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1/*
2 * drivers/pci/iov.c
3 *
4 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
5 *
6 * PCI Express I/O Virtualization (IOV) support.
7 * Single Root IOV 1.0
8 * Address Translation Service 1.0
9 */
10
11#include <linux/pci.h>
12#include <linux/slab.h>
13#include <linux/mutex.h>
14#include <linux/export.h>
15#include <linux/string.h>
16#include <linux/delay.h>
17#include <linux/pci-ats.h>
18#include "pci.h"
19
20#define VIRTFN_ID_LEN 16
21
22static inline u8 virtfn_bus(struct pci_dev *dev, int id)
23{
24 return dev->bus->number + ((dev->devfn + dev->sriov->offset +
25 dev->sriov->stride * id) >> 8);
26}
27
28static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
29{
30 return (dev->devfn + dev->sriov->offset +
31 dev->sriov->stride * id) & 0xff;
32}
33
34static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
35{
36 int rc;
37 struct pci_bus *child;
38
39 if (bus->number == busnr)
40 return bus;
41
42 child = pci_find_bus(pci_domain_nr(bus), busnr);
43 if (child)
44 return child;
45
46 child = pci_add_new_bus(bus, NULL, busnr);
47 if (!child)
48 return NULL;
49
50 child->subordinate = busnr;
51 child->dev.parent = bus->bridge;
52 rc = pci_bus_add_child(child);
53 if (rc) {
54 pci_remove_bus(child);
55 return NULL;
56 }
57
58 return child;
59}
60
61static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
62{
63 struct pci_bus *child;
64
65 if (bus->number == busnr)
66 return;
67
68 child = pci_find_bus(pci_domain_nr(bus), busnr);
69 BUG_ON(!child);
70
71 if (list_empty(&child->devices))
72 pci_remove_bus(child);
73}
74
75static int virtfn_add(struct pci_dev *dev, int id, int reset)
76{
77 int i;
78 int rc;
79 u64 size;
80 char buf[VIRTFN_ID_LEN];
81 struct pci_dev *virtfn;
82 struct resource *res;
83 struct pci_sriov *iov = dev->sriov;
84
85 virtfn = alloc_pci_dev();
86 if (!virtfn)
87 return -ENOMEM;
88
89 mutex_lock(&iov->dev->sriov->lock);
90 virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
91 if (!virtfn->bus) {
92 kfree(virtfn);
93 mutex_unlock(&iov->dev->sriov->lock);
94 return -ENOMEM;
95 }
96 virtfn->devfn = virtfn_devfn(dev, id);
97 virtfn->vendor = dev->vendor;
98 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
99 pci_setup_device(virtfn);
100 virtfn->dev.parent = dev->dev.parent;
101
102 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
103 res = dev->resource + PCI_IOV_RESOURCES + i;
104 if (!res->parent)
105 continue;
106 virtfn->resource[i].name = pci_name(virtfn);
107 virtfn->resource[i].flags = res->flags;
108 size = resource_size(res);
109 do_div(size, iov->total);
110 virtfn->resource[i].start = res->start + size * id;
111 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
112 rc = request_resource(res, &virtfn->resource[i]);
113 BUG_ON(rc);
114 }
115
116 if (reset)
117 __pci_reset_function(virtfn);
118
119 pci_device_add(virtfn, virtfn->bus);
120 mutex_unlock(&iov->dev->sriov->lock);
121
122 virtfn->physfn = pci_dev_get(dev);
123 virtfn->is_virtfn = 1;
124
125 rc = pci_bus_add_device(virtfn);
126 if (rc)
127 goto failed1;
128 sprintf(buf, "virtfn%u", id);
129 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
130 if (rc)
131 goto failed1;
132 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
133 if (rc)
134 goto failed2;
135
136 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
137
138 return 0;
139
140failed2:
141 sysfs_remove_link(&dev->dev.kobj, buf);
142failed1:
143 pci_dev_put(dev);
144 mutex_lock(&iov->dev->sriov->lock);
145 pci_stop_and_remove_bus_device(virtfn);
146 virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
147 mutex_unlock(&iov->dev->sriov->lock);
148
149 return rc;
150}
151
152static void virtfn_remove(struct pci_dev *dev, int id, int reset)
153{
154 char buf[VIRTFN_ID_LEN];
155 struct pci_bus *bus;
156 struct pci_dev *virtfn;
157 struct pci_sriov *iov = dev->sriov;
158
159 bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
160 if (!bus)
161 return;
162
163 virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
164 if (!virtfn)
165 return;
166
167 pci_dev_put(virtfn);
168
169 if (reset) {
170 device_release_driver(&virtfn->dev);
171 __pci_reset_function(virtfn);
172 }
173
174 sprintf(buf, "virtfn%u", id);
175 sysfs_remove_link(&dev->dev.kobj, buf);
176 /*
177 * pci_stop_dev() could have been called for this virtfn already,
178 * so the directory for the virtfn may have been removed before.
179 * Double check to avoid spurious sysfs warnings.
