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/signal.h>
16 #include <linux/poll.h>
17 #include <linux/pid.h>
20 #include <linux/slab.h>
21 #include <linux/sched/mm.h>
22 #include <asm/cputable.h>
23 #include <asm/current.h>
24 #include <asm/copro.h>
29 #define CXL_NUM_MINORS 256 /* Total to reserve */
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_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
40 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
44 static struct class *cxl_class
;
46 static int __afu_open(struct inode
*inode
, struct file
*file
, bool master
)
50 struct cxl_context
*ctx
;
51 int adapter_num
= CXL_DEVT_ADAPTER(inode
->i_rdev
);
52 int slice
= CXL_DEVT_AFU(inode
->i_rdev
);
55 pr_devel("afu_open afu%i.%i\n", slice
, adapter_num
);
57 if (!(adapter
= get_cxl_adapter(adapter_num
)))
60 if (slice
> adapter
->slices
)
63 spin_lock(&adapter
->afu_list_lock
);
64 if (!(afu
= adapter
->afu
[slice
])) {
65 spin_unlock(&adapter
->afu_list_lock
);
70 * taking a ref to the afu so that it doesn't go away
71 * for rest of the function. This ref is released before
75 spin_unlock(&adapter
->afu_list_lock
);
77 if (!afu
->current_mode
)
80 if (!cxl_ops
->link_ok(adapter
, afu
)) {
85 if (!(ctx
= cxl_context_alloc())) {
90 rc
= cxl_context_init(ctx
, afu
, master
);
94 cxl_context_set_mapping(ctx
, inode
->i_mapping
);
96 pr_devel("afu_open pe: %i\n", ctx
->pe
);
97 file
->private_data
= ctx
;
100 /* indicate success */
104 /* release the ref taken earlier */
107 put_device(&adapter
->dev
);
111 int afu_open(struct inode
*inode
, struct file
*file
)
113 return __afu_open(inode
, file
, false);
116 static int afu_master_open(struct inode
*inode
, struct file
*file
)
118 return __afu_open(inode
, file
, true);
121 int afu_release(struct inode
*inode
, struct file
*file
)
123 struct cxl_context
*ctx
= file
->private_data
;
125 pr_devel("%s: closing cxl file descriptor. pe: %i\n",
127 cxl_context_detach(ctx
);
131 * Delete the context's mapping pointer, unless it's created by the
132 * kernel API, in which case leave it so it can be freed by reclaim_ctx()
134 if (!ctx
->kernelapi
) {
135 mutex_lock(&ctx
->mapping_lock
);
137 mutex_unlock(&ctx
->mapping_lock
);
141 * At this this point all bottom halfs have finished and we should be
142 * getting no more IRQs from the hardware for this context. Once it's
143 * removed from the IDR (and RCU synchronised) it's safe to free the
146 cxl_context_free(ctx
);
151 static long afu_ioctl_start_work(struct cxl_context
*ctx
,
152 struct cxl_ioctl_start_work __user
*uwork
)
154 struct cxl_ioctl_start_work work
;
158 pr_devel("%s: pe: %i\n", __func__
, ctx
->pe
);
160 /* Do this outside the status_mutex to avoid a circular dependency with
161 * the locking in cxl_mmap_fault() */
162 if (copy_from_user(&work
, uwork
, sizeof(work
)))
165 mutex_lock(&ctx
->status_mutex
);
166 if (ctx
->status
!= OPENED
) {
172 * if any of the reserved fields are set or any of the unused
173 * flags are set it's invalid
175 if (work
.reserved1
|| work
.reserved2
|| work
.reserved3
||
176 work
.reserved4
|| work
.reserved5
|| work
.reserved6
||
177 (work
.flags
& ~CXL_START_WORK_ALL
)) {
182 if (!(work
.flags
& CXL_START_WORK_NUM_IRQS
))
183 work
.num_interrupts
= ctx
->afu
->pp_irqs
;
184 else if ((work
.num_interrupts
< ctx
->afu
->pp_irqs
) ||
185 (work
.num_interrupts
> ctx
->afu
->irqs_max
)) {
189 if ((rc
= afu_register_irqs(ctx
, work
.num_interrupts
)))
192 if (work
.flags
& CXL_START_WORK_AMR
)
193 amr
= work
.amr
& mfspr(SPRN_UAMOR
);
195 ctx
->mmio_err_ff
= !!(work
.flags
& CXL_START_WORK_ERR_FF
);
198 * Increment the mapped context count for adapter. This also checks
199 * if adapter_context_lock is taken.
201 rc
= cxl_adapter_context_get(ctx
->afu
->adapter
);
203 afu_release_irqs(ctx
, ctx
);
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.
