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6db71994 TT |
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> | |
5af50730 | 37 | #include <linux/of_irq.h> |
6db71994 TT |
38 | #include <linux/reboot.h> |
39 | #include <linux/uaccess.h> | |
40 | #include <linux/notifier.h> | |
f1f4ee01 | 41 | #include <linux/interrupt.h> |
6db71994 TT |
42 | |
43 | #include <linux/io.h> | |
44 | #include <asm/fsl_hcalls.h> | |
45 | ||
46 | #include <linux/fsl_hypervisor.h> | |
47 | ||
48 | static BLOCKING_NOTIFIER_HEAD(failover_subscribers); | |
49 | ||
50 | /* | |
51 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_RESTART | |
52 | * | |
53 | * Restart a running partition | |
54 | */ | |
55 | static long ioctl_restart(struct fsl_hv_ioctl_restart __user *p) | |
56 | { | |
57 | struct fsl_hv_ioctl_restart param; | |
58 | ||
59 | /* Get the parameters from the user */ | |
60 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_restart))) | |
61 | return -EFAULT; | |
62 | ||
63 | param.ret = fh_partition_restart(param.partition); | |
64 | ||
65 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) | |
66 | return -EFAULT; | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_STATUS | |
73 | * | |
74 | * Query the status of a partition | |
75 | */ | |
76 | static long ioctl_status(struct fsl_hv_ioctl_status __user *p) | |
77 | { | |
78 | struct fsl_hv_ioctl_status param; | |
79 | u32 status; | |
80 | ||
81 | /* Get the parameters from the user */ | |
82 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_status))) | |
83 | return -EFAULT; | |
84 | ||
85 | param.ret = fh_partition_get_status(param.partition, &status); | |
86 | if (!param.ret) | |
87 | param.status = status; | |
88 | ||
89 | if (copy_to_user(p, ¶m, sizeof(struct fsl_hv_ioctl_status))) | |
90 | return -EFAULT; | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | /* | |
96 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_START | |
97 | * | |
98 | * Start a stopped partition. | |
99 | */ | |
100 | static long ioctl_start(struct fsl_hv_ioctl_start __user *p) | |
101 | { | |
102 | struct fsl_hv_ioctl_start param; | |
103 | ||
104 | /* Get the parameters from the user */ | |
105 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_start))) | |
106 | return -EFAULT; | |
107 | ||
108 | param.ret = fh_partition_start(param.partition, param.entry_point, | |
109 | param.load); | |
110 | ||
111 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) | |
112 | return -EFAULT; | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | /* | |
118 | * Ioctl interface for FSL_HV_IOCTL_PARTITION_STOP | |
119 | * | |
120 | * Stop a running partition | |
121 | */ | |
122 | static long ioctl_stop(struct fsl_hv_ioctl_stop __user *p) | |
123 | { | |
124 | struct fsl_hv_ioctl_stop param; | |
125 | ||
126 | /* Get the parameters from the user */ | |
127 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_stop))) | |
128 | return -EFAULT; | |
129 | ||
130 | param.ret = fh_partition_stop(param.partition); | |
131 | ||
132 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) | |
133 | return -EFAULT; | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | /* | |
139 | * Ioctl interface for FSL_HV_IOCTL_MEMCPY | |
140 | * | |
141 | * The FH_MEMCPY hypercall takes an array of address/address/size structures | |
142 | * to represent the data being copied. As a convenience to the user, this | |
143 | * ioctl takes a user-create buffer and a pointer to a guest physically | |
144 | * contiguous buffer in the remote partition, and creates the | |
145 | * address/address/size array for the hypercall. | |
146 | */ | |
147 | static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) | |
148 | { | |
149 | struct fsl_hv_ioctl_memcpy param; | |
150 | ||
151 | struct page **pages = NULL; | |
152 | void *sg_list_unaligned = NULL; | |
