2 * Copyright 2014 IBM Corp.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/spinlock.h>
11 #include <linux/module.h>
12 #include <linux/export.h>
13 #include <linux/kernel.h>
14 #include <linux/bitmap.h>
15 #include <linux/sched.h>
16 #include <linux/poll.h>
17 #include <linux/pid.h>
20 #include <linux/slab.h>
21 #include <asm/cputable.h>
22 #include <asm/current.h>
23 #include <asm/copro.h>
28 #define CXL_NUM_MINORS 256 /* Total to reserve */
29 #define CXL_DEV_MINORS 13 /* 1 control + 4 AFUs * 3 (dedicated/master/shared) */
31 #define CXL_CARD_MINOR(adapter) (adapter->adapter_num * CXL_DEV_MINORS)
32 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
33 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
34 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
35 #define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
36 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
37 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
39 #define CXL_DEVT_ADAPTER(dev) (MINOR(dev) / CXL_DEV_MINORS)
40 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
42 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
46 static struct class *cxl_class;
48 static int __afu_open(struct inode *inode, struct file *file, bool master)
52 struct cxl_context *ctx;
53 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
54 int slice = CXL_DEVT_AFU(inode->i_rdev);
57 pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
59 if (!(adapter = get_cxl_adapter(adapter_num)))
62 if (slice > adapter->slices)
65 spin_lock(&adapter->afu_list_lock);
66 if (!(afu = adapter->afu[slice])) {
67 spin_unlock(&adapter->afu_list_lock);
72 * taking a ref to the afu so that it doesn't go away
73 * for rest of the function. This ref is released before
77 spin_unlock(&adapter->afu_list_lock);
79 if (!afu->current_mode)
82 if (!cxl_adapter_link_ok(adapter)) {
87 if (!(ctx = cxl_context_alloc())) {
92 if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
95 pr_devel("afu_open pe: %i\n", ctx->pe);
96 file->private_data = ctx;
98 /* indicate success */
102 /* release the ref taken earlier */
105 put_device(&adapter->dev);
109 int afu_open(struct inode *inode, struct file *file)
111 return __afu_open(inode, file, false);
114 static int afu_master_open(struct inode *inode, struct file *file)
116 return __afu_open(inode, file, true);
119 int afu_release(struct inode *inode, struct file *file)
121 struct cxl_context *ctx = file->private_data;
123 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
125 cxl_context_detach(ctx);
129 * Delete the context's mapping pointer, unless it's created by the
130 * kernel API, in which case leave it so it can be freed by reclaim_ctx()
132 if (!ctx->kernelapi) {
133 mutex_lock(&ctx->mapping_lock);
135 mutex_unlock(&ctx->mapping_lock);
139 * At this this point all bottom halfs have finished and we should be
140 * getting no more IRQs from the hardware for this context. Once it's
141 * removed from the IDR (and RCU synchronised) it's safe to free the
144 cxl_context_free(ctx);
149 static long afu_ioctl_start_work(struct cxl_context *ctx,
150 struct cxl_ioctl_start_work __user *uwork)
152 struct cxl_ioctl_start_work work;
156 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
158 /* Do this outside the status_mutex to avoid a circular dependency with
159 * the locking in cxl_mmap_fault() */
160 if (copy_from_user(&work, uwork, sizeof(work)))
163 mutex_lock(&ctx->status_mutex);
164 if (ctx->status != OPENED) {
170 * if any of the reserved fields are set or any of the unused
171 * flags are set it's invalid
173 if (work.reserved1 || work.reserved2 || work.reserved3 ||
174 work.reserved4 || work.reserved5 || work.reserved6 ||
175 (work.flags & ~CXL_START_WORK_ALL)) {
180 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
181 work.num_interrupts = ctx->afu->pp_irqs;
182 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
183 (work.num_interrupts > ctx->afu->irqs_max)) {
187 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
190 if (work.flags & CXL_START_WORK_AMR)
191 amr = work.amr & mfspr(SPRN_UAMOR);
193 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
196 * We grab the PID here and not in the file open to allow for the case
197 * where a process (master, some daemon, etc) has opened the chardev on
198 * behalf of another process, so the AFU's mm gets bound to the process
199 * that performs this ioctl and not the process that opened the file.