216 ctx
->pid
= get_task_pid(current
, PIDTYPE_PID
);
218 /* acquire a reference to the task's mm */
219 ctx
->mm
= get_task_mm(current
);
221 /* ensure this mm_struct can't be freed */
222 cxl_context_mm_count_get(ctx
);
224 /* decrement the use count */
228 trace_cxl_attach(ctx
, work
.work_element_descriptor
, work
.num_interrupts
, amr
);
230 if ((rc
= cxl_ops
->attach_process(ctx
, false, work
.work_element_descriptor
,
232 afu_release_irqs(ctx
, ctx
);
233 cxl_adapter_context_put(ctx
->afu
->adapter
);
236 cxl_context_mm_count_put(ctx
);
240 ctx
->status
= STARTED
;
243 mutex_unlock(&ctx
->status_mutex
);
247 static long afu_ioctl_process_element(struct cxl_context
*ctx
,
250 pr_devel("%s: pe: %i\n", __func__
, ctx
->pe
);
252 if (copy_to_user(upe
, &ctx
->external_pe
, sizeof(__u32
)))
258 static long afu_ioctl_get_afu_id(struct cxl_context
*ctx
,
259 struct cxl_afu_id __user
*upafuid
)
261 struct cxl_afu_id afuid
= { 0 };
263 afuid
.card_id
= ctx
->afu
->adapter
->adapter_num
;
264 afuid
.afu_offset
= ctx
->afu
->slice
;
265 afuid
.afu_mode
= ctx
->afu
->current_mode
;
267 /* set the flag bit in case the afu is a slave */
268 if (ctx
->afu
->current_mode
== CXL_MODE_DIRECTED
&& !ctx
->master
)
269 afuid
.flags
|= CXL_AFUID_FLAG_SLAVE
;
271 if (copy_to_user(upafuid
, &afuid
, sizeof(afuid
)))
277 long afu_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
279 struct cxl_context
*ctx
= file
->private_data
;
281 if (ctx
->status
== CLOSED
)
284 if (!cxl_ops
->link_ok(ctx
->afu
->adapter
, ctx
->afu
))
287 pr_devel("afu_ioctl\n");
289 case CXL_IOCTL_START_WORK
:
290 return afu_ioctl_start_work(ctx
, (struct cxl_ioctl_start_work __user
*)arg
);
291 case CXL_IOCTL_GET_PROCESS_ELEMENT
:
292 return afu_ioctl_process_element(ctx
, (__u32 __user
*)arg
);
293 case CXL_IOCTL_GET_AFU_ID
:
294 return afu_ioctl_get_afu_id(ctx
, (struct cxl_afu_id __user
*)
300 static long afu_compat_ioctl(struct file
*file
, unsigned int cmd
,
303 return afu_ioctl(file
, cmd
, arg
);
306 int afu_mmap(struct file
*file
, struct vm_area_struct
*vm
)
308 struct cxl_context
*ctx
= file
->private_data
;
310 /* AFU must be started before we can MMIO */
311 if (ctx
->status
!= STARTED
)
314 if (!cxl_ops
->link_ok(ctx
->afu
->adapter
, ctx
->afu
))
317 return cxl_context_iomap(ctx
, vm
);
320 static inline bool ctx_event_pending(struct cxl_context
*ctx
)
322 if (ctx
->pending_irq
|| ctx
->pending_fault
|| ctx
->pending_afu_err
)
325 if (ctx
->afu_driver_ops
&& atomic_read(&ctx
->afu_driver_events
))
331 unsigned int afu_poll(struct file
*file
, struct poll_table_struct
*poll
)
333 struct cxl_context
*ctx
= file
->private_data
;
338 poll_wait(file
, &ctx
->wq
, poll
);
340 pr_devel("afu_poll wait done pe: %i\n", ctx
->pe
);
342 spin_lock_irqsave(&ctx
->lock
, flags
);
343 if (ctx_event_pending(ctx
))
344 mask
|= POLLIN
| POLLRDNORM
;
345 else if (ctx
->status
== CLOSED
)
346 /* Only error on closed when there are no futher events pending
349 spin_unlock_irqrestore(&ctx
->lock
, flags
);
351 pr_devel("afu_poll pe: %i returning %#x\n", ctx
->pe
, mask
);
356 static ssize_t
afu_driver_event_copy(struct cxl_context
*ctx
,
358 struct cxl_event
*event
,
359 struct cxl_event_afu_driver_reserved
*pl
)
363 ctx
->afu_driver_ops
->event_delivered(ctx
, pl
, -EINVAL
);
367 /* Check event size */
368 event
->header
.size
+= pl
->data_size
;
369 if (event
->header
.size
> CXL_READ_MIN_SIZE
) {
370 ctx
->afu_driver_ops
->event_delivered(ctx
, pl
, -EINVAL
);
374 /* Copy event header */
375 if (copy_to_user(buf
, event
, sizeof(struct cxl_event_header
))) {
376 ctx