153 | struct fh_sg_list *sg_list = NULL; | |
154 | ||
155 | unsigned int num_pages; | |
156 | unsigned long lb_offset; /* Offset within a page of the local buffer */ | |
157 | ||
158 | unsigned int i; | |
159 | long ret = 0; | |
7f360bec | 160 | int num_pinned = 0; /* return value from get_user_pages_fast() */ |
6db71994 TT |
161 | phys_addr_t remote_paddr; /* The next address in the remote buffer */ |
162 | uint32_t count; /* The number of bytes left to copy */ | |
163 | ||
164 | /* Get the parameters from the user */ | |
165 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_memcpy))) | |
166 | return -EFAULT; | |
167 | ||
168 | /* | |
169 | * One partition must be local, the other must be remote. In other | |
170 | * words, if source and target are both -1, or are both not -1, then | |
171 | * return an error. | |
172 | */ | |
173 | if ((param.source == -1) == (param.target == -1)) | |
174 | return -EINVAL; | |
175 | ||
176 | /* | |
7f360bec | 177 | * The array of pages returned by get_user_pages_fast() covers only |
6db71994 TT |
178 | * page-aligned memory. Since the user buffer is probably not |
179 | * page-aligned, we need to handle the discrepancy. | |
180 | * | |
181 | * We calculate the offset within a page of the S/G list, and make | |
182 | * adjustments accordingly. This will result in a page list that looks | |
183 | * like this: | |
184 | * | |
185 | * ---- <-- first page starts before the buffer | |
186 | * | | | |
187 | * |////|-> ---- | |
188 | * |////| | | | |
189 | * ---- | | | |
190 | * | | | |
191 | * ---- | | | |
192 | * |////| | | | |
193 | * |////| | | | |
194 | * |////| | | | |
195 | * ---- | | | |
196 | * | | | |
197 | * ---- | | | |
198 | * |////| | | | |
199 | * |////| | | | |
200 | * |////| | | | |
201 | * ---- | | | |
202 | * | | | |
203 | * ---- | | | |
204 | * |////| | | | |
205 | * |////|-> ---- | |
206 | * | | <-- last page ends after the buffer | |
207 | * ---- | |
208 | * | |
209 | * The distance between the start of the first page and the start of the | |
210 | * buffer is lb_offset. The hashed (///) areas are the parts of the | |
211 | * page list that contain the actual buffer. | |
212 | * | |
213 | * The advantage of this approach is that the number of pages is | |
214 | * equal to the number of entries in the S/G list that we give to the | |
215 | * hypervisor. | |
216 | */ | |
217 | lb_offset = param.local_vaddr & (PAGE_SIZE - 1); | |
6a024330 DC |
218 | if (param.count == 0 || |
219 | param.count > U64_MAX - lb_offset - PAGE_SIZE + 1) | |
220 | return -EINVAL; | |
6db71994 TT |
221 | num_pages = (param.count + lb_offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
222 | ||
223 | /* Allocate the buffers we need */ | |
224 | ||
225 | /* | |
226 | * 'pages' is an array of struct page pointers that's initialized by | |
7f360bec | 227 | * get_user_pages_fast(). |
6db71994 | 228 | */ |
6396bb22 | 229 | pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); |
6db71994 TT |
230 | if (!pages) { |
231 | pr_debug("fsl-hv: could not allocate page list\n"); | |
232 | return -ENOMEM; | |
233 | } | |
234 | ||
235 | /* | |
236 | * sg_list is the list of fh_sg_list objects that we pass to the | |
237 | * hypervisor. | |
238 | */ | |
239 | sg_list_unaligned = kmalloc(num_pages * sizeof(struct fh_sg_list) + | |
240 | sizeof(struct fh_sg_list) - 1, GFP_KERNEL); | |
241 | if (!sg_list_unaligned) { | |
242 | pr_debug("fsl-hv: could not allocate S/G list\n"); | |
243 | ret = -ENOMEM; | |
7f360bec | 244 | goto free_pages; |
6db71994 TT |
245 | } |
246 | sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list)); | |
247 | ||
248 | /* Get the physical addresses of the source buffer */ | |
1aaa09ca | 249 | num_pinned = get_user_pages_fast(param.local_vaddr - lb_offset, |
