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1 | /* |
2 | * Freescale Hypervisor Management Driver |
3 | |
4 | * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. |
5 | * Author: Timur Tabi <timur@freescale.com> |
6 | * |
7 | * This file is licensed under the terms of the GNU General Public License |
8 | * version 2. This program is licensed "as is" without any warranty of any |
9 | * kind, whether express or implied. |
10 | * |
11 | * The Freescale hypervisor management driver provides several services to |
12 | * drivers and applications related to the Freescale hypervisor: |
13 | * |
14 | * 1. An ioctl interface for querying and managing partitions. |
15 | * |
16 | * 2. A file interface to reading incoming doorbells. |
17 | * |
18 | * 3. An interrupt handler for shutting down the partition upon receiving the |
19 | * shutdown doorbell from a manager partition. |
20 | * |
21 | * 4. A kernel interface for receiving callbacks when a managed partition |
22 | * shuts down. |
23 | */ |
24 | |
25 | #include <linux/kernel.h> |
26 | #include <linux/module.h> |
27 | #include <linux/init.h> |
28 | #include <linux/types.h> |
29 | #include <linux/err.h> |
30 | #include <linux/fs.h> |
31 | #include <linux/miscdevice.h> |
32 | #include <linux/mm.h> |
33 | #include <linux/pagemap.h> |
34 | #include <linux/slab.h> |
35 | #include <linux/poll.h> |
36 | #include <linux/of.h> |
37 | #include <linux/reboot.h> |
38 | #include <linux/uaccess.h> |
39 | #include <linux/notifier.h> |
40 | #include <linux/interrupt.h> |
41 | |
42 | #include <linux/io.h> |
43 | #include <asm/fsl_hcalls.h> |
44 | |
45 | #include <linux/fsl_hypervisor.h> |
46 | |
47 | static BLOCKING_NOTIFIER_HEAD(failover_subscribers); |
48 | |
49 | /* |
50 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_RESTART |
51 | * |
52 | * Restart a running partition |
53 | */ |
54 | static long ioctl_restart(struct fsl_hv_ioctl_restart __user *p) |
55 | { |
56 | struct fsl_hv_ioctl_restart param; |
57 | |
58 | /* Get the parameters from the user */ |
59 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_restart))) |
60 | return -EFAULT; |
61 | |
62 | param.ret = fh_partition_restart(param.partition); |
63 | |
64 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) |
65 | return -EFAULT; |
66 | |
67 | return 0; |
68 | } |
69 | |
70 | /* |
71 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_STATUS |
72 | * |
73 | * Query the status of a partition |
74 | */ |
75 | static long ioctl_status(struct fsl_hv_ioctl_status __user *p) |
76 | { |
77 | struct fsl_hv_ioctl_status param; |
78 | u32 status; |
79 | |
80 | /* Get the parameters from the user */ |
81 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_status))) |
82 | return -EFAULT; |
83 | |
84 | param.ret = fh_partition_get_status(param.partition, &status); |
85 | if (!param.ret) |
86 | param.status = status; |
87 | |
88 | if (copy_to_user(p, ¶m, sizeof(struct fsl_hv_ioctl_status))) |
89 | return -EFAULT; |
90 | |
91 | return 0; |
92 | } |
93 | |
94 | /* |
95 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_START |
96 | * |
97 | * Start a stopped partition. |
98 | */ |
99 | static long ioctl_start(struct fsl_hv_ioctl_start __user *p) |
100 | { |
101 | struct fsl_hv_ioctl_start param; |
102 | |
103 | /* Get the parameters from the user */ |
104 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_start))) |
105 | return -EFAULT; |
106 | |
107 | param.ret = fh_partition_start(param.partition, param.entry_point, |
108 | param.load); |
109 | |
110 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) |
111 | return -EFAULT; |
112 | |
113 | return 0; |
114 | } |
115 | |
116 | /* |
117 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_STOP |
