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 
41 static struct class *cxl_class;
42 
__afu_open(struct inode * inode,struct file * file,bool master)43 static int __afu_open(struct inode *inode, struct file *file, bool master)
44 {
45 	struct cxl *adapter;
46 	struct cxl_afu *afu;
47 	struct cxl_context *ctx;
48 	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
49 	int slice = CXL_DEVT_AFU(inode->i_rdev);
50 	int rc = -ENODEV;
51 
52 	pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
53 
54 	if (!(adapter = get_cxl_adapter(adapter_num)))
55 		return -ENODEV;
56 
57 	if (slice > adapter->slices)
58 		goto err_put_adapter;
59 
60 	spin_lock(&adapter->afu_list_lock);
61 	if (!(afu = adapter->afu[slice])) {
62 		spin_unlock(&adapter->afu_list_lock);
63 		goto err_put_adapter;
64 	}
65 
66 	/*
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
69 	 * we return.
70 	 */
71 	cxl_afu_get(afu);
72 	spin_unlock(&adapter->afu_list_lock);
73 
74 	if (!afu->current_mode)
75 		goto err_put_afu;
76 
77 	if (!cxl_ops->link_ok(adapter, afu)) {
78 		rc = -EIO;
79 		goto err_put_afu;
80 	}
81 
82 	if (!(ctx = cxl_context_alloc())) {
83 		rc = -ENOMEM;
84 		goto err_put_afu;
85 	}
86 
87 	rc = cxl_context_init(ctx, afu, master);
88 	if (rc)
89 		goto err_put_afu;
90 
91 	cxl_context_set_mapping(ctx, inode->i_mapping);
92 
93 	pr_devel("afu_open pe: %i\n", ctx->pe);
94 	file->private_data = ctx;
95 
96 	/* indicate success */
97 	rc = 0;
98 
99 err_put_afu:
100 	/* release the ref taken earlier */
101 	cxl_afu_put(afu);
102 err_put_adapter:
103 	put_device(&adapter->dev);
104 	return rc;
105 }
106 
afu_open(struct inode * inode,struct file * file)107 int afu_open(struct inode *inode, struct file *file)
108 {
109 	return __afu_open(inode, file, false);
110 }
111 
afu_master_open(struct inode * inode,struct file * file)112 static int afu_master_open(struct inode *inode, struct file *file)
113 {
114 	return __afu_open(inode, file, true);
115 }
116 
afu_release(struct inode * inode,struct file * file)117 int afu_release(struct inode *inode, struct file *file)
118 {
119 	struct cxl_context *ctx = file->private_data;
120 
121 	pr_devel("%s: closing cxl file descriptor. pe: %i\n",
122 		 __func__, ctx->pe);
123 	cxl_context_detach(ctx);
124 
125 
126 	/*
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()
129 	 */
130 	if (!ctx->kernelapi) {
131 		mutex_lock(&ctx->mapping_lock);
132 		ctx->mapping = NULL;
133 		mutex_unlock(&ctx->mapping_lock);
134 	}
135 
136 	/*
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
140 	 * sstp and context.
141 	 */
142 	cxl_context_free(ctx);
143 
144 	return 0;
145 }
146 
afu_ioctl_start_work(struct cxl_context * ctx,struct cxl_ioctl_start_work __user * uwork)147 static long afu_ioctl_start_work(struct cxl_context *ctx,
148 				 struct cxl_ioctl_start_work __user *uwork)
149 {
150 	struct cxl_ioctl_start_work work;
151 	u64 amr = 0;
152 	int rc;
153 
154 	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
155 
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)))
159 		return -EFAULT;
160 
161 	mutex_lock(&ctx->status_mutex);
162 	if (ctx->status != OPENED) {
163 		rc = -EIO;
164 		goto out;
165 	}
166 
167 	/*
168 	 * if any of the reserved fields are set or any of the unused
169 	 * flags are set it's invalid
170 	 */
171 	if (work.reserved1 || work.reserved2 || work.reserved3 ||
172 	    work.reserved4 || work.reserved5 ||
173 	    (work.flags & ~CXL_START_WORK_ALL)) {
174 		rc = -EINVAL;
175 		goto out;
176 	}
177 
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)) {
182 		rc =  -EINVAL;
183 		goto out;
184 	}
185 
186 	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
187 		goto out;
188 
189 	if (work.flags & CXL_START_WORK_AMR)
190 		amr = work.amr & mfspr(SPRN_UAMOR);
191 
192 	if (work.flags & CXL_START_WORK_TID)
193 		ctx->assign_tidr = true;
194 
195 	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
196 
197 	/*
198 	 * Increment the mapped context count for adapter. This also checks
199 	 * if adapter_context_lock is taken.