73b0140b | 250 | num_pages, param.source != -1 ? FOLL_WRITE : 0, pages); |
6db71994 TT |
251 | |
252 | if (num_pinned != num_pages) { | |
6db71994 TT |
253 | pr_debug("fsl-hv: could not lock source buffer\n"); |
254 | ret = (num_pinned < 0) ? num_pinned : -EFAULT; | |
255 | goto exit; | |
256 | } | |
257 | ||
258 | /* | |
259 | * Build the fh_sg_list[] array. The first page is special | |
260 | * because it's misaligned. | |
261 | */ | |
262 | if (param.source == -1) { | |
263 | sg_list[0].source = page_to_phys(pages[0]) + lb_offset; | |
264 | sg_list[0].target = param.remote_paddr; | |
265 | } else { | |
266 | sg_list[0].source = param.remote_paddr; | |
267 | sg_list[0].target = page_to_phys(pages[0]) + lb_offset; | |
268 | } | |
269 | sg_list[0].size = min_t(uint64_t, param.count, PAGE_SIZE - lb_offset); | |
270 | ||
271 | remote_paddr = param.remote_paddr + sg_list[0].size; | |
272 | count = param.count - sg_list[0].size; | |
273 | ||
274 | for (i = 1; i < num_pages; i++) { | |
275 | if (param.source == -1) { | |
276 | /* local to remote */ | |
277 | sg_list[i].source = page_to_phys(pages[i]); | |
278 | sg_list[i].target = remote_paddr; | |
279 | } else { | |
280 | /* remote to local */ | |
281 | sg_list[i].source = remote_paddr; | |
282 | sg_list[i].target = page_to_phys(pages[i]); | |
283 | } | |
284 | sg_list[i].size = min_t(uint64_t, count, PAGE_SIZE); | |
285 | ||
286 | remote_paddr += sg_list[i].size; | |
287 | count -= sg_list[i].size; | |
288 | } | |
289 | ||
290 | param.ret = fh_partition_memcpy(param.source, param.target, | |
291 | virt_to_phys(sg_list), num_pages); | |
292 | ||
293 | exit: | |
7f360bec SJ |
294 | if (pages && (num_pinned > 0)) { |
295 | for (i = 0; i < num_pinned; i++) | |
296 | put_page(pages[i]); | |
6db71994 TT |
297 | } |
298 | ||
299 | kfree(sg_list_unaligned); | |
7f360bec | 300 | free_pages: |
6db71994 TT |
301 | kfree(pages); |
302 | ||
303 | if (!ret) | |
304 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) | |
305 | return -EFAULT; | |
306 | ||
307 | return ret; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Ioctl interface for FSL_HV_IOCTL_DOORBELL | |
312 | * | |
313 | * Ring a doorbell | |
314 | */ | |
315 | static long ioctl_doorbell(struct fsl_hv_ioctl_doorbell __user *p) | |
316 | { | |
317 | struct fsl_hv_ioctl_doorbell param; | |
318 | ||
319 | /* Get the parameters from the user. */ | |
320 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_doorbell))) | |
321 | return -EFAULT; | |
322 | ||
323 | param.ret = ev_doorbell_send(param.doorbell); | |
324 | ||
325 | if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32))) | |
326 | return -EFAULT; | |
327 | ||
328 | return 0; | |
329 | } | |
330 | ||
331 | static long ioctl_dtprop(struct fsl_hv_ioctl_prop __user *p, int set) | |
332 | { | |
333 | struct fsl_hv_ioctl_prop param; | |
334 | char __user *upath, *upropname; | |
335 | void __user *upropval; | |
c8ea3663 DC |
336 | char *path, *propname; |
337 | void *propval; | |
6db71994 TT |
338 | int ret = 0; |
339 | ||
340 | /* Get the parameters from the user. */ | |
341 | if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_prop))) | |
342 | return -EFAULT; | |
343 | ||
344 | upath = (char __user *)(uintptr_t)param.path; | |
345 | upropname = (char __user *)(uintptr_t)param.propname; | |
346 | upropval = (void __user *)(uintptr_t)param.propval; | |
347 | ||
348 | path = strndup_user(upath, FH_DTPROP_MAX_PATHLEN); | |
c8ea3663 DC |
349 | if (IS_ERR(path)) |
350 | return PTR_ERR(path); | |
6db71994 TT |
351 | |
352 | propname = strndup_user(upropname, FH_DTPROP_MAX_PATHLEN); | |
353 | if (IS_ERR(propname)) { | |
354 | ret = PTR_ERR(propname); | |
c8ea3663 | 355 | goto err_free_path; |
6db71994 TT |
356 | } |
357 | ||
358 | if (param.proplen > FH_DTPROP_MAX_PROPLEN) { | |
359 | ret = -EINVAL; | |
c8ea3663 | 360 | goto err_free_propname; |
