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
pci_iov_virtfn_bus(struct pci_dev * dev,int vf_id)22 int 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
pci_iov_virtfn_devfn(struct pci_dev * dev,int vf_id)30 int 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 */
pci_iov_set_numvfs(struct pci_dev * dev,int nr_virtfn)44 static 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 */
compute_max_vf_buses(struct pci_dev * dev)60 static 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
77 out:
78 pci_iov_set_numvfs(dev, 0);
79 return rc;
80 }
81
virtfn_add_bus(struct pci_bus * bus,int busnr)82 static 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
virtfn_remove_bus(struct pci_bus * physbus,struct pci_bus * virtbus)102 static 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
pci_iov_resource_size(struct pci_dev * dev,int resno)108 resource_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
pci_iov_add_virtfn(struct pci_dev * dev,int id,int reset)116 int 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 rc = pci_setup_device(virtfn);
140 if (rc)
141 goto failed0;
142
143 virtfn->dev.parent = dev->dev.parent;
144 virtfn->physfn = pci_dev_get(dev);
145 virtfn->is_virtfn = 1;
146 virtfn->multifunction = 0;
147
148 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
149 res = &dev->resource[i + PCI_IOV_RESOURCES];
150 if (!res->parent)
151 continue;
152 virtfn->resource[i].name = pci_name(virtfn);
153 virtfn->resource[i].flags = res->flags;
154 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
155 virtfn->resource[i].start = res->start + size * id;
156 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
157 rc = request_resource(res, &virtfn->resource[i]);
158 BUG_ON(rc);
159 }
160
161 if (reset)
162 __pci_reset_function(virtfn);
163
164 pci_device_add(virtfn, virtfn->bus);
165 mutex_unlock(&iov->dev->sriov->lock);
166
167 sprintf(buf, "virtfn%u", id);
168 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
169 if (rc)
170 goto failed1;
171 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
172 if (rc)
173 goto failed2;
174
175 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
176
177 pci_bus_add_device(virtfn);
178
179 return 0;
180
181 failed2:
182 sysfs_remove_link(&dev->dev.kobj, buf);
183 failed1:
184 pci_dev_put(dev);
185 mutex_lock(&iov->dev->sriov->lock);
186 pci_stop_and_remove_bus_device(virtfn);
187 failed0:
188 virtfn_remove_bus(dev->bus, bus);
189 failed:
190 mutex_unlock(&iov->dev->sriov->lock);
191
192 return rc;
193 }
194
pci_iov_remove_virtfn(struct pci_dev * dev,int id,int reset)195 void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset)
196 {
197 char buf[VIRTFN_ID_LEN];
198 struct pci_dev *virtfn;
199 struct pci_sriov *iov = dev->sriov;
200
201 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
202 pci_iov_virtfn_bus(dev, id),
203 pci_iov_virtfn_devfn(dev, id));
204 if (!virtfn)
205 return;
206
207 if (reset) {
208 device_release_driver(&virtfn->dev);
209 __pci_reset_function(virtfn);
210 }
211
212 sprintf(buf, "virtfn%u", id);
213 sysfs_remove_link(&dev->dev.kobj, buf);
214 /*
215 * pci_stop_dev() could have been called for this virtfn already,
216 * so the directory for the virtfn may have been removed before.
217 * Double check to avoid spurious sysfs warnings.
