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ocfs2: fix several issues of append dio
[linux/fpc-iii.git] / drivers / vfio / pci / vfio_pci_intrs.c
blob1f577b4ac126029d2b7664b3380f25a9a1e4b267
1 /*
2 * VFIO PCI interrupt handling
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
5 * Author: Alex Williamson <alex.williamson@redhat.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Derived from original vfio:
12 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
13 * Author: Tom Lyon, pugs@cisco.com
14 */
15
16 #include <linux/device.h>
17 #include <linux/interrupt.h>
18 #include <linux/eventfd.h>
19 #include <linux/msi.h>
20 #include <linux/pci.h>
21 #include <linux/file.h>
22 #include <linux/vfio.h>
23 #include <linux/wait.h>
24 #include <linux/slab.h>
25
26 #include "vfio_pci_private.h"
27
28 /*
29 * INTx
30 */
31 static void vfio_send_intx_eventfd(void *opaque, void *unused)
32 {
33 struct vfio_pci_device *vdev = opaque;
34
35 if (likely(is_intx(vdev) && !vdev->virq_disabled))
36 eventfd_signal(vdev->ctx[0].trigger, 1);
37 }
38
39 void vfio_pci_intx_mask(struct vfio_pci_device *vdev)
40 {
41 struct pci_dev *pdev = vdev->pdev;
42 unsigned long flags;
43
44 spin_lock_irqsave(&vdev->irqlock, flags);
45
46 /*
47 * Masking can come from interrupt, ioctl, or config space
48 * via INTx disable. The latter means this can get called
49 * even when not using intx delivery. In this case, just
50 * try to have the physical bit follow the virtual bit.
51 */
52 if (unlikely(!is_intx(vdev))) {
53 if (vdev->pci_2_3)
54 pci_intx(pdev, 0);
55 } else if (!vdev->ctx[0].masked) {
56 /*
57 * Can't use check_and_mask here because we always want to
58 * mask, not just when something is pending.
59 */
60 if (vdev->pci_2_3)
61 pci_intx(pdev, 0);
62 else
63 disable_irq_nosync(pdev->irq);
64
65 vdev->ctx[0].masked = true;
66 }
67
68 spin_unlock_irqrestore(&vdev->irqlock, flags);
69 }
70
71 /*
72 * If this is triggered by an eventfd, we can't call eventfd_signal
73 * or else we'll deadlock on the eventfd wait queue. Return >0 when
74 * a signal is necessary, which can then be handled via a work queue
75 * or directly depending on the caller.
76 */
77 static int vfio_pci_intx_unmask_handler(void *opaque, void *unused)
78 {
79 struct vfio_pci_device *vdev = opaque;
80 struct pci_dev *pdev = vdev->pdev;
81 unsigned long flags;
82 int ret = 0;
83
84 spin_lock_irqsave(&vdev->irqlock, flags);
85
86 /*
87 * Unmasking comes from ioctl or config, so again, have the
88 * physical bit follow the virtual even when not using INTx.
89 */
90 if (unlikely(!is_intx(vdev))) {
91 if (vdev->pci_2_3)
92 pci_intx(pdev, 1);
93 } else if (vdev->ctx[0].masked && !vdev->virq_disabled) {
94 /*
95 * A pending interrupt here would immediately trigger,
96 * but we can avoid that overhead by just re-sending
97 * the interrupt to the user.
