __afu_open(struct inode *inode, struct file *file, bool master)
42 {
43 	struct cxl *adapter;
44 	struct cxl_afu *afu;
45 	struct cxl_context *ctx;
46 	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
47 	int slice = CXL_DEVT_AFU(inode->i_rdev);
48 	int rc = -ENODEV;
49 
50 	pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
51 
52 	if (!(adapter = get_cxl_adapter(adapter_num)))
53 		return -ENODEV;
54 
55 	if (slice > adapter->slices)
56 		goto err_put_adapter;
57 
58 	spin_lock(&adapter->afu_list_lock);
59 	if (!(afu = adapter->afu[slice])) {
60 		spin_unlock(&adapter->afu_list_lock);
61 		goto err_put_adapter;
62 	}
63 
64 	/*
65 	 * taking a ref to the afu so that it doesn't go away
66 	 * for rest of the function. This ref is released before
67 	 * we return.
68 	 */
69 	cxl_afu_get(afu);
70 	spin_unlock(&adapter->afu_list_lock);
71 
72 	if (!afu->current_mode)
73 		goto err_put_afu;
74 
75 	if (!cxl_ops->link_ok(adapter, afu)) {
76 		rc = -EIO;
77 		goto err_put_afu;
78 	}
79 
80 	if (!(ctx = cxl_context_alloc())) {
81 		rc = -ENOMEM;
82 		goto err_put_afu;
83 	}
84 
85 	rc = cxl_context_init(ctx, afu, master);
86 	if (rc)
87 		goto err_put_afu;
88 
89 	cxl_context_set_mapping(ctx, inode->i_mapping);
90 
91 	pr_devel("afu_open pe: %i\n", ctx->pe);
92 	file->private_data = ctx;
93 
94 	/* indicate success */
95 	rc = 0;
96 
97 err_put_afu:
98 	/* release the ref taken earlier */
99 	cxl_afu_put(afu);
100 err_put_adapter:
101 	put_device(&adapter->dev);
102 	return rc;
103 }
104 
afu_open(struct inode * inode,struct file * file)105 int afu_open(struct inode *inode, struct file *file)
106 {
107 	return __afu_open(inode, file, false);
108 }
109 
afu_master_open(struct inode * inode,struct file * file)110 static int afu_master_open(struct inode *inode, struct file *file)
111 {
112 	return __afu_open(inode, file, true);
113 }
114 
afu_release(struct inode * inode,struct file * file)115 int afu_release(struct inode *inode, struct file *file)
116 {
117 	struct cxl_context *ctx = file->private_data;
118 
119 	pr_devel("%s: closing cxl file descriptor. pe: %i\n",
120 		 __func__, ctx->pe);
121 	cxl_context_detach(ctx);
122 
123 
124 	/*
125 	 * Delete the context's mapping pointer, unless it's created by the
126 	 * kernel API, in which case leave it so it can be freed by reclaim_ctx()
127 	 */
128 	if (!ctx->kernelapi) {
129 		mutex_lock(&ctx->mapping_lock);
130 		ctx->mapping = NULL;
131 		mutex_unlock(&ctx->mapping_lock);
132 	}
133 
134 	/*
135 	 * At this this point all bottom halfs have finished and we should be
136 	 * getting no more IRQs from the hardware for this context.  Once it's
137 	 * removed from the IDR (and RCU synchronised) it's safe to free the
138 	 * sstp and context.