118 | * |
119 | * Stop a running partition |
120 | */ |
121 | static long ioctl_stop(struct fsl_hv_ioctl_stop __user *p) |
122 | { |
123 | struct fsl_hv_ioctl_stop param; |
124 | |
125 | /* Get the parameters from the user */ |
126 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_stop))) |
127 | return -EFAULT; |
128 | |
129 | param.ret = fh_partition_stop(param.partition); |
130 | |
131 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) |
132 | return -EFAULT; |
133 | |
134 | return 0; |
135 | } |
136 | |
137 | /* |
138 | * Ioctl interface for FSL_HV_IOCTL_MEMCPY |
139 | * |
140 | * The FH_MEMCPY hypercall takes an array of address/address/size structures |
141 | * to represent the data being copied. As a convenience to the user, this |
142 | * ioctl takes a user-create buffer and a pointer to a guest physically |
143 | * contiguous buffer in the remote partition, and creates the |
144 | * address/address/size array for the hypercall. |
145 | */ |
146 | static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) |
147 | { |
148 | struct fsl_hv_ioctl_memcpy param; |
149 | |
150 | struct page **pages = NULL; |
151 | void *sg_list_unaligned = NULL; |
152 | struct fh_sg_list *sg_list = NULL; |
153 | |
154 | unsigned int num_pages; |
155 | unsigned long lb_offset; /* Offset within a page of the local buffer */ |
156 | |
157 | unsigned int i; |
158 | long ret = 0; |
159 | int num_pinned; /* return value from get_user_pages() */ |
160 | phys_addr_t remote_paddr; /* The next address in the remote buffer */ |
161 | uint32_t count; /* The number of bytes left to copy */ |
162 | |
163 | /* Get the parameters from the user */ |
164 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_memcpy))) |
165 | return -EFAULT; |
166 | |
167 | /* |
168 | * One partition must be local, the other must be remote. In other |
169 | * words, if source and target are both -1, or are both not -1, then |
170 | * return an error. |
171 | */ |
172 | if ((param.source == -1) == (param.target == -1)) |
173 | return -EINVAL; |
174 | |
175 | /* |
176 | * The array of pages returned by get_user_pages() covers only |
177 | * page-aligned memory. Since the user buffer is probably not |
178 | * page-aligned, we need to handle the discrepancy. |
179 | * |
180 | * We calculate the offset within a page of the S/G list, and make |
181 | * adjustments accordingly. This will result in a page list that looks |
182 | * like this: |
183 | * |
184 | * ---- <-- first page starts before the buffer |
185 | * | | |
186 | * |////|-> ---- |
187 | * |////| | | |
188 | * ---- | | |
189 | * | | |
190 | * ---- | | |
191 | * |////| | | |
192 | * |////| | | |
193 | * |////| | | |
194 | * ---- | | |
195 | * | | |
196 | * ---- | | |
197 | * |////| | | |
198 | * |////| | | |
199 | * |////| | | |
200 | * ---- | | |
201 | * | | |
202 | * ---- | | |
203 | * |////| | | |
204 | * |////|-> ---- |
205 | * | | <-- last page ends after the buffer |
206 | * ---- |
207 | * |
208 | * The distance between the start of the first page and the start of the |
209 | * buffer is lb_offset. The hashed (///) areas are the parts of the |
210 | * page list that contain the actual buffer. |
211 | * |
212 | * The advantage of this approach is that the number of pages is |
213 | * equal to the number of entries in the S/G list that we give to the |
214 | * hypervisor. |
215 | */ |
216 | lb_offset = param.local_vaddr & (PAGE_SIZE - 1); |
217 | num_pages = (param.count + lb_offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
218 | |
219 | /* Allocate the buffers we need */ |
220 | |
221 | /* |
222 | * 'pages' is an array of struct page pointers that's initialized by |
