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
virtfn_add(struct pci_dev * dev,int id,int reset)116 static int virtfn_add(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 sprintf(buf, "virtfn%u", id);
165 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
166 if (rc)
167 goto failed1;
168 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
169 if (rc)
170 goto failed2;
171
172 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
173
174 pci_bus_add_device(virtfn);
175
176 return 0;
177
178 failed2:
179 sysfs_remove_link(&dev->dev.kobj, buf);
180 failed1:
181 pci_dev_put(dev);
182 mutex_lock(&iov->dev->sriov->lock);
183 pci_stop_and_remove_bus_device(virtfn);
184 failed0:
185 virtfn_remove_bus(dev->bus, bus);
186 failed:
187 mutex_unlock(&iov->dev->sriov->lock);
188
189 return rc;
190 }
191
virtfn_remove(struct pci_dev * dev,int id,int reset)192 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
193 {
194 char buf[VIRTFN_ID_LEN];
195 struct pci_dev *virtfn;
196 struct pci_sriov *iov = dev->sriov;
197
198 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
199 pci_iov_virtfn_bus(dev, id),
200 pci_iov_virtfn_devfn(dev, id));
201 if (!virtfn)
202 return;
203
204 if (reset) {
205 device_release_driver(&virtfn->dev);
206 __pci_reset_function(virtfn);
207 }
208
209 sprintf(buf, "virtfn%u", id);
210 sysfs_remove_link(&dev->dev.kobj, buf);
211 /*
212 * pci_stop_dev() could have been called for this virtfn already,
213 * so the directory for the virtfn may have been removed before.
214 * Double check to avoid spurious sysfs warnings.
215 */
216 if (virtfn->dev.kobj.sd)
217 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
218
219 mutex_lock(&iov->dev->sriov->lock);
220 pci_stop_and_remove_bus_device(virtfn);
221 virtfn_remove_bus(dev->bus, virtfn->bus);
222 mutex_unlock(&iov->dev->sriov->lock);
223
224 /* balance pci_get_domain_bus_and_slot() */
225 pci_dev_put(virtfn);
226 pci_dev_put(dev);
227 }
228
pcibios_sriov_enable(struct pci_dev * pdev,u16 num_vfs)229 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
230 {
231 return 0;
232 }
233
pcibios_sriov_disable(struct pci_dev * pdev)234 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
235 {
236 return 0;
237 }
238
sriov_enable(struct pci_dev * dev,int nr_virtfn)239 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
240 {
241 int rc;
242 int i;
243 int nres;
244 u16 initial;
245 struct resource *res;
246 struct pci_dev *pdev;
247 struct pci_sriov *iov = dev->sriov;
248 int bars = 0;
249 int bus;
250
251 if (!nr_virtfn)
252 return 0;
253
254 if (iov->num_VFs)
255 return -EINVAL;
256
257 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
258 if (initial > iov->total_VFs ||
259 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
260 return -EIO;
261
262 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
263 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
264 return -EINVAL;
265
266 nres = 0;
267 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
268 bars |= (1 << (i + PCI_IOV_RESOURCES));
269 res = &dev->resource[i + PCI_IOV_RESOURCES];
270 if (res->parent)
271 nres++;
272 }
273 if (nres != iov->nres) {
274 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
275 return -ENOMEM;
276 }
277
278 bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
279 if (bus > dev->bus->busn_res.end) {
280 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
281 nr_virtfn, bus, &dev->bus->busn_res);
282 return -ENOMEM;
283 }
284
285 if (pci_enable_resources(dev, bars)) {
286 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
287 return -ENOMEM;
288 }
289
290 if (iov->link != dev->devfn) {
291 pdev = pci_get_slot(dev->bus, iov->link);
292 if (!pdev)
293 return -ENODEV;
294
295 if (!pdev->is_physfn) {
296 pci_dev_put(pdev);
297 return -ENOSYS;
298 }
299
300 rc = sysfs_create_link(&dev->dev.kobj,
301 &pdev->dev.kobj, "dep_link");
302 pci_dev_put(pdev);
303 if (rc)
304 return rc;
305 }
306
307 iov->initial_VFs = initial;
308 if (nr_virtfn < initial)
309 initial = nr_virtfn;
310
311 rc = pcibios_sriov_enable(dev, initial);
312 if (rc) {
313 dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
314 goto err_pcibios;
315 }
316
317 pci_iov_set_numvfs(dev, nr_virtfn);
318 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
319 pci_cfg_access_lock(dev);
320 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
321 msleep(100);
322 pci_cfg_access_unlock(dev);
323
324 for (i = 0; i < initial; i++) {
325 rc = virtfn_add(dev, i, 0);
326 if (rc)
327 goto failed;
328 }
329
330 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
331 iov->num_VFs = nr_virtfn;
332
333 return 0;
334
335 failed:
336 while (i--)
337 virtfn_remove(dev, i, 0);
338