180 */
181 if (virtfn->dev.kobj.sd)
182 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
183
184 mutex_lock(&iov->dev->sriov->lock);
185 pci_stop_and_remove_bus_device(virtfn);
186 virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
187 mutex_unlock(&iov->dev->sriov->lock);
188
189 pci_dev_put(dev);
190}
191
192static int sriov_migration(struct pci_dev *dev)
193{
194 u16 status;
195 struct pci_sriov *iov = dev->sriov;
196
197 if (!iov->nr_virtfn)
198 return 0;
199
200 if (!(iov->cap & PCI_SRIOV_CAP_VFM))
201 return 0;
202
203 pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
204 if (!(status & PCI_SRIOV_STATUS_VFM))
205 return 0;
206
207 schedule_work(&iov->mtask);
208
209 return 1;
210}
211
212static void sriov_migration_task(struct work_struct *work)
213{
214 int i;
215 u8 state;
216 u16 status;
217 struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
218
219 for (i = iov->initial; i < iov->nr_virtfn; i++) {
220 state = readb(iov->mstate + i);
221 if (state == PCI_SRIOV_VFM_MI) {
222 writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
223 state = readb(iov->mstate + i);
224 if (state == PCI_SRIOV_VFM_AV)
225 virtfn_add(iov->self, i, 1);
226 } else if (state == PCI_SRIOV_VFM_MO) {
227 virtfn_remove(iov->self, i, 1);
228 writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
229 state = readb(iov->mstate + i);
230 if (state == PCI_SRIOV_VFM_AV)
231 virtfn_add(iov->self, i, 0);
232 }
233 }
234
235 pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
236 status &= ~PCI_SRIOV_STATUS_VFM;
237 pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
238}
239
240static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
241{
242 int bir;
243 u32 table;
244 resource_size_t pa;
245 struct pci_sriov *iov = dev->sriov;
246
247 if (nr_virtfn <= iov->initial)
248 return 0;
249
250 pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
251 bir = PCI_SRIOV_VFM_BIR(table);
252 if (bir > PCI_STD_RESOURCE_END)
253 return -EIO;
254
255 table = PCI_SRIOV_VFM_OFFSET(table);
256 if (table + nr_virtfn > pci_resource_len(dev, bir))
257 return -EIO;
258
259 pa = pci_resource_start(dev, bir) + table;
260 iov->mstate = ioremap(pa, nr_virtfn);
261 if (!iov->mstate)
262 return -ENOMEM;
263
264 INIT_WORK(&iov->mtask, sriov_migration_task);
265
266 iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
267 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
268
269 return 0;
270}
271
272static void sriov_disable_migration(struct pci_dev *dev)
273{
274 struct pci_sriov *iov = dev->sriov;
275
276 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
277 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
278
279 cancel_work_sync(&iov->mtask);
280 iounmap(iov->mstate);
281}
282
283static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
284{
285 int rc;
286 int i, j;
287 int nres;
288 u16 offset, stride, initial;
289 struct resource *res;
290 struct pci_dev *pdev;
291 struct pci_sriov *iov = dev->sriov;
292 int bars = 0;
293
294 if (!nr_virtfn)
295 return 0;
296
297 if (iov->nr_virtfn)
298 return -EINVAL;
299
300 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
301 if (initial > iov->total ||
302 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
303 return -EIO;
304
305 if (nr_virtfn < 0 || nr_virtfn > iov->total ||
306 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
307 return -EINVAL;
308
309 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
310 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
311 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
312 if (!offset || (nr_virtfn > 1 && !stride))
313 return -EIO;
314
315 nres = 0;
316 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
317 bars |= (1 << (i + PCI_IOV_RESOURCES));
318 res = dev->resource + PCI_IOV_RESOURCES + i;
319 if (res->parent)
320 nres++;
321 }
322 if (nres != iov->nres) {
323 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
324 return -ENOMEM;
325 }
326
327 iov->offset = offset;
328 iov->stride = stride;
329
330 if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->subordinate) {
331 dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
332 return -ENOMEM;
333 }
334
335 if (pci_enable_resources(dev, bars)) {
336 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
337 return -ENOMEM;
338 }
339
340 if (iov->link != dev->devfn) {
341 pdev = pci_get_slot(dev->bus, iov->link);
342 if (!pdev)
343 return -ENODEV;
344
345 pci_dev_put(pdev);
346
347 if (!pdev->is_physfn)
348 return -ENODEV;
349
350 rc = sysfs_create_link(&dev->dev.kobj,
351 &pdev->dev.kobj, "dep_link");
352 if (rc)
353 return rc;
354 }
355
356 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
357 pci_cfg_access_lock(dev);
358 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
359 msleep(100);
360 pci_cfg_access_unlock(dev);
361
362 iov->initial = initial;
363 if (nr_virtfn < initial)
364 initial = nr_virtfn;
365
366 for (i = 0; i < initial; i++) {
367 rc = virtfn_add(dev, i, 0);