223 | * get_user_pages(). |
224 | */ |
225 | pages = kzalloc(num_pages * sizeof(struct page *), GFP_KERNEL); |
226 | if (!pages) { |
227 | pr_debug("fsl-hv: could not allocate page list\n"); |
228 | return -ENOMEM; |
229 | } |
230 | |
231 | /* |
232 | * sg_list is the list of fh_sg_list objects that we pass to the |
233 | * hypervisor. |
234 | */ |
235 | sg_list_unaligned = kmalloc(num_pages * sizeof(struct fh_sg_list) + |
236 | sizeof(struct fh_sg_list) - 1, GFP_KERNEL); |
237 | if (!sg_list_unaligned) { |
238 | pr_debug("fsl-hv: could not allocate S/G list\n"); |
239 | ret = -ENOMEM; |
240 | goto exit; |
241 | } |
242 | sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list)); |
243 | |
244 | /* Get the physical addresses of the source buffer */ |
245 | down_read(¤t->mm->mmap_sem); |
246 | num_pinned = get_user_pages(current, current->mm, |
247 | param.local_vaddr - lb_offset, num_pages, |
248 | (param.source == -1) ? READ : WRITE, |
249 | 0, pages, NULL); |
250 | up_read(¤t->mm->mmap_sem); |
251 | |
252 | if (num_pinned != num_pages) { |
253 | /* get_user_pages() failed */ |
254 | pr_debug("fsl-hv: could not lock source buffer\n"); |
255 | ret = (num_pinned < 0) ? num_pinned : -EFAULT; |
256 | goto exit; |
257 | } |
258 | |
259 | /* |
260 | * Build the fh_sg_list[] array. The first page is special |
261 | * because it's misaligned. |
262 | */ |
263 | if (param.source == -1) { |
264 | sg_list[0].source = page_to_phys(pages[0]) + lb_offset; |
265 | sg_list[0].target = param.remote_paddr; |
266 | } else { |
267 | sg_list[0].source = param.remote_paddr; |
268 | sg_list[0].target = page_to_phys(pages[0]) + lb_offset; |
269 | } |
270 | sg_list[0].size = min_t(uint64_t, param.count, PAGE_SIZE - lb_offset); |
271 | |
272 | remote_paddr = param.remote_paddr + sg_list[0].size; |
273 | count = param.count - sg_list[0].size; |
274 | |
275 | for (i = 1; i < num_pages; i++) { |
276 | if (param.source == -1) { |
277 | /* local to remote */ |
278 | sg_list[i].source = page_to_phys(pages[i]); |
279 | sg_list[i].target = remote_paddr; |
280 | } else { |
281 | /* remote to local */ |
282 | sg_list[i].source = remote_paddr; |
283 | sg_list[i].target = page_to_phys(pages[i]); |
284 | } |
285 | sg_list[i].size = min_t(uint64_t, count, PAGE_SIZE); |
286 | |
287 | remote_paddr += sg_list[i].size; |
288 | count -= sg_list[i].size; |
289 | } |
290 | |
291 | param.ret = fh_partition_memcpy(param.source, param.target, |
292 | virt_to_phys(sg_list), num_pages); |
293 | |
294 | exit: |
295 | if (pages) { |
296 | for (i = 0; i < num_pages; i++) |
297 | if (pages[i]) |
298 | put_page(pages[i]); |
299 | } |
300 | |
301 | kfree(sg_list_unaligned); |
302 | kfree(pages); |
303 | |
304 | if (!ret) |
305 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) |
306 | return -EFAULT; |
307 | |
308 | return ret; |
309 | } |
310 | |
311 | /* |
312 | * Ioctl interface for FSL_HV_IOCTL_DOORBELL |
313 | * |
314 | * Ring a doorbell |
315 | */ |
316 | static long ioctl_doorbell(struct fsl_hv_ioctl_doorbell __user *p) |
317 | { |
318 | struct fsl_hv_ioctl_doorbell param; |
319 | |
320 | /* Get the parameters from the user. */ |
321 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_doorbell))) |
322 | return -EFAULT; |
323 | |
324 | param.ret = ev_doorbell_send(param.doorbell); |
325 | |
326 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) |
327 | return -EFAULT; |
328 | |
329 | return 0; |
330 | } |
331 | |
332 | static long ioctl_dtprop(struct fsl_hv_ioctl_prop __user *p, int set) |
333 | { |
334 | struct fsl_hv_ioctl_prop param; |
335 | char __user *upath, *upropname; |
336 | void __user *upropval; |
337 | char *path = NULL, *propname = NULL; |
338 | void *propval = NULL; |