218 */
219 if (virtfn->dev.kobj.sd)
220 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
221
222 mutex_lock(&iov->dev->sriov->lock);
223 pci_stop_and_remove_bus_device(virtfn);
224 virtfn_remove_bus(dev->bus, virtfn->bus);
225 mutex_unlock(&iov->dev->sriov->lock);
226
227 /* balance pci_get_domain_bus_and_slot() */
228 pci_dev_put(virtfn);
229 pci_dev_put(dev);
230 }
231
pcibios_sriov_enable(struct pci_dev * pdev,u16 num_vfs)232 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
233 {
234 return 0;
235 }
236
pcibios_sriov_disable(struct pci_dev * pdev)237 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
238 {
239 return 0;
240 }
241
sriov_enable(struct pci_dev * dev,int nr_virtfn)242 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
243 {
244 int rc;
245 int i;
246 int nres;
247 u16 initial;
248 struct resource *res;
249 struct pci_dev *pdev;
250 struct pci_sriov *iov = dev->sriov;
251 int bars = 0;
252 int bus;
253
254 if (!nr_virtfn)
255 return 0;
256
257 if (iov->num_VFs)
258 return -EINVAL;
259
260 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
261 if (initial > iov->total_VFs ||
262 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
263 return -EIO;
264
265 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
266 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
267 return -EINVAL;
268
269 nres = 0;
270 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
271 bars |= (1 << (i + PCI_IOV_RESOURCES));
272 res = &dev->resource[i + PCI_IOV_RESOURCES];
273 if (res->parent)
274 nres++;
275 }
276 if (nres != iov->nres) {
277 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
278 return -ENOMEM;
279 }
280
281 bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
282 if (bus > dev->bus->busn_res.end) {
283 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
284 nr_virtfn, bus, &dev->bus->busn_res);
285 return -ENOMEM;
286 }
287
288 if (pci_enable_resources(dev, bars)) {
289 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
290 return -ENOMEM;
291 }
292
293 if (iov->link != dev->devfn) {
294 pdev = pci_get_slot(dev->bus, iov->link);
295 if (!pdev)
296 return -ENODEV;
297
298 if (!pdev->is_physfn) {
299 pci_dev_put(pdev);
300 return -ENOSYS;
301 }
302
303 rc = sysfs_create_link(&dev->dev.kobj,
304 &pdev->dev.kobj, "dep_link");
305 pci_dev_put(pdev);
306 if (rc)
307 return rc;
308 }
309
310 iov->initial_VFs = initial;
311 if (nr_virtfn < initial)
312 initial = nr_virtfn;
313
314 rc = pcibios_sriov_enable(dev, initial);
315 if (rc) {
316 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
317 goto err_pcibios;
318 }
319
320 pci_iov_set_numvfs(dev, nr_virtfn);
321 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
322 pci_cfg_access_lock(dev);
323 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
324 msleep(100);
325 pci_cfg_access_unlock(dev);
326
327 for (i = 0; i < initial; i++) {
328 rc = pci_iov_add_virtfn(dev, i, 0);
329 if (rc)
330 goto failed;
331 }
332
333 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
334 iov->num_VFs = nr_virtfn;
335
336 return 0;
337
338 failed:
339 while (i--)
340 pci_iov_remove_virtfn(dev, i, 0);
341
342 pcibios_sriov_disable(dev);
343 err_pcibios:
344 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
345 pci_cfg_access_lock(dev);
346 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
347 ssleep(1);
348 pci_cfg_access_unlock(dev);
349
350 if (iov->link != dev->devfn)
351 sysfs_remove_link(&dev->dev.kobj, "dep_link");
352
353 pci_iov_set_numvfs(dev, 0);
354 return rc;
355 }
356
sriov_disable(struct pci_dev * dev)357 static void sriov_disable(struct pci_dev *dev)
358 {
359 int i;
360 struct pci_sriov *iov = dev->sriov;
361
362 if (!iov->num_VFs)
363 return;
364
365 for (i = 0; i < iov->num_VFs; i++)
366 pci_iov_remove_virtfn(dev, i, 0);
367
368 pcibios_sriov_disable(dev);
369
370 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
371 pci_cfg_access_lock(dev);
372 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
373 ssleep(1);
374 pci_cfg_access_unlock(dev);
375
376 if (iov->link != dev->devfn)
377 sysfs_remove_link(&dev->dev.kobj, "dep_link");
378
379 iov->num_VFs = 0;
380 pci_iov_set_numvfs(dev, 0);
381 }
382
sriov_init(struct pci_dev * dev,int pos)383 static int sriov_init(struct pci_dev *dev, int pos)
384 {
385 int i, bar64;
386 int rc;
387 int nres;
388 u32 pgsz;
389 u16 ctrl, total;
390 struct pci_sriov *iov;
391 struct resource *res;
392 struct pci_dev *pdev;
393
394 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
395 if (ctrl & PCI_SRIOV_CTRL_VFE) {
396 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
397 ssleep(1);
398 }
399
400 ctrl = 0;
401 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
402 if (pdev->is_physfn)
403 goto found;
404
405 pdev = NULL;
406 if (pci_ari_enabled(dev->bus))
407 ctrl |= PCI_SRIOV_CTRL_ARI;
408
409 found:
410 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
411
412 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
413 if (!total)
414 return 0;
415
416 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
417 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
418 pgsz &= ~((1 << i) - 1);
419 if (!pgsz)
420 return -EIO;
421
422 pgsz &= ~(pgsz - 1);
423 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
424
425 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
426 if (!iov)
427 return -ENOMEM;
428
429 nres = 0;
430 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
431 res = &dev->resource[i + PCI_IOV_RESOURCES];
432 /*
433 * If it is already FIXED, don't change it, something
434 * (perhaps EA or header fixups) wants it this way.