368 if (rc)
369 goto failed;
370 }
371
372 if (iov->cap & PCI_SRIOV_CAP_VFM) {
373 rc = sriov_enable_migration(dev, nr_virtfn);
374 if (rc)
375 goto failed;
376 }
377
378 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
379 iov->nr_virtfn = nr_virtfn;
380
381 return 0;
382
383failed:
384 for (j = 0; j < i; j++)
385 virtfn_remove(dev, j, 0);
386
387 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
388 pci_cfg_access_lock(dev);
389 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
390 ssleep(1);
391 pci_cfg_access_unlock(dev);
392
393 if (iov->link != dev->devfn)
394 sysfs_remove_link(&dev->dev.kobj, "dep_link");
395
396 return rc;
397}
398
399static void sriov_disable(struct pci_dev *dev)
400{
401 int i;
402 struct pci_sriov *iov = dev->sriov;
403
404 if (!iov->nr_virtfn)
405 return;
406
407 if (iov->cap & PCI_SRIOV_CAP_VFM)
408 sriov_disable_migration(dev);
409
410 for (i = 0; i < iov->nr_virtfn; i++)
411 virtfn_remove(dev, i, 0);
412
413 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
414 pci_cfg_access_lock(dev);
415 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
416 ssleep(1);
417 pci_cfg_access_unlock(dev);
418
419 if (iov->link != dev->devfn)
420 sysfs_remove_link(&dev->dev.kobj, "dep_link");
421
422 iov->nr_virtfn = 0;
423}
424
425static int sriov_init(struct pci_dev *dev, int pos)
426{
427 int i;
428 int rc;
429 int nres;
430 u32 pgsz;
431 u16 ctrl, total, offset, stride;
432 struct pci_sriov *iov;
433 struct resource *res;
434 struct pci_dev *pdev;
435
436 if (dev->pcie_type != PCI_EXP_TYPE_RC_END &&
437 dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
438 return -ENODEV;
439
440 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
441 if (ctrl & PCI_SRIOV_CTRL_VFE) {
442 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
443 ssleep(1);
444 }
445
446 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
447 if (!total)
448 return 0;
449
450 ctrl = 0;
451 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
452 if (pdev->is_physfn)
453 goto found;
454
455 pdev = NULL;
456 if (pci_ari_enabled(dev->bus))
457 ctrl |= PCI_SRIOV_CTRL_ARI;
458
459found:
460 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
461 pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
462 pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
463 if (!offset || (total > 1 && !stride))
464 return -EIO;
465
466 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
467 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
468 pgsz &= ~((1 << i) - 1);
469 if (!pgsz)
470 return -EIO;
471
472 pgsz &= ~(pgsz - 1);
473 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
474
475 nres = 0;
476 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
477 res = dev->resource + PCI_IOV_RESOURCES + i;
478 i += __pci_read_base(dev, pci_bar_unknown, res,
479 pos + PCI_SRIOV_BAR + i * 4);
480 if (!res->flags)
481 continue;
482 if (resource_size(res) & (PAGE_SIZE - 1)) {
483 rc = -EIO;
484 goto failed;
485 }
486 res->end = res->start + resource_size(res) * total - 1;
487 nres++;
488 }
489
490 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
491 if (!iov) {
492 rc = -ENOMEM;
493 goto failed;
494 }
495
496 iov->pos = pos;
497 iov->nres = nres;
498 iov->ctrl = ctrl;
499 iov->total = total;
500 iov->offset = offset;
501 iov->stride = stride;
502 iov->pgsz = pgsz;
503 iov->self = dev;
504 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
505 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
506 if (dev->pcie_type == PCI_EXP_TYPE_RC_END)
507 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
508
509 if (pdev)
510 iov->dev = pci_dev_get(pdev);
511 else
512 iov->dev = dev;
513
514 mutex_init(&iov->lock);
515
516 dev->sriov = iov;
517 dev->is_physfn = 1;
518
519 return 0;
520
521failed:
522 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
523 res = dev->resource + PCI_IOV_RESOURCES + i;
524 res->flags = 0;
525 }
526
527 return rc;
528}
529
530static void sriov_release(struct pci_dev *dev)
531{
532 BUG_ON(dev->sriov->nr_virtfn);
533
534 if (dev != dev->sriov->dev)
535 pci_dev_put(dev->sriov->dev);
536
537 mutex_destroy(&dev->sriov->lock);
538
539 kfree(dev->sriov);
540 dev->sriov = NULL;
541}
542
543static void sriov_restore_state(struct pci_dev *dev)
544{
545 int i;
546 u16 ctrl;
547 struct pci_sriov *iov = dev->sriov;
548
549 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
550 if (ctrl & PCI_SRIOV_CTRL_VFE)
551 return;
552
553 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
554 pci_update_resource(dev, i);
555
556 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
557 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
558 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
559 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
560 msleep(100);
561}
562
563/**
564 * pci_iov_init - initialize the IOV capability
565 * @dev: the PCI device
566 *
567 * Returns 0 on success, or negative on failure.
