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>
27 #define CXL_NUM_MINORS 256 /* Total to reserve */
28 #define CXL_DEV_MINORS 13 /* 1 control + 4 AFUs * 3 (dedicated/master/shared) */
30 #define CXL_CARD_MINOR(adapter) (adapter->adapter_num * CXL_DEV_MINORS)
31 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
32 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
33 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
34 #define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
35 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
36 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
38 #define CXL_DEVT_ADAPTER(dev) (MINOR(dev) / CXL_DEV_MINORS)
39 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
41 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
45 static struct class *cxl_class;
47 static int __afu_open(struct inode *inode, struct file *file, bool master)
51 struct cxl_context *ctx;
52 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
53 int slice = CXL_DEVT_AFU(inode->i_rdev);
56 pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
58 if (!(adapter = get_cxl_adapter(adapter_num)))
61 if (slice > adapter->slices)
64 spin_lock(&adapter->afu_list_lock);
65 if (!(afu = adapter->afu[slice])) {
66 spin_unlock(&adapter->afu_list_lock);
69 get_device(&afu->dev);
70 spin_unlock(&adapter->afu_list_lock);
72 if (!afu->current_mode)
75 if (!(ctx = cxl_context_alloc())) {
80 if ((rc = cxl_context_init(ctx, afu, master)))
83 pr_devel("afu_open pe: %i\n", ctx->pe);
84 file->private_data = ctx;
87 /* Our ref on the AFU will now hold the adapter */
88 put_device(&adapter->dev);
93 put_device(&afu->dev);
95 put_device(&adapter->dev);
98 static int afu_open(struct inode *inode, struct file *file)
100 return __afu_open(inode, file, false);
103 static int afu_master_open(struct inode *inode, struct file *file)
105 return __afu_open(inode, file, true);
108 static int afu_release(struct inode *inode, struct file *file)
110 struct cxl_context *ctx = file->private_data;
112 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
114 cxl_context_detach(ctx);
116 put_device(&ctx->afu->dev);
119 * At this this point all bottom halfs have finished and we should be
120 * getting no more IRQs from the hardware for this context. Once it's
121 * removed from the IDR (and RCU synchronised) it's safe to free the
124 cxl_context_free(ctx);
130 static long afu_ioctl_start_work(struct cxl_context *ctx,
131 struct cxl_ioctl_start_work __user *uwork)
133 struct cxl_ioctl_start_work work;
137 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
139 mutex_lock(&ctx->status_mutex);
140 if (ctx->status != OPENED) {
145 if (copy_from_user(&work, uwork,
146 sizeof(struct cxl_ioctl_start_work))) {
152 * if any of the reserved fields are set or any of the unused
153 * flags are set it's invalid
155 if (work.reserved1 || work.reserved2 || work.reserved3 ||
156 work.reserved4 || work.reserved5 || work.reserved6 ||
157 (work.flags & ~CXL_START_WORK_ALL)) {
162 if (!(work.flags & CXL_START_WORK_NUM_IRQS))
163 work.num_interrupts = ctx->afu->pp_irqs;
164 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
165 (work.num_interrupts > ctx->afu->irqs_max)) {
169 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
172 if (work.flags & CXL_START_WORK_AMR)
173 amr = work.amr & mfspr(SPRN_UAMOR);
176 * We grab the PID here and not in the file open to allow for the case
177 * where a process (master, some daemon, etc) has opened the chardev on
178 * behalf of another process, so the AFU's mm gets bound to the process
179 * that performs this ioctl and not the process that opened the file.
181 ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
183 if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor,
187 ctx->status = STARTED;
190 mutex_unlock(&ctx->status_mutex);
193 static long afu_ioctl_process_element(struct cxl_context *ctx,
196 pr_devel("%s: pe: %i\n", __func__, ctx->pe);
198 if (copy_to_user(upe, &ctx->pe, sizeof(__u32)))
204 static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
206 struct cxl_context *ctx = file->private_data;
208 if (ctx->status == CLOSED)
211 pr_devel("afu_ioctl\n");
213 case CXL_IOCTL_START_WORK:
214 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
215 case CXL_IOCTL_GET_PROCESS_ELEMENT:
216 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
221 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
224 return afu_ioctl(file, cmd, arg);
227 static int afu_mmap(struct file *file, struct vm_area_struct *vm)
229 struct cxl_context *ctx = file->private_data;
231 /* AFU must be started before we can MMIO */
232 if (ctx->status != STARTED)
235 return cxl_context_iomap(ctx, vm);
238 static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
240 struct cxl_context *ctx = file->private_data;
245 poll_wait(file, &ctx->wq, poll);
247 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
249 spin_lock_irqsave(&ctx->lock, flags);
250 if (ctx->pending_irq || ctx->pending_fault ||
251 ctx->pending_afu_err)
252 mask |= POLLIN | POLLRDNORM;
253 else if (ctx->status == CLOSED)
254 /* Only error on closed when there are no futher events pending
257 spin_unlock_irqrestore(&ctx->lock, flags);
259 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
264 static inline int ctx_event_pending(struct cxl_context *ctx)
266 return (ctx->pending_irq || ctx->pending_fault ||
267 ctx->pending_afu_err || (ctx->status == CLOSED));
270 static ssize_t afu_read(struct file *file, char __user *buf, size_t count,
273 struct cxl_context *ctx = file->private_data;