435 */
436 if (res->flags & IORESOURCE_PCI_FIXED)
437 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
438 else
439 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
440 pos + PCI_SRIOV_BAR + i * 4);
441 if (!res->flags)
442 continue;
443 if (resource_size(res) & (PAGE_SIZE - 1)) {
444 rc = -EIO;
445 goto failed;
446 }
447 iov->barsz[i] = resource_size(res);
448 res->end = res->start + resource_size(res) * total - 1;
449 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
450 i, res, i, total);
451 i += bar64;
452 nres++;
453 }
454
455 iov->pos = pos;
456 iov->nres = nres;
457 iov->ctrl = ctrl;
458 iov->total_VFs = total;
459 iov->pgsz = pgsz;
460 iov->self = dev;
461 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
462 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
463 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
464 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
465
466 if (pdev)
467 iov->dev = pci_dev_get(pdev);
468 else
469 iov->dev = dev;
470
471 mutex_init(&iov->lock);
472
473 dev->sriov = iov;
474 dev->is_physfn = 1;
475 rc = compute_max_vf_buses(dev);
476 if (rc)
477 goto fail_max_buses;
478
479 return 0;
480
481 fail_max_buses:
482 dev->sriov = NULL;
483 dev->is_physfn = 0;
484 failed:
485 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
486 res = &dev->resource[i + PCI_IOV_RESOURCES];
487 res->flags = 0;
488 }
489
490 kfree(iov);
491 return rc;
492 }
493
sriov_release(struct pci_dev * dev)494 static void sriov_release(struct pci_dev *dev)
495 {
496 BUG_ON(dev->sriov->num_VFs);
497
498 if (dev != dev->sriov->dev)
499 pci_dev_put(dev->sriov->dev);
500
501 mutex_destroy(&dev->sriov->lock);
502
503 kfree(dev->sriov);
504 dev->sriov = NULL;
505 }
506
sriov_restore_state(struct pci_dev * dev)507 static void sriov_restore_state(struct pci_dev *dev)
508 {
509 int i;
510 u16 ctrl;
511 struct pci_sriov *iov = dev->sriov;
512
513 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
514 if (ctrl & PCI_SRIOV_CTRL_VFE)
515 return;
516
517 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
518 pci_update_resource(dev, i);
519
520 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
521 pci_iov_set_numvfs(dev, iov->num_VFs);
522 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
523 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
524 msleep(100);
525 }
526
527 /**
528 * pci_iov_init - initialize the IOV capability
529 * @dev: the PCI device
530 *
531 * Returns 0 on success, or negative on failure.