568 */
569int pci_iov_init(struct pci_dev *dev)
570{
571 int pos;
572
573 if (!pci_is_pcie(dev))
574 return -ENODEV;
575
576 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
577 if (pos)
578 return sriov_init(dev, pos);
579
580 return -ENODEV;
581}
582
583/**
584 * pci_iov_release - release resources used by the IOV capability
585 * @dev: the PCI device
586 */
587void pci_iov_release(struct pci_dev *dev)
588{
589 if (dev->is_physfn)
590 sriov_release(dev);
591}
592
593/**
594 * pci_iov_resource_bar - get position of the SR-IOV BAR
595 * @dev: the PCI device
596 * @resno: the resource number
597 * @type: the BAR type to be filled in
598 *
599 * Returns position of the BAR encapsulated in the SR-IOV capability.
600 */
601int pci_iov_resource_bar(struct pci_dev *dev, int resno,
602 enum pci_bar_type *type)
603{
604 if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
605 return 0;
606
607 BUG_ON(!dev->is_physfn);
608
609 *type = pci_bar_unknown;
610
611 return dev->sriov->pos + PCI_SRIOV_BAR +
612 4 * (resno - PCI_IOV_RESOURCES);
613}
614
615/**
616 * pci_sriov_resource_alignment - get resource alignment for VF BAR
617 * @dev: the PCI device
618 * @resno: the resource number
619 *
620 * Returns the alignment of the VF BAR found in the SR-IOV capability.
621 * This is not the same as the resource size which is defined as
622 * the VF BAR size multiplied by the number of VFs. The alignment
623 * is just the VF BAR size.
624 */
625resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
626{
627 struct resource tmp;
628 enum pci_bar_type type;
629 int reg = pci_iov_resource_bar(dev, resno, &type);
630
631 if (!reg)
632 return 0;
633
634 __pci_read_base(dev, type, &tmp, reg);
635 return resource_alignment(&tmp);
636}
637
638/**
639 * pci_restore_iov_state - restore the state of the IOV capability
640 * @dev: the PCI device
641 */
642void pci_restore_iov_state(struct pci_dev *dev)
643{
644 if (dev->is_physfn)
645 sriov_restore_state(dev);
646}
647
648/**
649 * pci_iov_bus_range - find bus range used by Virtual Function
650 * @bus: the PCI bus
651 *
652 * Returns max number of buses (exclude current one) used by Virtual
653 * Functions.
654 */
655int pci_iov_bus_range(struct pci_bus *bus)
656{
657 int max = 0;
658 u8 busnr;
659 struct pci_dev *dev;
660
661 list_for_each_entry(dev, &bus->devices, bus_list) {
662 if (!dev->is_physfn)
663 continue;
664 busnr = virtfn_bus(dev, dev->sriov->total - 1);
665 if (busnr > max)
666 max = busnr;
667 }
668
669 return max ? max - bus->number : 0;
670}
671
672/**
673 * pci_enable_sriov - enable the SR-IOV capability
674 * @dev: the PCI device
675 * @nr_virtfn: number of virtual functions to enable
676 *
677 * Returns 0 on success, or negative on failure.
678 */
679int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
680{
681 might_sleep();
682
683 if (!dev->is_physfn)
684 return -ENODEV;
685
686 return sriov_enable(dev, nr_virtfn);
687}
688EXPORT_SYMBOL_GPL(pci_enable_sriov);
689
690/**
691 * pci_disable_sriov - disable the SR-IOV capability
692 * @dev: the PCI device
693 */
694void pci_disable_sriov(struct pci_dev *dev)
695{
696 might_sleep();
697
698 if (!dev->is_physfn)
699 return;
700
701 sriov_disable(dev);
702}
703EXPORT_SYMBOL_GPL(pci_disable_sriov);
704
705/**
706 * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
707 * @dev: the PCI device
708 *
709 * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
710 *
711 * Physical Function driver is responsible to register IRQ handler using
712 * VF Migration Interrupt Message Number, and call this function when the
713 * interrupt is generated by the hardware.
714 */
715irqreturn_t pci_sriov_migration(struct pci_dev *dev)
716{
717 if (!dev->is_physfn)
718 return IRQ_NONE;
719
720 return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
721}
722EXPORT_SYMBOL_GPL(pci_sriov_migration);
723
724/**
725 * pci_num_vf - return number of VFs associated with a PF device_release_driver
726 * @dev: the PCI device
727 *
728 * Returns number of VFs, or 0 if SR-IOV is not enabled.
729 */
730int pci_num_vf(struct pci_dev *dev)
731{
732 if (!dev || !dev->is_physfn)
733 return 0;
734 else
735 return dev->sriov->nr_virtfn;
736}
737EXPORT_SYMBOL_GPL(pci_num_vf);
1/*
2 * drivers/pci/iov.c
3 *
4 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
5 *
6 * PCI Express I/O Virtualization (IOV) support.