98 */
99 if (vdev->pci_2_3) {
100 if (!pci_check_and_unmask_intx(pdev))
101 ret = 1;
102 } else
103 enable_irq(pdev->irq);
104
105 vdev->ctx[0].masked = (ret > 0);
106 }
107
108 spin_unlock_irqrestore(&vdev->irqlock, flags);
109
110 return ret;
111 }
112
113 void vfio_pci_intx_unmask(struct vfio_pci_device *vdev)
114 {
115 if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0)
116 vfio_send_intx_eventfd(vdev, NULL);
117 }
118
119 static irqreturn_t vfio_intx_handler(int irq, void *dev_id)
120 {
121 struct vfio_pci_device *vdev = dev_id;
122 unsigned long flags;
123 int ret = IRQ_NONE;
124
125 spin_lock_irqsave(&vdev->irqlock, flags);
126
127 if (!vdev->pci_2_3) {
128 disable_irq_nosync(vdev->pdev->irq);
129 vdev->ctx[0].masked = true;
130 ret = IRQ_HANDLED;
131 } else if (!vdev->ctx[0].masked && /* may be shared */
132 pci_check_and_mask_intx(vdev->pdev)) {
133 vdev->ctx[0].masked = true;
134 ret = IRQ_HANDLED;
135 }
136
137 spin_unlock_irqrestore(&vdev->irqlock, flags);
138
139 if (ret == IRQ_HANDLED)
140 vfio_send_intx_eventfd(vdev, NULL);
141
142 return ret;
143 }
144
145 static int vfio_intx_enable(struct vfio_pci_device *vdev)
146 {
147 if (!is_irq_none(vdev))
148 return -EINVAL;
149
150 if (!vdev->pdev->irq)
151 return -ENODEV;
152
153 vdev->ctx = kzalloc(sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
154 if (!vdev->ctx)
155 return -ENOMEM;
156
157 vdev->num_ctx = 1;
158
159 /*
160 * If the virtual interrupt is masked, restore it. Devices
161 * supporting DisINTx can be masked at the hardware level
162 * here, non-PCI-2.3 devices will have to wait until the
163 * interrupt is enabled.
164 */
165 vdev->ctx[0].masked = vdev->virq_disabled;
166 if (vdev->pci_2_3)
167 pci_intx(vdev->pdev, !vdev->ctx[0].masked);
168
169 vdev->irq_type = VFIO_PCI_INTX_IRQ_INDEX;
170
171 return 0;
172 }
173
174 static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
175 {
176 struct pci_dev *pdev = vdev->pdev;
177 unsigned long irqflags = IRQF_SHARED;
178 struct eventfd_ctx *trigger;
179 unsigned long flags;
180 int ret;
181
182 if (vdev->ctx[0].trigger) {
183 free_irq(pdev->irq, vdev);
184 kfree(vdev->ctx[0].name);
185 eventfd_ctx_put(vdev->ctx[0].trigger);
186 vdev->ctx[0].trigger = NULL;
187 }
188
189 if (fd < 0) /* Disable only */
190 return 0;
191
192 vdev->ctx[0].name = kasprintf(GFP_KERNEL, "vfio-intx(%s)",
193 pci_name(pdev));
194 if (!vdev->ctx[0].name)
195 return -ENOMEM;
196
197 trigger = eventfd_ctx_fdget(fd);
198 if (IS_ERR(trigger)) {
199 kfree(vdev->ctx[0].name);
200 return PTR_ERR(trigger);
201 }
202
203 vdev->ctx[0].trigger = trigger;
204
205 if (!vdev->pci_2_3)
206 irqflags = 0;
207
208 ret = request_irq(pdev->irq, vfio_intx_handler,
209 irqflags, vdev->ctx[0].name, vdev);
210 if (ret) {
211 vdev->ctx[0].trigger = NULL;
212 kfree(vdev->ctx[0].name);
213 eventfd_ctx_put(trigger);
214 return ret;
215 }
216
217 /*
218 * INTx disable will stick across the new irq setup,
219 * disable_irq won't.