6db71994 TT |
361 | } |
362 | ||
363 | propval = kmalloc(param.proplen, GFP_KERNEL); | |
364 | if (!propval) { | |
365 | ret = -ENOMEM; | |
c8ea3663 | 366 | goto err_free_propname; |
6db71994 TT |
367 | } |
368 | ||
369 | if (set) { | |
370 | if (copy_from_user(propval, upropval, param.proplen)) { | |
371 | ret = -EFAULT; | |
c8ea3663 | 372 | goto err_free_propval; |
6db71994 TT |
373 | } |
374 | ||
375 | param.ret = fh_partition_set_dtprop(param.handle, | |
376 | virt_to_phys(path), | |
377 | virt_to_phys(propname), | |
378 | virt_to_phys(propval), | |
379 | param.proplen); | |
380 | } else { | |
381 | param.ret = fh_partition_get_dtprop(param.handle, | |
382 | virt_to_phys(path), | |
383 | virt_to_phys(propname), | |
384 | virt_to_phys(propval), | |
385 | ¶m.proplen); | |
386 | ||
387 | if (param.ret == 0) { | |
388 | if (copy_to_user(upropval, propval, param.proplen) || | |
389 | put_user(param.proplen, &p->proplen)) { | |
390 | ret = -EFAULT; | |
c8ea3663 | 391 | goto err_free_propval; |
6db71994 TT |
392 | } |
393 | } | |
394 | } | |
395 | ||
396 | if (put_user(param.ret, &p->ret)) | |
397 | ret = -EFAULT; | |
398 | ||
c8ea3663 | 399 | err_free_propval: |
6db71994 | 400 | kfree(propval); |
c8ea3663 | 401 | err_free_propname: |
6db71994 | 402 | kfree(propname); |
c8ea3663 DC |
403 | err_free_path: |
404 | kfree(path); | |
6db71994 TT |
405 | |
406 | return ret; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Ioctl main entry point | |
411 | */ | |
412 | static long fsl_hv_ioctl(struct file *file, unsigned int cmd, | |
413 | unsigned long argaddr) | |
414 | { | |
415 | void __user *arg = (void __user *)argaddr; | |
416 | long ret; | |
417 | ||
418 | switch (cmd) { | |
419 | case FSL_HV_IOCTL_PARTITION_RESTART: | |
420 | ret = ioctl_restart(arg); | |
421 | break; | |
422 | case FSL_HV_IOCTL_PARTITION_GET_STATUS: | |
423 | ret = ioctl_status(arg); | |
424 | break; | |
425 | case FSL_HV_IOCTL_PARTITION_START: | |
426 | ret = ioctl_start(arg); | |
427 | break; | |
428 | case FSL_HV_IOCTL_PARTITION_STOP: | |
429 | ret = ioctl_stop(arg); | |
430 | break; | |
431 | case FSL_HV_IOCTL_MEMCPY: | |
432 | ret = ioctl_memcpy(arg); | |
433 | break; | |
434 | case FSL_HV_IOCTL_DOORBELL: | |
435 | ret = ioctl_doorbell(arg); | |
436 | break; | |
437 | case FSL_HV_IOCTL_GETPROP: | |
438 | ret = ioctl_dtprop(arg, 0); | |
439 | break; | |
440 | case FSL_HV_IOCTL_SETPROP: | |
441 | ret = ioctl_dtprop(arg, 1); | |
442 | break; | |
443 | default: | |
444 | pr_debug("fsl-hv: bad ioctl dir=%u type=%u cmd=%u size=%u\n", | |
445 | _IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), | |
446 | _IOC_SIZE(cmd)); | |
447 | return -ENOTTY; | |
448 | } | |
449 | ||
450 | return ret; | |
451 | } | |
452 | ||
453 | /* Linked list of processes that have us open */ | |
454 | static struct list_head db_list; | |
455 | ||
456 | /* spinlock for db_list */ | |
457 | static DEFINE_SPINLOCK(db_list_lock); | |
458 | ||
459 | /* The size of the doorbell event queue. This must be a power of two. */ | |
460 | #define QSIZE 16 | |
461 | ||
462 | /* Returns the next head/tail pointer, wrapping around the queue if necessary */ | |
463 | #define nextp(x) (((x) + 1) & (QSIZE - 1)) | |
464 | ||
465 | /* Per-open data structure */ | |
466 | struct doorbell_queue { | |
467 | struct list_head list; | |
468 | spinlock_t lock; | |
469 | wait_queue_head_t wait; | |
470 | unsigned int head; | |
471 | unsigned int tail; | |
472 | uint32_t q[QSIZE]; | |
473 | }; | |
474 | ||
475 | /* Linked list of ISRs that we registered */ | |
476 | struct list_head isr_list; | |
477 | ||
478 | /* Per-ISR data structure */ | |
479 | struct doorbell_isr { | |
480 | struct list_head list; | |
481 | unsigned int irq; | |
482 | uint32_t doorbell; /* The doorbell handle */ | |