7 * Single Root IOV 1.0
8 * Address Translation Service 1.0
9 */
10
11#include <linux/pci.h>
12#include <linux/slab.h>
13#include <linux/mutex.h>
14#include <linux/export.h>
15#include <linux/string.h>
16#include <linux/delay.h>
17#include <linux/pci-ats.h>
18#include "pci.h"
19
20#define VIRTFN_ID_LEN 16
21
22int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
23{
24 if (!dev->is_physfn)
25 return -EINVAL;
26 return dev->bus->number + ((dev->devfn + dev->sriov->offset +
27 dev->sriov->stride * vf_id) >> 8);
28}
29
30int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
31{
32 if (!dev->is_physfn)
33 return -EINVAL;
34 return (dev->devfn + dev->sriov->offset +
35 dev->sriov->stride * vf_id) & 0xff;
36}
37
38/*
39 * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
40 * change when NumVFs changes.
41 *
42 * Update iov->offset and iov->stride when NumVFs is written.
43 */
44static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
45{
46 struct pci_sriov *iov = dev->sriov;
47
48 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
49 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
50 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
51}
52
53/*
54 * The PF consumes one bus number. NumVFs, First VF Offset, and VF Stride
55 * determine how many additional bus numbers will be consumed by VFs.
56 *
57 * Iterate over all valid NumVFs, validate offset and stride, and calculate
58 * the maximum number of bus numbers that could ever be required.
59 */
60static int compute_max_vf_buses(struct pci_dev *dev)
61{
62 struct pci_sriov *iov = dev->sriov;
63 int nr_virtfn, busnr, rc = 0;
64
65 for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
66 pci_iov_set_numvfs(dev, nr_virtfn);
67 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
68 rc = -EIO;
69 goto out;
70 }
71
72 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
73 if (busnr > iov->max_VF_buses)
74 iov->max_VF_buses = busnr;
75 }
76
77out:
78 pci_iov_set_numvfs(dev, 0);
79 return rc;
80}
81
82static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
83{
84 struct pci_bus *child;
85
86 if (bus->number == busnr)
87 return bus;
88
89 child = pci_find_bus(pci_domain_nr(bus), busnr);
90 if (child)
91 return child;
92
93 child = pci_add_new_bus(bus, NULL, busnr);
94 if (!child)
95 return NULL;
96
97 pci_bus_insert_busn_res(child, busnr, busnr);
98
99 return child;
100}
101
102static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
103{
104 if (physbus != virtbus && list_empty(&virtbus->devices))
105 pci_remove_bus(virtbus);
106}
107
108resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
109{
110 if (!dev->is_physfn)
111 return 0;
112
113 return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
114}
115
116int pci_iov_add_virtfn(struct pci_dev *dev, int id, int reset)
117{
118 int i;
119 int rc = -ENOMEM;
120 u64 size;
121 char buf[VIRTFN_ID_LEN];
122 struct pci_dev *virtfn;
123 struct resource *res;
124 struct pci_sriov *iov = dev->sriov;
125 struct pci_bus *bus;
126
127 mutex_lock(&iov->dev->sriov->lock);
128 bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
129 if (!bus)
130 goto failed;
131
132 virtfn = pci_alloc_dev(bus);
133 if (!virtfn)
134 goto failed0;
135
136 virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
137 virtfn->vendor = dev->vendor;
138 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
139 pci_setup_device(virtfn);
140 virtfn->dev.parent = dev->dev.parent;
141 virtfn->physfn = pci_dev_get(dev);
142 virtfn->is_virtfn = 1;
143 virtfn->multifunction = 0;
144
145 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
146 res = &dev->resource[i + PCI_IOV_RESOURCES];
147 if (!res->parent)
148 continue;
149 virtfn->resource[i].name = pci_name(virtfn);
150 virtfn->resource[i].flags = res->flags;
151 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
152 virtfn->resource[i].start = res->start + size * id;
153 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
154 rc = request_resource(res, &virtfn->resource[i]);
155 BUG_ON(rc);
156 }
157
158 if (reset)
159 __pci_reset_function(virtfn);
160
161 pci_device_add(virtfn, virtfn->bus);
162 mutex_unlock(&iov->dev->sriov->lock);
163
164 pci_bus_add_device(virtfn);
165 sprintf(buf, "virtfn%u", id);
166 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
167 if (rc)
168 goto failed1;
169 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
170 if (rc)
171 goto failed2;
172
173 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
174
175 return 0;
176
177failed2:
178 sysfs_remove_link(&dev->dev.kobj, buf);
179failed1:
180 pci_dev_put(dev);
181 mutex_lock(&iov->dev->sriov->lock);
182 pci_stop_and_remove_bus_device(virtfn);
183failed0:
184 virtfn_remove_bus(dev->bus, bus);
185failed:
186 mutex_unlock(&iov->dev->sriov->lock);
187
188 return rc;
189}
190
191void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset)
192{
193 char buf[VIRTFN_ID_LEN];
194 struct pci_dev *virtfn;
195 struct pci_sriov *iov = dev->sriov;
196
197 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
198 pci_iov_virtfn_bus(dev, id),
199 pci_iov_virtfn_devfn(dev, id));
200 if (!virtfn)
201 return;
202
203 if (reset) {
204 device_release_driver(&virtfn->dev);
205 __pci_reset_function(virtfn);
206 }
207
208 sprintf(buf, "virtfn%u", id);
209 sysfs_remove_link(&dev->dev.kobj, buf);
210 /*
211 * pci_stop_dev() could have been called for this virtfn already,
212 * so the directory for the virtfn may have been removed before.