139 	 */
140 	cxl_context_free(ctx);
141 
142 	return 0;
143 }
144 
afu_ioctl_start_work(struct cxl_context * ctx,struct cxl_ioctl_start_work __user * uwork)145 static long afu_ioctl_start_work(struct cxl_context *ctx,
146 				 struct cxl_ioctl_start_work __user *uwork)
147 {
148 	struct cxl_ioctl_start_work work;
149 	u64 amr = 0;
150 	int rc;
151 
152 	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
153 
154 	/* Do this outside the status_mutex to avoid a circular dependency with
155 	 * the locking in cxl_mmap_fault() */
156 	if (copy_from_user(&work, uwork, sizeof(work)))
157 		return -EFAULT;
158 
159 	mutex_lock(&ctx->status_mutex);
160 	if (ctx->status != OPENED) {
161 		rc = -EIO;
162 		goto out;
163 	}
164 
165 	/*
166 	 * if any of the reserved fields are set or any of the unused
167 	 * flags are set it's invalid
168 	 */
169 	if (work.reserved1 || work.reserved2 || work.reserved3 ||
170 	    work.reserved4 || work.reserved5 ||
171 	    (work.flags & ~CXL_START_WORK_ALL)) {
172 		rc = -EINVAL;
173 		goto out;
174 	}
175 
176 	if (!(work.flags & CXL_START_WORK_NUM_IRQS))
177 		work.num_interrupts = ctx->afu->pp_irqs;
178 	else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
179 		 (work.num_interrupts > ctx->afu->irqs_max)) {
180 		rc =  -EINVAL;
181 		goto out;
182 	}
183 
184 	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
185 		goto out;
186 
187 	if (work.flags & CXL_START_WORK_AMR)
188 		amr = work.amr & mfspr(SPRN_UAMOR);
189 
190 	if (work.flags & CXL_START_WORK_TID)
191 		ctx->assign_tidr = true;
192 
193 	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
194 
195 	/*
196 	 * Increment the mapped context count for adapter. This also checks
197 	 * if adapter_context_lock is taken.
198 	 */
199 	rc = cxl_adapter_context_get(ctx->afu->adapter);
200 	if (rc) {
201 		afu_release_irqs(ctx, ctx);
202 		goto out;
203 	}
204 
205 	/*
206 	 * We grab the PID here and not in the file open to allow for the case
207 	 * where a process (master, some daemon, etc) has opened the chardev on
208 	 * behalf of another process, so the AFU's mm gets bound to the process
209 	 * that performs this ioctl and not the process that opened the file.
210 	 * Also we grab the PID of the group leader so that if the task that
211 	 * has performed the attach operation exits the mm context of the
212 	 * process is still accessible.
213 	 */
214 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
215 
216 	/* acquire a reference to the task's mm */
217 	ctx->mm = get_task_mm(current);
218 
219 	/* ensure this mm_struct can't be freed */
220 	cxl_context_mm_count_get(ctx);
221 
222 	if (ctx->mm) {
223 		/* decrement the use count from above */
224 		mmput(ctx->mm);
225 		/* make TLBIs for this context global */
226 		mm_context_add_copro(ctx->mm);
227 	}
228 
229 	/*
230 	 * Increment driver use count. Enables global TLBIs for hash
231 	 * and callbacks to handle the segment table
232 	 */
233 	cxl_ctx_get();
234 
235 	/*
236 	 * A barrier is needed to make sure all TLBIs are global
237 	 * before we attach and the context starts being used by the
238 	 * adapter.
239 	 *
240 	 * Needed after mm_context_add_copro() for radix and
241 	 * cxl_ctx_get() for hash/p8.
242 	 *
243 	 * The barrier should really be mb(), since it involves a
244 	 * device. However, it's only useful when we have local
245 	 * vs. global TLBIs, i.e SMP=y. So keep smp_mb().
246 	 */
247 	smp_mb();
248 
249 	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
250 
251 	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
252 							amr))) {
253 		afu_release_irqs(ctx, ctx);
254 		cxl_adapter_context_put(ctx->afu->adapter);
255 		put_pid(ctx->pid);
256 		ctx->pid = NULL;
257 		cxl_ctx_put();
258 		cxl_context_mm_count_put(ctx);
259 		if (ctx->mm)
260 			mm_context_remove_copro(ctx->mm);
261 		goto out;
262 	}
263 
264 	rc = 0;
265 	if (work.flags & CXL_START_WORK_TID) {
266 		work.tid = ctx->tidr;
267 		if (copy_to_user(uwork, &work, sizeof(work)))
268 			rc = -EFAULT;
269 	}
270 
271 	ctx->status = STARTED;
272 
273 out:
274 	mutex_unlock(&ctx->status_mutex);
275 	return rc;
276 }
277 
afu_ioctl_process_element(struct cxl_context * ctx,int __user * upe)278 static long afu_ioctl_process_element(struct cxl_context *ctx,
279 				      int __user *upe)
280 {
281 	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