483 | uint32_t partition; /* The partition handle, if used */ | |
484 | }; | |
485 | ||
486 | /* | |
487 | * Add a doorbell to all of the doorbell queues | |
488 | */ | |
489 | static void fsl_hv_queue_doorbell(uint32_t doorbell) | |
490 | { | |
491 | struct doorbell_queue *dbq; | |
492 | unsigned long flags; | |
493 | ||
494 | /* Prevent another core from modifying db_list */ | |
495 | spin_lock_irqsave(&db_list_lock, flags); | |
496 | ||
497 | list_for_each_entry(dbq, &db_list, list) { | |
498 | if (dbq->head != nextp(dbq->tail)) { | |
499 | dbq->q[dbq->tail] = doorbell; | |
500 | /* | |
501 | * This memory barrier eliminates the need to grab | |
502 | * the spinlock for dbq. | |
503 | */ | |
504 | smp_wmb(); | |
505 | dbq->tail = nextp(dbq->tail); | |
506 | wake_up_interruptible(&dbq->wait); | |
507 | } | |
508 | } | |
509 | ||
510 | spin_unlock_irqrestore(&db_list_lock, flags); | |
511 | } | |
512 | ||
513 | /* | |
514 | * Interrupt handler for all doorbells | |
515 | * | |
516 | * We use the same interrupt handler for all doorbells. Whenever a doorbell | |
517 | * is rung, and we receive an interrupt, we just put the handle for that | |
518 | * doorbell (passed to us as *data) into all of the queues. | |
519 | */ | |
520 | static irqreturn_t fsl_hv_isr(int irq, void *data) | |
521 | { | |
522 | fsl_hv_queue_doorbell((uintptr_t) data); | |
523 | ||
524 | return IRQ_HANDLED; | |
525 | } | |
526 | ||
527 | /* | |
528 | * State change thread function | |
529 | * | |
530 | * The state change notification arrives in an interrupt, but we can't call | |
531 | * blocking_notifier_call_chain() in an interrupt handler. We could call | |
532 | * atomic_notifier_call_chain(), but that would require the clients' call-back | |
533 | * function to run in interrupt context. Since we don't want to impose that | |
534 | * restriction on the clients, we use a threaded IRQ to process the | |
535 | * notification in kernel context. | |
536 | */ | |
537 | static irqreturn_t fsl_hv_state_change_thread(int irq, void *data) | |
538 | { | |
539 | struct doorbell_isr *dbisr = data; | |
540 | ||
541 | blocking_notifier_call_chain(&failover_subscribers, dbisr->partition, | |
542 | NULL); | |
543 | ||
544 | return IRQ_HANDLED; | |
545 | } | |
546 | ||
547 | /* | |
548 | * Interrupt handler for state-change doorbells | |
549 | */ | |
550 | static irqreturn_t fsl_hv_state_change_isr(int irq, void *data) | |
551 | { | |
552 | unsigned int status; | |
553 | struct doorbell_isr *dbisr = data; | |
554 | int ret; | |
555 | ||
556 | /* It's still a doorbell, so add it to all the queues. */ | |
557 | fsl_hv_queue_doorbell(dbisr->doorbell); | |
558 | ||
559 | /* Determine the new state, and if it's stopped, notify the clients. */ | |
560 | ret = fh_partition_get_status(dbisr->partition, &status); | |
561 | if (!ret && (status == FH_PARTITION_STOPPED)) | |
562 | return IRQ_WAKE_THREAD; | |
563 | ||
564 | return IRQ_HANDLED; | |
565 | } | |
566 | ||
567 | /* | |
568 | * Returns a bitmask indicating whether a read will block | |
569 | */ | |
afc9a42b | 570 | static __poll_t fsl_hv_poll(struct file *filp, struct poll_table_struct *p) |
6db71994 TT |
571 | { |
572 | struct doorbell_queue *dbq = filp->private_data; | |
573 | unsigned long flags; | |
afc9a42b | 574 | __poll_t mask; |
6db71994 TT |
575 | |
576 | spin_lock_irqsave(&dbq->lock, flags); | |
577 | ||
578 | poll_wait(filp, &dbq->wait, p); | |
a9a08845 | 579 | mask = (dbq->head == dbq->tail) ? 0 : (EPOLLIN | EPOLLRDNORM); |
6db71994 TT |
580 | |
581 | spin_unlock_irqrestore(&dbq->lock, flags); | |
582 | ||
583 | return mask; | |
584 | } | |
585 | ||
586 | /* | |
587 | * Return the handles for any incoming doorbells | |
588 | * | |
589 | * If there are doorbell handles in the queue for this open instance, then | |
590 | * return them to the caller as an array of 32-bit integers. Otherwise, | |