->afu_driver_ops
->event_delivered(ctx
, pl
, -EFAULT
);
380 /* Copy event data */
381 buf
+= sizeof(struct cxl_event_header
);
382 if (copy_to_user(buf
, &pl
->data
, pl
->data_size
)) {
383 ctx
->afu_driver_ops
->event_delivered(ctx
, pl
, -EFAULT
);
387 ctx
->afu_driver_ops
->event_delivered(ctx
, pl
, 0); /* Success */
388 return event
->header
.size
;
391 ssize_t
afu_read(struct file
*file
, char __user
*buf
, size_t count
,
394 struct cxl_context
*ctx
= file
->private_data
;
395 struct cxl_event_afu_driver_reserved
*pl
= NULL
;
396 struct cxl_event event
;
401 if (!cxl_ops
->link_ok(ctx
->afu
->adapter
, ctx
->afu
))
404 if (count
< CXL_READ_MIN_SIZE
)
407 spin_lock_irqsave(&ctx
->lock
, flags
);
410 prepare_to_wait(&ctx
->wq
, &wait
, TASK_INTERRUPTIBLE
);
411 if (ctx_event_pending(ctx
) || (ctx
->status
== CLOSED
))
414 if (!cxl_ops
->link_ok(ctx
->afu
->adapter
, ctx
->afu
)) {
419 if (file
->f_flags
& O_NONBLOCK
) {
424 if (signal_pending(current
)) {
429 spin_unlock_irqrestore(&ctx
->lock
, flags
);
430 pr_devel("afu_read going to sleep...\n");
432 pr_devel("afu_read woken up\n");
433 spin_lock_irqsave(&ctx
->lock
, flags
);
436 finish_wait(&ctx
->wq
, &wait
);
438 memset(&event
, 0, sizeof(event
));
439 event
.header
.process_element
= ctx
->pe
;
440 event
.header
.size
= sizeof(struct cxl_event_header
);
441 if (ctx
->afu_driver_ops
&& atomic_read(&ctx
->afu_driver_events
)) {
442 pr_devel("afu_read delivering AFU driver specific event\n");
443 pl
= ctx
->afu_driver_ops
->fetch_event(ctx
);
444 atomic_dec(&ctx
->afu_driver_events
);
445 event
.header
.type
= CXL_EVENT_AFU_DRIVER
;
446 } else if (ctx
->pending_irq
) {
447 pr_devel("afu_read delivering AFU interrupt\n");
448 event
.header
.size
+= sizeof(struct cxl_event_afu_interrupt
);
449 event
.header
.type
= CXL_EVENT_AFU_INTERRUPT
;
450 event
.irq
.irq
= find_first_bit(ctx
->irq_bitmap
, ctx
->irq_count
) + 1;
451 clear_bit(event
.irq
.irq
- 1, ctx
->irq_bitmap
);
452 if (bitmap_empty(ctx
->irq_bitmap
, ctx
->irq_count
))
453 ctx
->pending_irq
= false;
454 } else if (ctx
->pending_fault
) {
455 pr_devel("afu_read delivering data storage fault\n");
456 event
.header
.size
+= sizeof(struct cxl_event_data_storage
);
457 event
.header
.type
= CXL_EVENT_DATA_STORAGE
;
458 event
.fault
.addr
= ctx
->fault_addr
;
459 event
.fault
.dsisr
= ctx
->fault_dsisr
;
460 ctx
->pending_fault
= false;
461 } else if (ctx
->pending_afu_err
) {
462 pr_devel("afu_read delivering afu error\n");
463 event
.header
.size
+= sizeof(struct cxl_event_afu_error
);
464 event
.header
.type
= CXL_EVENT_AFU_ERROR
;
465 event
.afu_error
.error
= ctx
->afu_err
;
466 ctx
->pending_afu_err
= false;
467 } else if (ctx
->status
== CLOSED
) {
468 pr_devel("afu_read fatal error\n");
469 spin_unlock_irqrestore(&ctx
->lock
, flags
);
472 WARN(1, "afu_read must be buggy\n");
474 spin_unlock_irqrestore(&ctx
->lock
, flags
);
476 if (event
.header
.type
== CXL_EVENT_AFU_DRIVER
)
477 return afu_driver_event_copy(ctx
, buf
, &event
, pl
);
479 if (copy_to_user(buf
, &event
, event
.header
.size
))
481 return event
.header
.size
;
484 finish_wait(&ctx
->wq
, &wait
);
485 spin_unlock_irqrestore(&ctx
->lock
, flags
);
490 * Note: if this is updated, we need to update api.c to patch the new ones in
493 const struct file_operations afu_fops
= {
494 .owner
= THIS_MODULE
,
498 .release
= afu_release
,
499 .unlocked_ioctl
= afu_ioctl
,
500 .compat_ioctl
= afu_compat_ioctl
,
504 static const struct file_operations afu_master_fops
= {
505 .owner
= THIS_MODULE
,
506 .open
= afu_master_open
,
509 .release
= afu_release