220 */
221 spin_lock_irqsave(&vdev->irqlock, flags);
222 if (!vdev->pci_2_3 && vdev->ctx[0].masked)
223 disable_irq_nosync(pdev->irq);
224 spin_unlock_irqrestore(&vdev->irqlock, flags);
225
226 return 0;
227 }
228
229 static void vfio_intx_disable(struct vfio_pci_device *vdev)
230 {
231 vfio_intx_set_signal(vdev, -1);
232 vfio_virqfd_disable(&vdev->ctx[0].unmask);
233 vfio_virqfd_disable(&vdev->ctx[0].mask);
234 vdev->irq_type = VFIO_PCI_NUM_IRQS;
235 vdev->num_ctx = 0;
236 kfree(vdev->ctx);
237 }
238
239 /*
240 * MSI/MSI-X
241 */
242 static irqreturn_t vfio_msihandler(int irq, void *arg)
243 {
244 struct eventfd_ctx *trigger = arg;
245
246 eventfd_signal(trigger, 1);
247 return IRQ_HANDLED;
248 }
249
250 static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix)
251 {
252 struct pci_dev *pdev = vdev->pdev;
253 int ret;
254
255 if (!is_irq_none(vdev))
256 return -EINVAL;
257
258 vdev->ctx = kzalloc(nvec * sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
259 if (!vdev->ctx)
260 return -ENOMEM;
261
262 if (msix) {
263 int i;
264
265 vdev->msix = kzalloc(nvec * sizeof(struct msix_entry),
266 GFP_KERNEL);
267 if (!vdev->msix) {
268 kfree(vdev->ctx);
269 return -ENOMEM;
270 }
271
272 for (i = 0; i < nvec; i++)
273 vdev->msix[i].entry = i;
274
275 ret = pci_enable_msix_range(pdev, vdev->msix, 1, nvec);
276 if (ret < nvec) {
277 if (ret > 0)
278 pci_disable_msix(pdev);
279 kfree(vdev->msix);
280 kfree(vdev->ctx);
281 return ret;
282 }
283 } else {
284 ret = pci_enable_msi_range(pdev, 1, nvec);
285 if (ret < nvec) {
286 if (ret > 0)
287 pci_disable_msi(pdev);
288 kfree(vdev->ctx);
289 return ret;
290 }
291 }
292
293 vdev->num_ctx = nvec;
294 vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX :
295 VFIO_PCI_MSI_IRQ_INDEX;
296
297 if (!msix) {
298 /*
299 * Compute the virtual hardware field for max msi vectors -
300 * it is the log base 2 of the number of vectors.
301 */
302 vdev->msi_qmax = fls(nvec * 2 - 1) - 1;
303 }
304
305 return 0;
306 }
307
308 static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev,
309 int vector, int fd, bool msix)
310 {
311 struct pci_dev *pdev = vdev->pdev;
312 int irq = msix ? vdev->msix[vector].vector : pdev->irq + vector;
313 char *name = msix ? "vfio-msix" : "vfio-msi";
314 struct eventfd_ctx *trigger;
315 int ret;
316
317 if (vector >= vdev->num_ctx)
318 return -EINVAL;
319
320 if (vdev->ctx[vector].trigger) {
321 free_irq(irq, vdev->ctx[vector].trigger);
322 kfree(vdev->ctx[vector].name);
323 eventfd_ctx_put(vdev->ctx[vector].trigger);
324 vdev->ctx[vector].trigger = NULL;
325 }
326
327 if (fd < 0)
328 return 0;
329
330 vdev->ctx[vector].name = kasprintf(GFP_KERNEL, "%s[%d](%s)",
331 name, vector, pci_name(pdev));
332 if (!vdev->ctx[vector].name)
333 return -ENOMEM;
334
335 trigger = eventfd_ctx_fdget(fd);
336 if (IS_ERR(trigger)) {
337 kfree(vdev->ctx[vector].name);
338 return PTR_ERR(trigger);
339 }
340
341 /*
342 * The MSIx vector table resides in device memory which may be cleared
343 * via backdoor resets. We don't allow direct access to the vector
344 * table so even if a userspace driver attempts to save/restore around
345 * such a reset it would be unsuccessful. To avoid this, restore the
346 * cached value of the message prior to enabling.
347 */
348 if (msix) {
349 struct msi_msg msg;
350
351 get_cached_msi_msg(irq, &msg);
352 pci_write_msi_msg(irq, &msg);
353 }
354
355 ret = request_irq(irq, vfio_msihandler, 0,
356 vdev->ctx[vector].name, trigger);
357 if (ret) {
358 kfree(vdev->ctx[vector].name);
359 eventfd_ctx_put(trigger);
360 return ret;
361 }
362
363 vdev->ctx[vector].trigger = trigger;
364
365 return 0;
366 }
367
368 static int vfio_msi_set_block(struct vfio_pci_device *vdev, unsigned start,
369 unsigned count, int32_t *fds, bool msix)
370 {
371 int i, j, ret = 0;
372
373 if (start + count > vdev->num_ctx)
374 return -EINVAL;
375
376 for (i = 0, j = start; i < count && !ret; i++, j++) {