339 | int ret = 0; |
340 | |
341 | /* Get the parameters from the user. */ |
342 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_prop))) |
343 | return -EFAULT; |
344 | |
345 | upath = (char __user *)(uintptr_t)param.path; |
346 | upropname = (char __user *)(uintptr_t)param.propname; |
347 | upropval = (void __user *)(uintptr_t)param.propval; |
348 | |
349 | path = strndup_user(upath, FH_DTPROP_MAX_PATHLEN); |
350 | if (IS_ERR(path)) { |
351 | ret = PTR_ERR(path); |
352 | goto out; |
353 | } |
354 | |
355 | propname = strndup_user(upropname, FH_DTPROP_MAX_PATHLEN); |
356 | if (IS_ERR(propname)) { |
357 | ret = PTR_ERR(propname); |
358 | goto out; |
359 | } |
360 | |
361 | if (param.proplen > FH_DTPROP_MAX_PROPLEN) { |
362 | ret = -EINVAL; |
363 | goto out; |
364 | } |
365 | |
366 | propval = kmalloc(param.proplen, GFP_KERNEL); |
367 | if (!propval) { |
368 | ret = -ENOMEM; |
369 | goto out; |
370 | } |
371 | |
372 | if (set) { |
373 | if (copy_from_user(propval, upropval, param.proplen)) { |
374 | ret = -EFAULT; |
375 | goto out; |
376 | } |
377 | |
378 | param.ret = fh_partition_set_dtprop(param.handle, |
379 | virt_to_phys(path), |
380 | virt_to_phys(propname), |
381 | virt_to_phys(propval), |
382 | param.proplen); |
383 | } else { |
384 | param.ret = fh_partition_get_dtprop(param.handle, |
385 | virt_to_phys(path), |
386 | virt_to_phys(propname), |
387 | virt_to_phys(propval), |
388 | ¶m.proplen); |
389 | |
390 | if (param.ret == 0) { |
391 | if (copy_to_user(upropval, propval, param.proplen) || |
392 | put_user(param.proplen, &p->proplen)) { |
393 | ret = -EFAULT; |
394 | goto out; |
395 | } |
396 | } |
397 | } |
398 | |
399 | if (put_user(param.ret, &p->ret)) |
400 | ret = -EFAULT; |
401 | |
402 | out: |
403 | kfree(path); |
404 | kfree(propval); |
405 | kfree(propname); |
406 | |
407 | return ret; |
408 | } |
409 | |
410 | /* |
411 | * Ioctl main entry point |
412 | */ |
413 | static long fsl_hv_ioctl(struct file *file, unsigned int cmd, |
414 | unsigned long argaddr) |
415 | { |
416 | void __user *arg = (void __user *)argaddr; |
417 | long ret; |
418 | |
419 | switch (cmd) { |
420 | case FSL_HV_IOCTL_PARTITION_RESTART: |
421 | ret = ioctl_restart(arg); |
422 | break; |
423 | case FSL_HV_IOCTL_PARTITION_GET_STATUS: |
424 | ret = ioctl_status(arg); |
425 | break; |
426 | case FSL_HV_IOCTL_PARTITION_START: |
427 | ret = ioctl_start(arg); |
428 | break; |
429 | case FSL_HV_IOCTL_PARTITION_STOP: |
430 | ret = ioctl_stop(arg); |
431 | break; |
432 | case FSL_HV_IOCTL_MEMCPY: |
433 | ret = ioctl_memcpy(arg); |
434 | break; |
435 | case FSL_HV_IOCTL_DOORBELL: |
436 | ret = ioctl_doorbell(arg); |
437 | break; |
438 | case FSL_HV_IOCTL_GETPROP: |
439 | ret = ioctl_dtprop(arg, 0); |
440 | break; |
441 | case FSL_HV_IOCTL_SETPROP: |
442 | ret = ioctl_dtprop(arg, 1); |
443 | break; |
444 | default: |
445 | pr_debug("fsl-hv: bad ioctl dir=%u type=%u cmd=%u size=%u\n", |
446 | _IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), |
447 | _IOC_SIZE(cmd)); |
448 | return -ENOTTY; |
449 | } |
450 | |
451 | return ret; |
452 | } |
453 | |
454 | /* Linked list of processes that have us open */ |
455 | static struct list_head db_list; |
456 | |
457 | /* spinlock for db_list */ |
458 | static DEFINE_SPINLOCK(db_list_lock); |
459 | |
460 | /* The size of the doorbell event queue. This must be a power of two. */ |
461 | #define QSIZE 16 |
462 | |
463 | /* Returns the next head/tail pointer, wrapping around the queue if necessary */ |
464 | #define nextp(x) (((x) + 1) & (QSIZE - 1)) |
465 | |
466 | /* Per-open data structure */ |
467 | struct doorbell_queue { |
468 | struct list_head list; |
469 | spinlock_t lock; |