591 | * block until there is at least one handle to return. | |
592 | */ | |
593 | static ssize_t fsl_hv_read(struct file *filp, char __user *buf, size_t len, | |
594 | loff_t *off) | |
595 | { | |
596 | struct doorbell_queue *dbq = filp->private_data; | |
597 | uint32_t __user *p = (uint32_t __user *) buf; /* for put_user() */ | |
598 | unsigned long flags; | |
599 | ssize_t count = 0; | |
600 | ||
601 | /* Make sure we stop when the user buffer is full. */ | |
602 | while (len >= sizeof(uint32_t)) { | |
603 | uint32_t dbell; /* Local copy of doorbell queue data */ | |
604 | ||
605 | spin_lock_irqsave(&dbq->lock, flags); | |
606 | ||
607 | /* | |
608 | * If the queue is empty, then either we're done or we need | |
609 | * to block. If the application specified O_NONBLOCK, then | |
610 | * we return the appropriate error code. | |
611 | */ | |
612 | if (dbq->head == dbq->tail) { | |
613 | spin_unlock_irqrestore(&dbq->lock, flags); | |
614 | if (count) | |
615 | break; | |
616 | if (filp->f_flags & O_NONBLOCK) | |
617 | return -EAGAIN; | |
618 | if (wait_event_interruptible(dbq->wait, | |
619 | dbq->head != dbq->tail)) | |
620 | return -ERESTARTSYS; | |
621 | continue; | |
622 | } | |
623 | ||
624 | /* | |
625 | * Even though we have an smp_wmb() in the ISR, the core | |
626 | * might speculatively execute the "dbell = ..." below while | |
627 | * it's evaluating the if-statement above. In that case, the | |
628 | * value put into dbell could be stale if the core accepts the | |
629 | * speculation. To prevent that, we need a read memory barrier | |
630 | * here as well. | |
631 | */ | |
632 | smp_rmb(); | |
633 | ||
634 | /* Copy the data to a temporary local buffer, because | |
635 | * we can't call copy_to_user() from inside a spinlock | |
636 | */ | |
637 | dbell = dbq->q[dbq->head]; | |
638 | dbq->head = nextp(dbq->head); | |
639 | ||
640 | spin_unlock_irqrestore(&dbq->lock, flags); | |
641 | ||
642 | if (put_user(dbell, p)) | |
643 | return -EFAULT; | |
644 | p++; | |
645 | count += sizeof(uint32_t); | |
646 | len -= sizeof(uint32_t); | |
647 | } | |
648 | ||
649 | return count; | |
650 | } | |
651 | ||
652 | /* | |
653 | * Open the driver and prepare for reading doorbells. | |
654 | * | |
655 | * Every time an application opens the driver, we create a doorbell queue | |
656 | * for that file handle. This queue is used for any incoming doorbells. | |
657 | */ | |
658 | static int fsl_hv_open(struct inode *inode, struct file *filp) | |
659 | { | |
660 | struct doorbell_queue *dbq; | |
661 | unsigned long flags; | |
6db71994 TT |
662 | |
663 | dbq = kzalloc(sizeof(struct doorbell_queue), GFP_KERNEL); | |
664 | if (!dbq) { | |
665 | pr_err("fsl-hv: out of memory\n"); | |
666 | return -ENOMEM; | |
667 | } | |
668 | ||
669 | spin_lock_init(&dbq->lock); | |
670 | init_waitqueue_head(&dbq->wait); | |
671 | ||
672 | spin_lock_irqsave(&db_list_lock, flags); | |
673 | list_add(&dbq->list, &db_list); | |
674 | spin_unlock_irqrestore(&db_list_lock, flags); | |
675 | ||
676 | filp->private_data = dbq; | |
677 | ||
4647769b | 678 | return 0; |
6db71994 TT |
679 | } |
680 | ||
681 | /* | |
682 | * Close the driver | |
683 | */ | |
684 | static int fsl_hv_close(struct inode *inode, struct file *filp) | |
685 | { | |
686 | struct doorbell_queue *dbq = filp->private_data; | |
687 | unsigned long flags; | |
688 | ||
6db71994 TT |
689 | spin_lock_irqsave(&db_list_lock, flags); |
690 | list_del(&dbq->list); | |
691 | spin_unlock_irqrestore(&db_list_lock, flags); | |
692 | ||
693 | kfree(dbq); | |
694 | ||
b734fed0 | 695 | return 0; |
6db71994 TT |
696 | } |
697 | ||
698 | static const struct file_operations fsl_hv_fops = { | |
699 | .owner = THIS_MODULE, | |
700 | .open = fsl_hv_open, | |
701 | .release = fsl_hv_close, | |
