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 (!(ctx = cxl_context_alloc())) {
81 if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
84 pr_devel("afu_open pe: %i\n", ctx->pe);
85 file->private_data = ctx;
88 /* Our ref on the AFU will now hold the adapter */
89 put_device(&adapter->dev);
94 put_device(&afu->dev);
96 put_device(&adapter->dev);
99 static int afu_open(struct inode *inode, struct file *file)
101 return __afu_open(inode, file, false);
104 static int afu_master_open(struct inode *inode, struct file *file)
106 return __afu_open(inode, file, true);
109 static int afu_release(struct inode *inode, struct file *file)
111 struct cxl_context *ctx = file->private_data;
113 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
115 cxl_context_detach(ctx);
117 mutex_lock(&ctx->mapping_lock);
119 mutex_unlock(&ctx->mapping_lock);
121 put_device(&ctx->afu->dev);
124 * At this this point all bottom halfs have finished and we should be
125 * getting no more IRQs from the hardware for this context. Once it's
126 * removed from the IDR (and RCU synchronised) it's safe to free the
129 cxl_context_free(ctx);
135 static long afu_ioctl_start_work(struct cxl_context *ctx,
136 struct cxl_ioctl_start_work __user *uwork)
138 struct cxl_ioctl_start_work work;
142 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
144 mutex_lock(&ctx->status_mutex);
145 if (ctx->status != OPENED) {
150 if (copy_from_user(&work, uwork,
151 sizeof(struct cxl_ioctl_start_work))) {
157 * if any of the reserved fields are set or any of the unused
158 * flags are set it's invalid
160 if (work.reserved1 || work.reserved2 || work.reserved3 ||
161 work.reserved4 || work.reserved5 || work.reserved6 ||
162 (work.flags & ~CXL_START_WORK_ALL)) {
167 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
168 work.num_interrupts = ctx->afu->pp_irqs;
169 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
170 (work.num_interrupts > ctx->afu->irqs_max)) {
174 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
177 if (work.flags & CXL_START_WORK_AMR)
178 amr = work.amr & mfspr(SPRN_UAMOR);
181 * We grab the PID here and not in the file open to allow for the case
182 * where a process (master, some daemon, etc) has opened the chardev on
183 * behalf of another process, so the AFU's mm gets bound to the process
184 * that performs this ioctl and not the process that opened the file.
186 ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
188 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
190 if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor,
192 afu_release_irqs(ctx);
196 ctx->status = STARTED;
199 mutex_unlock(&ctx->status_mutex);
202 static long afu_ioctl_process_element(struct cxl_context *ctx,
205 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
207 if (copy_to_user(upe, &ctx->pe, sizeof(__u32)))
213 static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
215 struct cxl_context *ctx = file->private_data;
217 if (ctx->status == CLOSED)
220 pr_devel("afu_ioctl\n");
222 case CXL_IOCTL_START_WORK:
223 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
224 case CXL_IOCTL_GET_PROCESS_ELEMENT:
225 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
230 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
233 return afu_ioctl(file, cmd, arg);
236 static int afu_mmap(struct file *file, struct vm_area_struct *vm)
238 struct cxl_context *ctx = file->private_data;
240 /* AFU must be started before we can MMIO */
241 if (ctx->status != STARTED)
244 return cxl_context_iomap(ctx, vm);
247 static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
249 struct cxl_context *ctx = file->private_data;
254 poll_wait(file, &ctx->wq, poll);
256 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
258 spin_lock_irqsave(&ctx->lock, flags);
259 if (ctx->pending_irq || ctx->pending_fault ||
260 ctx->pending_afu_err)
261 mask |= POLLIN | POLLRDNORM;
262 else if (ctx->status == CLOSED)
263 /* Only error on closed when there are no futher events pending
266 spin_unlock_irqrestore(&ctx->lock, flags);
268 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
273 static inline int ctx_event_pending(struct cxl_context *ctx)
275 return (ctx->pending_irq || ctx->pending_fault ||
276 ctx->pending_afu_err || (ctx->status == CLOSED));
279 static ssize_t afu_read(struct file *file, char __user *buf, size_t count,
282 struct cxl_context *ctx = file->private_data;
283 struct cxl_event event;
288 if (count < CXL_READ_MIN_SIZE)
291 spin_lock_irqsave(&ctx->lock, flags);
294 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
295 if (ctx_event_pending(ctx))
298 if (file->f_flags & O_NONBLOCK) {
303 if (signal_pending(current)) {
308 spin_unlock_irqrestore(&ctx->lock, flags);
309 pr_devel("afu_read going to sleep...\n");
311 pr_devel("afu_read woken up\n");
312 spin_lock_irqsave(&ctx->lock, flags);
315 finish_wait(&ctx->wq, &wait);
317 memset(&event, 0, sizeof(event));
318 event.header.process_element = ctx->pe;