470 | wait_queue_head_t wait; |
471 | unsigned int head; |
472 | unsigned int tail; |
473 | uint32_t q[QSIZE]; |
474 | }; |
475 | |
476 | /* Linked list of ISRs that we registered */ |
477 | struct list_head isr_list; |
478 | |
479 | /* Per-ISR data structure */ |
480 | struct doorbell_isr { |
481 | struct list_head list; |
482 | unsigned int irq; |
483 | uint32_t doorbell; /* The doorbell handle */ |
484 | uint32_t partition; /* The partition handle, if used */ |
485 | }; |
486 | |
487 | /* |
488 | * Add a doorbell to all of the doorbell queues |
489 | */ |
490 | static void fsl_hv_queue_doorbell(uint32_t doorbell) |
491 | { |
492 | struct doorbell_queue *dbq; |
493 | unsigned long flags; |
494 | |
495 | /* Prevent another core from modifying db_list */ |
496 | spin_lock_irqsave(&db_list_lock, flags); |
497 | |
498 | list_for_each_entry(dbq, &db_list, list) { |
499 | if (dbq->head != nextp(dbq->tail)) { |
500 | dbq->q[dbq->tail] = doorbell; |
501 | /* |
502 | * This memory barrier eliminates the need to grab |
503 | * the spinlock for dbq. |
504 | */ |
505 | smp_wmb(); |
506 | dbq->tail = nextp(dbq->tail); |
507 | wake_up_interruptible(&dbq->wait); |
508 | } |
509 | } |
510 | |
511 | spin_unlock_irqrestore(&db_list_lock, flags); |
512 | } |
513 | |
514 | /* |
515 | * Interrupt handler for all doorbells |
516 | * |
517 | * We use the same interrupt handler for all doorbells. Whenever a doorbell |
518 | * is rung, and we receive an interrupt, we just put the handle for that |
519 | * doorbell (passed to us as *data) into all of the queues. |
520 | */ |
521 | static irqreturn_t fsl_hv_isr(int irq, void *data) |
522 | { |
523 | fsl_hv_queue_doorbell((uintptr_t) data); |
524 | |
525 | return IRQ_HANDLED; |
526 | } |
527 | |
528 | /* |
529 | * State change thread function |
530 | * |
531 | * The state change notification arrives in an interrupt, but we can't call |
532 | * blocking_notifier_call_chain() in an interrupt handler. We could call |
533 | * atomic_notifier_call_chain(), but that would require the clients' call-back |
534 | * function to run in interrupt context. Since we don't want to impose that |
535 | * restriction on the clients, we use a threaded IRQ to process the |
536 | * notification in kernel context. |
537 | */ |
538 | static irqreturn_t fsl_hv_state_change_thread(int irq, void *data) |
539 | { |
540 | struct doorbell_isr *dbisr = data; |
541 | |
542 | blocking_notifier_call_chain(&failover_subscribers, dbisr->partition, |
543 | NULL); |
544 | |
545 | return IRQ_HANDLED; |
546 | } |
547 | |
548 | /* |
549 | * Interrupt handler for state-change doorbells |
550 | */ |
551 | static irqreturn_t fsl_hv_state_change_isr(int irq, void *data) |
552 | { |
553 | unsigned int status; |
554 | struct doorbell_isr *dbisr = data; |
555 | int ret; |
556 | |
557 | /* It's still a doorbell, so add it to all the queues. */ |
558 | fsl_hv_queue_doorbell(dbisr->doorbell); |
559 | |
560 | /* Determine the new state, and if it's stopped, notify the clients. */ |
561 | ret = fh_partition_get_status(dbisr->partition, &status); |
562 | if (!ret && (status == FH_PARTITION_STOPPED)) |
563 | return IRQ_WAKE_THREAD; |
564 | |
565 | return IRQ_HANDLED; |
566 | } |
567 | |
568 | /* |
569 | * Returns a bitmask indicating whether a read will block |
570 | */ |
571 | static unsigned int fsl_hv_poll(struct file *filp, struct poll_table_struct *p) |
572 | { |
573 | struct doorbell_queue *dbq = filp->private_data; |
574 | unsigned long flags; |
575 | unsigned int mask; |
576 | |
577 | spin_lock_irqsave(&dbq->lock, flags); |
578 | |
579 | poll_wait(filp, &dbq->wait, p); |
580 | mask = (dbq->head == dbq->tail) ? 0 : (POLLIN | POLLRDNORM); |
581 | |