213 * Double check to avoid spurious sysfs warnings.
214 */
215 if (virtfn->dev.kobj.sd)
216 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
217
218 mutex_lock(&iov->dev->sriov->lock);
219 pci_stop_and_remove_bus_device(virtfn);
220 virtfn_remove_bus(dev->bus, virtfn->bus);
221 mutex_unlock(&iov->dev->sriov->lock);
222
223 /* balance pci_get_domain_bus_and_slot() */
224 pci_dev_put(virtfn);
225 pci_dev_put(dev);
226}
227
228int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
229{
230 return 0;
231}
232
233int __weak pcibios_sriov_disable(struct pci_dev *pdev)
234{
235 return 0;
236}
237
238static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
239{
240 int rc;
241 int i;
242 int nres;
243 u16 initial;
244 struct resource *res;
245 struct pci_dev *pdev;
246 struct pci_sriov *iov = dev->sriov;
247 int bars = 0;
248 int bus;
249
250 if (!nr_virtfn)
251 return 0;
252
253 if (iov->num_VFs)
254 return -EINVAL;
255
256 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
257 if (initial > iov->total_VFs ||
258 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
259 return -EIO;
260
261 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
262 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
263 return -EINVAL;
264
265 nres = 0;
266 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
267 bars |= (1 << (i + PCI_IOV_RESOURCES));
268 res = &dev->resource[i + PCI_IOV_RESOURCES];
269 if (res->parent)
270 nres++;
271 }
272 if (nres != iov->nres) {
273 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
274 return -ENOMEM;
275 }
276
277 bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
278 if (bus > dev->bus->busn_res.end) {
279 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
280 nr_virtfn, bus, &dev->bus->busn_res);
281 return -ENOMEM;
282 }
283
284 if (pci_enable_resources(dev, bars)) {
285 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
286 return -ENOMEM;
287 }
288
289 if (iov->link != dev->devfn) {
290 pdev = pci_get_slot(dev->bus, iov->link);
291 if (!pdev)
292 return -ENODEV;
293
294 if (!pdev->is_physfn) {
295 pci_dev_put(pdev);
296 return -ENOSYS;
297 }
298
299 rc = sysfs_create_link(&dev->dev.kobj,
300 &pdev->dev.kobj, "dep_link");
301 pci_dev_put(pdev);
302 if (rc)
303 return rc;
304 }
305
306 pci_iov_set_numvfs(dev, nr_virtfn);
307 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
308 pci_cfg_access_lock(dev);
309 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
310 msleep(100);
311 pci_cfg_access_unlock(dev);
312
313 iov->initial_VFs = initial;
314 if (nr_virtfn < initial)
315 initial = nr_virtfn;
316
317 rc = pcibios_sriov_enable(dev, initial);
318 if (rc) {
319 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
320 goto err_pcibios;
321 }
322
323 for (i = 0; i < initial; i++) {
324 rc = pci_iov_add_virtfn(dev, i, 0);
325 if (rc)
326 goto failed;
327 }
328
329 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
330 iov->num_VFs = nr_virtfn;
331
332 return 0;
333
334failed:
335 while (i--)
336 pci_iov_remove_virtfn(dev, i, 0);
337
338 pcibios_sriov_disable(dev);
339err_pcibios:
340 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
341 pci_cfg_access_lock(dev);
342 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
343 ssleep(1);
344 pci_cfg_access_unlock(dev);
345
346 if (iov->link != dev->devfn)
347 sysfs_remove_link(&dev->dev.kobj, "dep_link");
348
349 pci_iov_set_numvfs(dev, 0);
350 return rc;
351}
352
353static void sriov_disable(struct pci_dev *dev)
354{
355 int i;
356 struct pci_sriov *iov = dev->sriov;
357
358 if (!iov->num_VFs)
359 return;
360
361 for (i = 0; i < iov->num_VFs; i++)
362 pci_iov_remove_virtfn(dev, i, 0);
363
364 pcibios_sriov_disable(dev);
365
366 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
367 pci_cfg_access_lock(dev);
368 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
369 ssleep(1);
370 pci_cfg_access_unlock(dev);
371
372 if (iov->link != dev->devfn)
373 sysfs_remove_link(&dev->dev.kobj, "dep_link");
374
375 iov->num_VFs = 0;
376 pci_iov_set_numvfs(dev, 0);
377}
378
379static int sriov_init(struct pci_dev *dev, int pos)
380{
381 int i, bar64;
382 int rc;
383 int nres;
384 u32 pgsz;
385 u16 ctrl, total;
386 struct pci_sriov *iov;
387 struct resource *res;
388 struct pci_dev *pdev;
389
390 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
391 if (ctrl & PCI_SRIOV_CTRL_VFE) {
392 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
393 ssleep(1);
394 }
395
396 ctrl = 0;
397 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
398 if (pdev->is_physfn)
399 goto found;
400
401 pdev = NULL;
402 if (pci_ari_enabled(dev->bus))
403 ctrl |= PCI_SRIOV_CTRL_ARI;
404
405found:
406 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
407
408 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
409 if (!total)
410 return 0;
411
412 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
413 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
414 pgsz &= ~((1 << i) - 1);
415 if (!pgsz)
416 return -EIO;
417
418 pgsz &= ~(pgsz - 1);
419 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
420
421 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
422 if (!iov)
423 return -ENOMEM;
424
425 nres = 0;
426 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
427 res = &dev->resource[i + PCI_IOV_RESOURCES];
428 /*
429 * If it is already FIXED, don't change it, something
430 * (perhaps EA or header fixups) wants it this way.