282 
283 	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
284 		return -EFAULT;
285 
286 	return 0;
287 }
288 
afu_ioctl_get_afu_id(struct cxl_context * ctx,struct cxl_afu_id __user * upafuid)289 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
290 				 struct cxl_afu_id __user *upafuid)
291 {
292 	struct cxl_afu_id afuid = { 0 };
293 
294 	afuid.card_id = ctx->afu->adapter->adapter_num;
295 	afuid.afu_offset = ctx->afu->slice;
296 	afuid.afu_mode = ctx->afu->current_mode;
297 
298 	/* set the flag bit in case the afu is a slave */
299 	if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
300 		afuid.flags |= CXL_AFUID_FLAG_SLAVE;
301 
302 	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
303 		return -EFAULT;
304 
305 	return 0;
306 }
307 
afu_ioctl(struct file * file,unsigned int cmd,unsigned long arg)308 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
309 {
310 	struct cxl_context *ctx = file->private_data;
311 
312 	if (ctx->status == CLOSED)
313 		return -EIO;
314 
315 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
316 		return -EIO;
317 
318 	pr_devel("afu_ioctl\n");
319 	switch (cmd) {
320 	case CXL_IOCTL_START_WORK:
321 		return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
322 	case CXL_IOCTL_GET_PROCESS_ELEMENT:
323 		return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
324 	case CXL_IOCTL_GET_AFU_ID:
325 		return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
326 					    arg);
327 	}
328 	return -EINVAL;
329 }
330 
afu_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)331 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
332 			     unsigned long arg)
333 {
334 	return afu_ioctl(file, cmd, arg);
335 }
336 
afu_mmap(struct file * file,struct vm_area_struct * vm)337 int afu_mmap(struct file *file, struct vm_area_struct *vm)
338 {
339 	struct cxl_context *ctx = file->private_data;
340 
341 	/* AFU must be started before we can MMIO */
342 	if (ctx->status != STARTED)
343 		return -EIO;
344 
345 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
346 		return -EIO;
347 
348 	return cxl_context_iomap(ctx, vm);
349 }
350 
ctx_event_pending(struct cxl_context * ctx)351 static inline bool ctx_event_pending(struct cxl_context *ctx)
352 {
353 	if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)
354 		return true;
355 
356 	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
357 		return true;
358 
359 	return false;
360 }
361 
afu_poll(struct file * file,struct poll_table_struct * poll)362 __poll_t afu_poll(struct file *file, struct poll_table_struct *poll)
363 {
364 	struct cxl_context *ctx = file->private_data;
365 	__poll_t mask = 0;
366 	unsigned long flags;
367 
368 
369 	poll_wait(file, &ctx->wq, poll);
370 
371 	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
372 
373 	spin_lock_irqsave(&ctx->lock, flags);
374 	if (ctx_event_pending(ctx))
375 		mask |= EPOLLIN | EPOLLRDNORM;
376 	else if (ctx->status == CLOSED)
377 		/* Only error on closed when there are no futher events pending
378 		 */
379 		mask |= EPOLLERR;
380 	spin_unlock_irqrestore(&ctx->lock, flags);
381 
382 	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
383 
384 	return mask;
385 }
386 
afu_driver_event_copy(struct cxl_context * ctx,char __user * buf,struct cxl_event * event,struct cxl_event_afu_driver_reserved * pl)387 static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
388 				     char __user *buf,
389 				     struct cxl_event *event,
390 				     struct cxl_event_afu_driver_reserved *pl)
391 {
392 	/* Check event */
393 	if (!pl) {
394 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
395 		return -EFAULT;
396 	}
397 
398 	/* Check event size */
399 	event->header.size += pl->data_size;
400 	if (event->header.size > CXL_READ_MIN_SIZE) {
401 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
402 		return -EFAULT;
403 	}
404 
405 	/* Copy event header */
406 	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
407 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
408 		return -EFAULT;
409 	}
410 
411 	/* Copy event data */
412 	buf += sizeof(struct cxl_event_header);
413 	if (copy_to_user(buf, &pl->data, pl->data_size)) {
414 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
415 		return -EFAULT;
416 	}
417 
418 	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
419 	return event->header.size;