582 | spin_unlock_irqrestore(&dbq->lock, flags); |
583 | |
584 | return mask; |
585 | } |
586 | |
587 | /* |
588 | * Return the handles for any incoming doorbells |
589 | * |
590 | * If there are doorbell handles in the queue for this open instance, then |
591 | * return them to the caller as an array of 32-bit integers. Otherwise, |
592 | * block until there is at least one handle to return. |
593 | */ |
594 | static ssize_t fsl_hv_read(struct file *filp, char __user *buf, size_t len, |
595 | loff_t *off) |
596 | { |
597 | struct doorbell_queue *dbq = filp->private_data; |
598 | uint32_t __user *p = (uint32_t __user *) buf; /* for put_user() */ |
599 | unsigned long flags; |
600 | ssize_t count = 0; |
601 | |
602 | /* Make sure we stop when the user buffer is full. */ |
603 | while (len >= sizeof(uint32_t)) { |
604 | uint32_t dbell; /* Local copy of doorbell queue data */ |
605 | |
606 | spin_lock_irqsave(&dbq->lock, flags); |
607 | |
608 | /* |
609 | * If the queue is empty, then either we're done or we need |
610 | * to block. If the application specified O_NONBLOCK, then |
611 | * we return the appropriate error code. |
612 | */ |
613 | if (dbq->head == dbq->tail) { |
614 | spin_unlock_irqrestore(&dbq->lock, flags); |
615 | if (count) |
616 | break; |
617 | if (filp->f_flags & O_NONBLOCK) |
618 | return -EAGAIN; |
619 | if (wait_event_interruptible(dbq->wait, |
620 | dbq->head != dbq->tail)) |
621 | return -ERESTARTSYS; |
622 | continue; |
623 | } |
624 | |
625 | /* |
626 | * Even though we have an smp_wmb() in the ISR, the core |
627 | * might speculatively execute the "dbell = ..." below while |
628 | * it's evaluating the if-statement above. In that case, the |
629 | * value put into dbell could be stale if the core accepts the |
630 | * speculation. To prevent that, we need a read memory barrier |
631 | * here as well. |
632 | */ |
633 | smp_rmb(); |
634 | |
635 | /* Copy the data to a temporary local buffer, because |
636 | * we can't call copy_to_user() from inside a spinlock |
637 | */ |
638 | dbell = dbq->q[dbq->head]; |
639 | dbq->head = nextp(dbq->head); |
640 | |
641 | spin_unlock_irqrestore(&dbq->lock, flags); |
642 | |
643 | if (put_user(dbell, p)) |
644 | return -EFAULT; |
645 | p++; |
646 | count += sizeof(uint32_t); |
647 | len -= sizeof(uint32_t); |
648 | } |
649 | |
650 | return count; |
651 | } |
652 | |
653 | /* |
654 | * Open the driver and prepare for reading doorbells. |
655 | * |
656 | * Every time an application opens the driver, we create a doorbell queue |
657 | * for that file handle. This queue is used for any incoming doorbells. |
658 | */ |
659 | static int fsl_hv_open(struct inode *inode, struct file *filp) |
660 | { |
661 | struct doorbell_queue *dbq; |
662 | unsigned long flags; |
663 | int ret = 0; |
664 | |
665 | dbq = kzalloc(sizeof(struct doorbell_queue), GFP_KERNEL); |
666 | if (!dbq) { |
667 | pr_err("fsl-hv: out of memory\n"); |
668 | return -ENOMEM; |
669 | } |
670 | |
671 | spin_lock_init(&dbq->lock); |
672 | init_waitqueue_head(&dbq->wait); |
673 | |
674 | spin_lock_irqsave(&db_list_lock, flags); |
675 | list_add(&dbq->list, &db_list); |
676 | spin_unlock_irqrestore(&db_list_lock, flags); |
677 | |
678 | filp->private_data = dbq; |
679 | |
680 | return ret; |
681 | } |
682 | |
683 | /* |
684 | * Close the driver |
685 | */ |
686 | static int fsl_hv_close(struct inode *inode, struct file *filp) |
687 | { |
688 | struct doorbell_queue *dbq = filp->private_data; |
689 | unsigned long flags; |
690 | |
691 | int ret = 0; |
692 | |
693 | spin_lock_irqsave(&db_list_lock, flags); |
694 | list_del(&dbq->list); |
695 | spin_unlock_irqrestore(&db_list_lock, flags); |
696 | |
697 | kfree(dbq); |
698 | |