200 * Also we grab the PID of the group leader so that if the task that
201 * has performed the attach operation exits the mm context of the
202 * process is still accessible.
204 ctx->pid = get_task_pid(current, PIDTYPE_PID);
205 ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
208 * Increment driver use count. Enables global TLBIs for hash
209 * and callbacks to handle the segment table
213 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
215 if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor,
217 afu_release_irqs(ctx, ctx);
222 ctx->status = STARTED;
225 mutex_unlock(&ctx->status_mutex);
228 static long afu_ioctl_process_element(struct cxl_context *ctx,
231 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
233 if (copy_to_user(upe, &ctx->pe, sizeof(__u32)))
239 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
240 struct cxl_afu_id __user *upafuid)
242 struct cxl_afu_id afuid = { 0 };
244 afuid.card_id = ctx->afu->adapter->adapter_num;
245 afuid.afu_offset = ctx->afu->slice;
246 afuid.afu_mode = ctx->afu->current_mode;
248 /* set the flag bit in case the afu is a slave */
249 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
250 afuid.flags |= CXL_AFUID_FLAG_SLAVE;
252 if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
258 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
260 struct cxl_context *ctx = file->private_data;
262 if (ctx->status == CLOSED)
265 if (!cxl_adapter_link_ok(ctx->afu->adapter))
268 pr_devel("afu_ioctl\n");
270 case CXL_IOCTL_START_WORK:
271 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
272 case CXL_IOCTL_GET_PROCESS_ELEMENT:
273 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
274 case CXL_IOCTL_GET_AFU_ID:
275 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
281 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
284 return afu_ioctl(file, cmd, arg);
287 int afu_mmap(struct file *file, struct vm_area_struct *vm)
289 struct cxl_context *ctx = file->private_data;
291 /* AFU must be started before we can MMIO */
292 if (ctx->status != STARTED)
295 if (!cxl_adapter_link_ok(ctx->afu->adapter))
298 return cxl_context_iomap(ctx, vm);
301 unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
303 struct cxl_context *ctx = file->private_data;
308 poll_wait(file, &ctx->wq, poll);
310 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
312 spin_lock_irqsave(&ctx->lock, flags);
313 if (ctx->pending_irq || ctx->pending_fault ||
314 ctx->pending_afu_err)
315 mask |= POLLIN | POLLRDNORM;
316 else if (ctx->status == CLOSED)
317 /* Only error on closed when there are no futher events pending
320 spin_unlock_irqrestore(&ctx->lock, flags);
322 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
327 static inline int ctx_event_pending(struct cxl_context *ctx)
329 return (ctx->pending_irq || ctx->pending_fault ||
330 ctx->pending_afu_err || (ctx->status == CLOSED));
333 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
336 struct cxl_context *ctx = file->private_data;
337 struct cxl_event event;
342 if (!cxl_adapter_link_ok(ctx->afu->adapter))
345 if (count < CXL_READ_MIN_SIZE)
348 spin_lock_irqsave(&ctx->lock, flags);
351 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
352 if (ctx_event_pending(ctx))
355 if (!cxl_adapter_link_ok(ctx->afu->adapter)) {
360 if (file->f_flags & O_NONBLOCK) {
365 if (signal_pending(current)) {
370 spin_unlock_irqrestore(&ctx->lock, flags);
371 pr_devel("afu_read going to sleep...\n");
373 pr_devel("afu_read woken up\n");
374 spin_lock_irqsave(&ctx->lock, flags);
377 finish_wait(&ctx->wq, &wait);
379 memset(&event, 0, sizeof(event));
380 event.header.process_element = ctx->pe;
381 event.header.size = sizeof(struct cxl_event_header);
382 if (ctx->pending_irq) {
383 pr_devel("afu_read delivering AFU interrupt\n");
384 event.header.size += sizeof(struct cxl_event_afu_interrupt);
385 event.header.type = CXL_EVENT_AFU_INTERRUPT;
386 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
387 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
388 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
389 ctx->pending_irq = false;
390 } else if (ctx->pending_fault) {
391 pr_devel("afu_read delivering data storage fault\n");
392 event.header.size += sizeof(struct cxl_event_data_storage);
393 event.header.type = CXL_EVENT_DATA_STORAGE;
394 event.fault.addr = ctx->fault_addr;