431 */
432 if (res->flags & IORESOURCE_PCI_FIXED)
433 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
434 else
435 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
436 pos + PCI_SRIOV_BAR + i * 4);
437 if (!res->flags)
438 continue;
439 if (resource_size(res) & (PAGE_SIZE - 1)) {
440 rc = -EIO;
441 goto failed;
442 }
443 iov->barsz[i] = resource_size(res);
444 res->end = res->start + resource_size(res) * total - 1;
445 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
446 i, res, i, total);
447 i += bar64;
448 nres++;
449 }
450
451 iov->pos = pos;
452 iov->nres = nres;
453 iov->ctrl = ctrl;
454 iov->total_VFs = total;
455 iov->pgsz = pgsz;
456 iov->self = dev;
457 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
458 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
459 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
460 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
461
462 if (pdev)
463 iov->dev = pci_dev_get(pdev);
464 else
465 iov->dev = dev;
466
467 mutex_init(&iov->lock);
468
469 dev->sriov = iov;
470 dev->is_physfn = 1;
471 rc = compute_max_vf_buses(dev);
472 if (rc)
473 goto fail_max_buses;
474
475 return 0;
476
477fail_max_buses:
478 dev->sriov = NULL;
479 dev->is_physfn = 0;
480failed:
481 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
482 res = &dev->resource[i + PCI_IOV_RESOURCES];
483 res->flags = 0;
484 }
485
486 kfree(iov);
487 return rc;
488}
489
490static void sriov_release(struct pci_dev *dev)
491{
492 BUG_ON(dev->sriov->num_VFs);
493
494 if (dev != dev->sriov->dev)
495 pci_dev_put(dev->sriov->dev);
496
497 mutex_destroy(&dev->sriov->lock);
498
499 kfree(dev->sriov);
500 dev->sriov = NULL;
501}
502
503static void sriov_restore_state(struct pci_dev *dev)
504{
505 int i;
506 u16 ctrl;
507 struct pci_sriov *iov = dev->sriov;
508
509 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
510 if (ctrl & PCI_SRIOV_CTRL_VFE)
511 return;
512
513 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
514 pci_update_resource(dev, i);
515
516 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
517 pci_iov_set_numvfs(dev, iov->num_VFs);
518 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
519 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
520 msleep(100);
521}
522
523/**
524 * pci_iov_init - initialize the IOV capability
525 * @dev: the PCI device
526 *
527 * Returns 0 on success, or negative on failure.
528 */
529int pci_iov_init(struct pci_dev *dev)
530{
531 int pos;
532
533 if (!pci_is_pcie(dev))
534 return -ENODEV;
535
536 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
537 if (pos)
538 return sriov_init(dev, pos);
539
540 return -ENODEV;
541}
542
543/**
544 * pci_iov_release - release resources used by the IOV capability
545 * @dev: the PCI device
546 */
547void pci_iov_release(struct pci_dev *dev)
548{
549 if (dev->is_physfn)
550 sriov_release(dev);
551}
552
553/**
554 * pci_iov_resource_bar - get position of the SR-IOV BAR
555 * @dev: the PCI device
556 * @resno: the resource number
557 *
558 * Returns position of the BAR encapsulated in the SR-IOV capability.
559 */
560int pci_iov_resource_bar(struct pci_dev *dev, int resno)
561{
562 if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
563 return 0;
564
565 BUG_ON(!dev->is_physfn);
566
567 return dev->sriov->pos + PCI_SRIOV_BAR +
568 4 * (resno - PCI_IOV_RESOURCES);
569}
570
571resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
572 int resno)
573{
574 return pci_iov_resource_size(dev, resno);
575}
576
577/**
578 * pci_sriov_resource_alignment - get resource alignment for VF BAR
579 * @dev: the PCI device
580 * @resno: the resource number
581 *
582 * Returns the alignment of the VF BAR found in the SR-IOV capability.
583 * This is not the same as the resource size which is defined as
584 * the VF BAR size multiplied by the number of VFs. The alignment
585 * is just the VF BAR size.
