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);
70 get_device(&afu->dev);
71 spin_unlock(&adapter->afu_list_lock);
73 if (!afu->current_mode)
76 if (!cxl_adapter_link_ok(adapter)) {
81 if (!(ctx = cxl_context_alloc())) {
86 if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
89 pr_devel("afu_open pe: %i\n", ctx->pe);
90 file->private_data = ctx;
93 /* Our ref on the AFU will now hold the adapter */
94 put_device(&adapter->dev);
99 put_device(&afu->dev);
101 put_device(&adapter->dev);
105 int afu_open(struct inode *inode, struct file *file)
107 return __afu_open(inode, file, false);
110 static int afu_master_open(struct inode *inode, struct file *file)
112 return __afu_open(inode, file, true);
115 int afu_release(struct inode *inode, struct file *file)
117 struct cxl_context *ctx = file->private_data;
119 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
121 cxl_context_detach(ctx);
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()
128 if (!ctx->kernelapi) {
129 mutex_lock(&ctx->mapping_lock);
131 mutex_unlock(&ctx->mapping_lock);
134 put_device(&ctx->afu->dev);
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,
159 sizeof(struct cxl_ioctl_start_work))) {
164 mutex_lock(&ctx->status_mutex);
165 if (ctx->status != OPENED) {
171 * if any of the reserved fields are set or any of the unused
172 * flags are set it's invalid
174 if (work.reserved1 || work.reserved2 || work.reserved3 ||
175 work.reserved4 || work.reserved5 || work.reserved6 ||
176 (work.flags & ~CXL_START_WORK_ALL)) {
181 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
182 work.num_interrupts = ctx->afu->pp_irqs;
183 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
184 (work.num_interrupts > ctx->afu->irqs_max)) {
188 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
191 if (work.flags & CXL_START_WORK_AMR)
192 amr = work.amr & mfspr(SPRN_UAMOR);
194 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
197 * We grab the PID here and not in the file open to allow for the case
198 * where a process (master, some daemon, etc) has opened the chardev on
199 * behalf of another process, so the AFU's mm gets bound to the process
200 * that performs this ioctl and not the process that opened the file.
202 ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
204 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
206 if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor,
208 afu_release_irqs(ctx, ctx);
212 ctx->status = STARTED;
215 mutex_unlock(&ctx->status_mutex);
218 static long afu_ioctl_process_element(struct cxl_context *ctx,
221 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
223 if (copy_to_user(upe, &ctx->pe, sizeof(__u32)))
229 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
230 struct cxl_afu_id __user *upafuid)
232 struct cxl_afu_id afuid = { 0 };
234 afuid.card_id = ctx->afu->adapter->adapter_num;
235 afuid.afu_offset = ctx->afu->slice;
236 afuid.afu_mode = ctx->afu->current_mode;
238 /* set the flag bit in case the afu is a slave */
239 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
240 afuid.flags |= CXL_AFUID_FLAG_SLAVE;
242 if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
248 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
250 struct cxl_context *ctx = file->private_data;
252 if (ctx->status == CLOSED)
255 if (!cxl_adapter_link_ok(ctx->afu->adapter))
258 pr_devel("afu_ioctl\n");
260 case CXL_IOCTL_START_WORK:
261 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
262 case CXL_IOCTL_GET_PROCESS_ELEMENT:
263 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
264 case CXL_IOCTL_GET_AFU_ID:
265 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
271 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
274 return afu_ioctl(file, cmd, arg);
277 int afu_mmap(struct file *file, struct vm_area_struct *vm)
279 struct cxl_context *ctx = file->private_data;
281 /* AFU must be started before we can MMIO */
282 if (ctx->status != STARTED)
285 if (!cxl_adapter_link_ok(ctx->afu->adapter))
288 return cxl_context_iomap(ctx, vm);
291 unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
293 struct cxl_context *ctx = file->private_data;
298 poll_wait(file, &ctx->wq, poll);
300 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
302 spin_lock_irqsave(&ctx->lock, flags);
303 if (ctx->pending_irq || ctx->pending_fault ||
304 ctx->pending_afu_err)
305 mask |= POLLIN | POLLRDNORM;
306 else if (ctx->status == CLOSED)
307 /* Only error on closed when there are no futher events pending
310 spin_unlock_irqrestore(&ctx->lock, flags);
312 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
317 static inline int ctx_event_pending(struct cxl_context *ctx)
319 return (ctx->pending_irq || ctx->pending_fault ||
320 ctx->pending_afu_err || (ctx->status == CLOSED));
323 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
326 struct cxl_context *ctx = file->private_data;
327 struct cxl_event event;
332 if (!cxl_adapter_link_ok(ctx->afu->adapter))
335 if (count < CXL_READ_MIN_SIZE)
338 spin_lock_irqsave(&ctx->lock, flags);
341 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
342 if (ctx_event_pending(ctx))
345 if (!cxl_adapter_link_ok(ctx->afu->adapter)) {
350 if (file->f_flags & O_NONBLOCK) {
355 if (signal_pending(current)) {
360 spin_unlock_irqrestore(&ctx->lock, flags);