274 struct cxl_event event;
279 if (count < CXL_READ_MIN_SIZE)
282 spin_lock_irqsave(&ctx->lock, flags);
285 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
286 if (ctx_event_pending(ctx))
289 if (file->f_flags & O_NONBLOCK) {
294 if (signal_pending(current)) {
299 spin_unlock_irqrestore(&ctx->lock, flags);
300 pr_devel("afu_read going to sleep...\n");
302 pr_devel("afu_read woken up\n");
303 spin_lock_irqsave(&ctx->lock, flags);
306 finish_wait(&ctx->wq, &wait);
308 memset(&event, 0, sizeof(event));
309 event.header.process_element = ctx->pe;
310 event.header.size = sizeof(struct cxl_event_header);
311 if (ctx->pending_irq) {
312 pr_devel("afu_read delivering AFU interrupt\n");
313 event.header.size += sizeof(struct cxl_event_afu_interrupt);
314 event.header.type = CXL_EVENT_AFU_INTERRUPT;
315 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
316 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
317 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
318 ctx->pending_irq = false;
319 } else if (ctx->pending_fault) {
320 pr_devel("afu_read delivering data storage fault\n");
321 event.header.size += sizeof(struct cxl_event_data_storage);
322 event.header.type = CXL_EVENT_DATA_STORAGE;
323 event.fault.addr = ctx->fault_addr;
324 event.fault.dsisr = ctx->fault_dsisr;
325 ctx->pending_fault = false;
326 } else if (ctx->pending_afu_err) {
327 pr_devel("afu_read delivering afu error\n");
328 event.header.size += sizeof(struct cxl_event_afu_error);
329 event.header.type = CXL_EVENT_AFU_ERROR;
330 event.afu_error.error = ctx->afu_err;
331 ctx->pending_afu_err = false;
332 } else if (ctx->status == CLOSED) {
333 pr_devel("afu_read fatal error\n");
334 spin_unlock_irqrestore(&ctx->lock, flags);
337 WARN(1, "afu_read must be buggy\n");
339 spin_unlock_irqrestore(&ctx->lock, flags);
341 if (copy_to_user(buf, &event, event.header.size))
343 return event.header.size;
346 finish_wait(&ctx->wq, &wait);
347 spin_unlock_irqrestore(&ctx->lock, flags);
351 static const struct file_operations afu_fops = {
352 .owner = THIS_MODULE,
356 .release = afu_release,
357 .unlocked_ioctl = afu_ioctl,
358 .compat_ioctl = afu_compat_ioctl,
362 static const struct file_operations afu_master_fops = {
363 .owner = THIS_MODULE,
364 .open = afu_master_open,
367 .release = afu_release,
368 .unlocked_ioctl = afu_ioctl,
369 .compat_ioctl = afu_compat_ioctl,
374 static char *cxl_devnode(struct device *dev, umode_t *mode)
376 if (CXL_DEVT_IS_CARD(dev->devt)) {
378 * These minor numbers will eventually be used to program the
379 * PSL and AFUs once we have dynamic reprogramming support
383 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
386 extern struct class *cxl_class;
388 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
389 struct device **chardev, char *postfix, char *desc,
390 const struct file_operations *fops)
395 cdev_init(cdev, fops);
396 if ((rc = cdev_add(cdev, devt, 1))) {
397 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
401 dev = device_create(cxl_class, &afu->dev, devt, afu,
402 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
404 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
417 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
419 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
420 &afu->chardev_d, "d", "dedicated",
421 &afu_master_fops); /* Uses master fops */
424 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
426 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
427 &afu->chardev_m, "m", "master",
431 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
433 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
434 &afu->chardev_s, "s", "shared",
438 void cxl_chardev_afu_remove(struct cxl_afu *afu)
440 if (afu->chardev_d) {
441 cdev_del(&afu->afu_cdev_d);
442 device_unregister(afu->chardev_d);
443 afu->chardev_d = NULL;
445 if (afu->chardev_m) {
446 cdev_del(&afu->afu_cdev_m);
447 device_unregister(afu->chardev_m);
448 afu->chardev_m = NULL;
450 if (afu->chardev_s) {
451 cdev_del(&afu->afu_cdev_s);
452 device_unregister(afu->chardev_s);
453 afu->chardev_s = NULL;
457 int cxl_register_afu(struct cxl_afu *afu)
459 afu->dev.class = cxl_class;
461 return device_register(&afu->dev);
464 int cxl_register_adapter(struct cxl *adapter)
466 adapter->dev.class = cxl_class;
469 * Future: When we support dynamically reprogramming the PSL & AFU we
470 * will expose the interface to do that via a chardev:
471 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
474 return device_register(&adapter->dev);
477 int __init cxl_file_init(void)
482 * If these change we really need to update API. Either change some
483 * flags or update API version number CXL_API_VERSION.
485 BUILD_BUG_ON(CXL_API_VERSION != 1);
486 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
487 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
488 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
489 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
490 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
492 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
493 pr_err("Unable to allocate CXL major number: %i\n", rc);
497 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
499 cxl_class = class_create(THIS_MODULE, "cxl");
500 if (IS_ERR(cxl_class)) {
501 pr_err("Unable to create CXL class\n");
502 rc = PTR_ERR(cxl_class);
505 cxl_class->devnode = cxl_devnode;
510 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
514 void cxl_file_exit(void)
516 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
517 class_destroy(cxl_class);