702 | .poll = fsl_hv_poll, | |
703 | .read = fsl_hv_read, | |
704 | .unlocked_ioctl = fsl_hv_ioctl, | |
1832f2d8 | 705 | .compat_ioctl = compat_ptr_ioctl, |
6db71994 TT |
706 | }; |
707 | ||
708 | static struct miscdevice fsl_hv_misc_dev = { | |
709 | MISC_DYNAMIC_MINOR, | |
710 | "fsl-hv", | |
711 | &fsl_hv_fops | |
712 | }; | |
713 | ||
714 | static irqreturn_t fsl_hv_shutdown_isr(int irq, void *data) | |
715 | { | |
716 | orderly_poweroff(false); | |
717 | ||
718 | return IRQ_HANDLED; | |
719 | } | |
720 | ||
721 | /* | |
722 | * Returns the handle of the parent of the given node | |
723 | * | |
724 | * The handle is the value of the 'hv-handle' property | |
725 | */ | |
726 | static int get_parent_handle(struct device_node *np) | |
727 | { | |
728 | struct device_node *parent; | |
729 | const uint32_t *prop; | |
730 | uint32_t handle; | |
731 | int len; | |
732 | ||
733 | parent = of_get_parent(np); | |
734 | if (!parent) | |
735 | /* It's not really possible for this to fail */ | |
736 | return -ENODEV; | |
737 | ||
738 | /* | |
739 | * The proper name for the handle property is "hv-handle", but some | |
740 | * older versions of the hypervisor used "reg". | |
741 | */ | |
742 | prop = of_get_property(parent, "hv-handle", &len); | |
743 | if (!prop) | |
744 | prop = of_get_property(parent, "reg", &len); | |
745 | ||
746 | if (!prop || (len != sizeof(uint32_t))) { | |
747 | /* This can happen only if the node is malformed */ | |
748 | of_node_put(parent); | |
749 | return -ENODEV; | |
750 | } | |
751 | ||
752 | handle = be32_to_cpup(prop); | |
753 | of_node_put(parent); | |
754 | ||
755 | return handle; | |
756 | } | |
757 | ||
758 | /* | |
759 | * Register a callback for failover events | |
760 | * | |
761 | * This function is called by device drivers to register their callback | |
762 | * functions for fail-over events. | |
763 | */ | |
764 | int fsl_hv_failover_register(struct notifier_block *nb) | |
765 | { | |
766 | return blocking_notifier_chain_register(&failover_subscribers, nb); | |
767 | } | |
768 | EXPORT_SYMBOL(fsl_hv_failover_register); | |
769 | ||
770 | /* | |
771 | * Unregister a callback for failover events | |
772 | */ | |
773 | int fsl_hv_failover_unregister(struct notifier_block *nb) | |
774 | { | |
775 | return blocking_notifier_chain_unregister(&failover_subscribers, nb); | |
776 | } | |
777 | EXPORT_SYMBOL(fsl_hv_failover_unregister); | |
778 | ||
779 | /* | |
780 | * Return TRUE if we're running under FSL hypervisor | |
781 | * | |
782 | * This function checks to see if we're running under the Freescale | |
783 | * hypervisor, and returns zero if we're not, or non-zero if we are. | |
784 | * | |
785 | * First, it checks if MSR[GS]==1, which means we're running under some | |
786 | * hypervisor. Then it checks if there is a hypervisor node in the device | |
787 | * tree. Currently, that means there needs to be a node in the root called | |
788 | * "hypervisor" and which has a property named "fsl,hv-version". | |
789 | */ | |
790 | static int has_fsl_hypervisor(void) | |
791 | { | |
792 | struct device_node *node; | |
793 | int ret; | |
794 | ||
6db71994 TT |
795 | node = of_find_node_by_path("/hypervisor"); |
796 | if (!node) | |
797 | return 0; | |
798 | ||
799 | ret = of_find_property(node, "fsl,hv-version", NULL) != NULL; | |
800 | ||
801 | of_node_put(node); | |
802 | ||
803 | return ret; | |
804 | } | |
805 | ||
806 | /* | |
807 | * Freescale hypervisor management driver init | |
808 | * | |
809 | * This function is called when this module is loaded. | |
810 | * | |
811 | * Register ourselves as a miscellaneous driver. This will register the | |
812 | * fops structure and create the right sysfs entries for udev. | |
813 | */ | |
814 | static int __init fsl_hypervisor_init(void) | |
815 | { | |
816 | struct device_node *np; | |