395 event.fault.dsisr = ctx->fault_dsisr;
396 ctx->pending_fault = false;
397 } else if (ctx->pending_afu_err) {
398 pr_devel("afu_read delivering afu error\n");
399 event.header.size += sizeof(struct cxl_event_afu_error);
400 event.header.type = CXL_EVENT_AFU_ERROR;
401 event.afu_error.error = ctx->afu_err;
402 ctx->pending_afu_err = false;
403 } else if (ctx->status == CLOSED) {
404 pr_devel("afu_read fatal error\n");
405 spin_unlock_irqrestore(&ctx->lock, flags);
408 WARN(1, "afu_read must be buggy\n");
410 spin_unlock_irqrestore(&ctx->lock, flags);
412 if (copy_to_user(buf, &event, event.header.size))
414 return event.header.size;
417 finish_wait(&ctx->wq, &wait);
418 spin_unlock_irqrestore(&ctx->lock, flags);
423 * Note: if this is updated, we need to update api.c to patch the new ones in
426 const struct file_operations afu_fops = {
427 .owner = THIS_MODULE,
431 .release = afu_release,
432 .unlocked_ioctl = afu_ioctl,
433 .compat_ioctl = afu_compat_ioctl,
437 static const struct file_operations afu_master_fops = {
438 .owner = THIS_MODULE,
439 .open = afu_master_open,
442 .release = afu_release,
443 .unlocked_ioctl = afu_ioctl,
444 .compat_ioctl = afu_compat_ioctl,
449 static char *cxl_devnode(struct device *dev, umode_t *mode)
451 if (CXL_DEVT_IS_CARD(dev->devt)) {
453 * These minor numbers will eventually be used to program the
454 * PSL and AFUs once we have dynamic reprogramming support
458 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
461 extern struct class *cxl_class;
463 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
464 struct device **chardev, char *postfix, char *desc,
465 const struct file_operations *fops)
470 cdev_init(cdev, fops);
471 if ((rc = cdev_add(cdev, devt, 1))) {
472 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
476 dev = device_create(cxl_class, &afu->dev, devt, afu,
477 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
479 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
492 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
494 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
495 &afu->chardev_d, "d", "dedicated",
496 &afu_master_fops); /* Uses master fops */
499 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
501 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
502 &afu->chardev_m, "m", "master",
506 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
508 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
509 &afu->chardev_s, "s", "shared",
513 void cxl_chardev_afu_remove(struct cxl_afu *afu)
515 if (afu->chardev_d) {
516 cdev_del(&afu->afu_cdev_d);
517 device_unregister(afu->chardev_d);
518 afu->chardev_d = NULL;
520 if (afu->chardev_m) {
521 cdev_del(&afu->afu_cdev_m);
522 device_unregister(afu->chardev_m);
523 afu->chardev_m = NULL;
525 if (afu->chardev_s) {
526 cdev_del(&afu->afu_cdev_s);
527 device_unregister(afu->chardev_s);
528 afu->chardev_s = NULL;
532 int cxl_register_afu(struct cxl_afu *afu)
534 afu->dev.class = cxl_class;
536 return device_register(&afu->dev);
539 int cxl_register_adapter(struct cxl *adapter)
541 adapter->dev.class = cxl_class;
544 * Future: When we support dynamically reprogramming the PSL & AFU we
545 * will expose the interface to do that via a chardev:
546 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
549 return device_register(&adapter->dev);
552 int __init cxl_file_init(void)
557 * If these change we really need to update API. Either change some
558 * flags or update API version number CXL_API_VERSION.
560 BUILD_BUG_ON(CXL_API_VERSION != 2);
561 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
562 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
563 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
564 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
565 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
567 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
568 pr_err("Unable to allocate CXL major number: %i\n", rc);
572 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
574 cxl_class = class_create(THIS_MODULE, "cxl");
575 if (IS_ERR(cxl_class)) {
576 pr_err("Unable to create CXL class\n");
577 rc = PTR_ERR(cxl_class);
580 cxl_class->devnode = cxl_devnode;
585 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
589 void cxl_file_exit(void)
591 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
592 class_destroy(cxl_class);