532 */
pci_iov_init(struct pci_dev * dev)533 int pci_iov_init(struct pci_dev *dev)
534 {
535 int pos;
536
537 if (!pci_is_pcie(dev))
538 return -ENODEV;
539
540 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
541 if (pos)
542 return sriov_init(dev, pos);
543
544 return -ENODEV;
545 }
546
547 /**
548 * pci_iov_release - release resources used by the IOV capability
549 * @dev: the PCI device
550 */
pci_iov_release(struct pci_dev * dev)551 void pci_iov_release(struct pci_dev *dev)
552 {
553 if (dev->is_physfn)
554 sriov_release(dev);
555 }
556
557 /**
558 * pci_iov_update_resource - update a VF BAR
559 * @dev: the PCI device
560 * @resno: the resource number
561 *
562 * Update a VF BAR in the SR-IOV capability of a PF.
563 */
pci_iov_update_resource(struct pci_dev * dev,int resno)564 void pci_iov_update_resource(struct pci_dev *dev, int resno)
565 {
566 struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
567 struct resource *res = dev->resource + resno;
568 int vf_bar = resno - PCI_IOV_RESOURCES;
569 struct pci_bus_region region;
570 u16 cmd;
571 u32 new;
572 int reg;
573
574 /*
575 * The generic pci_restore_bars() path calls this for all devices,
576 * including VFs and non-SR-IOV devices. If this is not a PF, we
577 * have nothing to do.
578 */
579 if (!iov)
580 return;
581
582 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
583 if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
584 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
585 vf_bar, res);
586 return;
587 }
588
589 /*
590 * Ignore unimplemented BARs, unused resource slots for 64-bit
591 * BARs, and non-movable resources, e.g., those described via
592 * Enhanced Allocation.
593 */
594 if (!res->flags)
595 return;
596
597 if (res->flags & IORESOURCE_UNSET)
598 return;
599
600 if (res->flags & IORESOURCE_PCI_FIXED)
601 return;
602
603 pcibios_resource_to_bus(dev->bus, ®ion, res);
604 new = region.start;
605 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
606
607 reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
608 pci_write_config_dword(dev, reg, new);
609 if (res->flags & IORESOURCE_MEM_64) {
610 new = region.start >> 16 >> 16;
611 pci_write_config_dword(dev, reg + 4, new);
612 }
613 }
614
pcibios_iov_resource_alignment(struct pci_dev * dev,int resno)615 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
616 int resno)
617 {
618 return pci_iov_resource_size(dev, resno);
619 }
620
621 /**
622 * pci_sriov_resource_alignment - get resource alignment for VF BAR
623 * @dev: the PCI device
624 * @resno: the resource number
625 *
626 * Returns the alignment of the VF BAR found in the SR-IOV capability.
627 * This is not the same as the resource size which is defined as
628 * the VF BAR size multiplied by the number of VFs. The alignment
629 * is just the VF BAR size.
630 */
pci_sriov_resource_alignment(struct pci_dev * dev,int resno)631 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
632 {
633 return pcibios_iov_resource_alignment(dev, resno);
634 }
635
636 /**
637 * pci_restore_iov_state - restore the state of the IOV capability
638 * @dev: the PCI device
639 */
pci_restore_iov_state(struct pci_dev * dev)640 void pci_restore_iov_state(struct pci_dev *dev)
641 {
642 if (dev->is_physfn)
643 sriov_restore_state(dev);
644 }
645
646 /**
647 * pci_iov_bus_range - find bus range used by Virtual Function
648 * @bus: the PCI bus
649 *
650 * Returns max number of buses (exclude current one) used by Virtual
651 * Functions.
652 */
pci_iov_bus_range(struct pci_bus * bus)653 int pci_iov_bus_range(struct pci_bus *bus)
654 {
655 int max = 0;
656 struct pci_dev *dev;
657
658 list_for_each_entry(dev, &bus->devices, bus_list) {
659 if (!dev->is_physfn)
660 continue;
661 if (dev->sriov->max_VF_buses > max)
662 max = dev->sriov->max_VF_buses;
663 }
664
665 return max ? max - bus->number : 0;
666 }
667
668 /**
669 * pci_enable_sriov - enable the SR-IOV capability
670 * @dev: the PCI device
671 * @nr_virtfn: number of virtual functions to enable
672 *
673 * Returns 0 on success, or negative on failure.