699 | return ret; |
700 | } |
701 | |
702 | static const struct file_operations fsl_hv_fops = { |
703 | .owner = THIS_MODULE, |
704 | .open = fsl_hv_open, |
705 | .release = fsl_hv_close, |
706 | .poll = fsl_hv_poll, |
707 | .read = fsl_hv_read, |
708 | .unlocked_ioctl = fsl_hv_ioctl, |
709 | .compat_ioctl = fsl_hv_ioctl, |
710 | }; |
711 | |
712 | static struct miscdevice fsl_hv_misc_dev = { |
713 | MISC_DYNAMIC_MINOR, |
714 | "fsl-hv", |
715 | &fsl_hv_fops |
716 | }; |
717 | |
718 | static irqreturn_t fsl_hv_shutdown_isr(int irq, void *data) |
719 | { |
720 | orderly_poweroff(false); |
721 | |
722 | return IRQ_HANDLED; |
723 | } |
724 | |
725 | /* |
726 | * Returns the handle of the parent of the given node |
727 | * |
728 | * The handle is the value of the 'hv-handle' property |
729 | */ |
730 | static int get_parent_handle(struct device_node *np) |
731 | { |
732 | struct device_node *parent; |
733 | const uint32_t *prop; |
734 | uint32_t handle; |
735 | int len; |
736 | |
737 | parent = of_get_parent(np); |
738 | if (!parent) |
739 | /* It's not really possible for this to fail */ |
740 | return -ENODEV; |
741 | |
742 | /* |
743 | * The proper name for the handle property is "hv-handle", but some |
744 | * older versions of the hypervisor used "reg". |
745 | */ |
746 | prop = of_get_property(parent, "hv-handle", &len); |
747 | if (!prop) |
748 | prop = of_get_property(parent, "reg", &len); |
749 | |
750 | if (!prop || (len != sizeof(uint32_t))) { |
751 | /* This can happen only if the node is malformed */ |
752 | of_node_put(parent); |
753 | return -ENODEV; |
754 | } |
755 | |
756 | handle = be32_to_cpup(prop); |
757 | of_node_put(parent); |
758 | |
759 | return handle; |
760 | } |
761 | |
762 | /* |
763 | * Register a callback for failover events |
764 | * |
765 | * This function is called by device drivers to register their callback |
766 | * functions for fail-over events. |
767 | */ |
768 | int fsl_hv_failover_register(struct notifier_block *nb) |
769 | { |
770 | return blocking_notifier_chain_register(&failover_subscribers, nb); |
771 | } |
772 | EXPORT_SYMBOL(fsl_hv_failover_register); |
773 | |
774 | /* |
775 | * Unregister a callback for failover events |
776 | */ |
777 | int fsl_hv_failover_unregister(struct notifier_block *nb) |
778 | { |
779 | return blocking_notifier_chain_unregister(&failover_subscribers, nb); |
780 | } |
781 | EXPORT_SYMBOL(fsl_hv_failover_unregister); |
782 | |
783 | /* |
784 | * Return TRUE if we're running under FSL hypervisor |
785 | * |
786 | * This function checks to see if we're running under the Freescale |
787 | * hypervisor, and returns zero if we're not, or non-zero if we are. |
788 | * |
789 | * First, it checks if MSR[GS]==1, which means we're running under some |
790 | * hypervisor. Then it checks if there is a hypervisor node in the device |
791 | * tree. Currently, that means there needs to be a node in the root called |
792 | * "hypervisor" and which has a property named "fsl,hv-version". |
793 | */ |
794 | static int has_fsl_hypervisor(void) |
795 | { |
796 | struct device_node *node; |
797 | int ret; |
798 | |
799 | node = of_find_node_by_path("/hypervisor"); |
800 | if (!node) |
801 | return 0; |
802 | |
803 | ret = of_find_property(node, "fsl,hv-version", NULL) != NULL; |
804 | |
805 | of_node_put(node); |
806 | |
807 | return ret; |
808 | } |
809 | |
810 | /* |
811 | * Freescale hypervisor management driver init |
812 | * |
813 | * This function is called when this module is loaded. |
814 | * |
815 | * Register ourselves as a miscellaneous driver. This will register the |
816 | * fops structure and create the right sysfs entries for udev. |
817 | */ |
818 | static int __init fsl_hypervisor_init(void) |