361 pr_devel("afu_read going to sleep...\n");
363 pr_devel("afu_read woken up\n");
364 spin_lock_irqsave(&ctx->lock, flags);
367 finish_wait(&ctx->wq, &wait);
369 memset(&event, 0, sizeof(event));
370 event.header.process_element = ctx->pe;
371 event.header.size = sizeof(struct cxl_event_header);
372 if (ctx->pending_irq) {
373 pr_devel("afu_read delivering AFU interrupt\n");
374 event.header.size += sizeof(struct cxl_event_afu_interrupt);
375 event.header.type = CXL_EVENT_AFU_INTERRUPT;
376 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
377 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
378 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
379 ctx->pending_irq = false;
380 } else if (ctx->pending_fault) {
381 pr_devel("afu_read delivering data storage fault\n");
382 event.header.size += sizeof(struct cxl_event_data_storage);
383 event.header.type = CXL_EVENT_DATA_STORAGE;
384 event.fault.addr = ctx->fault_addr;
385 event.fault.dsisr = ctx->fault_dsisr;
386 ctx->pending_fault = false;
387 } else if (ctx->pending_afu_err) {
388 pr_devel("afu_read delivering afu error\n");
389 event.header.size += sizeof(struct cxl_event_afu_error);
390 event.header.type = CXL_EVENT_AFU_ERROR;
391 event.afu_error.error = ctx->afu_err;
392 ctx->pending_afu_err = false;
393 } else if (ctx->status == CLOSED) {
394 pr_devel("afu_read fatal error\n");
395 spin_unlock_irqrestore(&ctx->lock, flags);
398 WARN(1, "afu_read must be buggy\n");
400 spin_unlock_irqrestore(&ctx->lock, flags);
402 if (copy_to_user(buf, &event, event.header.size))
404 return event.header.size;
407 finish_wait(&ctx->wq, &wait);
408 spin_unlock_irqrestore(&ctx->lock, flags);
413 * Note: if this is updated, we need to update api.c to patch the new ones in
416 const struct file_operations afu_fops = {
417 .owner = THIS_MODULE,
421 .release = afu_release,
422 .unlocked_ioctl = afu_ioctl,
423 .compat_ioctl = afu_compat_ioctl,
427 static const struct file_operations afu_master_fops = {
428 .owner = THIS_MODULE,
429 .open = afu_master_open,
432 .release = afu_release,
433 .unlocked_ioctl = afu_ioctl,
434 .compat_ioctl = afu_compat_ioctl,
439 static char *cxl_devnode(struct device *dev, umode_t *mode)
441 if (CXL_DEVT_IS_CARD(dev->devt)) {
443 * These minor numbers will eventually be used to program the
444 * PSL and AFUs once we have dynamic reprogramming support
448 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
451 extern struct class *cxl_class;
453 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
454 struct device **chardev, char *postfix, char *desc,
455 const struct file_operations *fops)
460 cdev_init(cdev, fops);
461 if ((rc = cdev_add(cdev, devt, 1))) {
462 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
466 dev = device_create(cxl_class, &afu->dev, devt, afu,
467 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
469 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
482 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
484 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
485 &afu->chardev_d, "d", "dedicated",
486 &afu_master_fops); /* Uses master fops */
489 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
491 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
492 &afu->chardev_m, "m", "master",
496 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
498 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
499 &afu->chardev_s, "s", "shared",
503 void cxl_chardev_afu_remove(struct cxl_afu *afu)
505 if (afu->chardev_d) {
506 cdev_del(&afu->afu_cdev_d);
507 device_unregister(afu->chardev_d);
508 afu->chardev_d = NULL;
510 if (afu->chardev_m) {
511 cdev_del(&afu->afu_cdev_m);
512 device_unregister(afu->chardev_m);
513 afu->chardev_m = NULL;
515 if (afu->chardev_s) {
516 cdev_del(&afu->afu_cdev_s);
517 device_unregister(afu->chardev_s);
518 afu->chardev_s = NULL;
522 int cxl_register_afu(struct cxl_afu *afu)
524 afu->dev.class = cxl_class;
526 return device_register(&afu->dev);
529 int cxl_register_adapter(struct cxl *adapter)
531 adapter->dev.class = cxl_class;
534 * Future: When we support dynamically reprogramming the PSL & AFU we
535 * will expose the interface to do that via a chardev:
536 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
539 return device_register(&adapter->dev);
542 int __init cxl_file_init(void)
547 * If these change we really need to update API. Either change some
548 * flags or update API version number CXL_API_VERSION.
550 BUILD_BUG_ON(CXL_API_VERSION != 2);
551 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
552 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
553 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
554 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
555 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
557 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
558 pr_err("Unable to allocate CXL major number: %i\n", rc);
562 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
564 cxl_class = class_create(THIS_MODULE, "cxl");
565 if (IS_ERR(cxl_class)) {
566 pr_err("Unable to create CXL class\n");
567 rc = PTR_ERR(cxl_class);
570 cxl_class->devnode = cxl_devnode;
575 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
579 void cxl_file_exit(void)
581 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
582 class_destroy(cxl_class);