674 */
pci_enable_sriov(struct pci_dev * dev,int nr_virtfn)675 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
676 {
677 might_sleep();
678
679 if (!dev->is_physfn)
680 return -ENOSYS;
681
682 return sriov_enable(dev, nr_virtfn);
683 }
684 EXPORT_SYMBOL_GPL(pci_enable_sriov);
685
686 /**
687 * pci_disable_sriov - disable the SR-IOV capability
688 * @dev: the PCI device
689 */
pci_disable_sriov(struct pci_dev * dev)690 void pci_disable_sriov(struct pci_dev *dev)
691 {
692 might_sleep();
693
694 if (!dev->is_physfn)
695 return;
696
697 sriov_disable(dev);
698 }
699 EXPORT_SYMBOL_GPL(pci_disable_sriov);
700
701 /**
702 * pci_num_vf - return number of VFs associated with a PF device_release_driver
703 * @dev: the PCI device
704 *
705 * Returns number of VFs, or 0 if SR-IOV is not enabled.
706 */
pci_num_vf(struct pci_dev * dev)707 int pci_num_vf(struct pci_dev *dev)
708 {
709 if (!dev->is_physfn)
710 return 0;
711
712 return dev->sriov->num_VFs;
713 }
714 EXPORT_SYMBOL_GPL(pci_num_vf);
715
716 /**
717 * pci_vfs_assigned - returns number of VFs are assigned to a guest
718 * @dev: the PCI device
719 *
720 * Returns number of VFs belonging to this device that are assigned to a guest.
721 * If device is not a physical function returns 0.
722 */
pci_vfs_assigned(struct pci_dev * dev)723 int pci_vfs_assigned(struct pci_dev *dev)
724 {
725 struct pci_dev *vfdev;
726 unsigned int vfs_assigned = 0;
727 unsigned short dev_id;
728
729 /* only search if we are a PF */
730 if (!dev->is_physfn)
731 return 0;
732
733 /*
734 * determine the device ID for the VFs, the vendor ID will be the
735 * same as the PF so there is no need to check for that one
736 */
737 pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
738
739 /* loop through all the VFs to see if we own any that are assigned */
740 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
741 while (vfdev) {
742 /*
743 * It is considered assigned if it is a virtual function with
744 * our dev as the physical function and the assigned bit is set
745 */
746 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
747 pci_is_dev_assigned(vfdev))
748 vfs_assigned++;
749
750 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
751 }
752
753 return vfs_assigned;
754 }
755 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
756
757 /**
758 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
759 * @dev: the PCI PF device
760 * @numvfs: number that should be used for TotalVFs supported
761 *
762 * Should be called from PF driver's probe routine with
763 * device's mutex held.
764 *
765 * Returns 0 if PF is an SRIOV-capable device and
766 * value of numvfs valid. If not a PF return -ENOSYS;
767 * if numvfs is invalid return -EINVAL;
768 * if VFs already enabled, return -EBUSY.
769 */
pci_sriov_set_totalvfs(struct pci_dev * dev,u16 numvfs)770 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
771 {
772 if (!dev->is_physfn)
773 return -ENOSYS;
774 if (numvfs > dev->sriov->total_VFs)
775 return -EINVAL;
776
777 /* Shouldn't change if VFs already enabled */
778 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
779 return -EBUSY;
780 else
781 dev->sriov->driver_max_VFs = numvfs;
782
783 return 0;
784 }
785 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
786
787 /**
788 * pci_sriov_get_totalvfs -- get total VFs supported on this device
789 * @dev: the PCI PF device
790 *
791 * For a PCIe device with SRIOV support, return the PCIe
792 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
793 * if the driver reduced it. Otherwise 0.
794 */
pci_sriov_get_totalvfs(struct pci_dev * dev)795 int pci_sriov_get_totalvfs(struct pci_dev *dev)
796 {
797 if (!dev->is_physfn)
798 return 0;
799
800 if (dev->sriov->driver_max_VFs)
801 return dev->sriov->driver_max_VFs;
802
803 return dev->sriov->total_VFs;
804 }
805 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
806