817 | struct doorbell_isr *dbisr, *n; | |
818 | int ret; | |
819 | ||
820 | pr_info("Freescale hypervisor management driver\n"); | |
821 | ||
822 | if (!has_fsl_hypervisor()) { | |
823 | pr_info("fsl-hv: no hypervisor found\n"); | |
824 | return -ENODEV; | |
825 | } | |
826 | ||
827 | ret = misc_register(&fsl_hv_misc_dev); | |
828 | if (ret) { | |
829 | pr_err("fsl-hv: cannot register device\n"); | |
830 | return ret; | |
831 | } | |
832 | ||
833 | INIT_LIST_HEAD(&db_list); | |
834 | INIT_LIST_HEAD(&isr_list); | |
835 | ||
836 | for_each_compatible_node(np, NULL, "epapr,hv-receive-doorbell") { | |
837 | unsigned int irq; | |
838 | const uint32_t *handle; | |
839 | ||
840 | handle = of_get_property(np, "interrupts", NULL); | |
841 | irq = irq_of_parse_and_map(np, 0); | |
02c39bbb | 842 | if (!handle || !irq) { |
55e18b18 RH |
843 | pr_err("fsl-hv: no 'interrupts' property in %pOF node\n", |
844 | np); | |
6db71994 TT |
845 | continue; |
846 | } | |
847 | ||
848 | dbisr = kzalloc(sizeof(*dbisr), GFP_KERNEL); | |
849 | if (!dbisr) | |
850 | goto out_of_memory; | |
851 | ||
852 | dbisr->irq = irq; | |
853 | dbisr->doorbell = be32_to_cpup(handle); | |
854 | ||
855 | if (of_device_is_compatible(np, "fsl,hv-shutdown-doorbell")) { | |
856 | /* The shutdown doorbell gets its own ISR */ | |
857 | ret = request_irq(irq, fsl_hv_shutdown_isr, 0, | |
858 | np->name, NULL); | |
859 | } else if (of_device_is_compatible(np, | |
860 | "fsl,hv-state-change-doorbell")) { | |
861 | /* | |
862 | * The state change doorbell triggers a notification if | |
863 | * the state of the managed partition changes to | |
864 | * "stopped". We need a separate interrupt handler for | |
865 | * that, and we also need to know the handle of the | |
866 | * target partition, not just the handle of the | |
867 | * doorbell. | |
868 | */ | |
869 | dbisr->partition = ret = get_parent_handle(np); | |
870 | if (ret < 0) { | |
55e18b18 RH |
871 | pr_err("fsl-hv: node %pOF has missing or " |
872 | "malformed parent\n", np); | |
6db71994 TT |
873 | kfree(dbisr); |
874 | continue; | |
875 | } | |
876 | ret = request_threaded_irq(irq, fsl_hv_state_change_isr, | |
877 | fsl_hv_state_change_thread, | |
878 | 0, np->name, dbisr); | |
879 | } else | |
880 | ret = request_irq(irq, fsl_hv_isr, 0, np->name, dbisr); | |
881 | ||
882 | if (ret < 0) { | |
55e18b18 RH |
883 | pr_err("fsl-hv: could not request irq %u for node %pOF\n", |
884 | irq, np); | |
6db71994 TT |
885 | kfree(dbisr); |
886 | continue; | |
887 | } | |
888 | ||
889 | list_add(&dbisr->list, &isr_list); | |
890 | ||
891 | pr_info("fsl-hv: registered handler for doorbell %u\n", | |
892 | dbisr->doorbell); | |
893 | } | |
894 | ||
895 | return 0; | |
896 | ||
897 | out_of_memory: | |
898 | list_for_each_entry_safe(dbisr, n, &isr_list, list) { | |
899 | free_irq(dbisr->irq, dbisr); | |
900 | list_del(&dbisr->list); | |
901 | kfree(dbisr); | |
902 | } | |
903 | ||
904 | misc_deregister(&fsl_hv_misc_dev); | |
905 | ||
906 | return -ENOMEM; | |
907 | } | |
908 | ||
909 | /* | |
910 | * Freescale hypervisor management driver termination | |
911 | * | |
912 | * This function is called when this driver is unloaded. | |
913 | */ | |
914 | static void __exit fsl_hypervisor_exit(void) | |
915 | { | |
916 | struct doorbell_isr *dbisr, *n; | |
917 | ||
918 | list_for_each_entry_safe(dbisr, n, &isr_list, list) { | |
919 | free_irq(dbisr->irq, dbisr); | |
920 | list_del(&dbisr->list); | |
921 | kfree(dbisr); | |
922 | } | |
923 | ||
924 | misc_deregister(&fsl_hv_misc_dev); | |
925 | } | |
926 | ||
927 | module_init(fsl_hypervisor_init); | |
928 | module_exit(fsl_hypervisor_exit); | |
929 | ||
930 | MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); | |
931 | MODULE_DESCRIPTION("Freescale hypervisor management driver"); | |
932 | MODULE_LICENSE("GPL v2"); |