200 	 */
201 	rc = cxl_adapter_context_get(ctx->afu->adapter);
202 	if (rc) {
203 		afu_release_irqs(ctx, ctx);
204 		goto out;
205 	}
206 
207 	/*
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.
215 	 */
216 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
217 
218 	/* acquire a reference to the task's mm */
219 	ctx->mm = get_task_mm(current);
220 
221 	/* ensure this mm_struct can't be freed */
222 	cxl_context_mm_count_get(ctx);
223 
224 	if (ctx->mm) {
225 		/* decrement the use count from above */
226 		mmput(ctx->mm);
227 		/* make TLBIs for this context global */
228 		mm_context_add_copro(ctx->mm);
229 	}
230 
231 	/*
232 	 * Increment driver use count. Enables global TLBIs for hash
233 	 * and callbacks to handle the segment table
234 	 */
235 	cxl_ctx_get();
236 
237 	/*
238 	 * A barrier is needed to make sure all TLBIs are global
239 	 * before we attach and the context starts being used by the
240 	 * adapter.
241 	 *
242 	 * Needed after mm_context_add_copro() for radix and
243 	 * cxl_ctx_get() for hash/p8.
244 	 *
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().
248 	 */
249 	smp_mb();
250 
251 	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
252 
253 	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
254 							amr))) {
255 		afu_release_irqs(ctx, ctx);
256 		cxl_adapter_context_put(ctx->afu->adapter);
257 		put_pid(ctx->pid);
258 		ctx->pid = NULL;
259 		cxl_ctx_put();
260 		cxl_context_mm_count_put(ctx);
261 		if (ctx->mm)
262 			mm_context_remove_copro(ctx->mm);
263 		goto out;
264 	}
265 
266 	rc = 0;
267 	if (work.flags & CXL_START_WORK_TID) {
268 		work.tid = ctx->tidr;
269 		if (copy_to_user(uwork, &work, sizeof(work)))
270 			rc = -EFAULT;
271 	}
272 
273 	ctx->status = STARTED;
274 
275 out:
276 	mutex_unlock(&ctx->status_mutex);
277 	return rc;
278 }
279 
afu_ioctl_process_element(struct cxl_context * ctx,int __user * upe)280 static long afu_ioctl_process_element(struct cxl_context *ctx,
281 				      int __user *upe)
282 {
283 	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
284 
285 	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
286 		return -EFAULT;
287 
288 	return 0;
289 }
290 
afu_ioctl_get_afu_id(struct cxl_context * ctx,struct cxl_afu_id __user * upafuid)291 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
292 				 struct cxl_afu_id __user *upafuid)
293 {
294 	struct cxl_afu_id afuid = { 0 };
295 
296 	afuid.card_id = ctx->afu->adapter->adapter_num;
297 	afuid.afu_offset = ctx->afu->slice;
298 	afuid.afu_mode = ctx->afu->current_mode;
299 
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;
303 
304 	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
305 		return -EFAULT;
306 
307 	return 0;
308 }
309 
afu_ioctl(struct file * file,unsigned int cmd,unsigned long arg)310 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
311 {
312 	struct cxl_context *ctx = file->private_data;
313 
314 	if (ctx->status == CLOSED)
315 		return -EIO;
316 
317 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
318 		return -EIO;
319 
320 	pr_devel("afu_ioctl\n");
321 	switch (cmd) {
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 *)
328 					    arg);
329 	}
330 	return -EINVAL;
331 }
332 
afu_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)333 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
334 			     unsigned long arg)
335 {
336 	return afu_ioctl(file, cmd, arg);
337 }
338 
afu_mmap(struct file * file,struct vm_area_struct * vm)339 int afu_mmap(struct file *file, struct vm_area_struct *vm)
340 {
341 	struct cxl_context *ctx = file->private_data;
342 
343 	/* AFU must be started before we can MMIO */
344 	if (ctx->status != STARTED)
345 		return -EIO;
346 
347 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
348 		return -EIO;
349 
350 	return cxl_context_iomap(ctx, vm);
351 }
352 
ctx_event_pending(struct cxl_context * ctx)353 static inline bool ctx_event_pending(struct cxl_context *ctx)
354 {
355 	if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)
356 		return true;
357 
358 	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
359 		return true;
360 
361 	return false;
362 }
363 