420 }
421 
afu_read(struct file * file,char __user * buf,size_t count,loff_t * off)422 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
423 			loff_t *off)
424 {
425 	struct cxl_context *ctx = file->private_data;
426 	struct cxl_event_afu_driver_reserved *pl = NULL;
427 	struct cxl_event event;
428 	unsigned long flags;
429 	int rc;
430 	DEFINE_WAIT(wait);
431 
432 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
433 		return -EIO;
434 
435 	if (count < CXL_READ_MIN_SIZE)
436 		return -EINVAL;
437 
438 	spin_lock_irqsave(&ctx->lock, flags);
439 
440 	for (;;) {
441 		prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
442 		if (ctx_event_pending(ctx) || (ctx->status == CLOSED))
443 			break;
444 
445 		if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
446 			rc = -EIO;
447 			goto out;
448 		}
449 
450 		if (file->f_flags & O_NONBLOCK) {
451 			rc = -EAGAIN;
452 			goto out;
453 		}
454 
455 		if (signal_pending(current)) {
456 			rc = -ERESTARTSYS;
457 			goto out;
458 		}
459 
460 		spin_unlock_irqrestore(&ctx->lock, flags);
461 		pr_devel("afu_read going to sleep...\n");
462 		schedule();
463 		pr_devel("afu_read woken up\n");
464 		spin_lock_irqsave(&ctx->lock, flags);
465 	}
466 
467 	finish_wait(&ctx->wq, &wait);
468 
469 	memset(&event, 0, sizeof(event));
470 	event.header.process_element = ctx->pe;
471 	event.header.size = sizeof(struct cxl_event_header);
472 	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
473 		pr_devel("afu_read delivering AFU driver specific event\n");
474 		pl = ctx->afu_driver_ops->fetch_event(ctx);
475 		atomic_dec(&ctx->afu_driver_events);
476 		event.header.type = CXL_EVENT_AFU_DRIVER;
477 	} else if (ctx->pending_irq) {
478 		pr_devel("afu_read delivering AFU interrupt\n");
479 		event.header.size += sizeof(struct cxl_event_afu_interrupt);
480 		event.header.type = CXL_EVENT_AFU_INTERRUPT;
481 		event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
482 		clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
483 		if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
484 			ctx->pending_irq = false;
485 	} else if (ctx->pending_fault) {
486 		pr_devel("afu_read delivering data storage fault\n");
487 		event.header.size += sizeof(struct cxl_event_data_storage);
488 		event.header.type = CXL_EVENT_DATA_STORAGE;
489 		event.fault.addr = ctx->fault_addr;
490 		event.fault.dsisr = ctx->fault_dsisr;
491 		ctx->pending_fault = false;
492 	} else if (ctx->pending_afu_err) {
493 		pr_devel("afu_read delivering afu error\n");
494 		event.header.size += sizeof(struct cxl_event_afu_error);
495 		event.header.type = CXL_EVENT_AFU_ERROR;
496 		event.afu_error.error = ctx->afu_err;
497 		ctx->pending_afu_err = false;
498 	} else if (ctx->status == CLOSED) {
499 		pr_devel("afu_read fatal error\n");
500 		spin_unlock_irqrestore(&ctx->lock, flags);
501 		return -EIO;
502 	} else
503 		WARN(1, "afu_read must be buggy\n");
504 
505 	spin_unlock_irqrestore(&ctx->lock, flags);
506 
507 	if (event.header.type == CXL_EVENT_AFU_DRIVER)
508 		return afu_driver_event_copy(ctx, buf, &event, pl);
509 
510 	if (copy_to_user(buf, &event, event.header.size))
511 		return -EFAULT;
512 	return event.header.size;
513 
514 out:
515 	finish_wait(&ctx->wq, &wait);
516 	spin_unlock_irqrestore(&ctx->lock, flags);
517 	return rc;
518 }
519 
520 /*
521  * Note: if this is updated, we need to update api.c to patch the new ones in
522  * too
523  */
524 const struct file_operations afu_fops = {
525 	.owner		= THIS_MODULE,
526 	.open           = afu_open,
527 	.poll		= afu_poll,
528 	.read		= afu_read,
529 	.release        = afu_release,
530 	.unlocked_ioctl = afu_ioctl,
531 	.compat_ioctl   = afu_compat_ioctl,
532 	.mmap           = afu_mmap,
533 };
534 
535 static const struct file_operations afu_master_fops = {
536 	.owner		= THIS_MODULE,
537 	.open           = afu_master_open,
538 	.poll		= afu_poll,
539 	.read		= afu_read,
540 	.release        = afu_release,
541 	.unlocked_ioctl = afu_ioctl,
542 	.compat_ioctl   = afu_compat_ioctl,
543 	.mmap           = afu_mmap,
544 };
545 
546 
cxl_devnode(const struct device * dev,umode_t * mode)547 static char *cxl_devnode(const struct device *dev, umode_t *mode)
548 {
549 	if (cpu_has_feature(CPU_FTR_HVMODE) &&
550 	    CXL_DEVT_IS_CARD(dev->devt)) {
551 		/*
552 		 * These minor numbers will eventually be used to program the