586 */
587resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
588{
589 return pcibios_iov_resource_alignment(dev, resno);
590}
591
592/**
593 * pci_restore_iov_state - restore the state of the IOV capability
594 * @dev: the PCI device
595 */
596void pci_restore_iov_state(struct pci_dev *dev)
597{
598 if (dev->is_physfn)
599 sriov_restore_state(dev);
600}
601
602/**
603 * pci_iov_bus_range - find bus range used by Virtual Function
604 * @bus: the PCI bus
605 *
606 * Returns max number of buses (exclude current one) used by Virtual
607 * Functions.
608 */
609int pci_iov_bus_range(struct pci_bus *bus)
610{
611 int max = 0;
612 struct pci_dev *dev;
613
614 list_for_each_entry(dev, &bus->devices, bus_list) {
615 if (!dev->is_physfn)
616 continue;
617 if (dev->sriov->max_VF_buses > max)
618 max = dev->sriov->max_VF_buses;
619 }
620
621 return max ? max - bus->number : 0;
622}
623
624/**
625 * pci_enable_sriov - enable the SR-IOV capability
626 * @dev: the PCI device
627 * @nr_virtfn: number of virtual functions to enable
628 *
629 * Returns 0 on success, or negative on failure.
630 */
631int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
632{
633 might_sleep();
634
635 if (!dev->is_physfn)
636 return -ENOSYS;
637
638 return sriov_enable(dev, nr_virtfn);
639}
640EXPORT_SYMBOL_GPL(pci_enable_sriov);
641
642/**
643 * pci_disable_sriov - disable the SR-IOV capability
644 * @dev: the PCI device
645 */
646void pci_disable_sriov(struct pci_dev *dev)
647{
648 might_sleep();
649
650 if (!dev->is_physfn)
651 return;
652
653 sriov_disable(dev);
654}
655EXPORT_SYMBOL_GPL(pci_disable_sriov);
656
657/**
658 * pci_num_vf - return number of VFs associated with a PF device_release_driver
659 * @dev: the PCI device
660 *
661 * Returns number of VFs, or 0 if SR-IOV is not enabled.
662 */
663int pci_num_vf(struct pci_dev *dev)
664{
665 if (!dev->is_physfn)
666 return 0;
667
668 return dev->sriov->num_VFs;
669}
670EXPORT_SYMBOL_GPL(pci_num_vf);
671
672/**
673 * pci_vfs_assigned - returns number of VFs are assigned to a guest
674 * @dev: the PCI device
675 *
676 * Returns number of VFs belonging to this device that are assigned to a guest.
677 * If device is not a physical function returns 0.
678 */
679int pci_vfs_assigned(struct pci_dev *dev)
680{
681 struct pci_dev *vfdev;
682 unsigned int vfs_assigned = 0;
683 unsigned short dev_id;
684
685 /* only search if we are a PF */
686 if (!dev->is_physfn)
687 return 0;
688
689 /*
690 * determine the device ID for the VFs, the vendor ID will be the
691 * same as the PF so there is no need to check for that one
692 */
693 pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
694
695 /* loop through all the VFs to see if we own any that are assigned */
696 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
697 while (vfdev) {
698 /*
699 * It is considered assigned if it is a virtual function with
700 * our dev as the physical function and the assigned bit is set
701 */
702 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
703 pci_is_dev_assigned(vfdev))
704 vfs_assigned++;
705
706 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
707 }
708
709 return vfs_assigned;
710}
711EXPORT_SYMBOL_GPL(pci_vfs_assigned);
712
713/**
714 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
715 * @dev: the PCI PF device
716 * @numvfs: number that should be used for TotalVFs supported
717 *
718 * Should be called from PF driver's probe routine with
719 * device's mutex held.
720 *
721 * Returns 0 if PF is an SRIOV-capable device and
722 * value of numvfs valid. If not a PF return -ENOSYS;
723 * if numvfs is invalid return -EINVAL;
724 * if VFs already enabled, return -EBUSY.
725 */
726int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
727{
728 if (!dev->is_physfn)
729 return -ENOSYS;
730 if (numvfs > dev->sriov->total_VFs)
731 return -EINVAL;
732
733 /* Shouldn't change if VFs already enabled */
734 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
735 return -EBUSY;
736 else
737 dev->sriov->driver_max_VFs = numvfs;
738
739 return 0;
740}
741EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
742
743/**
744 * pci_sriov_get_totalvfs -- get total VFs supported on this device
745 * @dev: the PCI PF device
746 *
747 * For a PCIe device with SRIOV support, return the PCIe
748 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
749 * if the driver reduced it. Otherwise 0.
750 */
751int pci_sriov_get_totalvfs(struct pci_dev *dev)
752{
753 if (!dev->is_physfn)
754 return 0;
755
756 if (dev->sriov->driver_max_VFs)
757 return dev->sriov->driver_max_VFs;
758
759 return dev->sriov->total_VFs;
760}
761EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);