afu_poll(struct file * file,struct poll_table_struct * poll)364 __poll_t afu_poll(struct file *file, struct poll_table_struct *poll)
365 {
366 	struct cxl_context *ctx = file->private_data;
367 	__poll_t mask = 0;
368 	unsigned long flags;
369 
370 
371 	poll_wait(file, &ctx->wq, poll);
372 
373 	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
374 
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
380 		 */
381 		mask |= EPOLLERR;
382 	spin_unlock_irqrestore(&ctx->lock, flags);
383 
384 	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
385 
386 	return mask;
387 }
388 
afu_driver_event_copy(struct cxl_context * ctx,char __user * buf,struct cxl_event * event,struct cxl_event_afu_driver_reserved * pl)389 static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
390 				     char __user *buf,
391 				     struct cxl_event *event,
392 				     struct cxl_event_afu_driver_reserved *pl)
393 {
394 	/* Check event */
395 	if (!pl) {
396 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
397 		return -EFAULT;
398 	}
399 
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);
404 		return -EFAULT;
405 	}
406 
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);
410 		return -EFAULT;
411 	}
412 
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);
417 		return -EFAULT;
418 	}
419 
420 	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
421 	return event->header.size;
422 }
423 
afu_read(struct file * file,char __user * buf,size_t count,loff_t * off)424 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
425 			loff_t *off)
426 {
427 	struct cxl_context *ctx = file->private_data;
428 	struct cxl_event_afu_driver_reserved *pl = NULL;
429 	struct cxl_event event;
430 	unsigned long flags;
431 	int rc;
432 	DEFINE_WAIT(wait);
433 
434 	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
435 		return -EIO;
436 
437 	if (count < CXL_READ_MIN_SIZE)
438 		return -EINVAL;
439 
440 	spin_lock_irqsave(&ctx->lock, flags);
441 
442 	for (;;) {
443 		prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
444 		if (ctx_event_pending(ctx) || (ctx->status == CLOSED))
445 			break;
446 
447 		if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
448 			rc = -EIO;
449 			goto out;
450 		}
451 
452 		if (file->f_flags & O_NONBLOCK) {
453 			rc = -EAGAIN;
454 			goto out;
455 		}
456 
457 		if (signal_pending(current)) {
458 			rc = -ERESTARTSYS;
459 			goto out;
460 		}
461 
462 		spin_unlock_irqrestore(&ctx->lock, flags);
463 		pr_devel("afu_read going to sleep...\n");
464 		schedule();
465 		pr_devel("afu_read woken up\n");
466 		spin_lock_irqsave(&ctx->lock, flags);
467 	}
468 
469 	finish_wait(&ctx->wq, &wait);
470 
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);
503 		return -EIO;
504 	} else
505 		WARN(1, "afu_read must be buggy\n");
506 
507 	spin_unlock_irqrestore(&ctx->lock, flags);
508 
509 	if (event.header.type == CXL_EVENT_AFU_DRIVER)
510 		return afu_driver_event_copy(ctx, buf, &event, pl);
511 
512 	if (copy_to_user(buf, &event, event.header.size))
513 		return -EFAULT;
514 	return event.header.size;
515 
516 out:
517 	finish_wait(&ctx->wq, &wait);
518 	spin_unlock_irqrestore(&ctx->lock, flags);
519 	return rc;
520 }
521 
522 /*
523  * Note: if this is updated, we need to update api.c to patch the new ones in
524  * too
525  */
526 const struct file_operations afu_fops = {
527 	.owner		= THIS_MODULE,
528 	.open           = afu_open,
529 	.poll		= afu_poll,
530 	.read		= afu_read,
531 	.release        = afu_release,
532 	.unlocked_ioctl = afu_ioctl,
533 	.compat_ioctl   = afu_compat_ioctl,
534 	.mmap           = afu_mmap,
535 };
536 
537 static const struct file_operations afu_master_fops = {
538 	.owner		= THIS_MODULE,
539 	.open           = afu_master_open,
540 	.poll		= afu_poll,
541 	.read		= afu_read,
542 	.release        = afu_release,
543 	.unlocked_ioctl = afu_ioctl,
544 	.compat_ioctl   = afu_compat_ioctl,
545 	.mmap           = afu_mmap,
546 };
547 
548 
cxl_devnode(struct device * dev,umode_t * mode)549 static char *cxl_devnode(struct device *dev, umode_t *mode)
550 {
551 	if (cpu_has_feature(CPU_FTR_HVMODE) &&
552 	    CXL_DEVT_IS_CARD(dev->devt)) {
553 		/*
554 		 * These minor numbers will eventually be used to program the