377 int fd = fds ? fds[i] : -1;
378 ret = vfio_msi_set_vector_signal(vdev, j, fd, msix);
379 }
380
381 if (ret) {
382 for (--j; j >= start; j--)
383 vfio_msi_set_vector_signal(vdev, j, -1, msix);
384 }
385
386 return ret;
387 }
388
389 static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
390 {
391 struct pci_dev *pdev = vdev->pdev;
392 int i;
393
394 vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
395
396 for (i = 0; i < vdev->num_ctx; i++) {
397 vfio_virqfd_disable(&vdev->ctx[i].unmask);
398 vfio_virqfd_disable(&vdev->ctx[i].mask);
399 }
400
401 if (msix) {
402 pci_disable_msix(vdev->pdev);
403 kfree(vdev->msix);
404 } else
405 pci_disable_msi(pdev);
406
407 vdev->irq_type = VFIO_PCI_NUM_IRQS;
408 vdev->num_ctx = 0;
409 kfree(vdev->ctx);
410 }
411
412 /*
413 * IOCTL support
414 */
415 static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
416 unsigned index, unsigned start,
417 unsigned count, uint32_t flags, void *data)
418 {
419 if (!is_intx(vdev) || start != 0 || count != 1)
420 return -EINVAL;
421
422 if (flags & VFIO_IRQ_SET_DATA_NONE) {
423 vfio_pci_intx_unmask(vdev);
424 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
425 uint8_t unmask = *(uint8_t *)data;
426 if (unmask)
427 vfio_pci_intx_unmask(vdev);
428 } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
429 int32_t fd = *(int32_t *)data;
430 if (fd >= 0)
431 return vfio_virqfd_enable((void *) vdev,
432 vfio_pci_intx_unmask_handler,
433 vfio_send_intx_eventfd, NULL,
434 &vdev->ctx[0].unmask, fd);
435
436 vfio_virqfd_disable(&vdev->ctx[0].unmask);
437 }
438
439 return 0;
440 }
441
442 static int vfio_pci_set_intx_mask(struct vfio_pci_device *vdev,
443 unsigned index, unsigned start,
444 unsigned count, uint32_t flags, void *data)
445 {
446 if (!is_intx(vdev) || start != 0 || count != 1)
447 return -EINVAL;
448
449 if (flags & VFIO_IRQ_SET_DATA_NONE) {
450 vfio_pci_intx_mask(vdev);
451 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
452 uint8_t mask = *(uint8_t *)data;
453 if (mask)
454 vfio_pci_intx_mask(vdev);
455 } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
456 return -ENOTTY; /* XXX implement me */
457 }
458
459 return 0;
460 }
461
462 static int vfio_pci_set_intx_trigger(struct vfio_pci_device *vdev,
463 unsigned index, unsigned start,
464 unsigned count, uint32_t flags, void *data)
465 {
466 if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
467 vfio_intx_disable(vdev);
468 return 0;
469 }
470
471 if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1)
472 return -EINVAL;
473
474 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
475 int32_t fd = *(int32_t *)data;
476 int ret;
477
478 if (is_intx(vdev))
479 return vfio_intx_set_signal(vdev, fd);
480
481 ret = vfio_intx_enable(vdev);
482 if (ret)
483 return ret;
484
485 ret = vfio_intx_set_signal(vdev, fd);
486 if (ret)
487 vfio_intx_disable(vdev);
488
489 return ret;
490 }
491
492 if (!is_intx(vdev))
493 return -EINVAL;
494
495 if (flags & VFIO_IRQ_SET_DATA_NONE) {
496 vfio_send_intx_eventfd(vdev, NULL);
497 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
498 uint8_t trigger = *(uint8_t *)data;
499 if (trigger)
500 vfio_send_intx_eventfd(vdev, NULL);
501 }
502 return 0;
503 }
504
505 static int vfio_pci_set_msi_trigger(struct vfio_pci_device *vdev,
506 unsigned index, unsigned start,
507 unsigned count, uint32_t flags, void *data)
508 {
509 int i;
510 bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
511
512 if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
513 vfio_msi_disable(vdev, msix);
514 return 0;
515 }
516
517 if (!(irq_is(vdev, index) || is_irq_none(vdev)))
518 return -EINVAL;
519
520 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
521 int32_t *fds = data;
522 int ret;
523
524 if (vdev->irq_type == index)
525 return vfio_msi_set_block(vdev, start, count,
526 fds, msix);
527
528 ret = vfio_msi_enable(vdev, start + count, msix);