819 | { |
820 | struct device_node *np; |
821 | struct doorbell_isr *dbisr, *n; |
822 | int ret; |
823 | |
824 | pr_info("Freescale hypervisor management driver\n"); |
825 | |
826 | if (!has_fsl_hypervisor()) { |
827 | pr_info("fsl-hv: no hypervisor found\n"); |
828 | return -ENODEV; |
829 | } |
830 | |
831 | ret = misc_register(&fsl_hv_misc_dev); |
832 | if (ret) { |
833 | pr_err("fsl-hv: cannot register device\n"); |
834 | return ret; |
835 | } |
836 | |
837 | INIT_LIST_HEAD(&db_list); |
838 | INIT_LIST_HEAD(&isr_list); |
839 | |
840 | for_each_compatible_node(np, NULL, "epapr,hv-receive-doorbell") { |
841 | unsigned int irq; |
842 | const uint32_t *handle; |
843 | |
844 | handle = of_get_property(np, "interrupts", NULL); |
845 | irq = irq_of_parse_and_map(np, 0); |
846 | if (!handle || (irq == NO_IRQ)) { |
847 | pr_err("fsl-hv: no 'interrupts' property in %s node\n", |
848 | np->full_name); |
849 | continue; |
850 | } |
851 | |
852 | dbisr = kzalloc(sizeof(*dbisr), GFP_KERNEL); |
853 | if (!dbisr) |
854 | goto out_of_memory; |
855 | |
856 | dbisr->irq = irq; |
857 | dbisr->doorbell = be32_to_cpup(handle); |
858 | |
859 | if (of_device_is_compatible(np, "fsl,hv-shutdown-doorbell")) { |
860 | /* The shutdown doorbell gets its own ISR */ |
861 | ret = request_irq(irq, fsl_hv_shutdown_isr, 0, |
862 | np->name, NULL); |
863 | } else if (of_device_is_compatible(np, |
864 | "fsl,hv-state-change-doorbell")) { |
865 | /* |
866 | * The state change doorbell triggers a notification if |
867 | * the state of the managed partition changes to |
868 | * "stopped". We need a separate interrupt handler for |
869 | * that, and we also need to know the handle of the |
870 | * target partition, not just the handle of the |
871 | * doorbell. |
872 | */ |
873 | dbisr->partition = ret = get_parent_handle(np); |
874 | if (ret < 0) { |
875 | pr_err("fsl-hv: node %s has missing or " |
876 | "malformed parent\n", np->full_name); |
877 | kfree(dbisr); |
878 | continue; |
879 | } |
880 | ret = request_threaded_irq(irq, fsl_hv_state_change_isr, |
881 | fsl_hv_state_change_thread, |
882 | 0, np->name, dbisr); |
883 | } else |
884 | ret = request_irq(irq, fsl_hv_isr, 0, np->name, dbisr); |
885 | |
886 | if (ret < 0) { |
887 | pr_err("fsl-hv: could not request irq %u for node %s\n", |
888 | irq, np->full_name); |
889 | kfree(dbisr); |
890 | continue; |
891 | } |
892 | |
893 | list_add(&dbisr->list, &isr_list); |
894 | |
895 | pr_info("fsl-hv: registered handler for doorbell %u\n", |
896 | dbisr->doorbell); |
897 | } |
898 | |
899 | return 0; |
900 | |
901 | out_of_memory: |
902 | list_for_each_entry_safe(dbisr, n, &isr_list, list) { |
903 | free_irq(dbisr->irq, dbisr); |
904 | list_del(&dbisr->list); |
905 | kfree(dbisr); |
906 | } |
907 | |
908 | misc_deregister(&fsl_hv_misc_dev); |
909 | |
910 | return -ENOMEM; |
911 | } |
912 | |
913 | /* |
914 | * Freescale hypervisor management driver termination |
915 | * |
916 | * This function is called when this driver is unloaded. |
917 | */ |
918 | static void __exit fsl_hypervisor_exit(void) |
919 | { |
920 | struct doorbell_isr *dbisr, *n; |
921 | |
922 | list_for_each_entry_safe(dbisr, n, &isr_list, list) { |
923 | free_irq(dbisr->irq, dbisr); |
924 | list_del(&dbisr->list); |
925 | kfree(dbisr); |
926 | } |
927 | |
928 | misc_deregister(&fsl_hv_misc_dev); |
929 | } |
930 | |
931 | module_init(fsl_hypervisor_init); |
932 | module_exit(fsl_hypervisor_exit); |
933 | |
934 | MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); |
935 | MODULE_DESCRIPTION("Freescale hypervisor management driver"); |
936 | MODULE_LICENSE("GPL v2"); |
937 |
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