555 		 * PSL and AFUs once we have dynamic reprogramming support
556 		 */
557 		return NULL;
558 	}
559 	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
560 }
561 
562 extern struct class *cxl_class;
563 
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)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)
567 {
568 	struct device *dev;
569 	int rc;
570 
571 	cdev_init(cdev, fops);
572 	rc = cdev_add(cdev, devt, 1);
573 	if (rc) {
574 		dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
575 		return rc;
576 	}
577 
578 	dev = device_create(cxl_class, &afu->dev, devt, afu,
579 			"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
580 	if (IS_ERR(dev)) {
581 		rc = PTR_ERR(dev);
582 		dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
583 		goto err;
584 	}
585 
586 	*chardev = dev;
587 
588 	return 0;
589 err:
590 	cdev_del(cdev);
591 	return rc;
592 }
593 
cxl_chardev_d_afu_add(struct cxl_afu * afu)594 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
595 {
596 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
597 			       &afu->chardev_d, "d", "dedicated",
598 			       &afu_master_fops); /* Uses master fops */
599 }
600 
cxl_chardev_m_afu_add(struct cxl_afu * afu)601 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
602 {
603 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
604 			       &afu->chardev_m, "m", "master",
605 			       &afu_master_fops);
606 }
607 
cxl_chardev_s_afu_add(struct cxl_afu * afu)608 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
609 {
610 	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
611 			       &afu->chardev_s, "s", "shared",
612 			       &afu_fops);
613 }
614 
cxl_chardev_afu_remove(struct cxl_afu * afu)615 void cxl_chardev_afu_remove(struct cxl_afu *afu)
616 {
617 	if (afu->chardev_d) {
618 		cdev_del(&afu->afu_cdev_d);
619 		device_unregister(afu->chardev_d);
620 		afu->chardev_d = NULL;
621 	}
622 	if (afu->chardev_m) {
623 		cdev_del(&afu->afu_cdev_m);
624 		device_unregister(afu->chardev_m);
625 		afu->chardev_m = NULL;
626 	}
627 	if (afu->chardev_s) {
628 		cdev_del(&afu->afu_cdev_s);
629 		device_unregister(afu->chardev_s);
630 		afu->chardev_s = NULL;
631 	}
632 }
633 
cxl_register_afu(struct cxl_afu * afu)634 int cxl_register_afu(struct cxl_afu *afu)
635 {
636 	afu->dev.class = cxl_class;
637 
638 	return device_register(&afu->dev);
639 }
640 
cxl_register_adapter(struct cxl * adapter)641 int cxl_register_adapter(struct cxl *adapter)
642 {
643 	adapter->dev.class = cxl_class;
644 
645 	/*
646 	 * Future: When we support dynamically reprogramming the PSL & AFU we
647 	 * will expose the interface to do that via a chardev:
648 	 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
649 	 */
650 
651 	return device_register(&adapter->dev);
652 }
653 
cxl_get_dev(void)654 dev_t cxl_get_dev(void)
655 {
656 	return cxl_dev;
657 }
658 
cxl_file_init(void)659 int __init cxl_file_init(void)
660 {
661 	int rc;
662 
663 	/*
664 	 * If these change we really need to update API.  Either change some
665 	 * flags or update API version number CXL_API_VERSION.
666 	 */
667 	BUILD_BUG_ON(CXL_API_VERSION != 3);
668 	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
669 	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
670 	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
671 	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
672 	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
673 
674 	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
675 		pr_err("Unable to allocate CXL major number: %i\n", rc);
676 		return rc;
677 	}
678 
679 	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
680 
681 	cxl_class = class_create(THIS_MODULE, "cxl");
682 	if (IS_ERR(cxl_class)) {
683 		pr_err("Unable to create CXL class\n");
684 		rc = PTR_ERR(cxl_class);
685 		goto err;
686 	}
687 	cxl_class->devnode = cxl_devnode;
688 
689 	return 0;
690 
691 err:
692 	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
693 	return rc;
694 }
695 
cxl_file_exit(void)696 void cxl_file_exit(void)
697 {
698 	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
699 	class_destroy(cxl_class);
700 }
701