,
510 .unlocked_ioctl
= afu_ioctl
,
511 .compat_ioctl
= afu_compat_ioctl
,
516 static char *cxl_devnode(struct device
*dev
, umode_t
*mode
)
518 if (cpu_has_feature(CPU_FTR_HVMODE
) &&
519 CXL_DEVT_IS_CARD(dev
->devt
)) {
521 * These minor numbers will eventually be used to program the
522 * PSL and AFUs once we have dynamic reprogramming support
526 return kasprintf(GFP_KERNEL
, "cxl/%s", dev_name(dev
));
529 extern struct class *cxl_class
;
531 static int cxl_add_chardev(struct cxl_afu
*afu
, dev_t devt
, struct cdev
*cdev
,
532 struct device
**chardev
, char *postfix
, char *desc
,
533 const struct file_operations
*fops
)
538 cdev_init(cdev
, fops
);
539 if ((rc
= cdev_add(cdev
, devt
, 1))) {
540 dev_err(&afu
->dev
, "Unable to add %s chardev: %i\n", desc
, rc
);
544 dev
= device_create(cxl_class
, &afu
->dev
, devt
, afu
,
545 "afu%i.%i%s", afu
->adapter
->adapter_num
, afu
->slice
, postfix
);
547 dev_err(&afu
->dev
, "Unable to create %s chardev in sysfs: %i\n", desc
, rc
);
560 int cxl_chardev_d_afu_add(struct cxl_afu
*afu
)
562 return cxl_add_chardev(afu
, CXL_AFU_MKDEV_D(afu
), &afu
->afu_cdev_d
,
563 &afu
->chardev_d
, "d", "dedicated",
564 &afu_master_fops
); /* Uses master fops */
567 int cxl_chardev_m_afu_add(struct cxl_afu
*afu
)
569 return cxl_add_chardev(afu
, CXL_AFU_MKDEV_M(afu
), &afu
->afu_cdev_m
,
570 &afu
->chardev_m
, "m", "master",
574 int cxl_chardev_s_afu_add(struct cxl_afu
*afu
)
576 return cxl_add_chardev(afu
, CXL_AFU_MKDEV_S(afu
), &afu
->afu_cdev_s
,
577 &afu
->chardev_s
, "s", "shared",
581 void cxl_chardev_afu_remove(struct cxl_afu
*afu
)
583 if (afu
->chardev_d
) {
584 cdev_del(&afu
->afu_cdev_d
);
585 device_unregister(afu
->chardev_d
);
586 afu
->chardev_d
= NULL
;
588 if (afu
->chardev_m
) {
589 cdev_del(&afu
->afu_cdev_m
);
590 device_unregister(afu
->chardev_m
);
591 afu
->chardev_m
= NULL
;
593 if (afu
->chardev_s
) {
594 cdev_del(&afu
->afu_cdev_s
);
595 device_unregister(afu
->chardev_s
);
596 afu
->chardev_s
= NULL
;
600 int cxl_register_afu(struct cxl_afu
*afu
)
602 afu
->dev
.class = cxl_class
;
604 return device_register(&afu
->dev
);
607 int cxl_register_adapter(struct cxl
*adapter
)
609 adapter
->dev
.class = cxl_class
;
612 * Future: When we support dynamically reprogramming the PSL & AFU we
613 * will expose the interface to do that via a chardev:
614 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
617 return device_register(&adapter
->dev
);
620 dev_t
cxl_get_dev(void)
625 int __init
cxl_file_init(void)
630 * If these change we really need to update API. Either change some
631 * flags or update API version number CXL_API_VERSION.
633 BUILD_BUG_ON(CXL_API_VERSION
!= 3);
634 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work
) != 64);
635 BUILD_BUG_ON(sizeof(struct cxl_event_header
) != 8);
636 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt
) != 8);
637 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage
) != 32);
638 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error
) != 16);
640 if ((rc
= alloc_chrdev_region(&cxl_dev
, 0, CXL_NUM_MINORS
, "cxl"))) {
641 pr_err("Unable to allocate CXL major number: %i\n", rc
);
645 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev
));
647 cxl_class
= class_create(THIS_MODULE
, "cxl");
648 if (IS_ERR(cxl_class
)) {
649 pr_err("Unable to create CXL class\n");
650 rc
= PTR_ERR(cxl_class
);
653 cxl_class
->devnode
= cxl_devnode
;
658 unregister_chrdev_region(cxl_dev
, CXL_NUM_MINORS
);
662 void cxl_file_exit(void)
664 unregister_chrdev_region(cxl_dev
, CXL_NUM_MINORS
);
665 class_destroy(cxl_class
);