553 		 * PSL and AFUs once we have dynamic reprogramming support
554 		 */
555 		return NULL;
556 	}
557 	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
558 }
559 
560 static const struct class cxl_class = {
561 	.name =		"cxl",
562 	.devnode =	cxl_devnode,
563 };
564 
cxl_add_chardev(struct cxl_afu * afu,dev_t devt,struct cdev * cdev,struct device ** chardev,char * postfix,char * desc,const struct file_operations * fops)565 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
566 			   struct device **chardev, char *postfix, char *desc,
567 			   const struct file_operations *fops)
568 {
569 	struct device *dev;
570 	int rc;
571 
572 	cdev_init(cdev, fops);
573 	rc = cdev_add(cdev, devt, 1);
574 	if (rc) {
575 		dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
576 		return rc;
577 	}
578 
579 	dev = device_create(&cxl_class, &afu->dev, devt, afu,
580 			"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
581 	if (IS_ERR(dev)) {
582 		rc = PTR_ERR(dev);
583 		dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
584 		goto err;
585 	}
586 
587 	*chardev = dev;
588 
589 	return 0;
590 err:
591 	cdev_del(cdev);
592 	return rc;
593 }
594 
cxl_chardev_d_afu_add(struct cxl_afu * afu)595 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
596 {
597 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
598 			       &afu->chardev_d, "d", "dedicated",
599 			       &afu_master_fops); /* Uses master fops */
600 }
601 
cxl_chardev_m_afu_add(struct cxl_afu * afu)602 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
603 {
604 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
605 			       &afu->chardev_m, "m", "master",
606 			       &afu_master_fops);
607 }
608 
cxl_chardev_s_afu_add(struct cxl_afu * afu)609 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
610 {
611 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
612 			       &afu->chardev_s, "s", "shared",
613 			       &afu_fops);
614 }
615 
cxl_chardev_afu_remove(struct cxl_afu * afu)616 void cxl_chardev_afu_remove(struct cxl_afu *afu)
617 {
618 	if (afu->chardev_d) {
619 		cdev_del(&afu->afu_cdev_d);
620 		device_unregister(afu->chardev_d);
621 		afu->chardev_d = NULL;
622 	}
623 	if (afu->chardev_m) {
624 		cdev_del(&afu->afu_cdev_m);
625 		device_unregister(afu->chardev_m);
626 		afu->chardev_m = NULL;
627 	}
628 	if (afu->chardev_s) {
629 		cdev_del(&afu->afu_cdev_s);
630 		device_unregister(afu->chardev_s);
631 		afu->chardev_s = NULL;
632 	}
633 }
634 
cxl_register_afu(struct cxl_afu * afu)635 int cxl_register_afu(struct cxl_afu *afu)
636 {
637 	afu->dev.class = &cxl_class;
638 
639 	return device_register(&afu->dev);
640 }
641 
cxl_register_adapter(struct cxl * adapter)642 int cxl_register_adapter(struct cxl *adapter)
643 {
644 	adapter->dev.class = &cxl_class;
645 
646 	/*
647 	 * Future: When we support dynamically reprogramming the PSL & AFU we
648 	 * will expose the interface to do that via a chardev:
649 	 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
650 	 */
651 
652 	return device_register(&adapter->dev);
653 }
654 
cxl_get_dev(void)655 dev_t cxl_get_dev(void)
656 {
657 	return cxl_dev;
658 }
659 
cxl_file_init(void)660 int __init cxl_file_init(void)
661 {
662 	int rc;
663 
664 	/*
665 	 * If these change we really need to update API.  Either change some
666 	 * flags or update API version number CXL_API_VERSION.
667 	 */
668 	BUILD_BUG_ON(CXL_API_VERSION != 3);
669 	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
670 	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
671 	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
672 	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
673 	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
674 
675 	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
676 		pr_err("Unable to allocate CXL major number: %i\n", rc);
677 		return rc;
678 	}
679 
680 	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
681 
682 	rc = class_register(&cxl_class);
683 	if (rc) {
684 		pr_err("Unable to create CXL class\n");
685 		goto err;
686 	}
687 
688 	return 0;
689 
690 err:
691 	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
692 	return rc;
693 }
694 
cxl_file_exit(void)695 void cxl_file_exit(void)
696 {
697 	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
698 	class_unregister(&cxl_class);
699 }
700