529 if (ret)
530 return ret;
531
532 ret = vfio_msi_set_block(vdev, start, count, fds, msix);
533 if (ret)
534 vfio_msi_disable(vdev, msix);
535
536 return ret;
537 }
538
539 if (!irq_is(vdev, index) || start + count > vdev->num_ctx)
540 return -EINVAL;
541
542 for (i = start; i < start + count; i++) {
543 if (!vdev->ctx[i].trigger)
544 continue;
545 if (flags & VFIO_IRQ_SET_DATA_NONE) {
546 eventfd_signal(vdev->ctx[i].trigger, 1);
547 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
548 uint8_t *bools = data;
549 if (bools[i - start])
550 eventfd_signal(vdev->ctx[i].trigger, 1);
551 }
552 }
553 return 0;
554 }
555
556 static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
557 uint32_t flags, void *data)
558 {
559 int32_t fd = *(int32_t *)data;
560
561 if (!(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
562 return -EINVAL;
563
564 /* DATA_NONE/DATA_BOOL enables loopback testing */
565 if (flags & VFIO_IRQ_SET_DATA_NONE) {
566 if (*ctx)
567 eventfd_signal(*ctx, 1);
568 return 0;
569 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
570 uint8_t trigger = *(uint8_t *)data;
571 if (trigger && *ctx)
572 eventfd_signal(*ctx, 1);
573 return 0;
574 }
575
576 /* Handle SET_DATA_EVENTFD */
577 if (fd == -1) {
578 if (*ctx)
579 eventfd_ctx_put(*ctx);
580 *ctx = NULL;
581 return 0;
582 } else if (fd >= 0) {
583 struct eventfd_ctx *efdctx;
584 efdctx = eventfd_ctx_fdget(fd);
585 if (IS_ERR(efdctx))
586 return PTR_ERR(efdctx);
587 if (*ctx)
588 eventfd_ctx_put(*ctx);
589 *ctx = efdctx;
590 return 0;
591 } else
592 return -EINVAL;
593 }
594
595 static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
596 unsigned index, unsigned start,
597 unsigned count, uint32_t flags, void *data)
598 {
599 if (index != VFIO_PCI_ERR_IRQ_INDEX)
600 return -EINVAL;
601
602 /*
603 * We should sanitize start & count, but that wasn't caught
604 * originally, so this IRQ index must forever ignore them :-(
605 */
606
607 return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data);
608 }
609
610 static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
611 unsigned index, unsigned start,
612 unsigned count, uint32_t flags, void *data)
613 {
614 if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1)
615 return -EINVAL;
616
617 return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data);
618 }
619
620 int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
621 unsigned index, unsigned start, unsigned count,
622 void *data)
623 {
624 int (*func)(struct vfio_pci_device *vdev, unsigned index,
625 unsigned start, unsigned count, uint32_t flags,
626 void *data) = NULL;
627
628 switch (index) {
629 case VFIO_PCI_INTX_IRQ_INDEX:
630 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
631 case VFIO_IRQ_SET_ACTION_MASK:
632 func = vfio_pci_set_intx_mask;
633 break;
634 case VFIO_IRQ_SET_ACTION_UNMASK:
635 func = vfio_pci_set_intx_unmask;
636 break;
637 case VFIO_IRQ_SET_ACTION_TRIGGER:
638 func = vfio_pci_set_intx_trigger;
639 break;
640 }
641 break;
642 case VFIO_PCI_MSI_IRQ_INDEX:
643 case VFIO_PCI_MSIX_IRQ_INDEX:
644 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
645 case VFIO_IRQ_SET_ACTION_MASK:
646 case VFIO_IRQ_SET_ACTION_UNMASK:
647 /* XXX Need masking support exported */
648 break;
649 case VFIO_IRQ_SET_ACTION_TRIGGER:
650 func = vfio_pci_set_msi_trigger;
651 break;
652 }
653 break;
654 case VFIO_PCI_ERR_IRQ_INDEX:
655 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
656 case VFIO_IRQ_SET_ACTION_TRIGGER:
657 if (pci_is_pcie(vdev->pdev))
658 func = vfio_pci_set_err_trigger;
659 break;
660 }
661 break;
662 case VFIO_PCI_REQ_IRQ_INDEX:
663 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
664 case VFIO_IRQ_SET_ACTION_TRIGGER:
665 func = vfio_pci_set_req_trigger;
666 break;
667 }
668 break;
669 }
670
671 if (!func)
672 return -ENOTTY;
673
674 return func(vdev, index, start, count, flags, data);
675 }
Linux with added FPC-III support