319 event.header.size = sizeof(struct cxl_event_header);
320 if (ctx->pending_irq) {
321 pr_devel("afu_read delivering AFU interrupt\n");
322 event.header.size += sizeof(struct cxl_event_afu_interrupt);
323 event.header.type = CXL_EVENT_AFU_INTERRUPT;
324 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
325 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
326 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
327 ctx->pending_irq = false;
328 } else if (ctx->pending_fault) {
329 pr_devel("afu_read delivering data storage fault\n");
330 event.header.size += sizeof(struct cxl_event_data_storage);
331 event.header.type = CXL_EVENT_DATA_STORAGE;
332 event.fault.addr = ctx->fault_addr;
333 event.fault.dsisr = ctx->fault_dsisr;
334 ctx->pending_fault = false;
335 } else if (ctx->pending_afu_err) {
336 pr_devel("afu_read delivering afu error\n");
337 event.header.size += sizeof(struct cxl_event_afu_error);
338 event.header.type = CXL_EVENT_AFU_ERROR;
339 event.afu_error.error = ctx->afu_err;
340 ctx->pending_afu_err = false;
341 } else if (ctx->status == CLOSED) {
342 pr_devel("afu_read fatal error\n");
343 spin_unlock_irqrestore(&ctx->lock, flags);
346 WARN(1, "afu_read must be buggy\n");
348 spin_unlock_irqrestore(&ctx->lock, flags);
350 if (copy_to_user(buf, &event, event.header.size))
352 return event.header.size;
355 finish_wait(&ctx->wq, &wait);
356 spin_unlock_irqrestore(&ctx->lock, flags);
360 static const struct file_operations afu_fops = {
361 .owner = THIS_MODULE,
365 .release = afu_release,
366 .unlocked_ioctl = afu_ioctl,
367 .compat_ioctl = afu_compat_ioctl,
371 static const struct file_operations afu_master_fops = {
372 .owner = THIS_MODULE,
373 .open = afu_master_open,
376 .release = afu_release,
377 .unlocked_ioctl = afu_ioctl,
378 .compat_ioctl = afu_compat_ioctl,
383 static char *cxl_devnode(struct device *dev, umode_t *mode)
385 if (CXL_DEVT_IS_CARD(dev->devt)) {
387 * These minor numbers will eventually be used to program the
388 * PSL and AFUs once we have dynamic reprogramming support
392 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
395 extern struct class *cxl_class;
397 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
398 struct device **chardev, char *postfix, char *desc,
399 const struct file_operations *fops)
404 cdev_init(cdev, fops);
405 if ((rc = cdev_add(cdev, devt, 1))) {
406 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
410 dev = device_create(cxl_class, &afu->dev, devt, afu,
411 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
413 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
426 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
428 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
429 &afu->chardev_d, "d", "dedicated",
430 &afu_master_fops); /* Uses master fops */
433 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
435 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
436 &afu->chardev_m, "m", "master",
440 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
442 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
443 &afu->chardev_s, "s", "shared",
447 void cxl_chardev_afu_remove(struct cxl_afu *afu)
449 if (afu->chardev_d) {
450 cdev_del(&afu->afu_cdev_d);
451 device_unregister(afu->chardev_d);
452 afu->chardev_d = NULL;
454 if (afu->chardev_m) {
455 cdev_del(&afu->afu_cdev_m);
456 device_unregister(afu->chardev_m);
457 afu->chardev_m = NULL;
459 if (afu->chardev_s) {
460 cdev_del(&afu->afu_cdev_s);
461 device_unregister(afu->chardev_s);
462 afu->chardev_s = NULL;
466 int cxl_register_afu(struct cxl_afu *afu)
468 afu->dev.class = cxl_class;
470 return device_register(&afu->dev);
473 int cxl_register_adapter(struct cxl *adapter)
475 adapter->dev.class = cxl_class;
478 * Future: When we support dynamically reprogramming the PSL & AFU we
479 * will expose the interface to do that via a chardev:
480 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
483 return device_register(&adapter->dev);
486 int __init cxl_file_init(void)
491 * If these change we really need to update API. Either change some
492 * flags or update API version number CXL_API_VERSION.
494 BUILD_BUG_ON(CXL_API_VERSION != 1);
495 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
496 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
497 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
498 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
499 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
501 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
502 pr_err("Unable to allocate CXL major number: %i\n", rc);
506 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
508 cxl_class = class_create(THIS_MODULE, "cxl");
509 if (IS_ERR(cxl_class)) {
510 pr_err("Unable to create CXL class\n");
511 rc = PTR_ERR(cxl_class);
514 cxl_class->devnode = cxl_devnode;
519 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
523 void cxl_file_exit(void)
525 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
526 class_destroy(cxl_class);