339 pcibios_sriov_disable(dev);
340 err_pcibios:
341 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
342 pci_cfg_access_lock(dev);
343 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
344 ssleep(1);
345 pci_cfg_access_unlock(dev);
346
347 if (iov->link != dev->devfn)
348 sysfs_remove_link(&dev->dev.kobj, "dep_link");
349
350 pci_iov_set_numvfs(dev, 0);
351 return rc;
352 }
353
sriov_disable(struct pci_dev * dev)354 static void sriov_disable(struct pci_dev *dev)
355 {
356 int i;
357 struct pci_sriov *iov = dev->sriov;
358
359 if (!iov->num_VFs)
360 return;
361
362 for (i = 0; i < iov->num_VFs; i++)
363 virtfn_remove(dev, i, 0);
364
365 pcibios_sriov_disable(dev);
366
367 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
368 pci_cfg_access_lock(dev);
369 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
370 ssleep(1);
371 pci_cfg_access_unlock(dev);
372
373 if (iov->link != dev->devfn)
374 sysfs_remove_link(&dev->dev.kobj, "dep_link");
375
376 iov->num_VFs = 0;
377 pci_iov_set_numvfs(dev, 0);
378 }
379
sriov_init(struct pci_dev * dev,int pos)380 static int sriov_init(struct pci_dev *dev, int pos)
381 {
382 int i, bar64;
383 int rc;
384 int nres;
385 u32 pgsz;
386 u16 ctrl, total;
387 struct pci_sriov *iov;
388 struct resource *res;
389 struct pci_dev *pdev;
390
391 if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
392 pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
393 return -ENODEV;
394
395 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
396 if (ctrl & PCI_SRIOV_CTRL_VFE) {
397 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
398 ssleep(1);
399 }
400
401 ctrl = 0;
402 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
403 if (pdev->is_physfn)
404 goto found;
405
406 pdev = NULL;
407 if (pci_ari_enabled(dev->bus))
408 ctrl |= PCI_SRIOV_CTRL_ARI;
409
410 found:
411 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
412
413 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
414 if (!total)
415 return 0;
416
417 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
418 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
419 pgsz &= ~((1 << i) - 1);
420 if (!pgsz)
421 return -EIO;
422
423 pgsz &= ~(pgsz - 1);
424 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
425
426 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
427 if (!iov)
428 return -ENOMEM;
429
430 nres = 0;
431 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
432 res = &dev->resource[i + PCI_IOV_RESOURCES];
433 /*
434 * If it is already FIXED, don't change it, something
435 * (perhaps EA or header fixups) wants it this way.
436 */
437 if (res->flags & IORESOURCE_PCI_FIXED)
438 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
439 else
440 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
441 pos + PCI_SRIOV_BAR + i * 4);
442 if (!res->flags)
443 continue;
444 if (resource_size(res) & (PAGE_SIZE - 1)) {
445 rc = -EIO;
446 goto failed;
447 }
448 iov->barsz[i] = resource_size(res);
449 res->end = res->start + resource_size(res) * total - 1;
450 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
451 i, res, i, total);
452 i += bar64;
453 nres++;
454 }
455
456 iov->pos = pos;
457 iov->nres = nres;
458 iov->ctrl = ctrl;
459 iov->total_VFs = total;
460 iov->pgsz = pgsz;
461 iov->self = dev;
462 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
463 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
464 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
465 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
466
467 if (pdev)
468 iov->dev = pci_dev_get(pdev);
469 else
470 iov->dev = dev;
471
472 mutex_init(&iov->lock);
473
474 dev->sriov = iov;
475 dev->is_physfn = 1;
476 rc = compute_max_vf_buses(dev);
477 if (rc)
478 goto fail_max_buses;
479
480 return 0;
481
482 fail_max_buses:
483 dev->sriov = NULL;
484 dev->is_physfn = 0;
485 failed:
486 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
487 res = &dev->resource[i + PCI_IOV_RESOURCES];
488 res->flags = 0;
489 }
490
491 kfree(iov);
492 return rc;
493 }
494
sriov_release(struct pci_dev * dev)495 static void sriov_release(struct pci_dev *dev)
496 {
497 BUG_ON(dev->sriov->num_VFs);
498
499 if (dev != dev->sriov->dev)
500 pci_dev_put(dev->sriov->dev);
501
502 mutex_destroy(&dev->sriov->lock);
503
504 kfree(dev->sriov);
505 dev->sriov = NULL;
506 }
507
sriov_restore_state(struct pci_dev * dev)508 static void sriov_restore_state(struct pci_dev *dev)
509 {
510 int i;
511 u16 ctrl;
512 struct pci_sriov *iov = dev->sriov;
513
514 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
515 if (ctrl & PCI_SRIOV_CTRL_VFE)
516 return;
517
518 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
519 pci_update_resource(dev, i);
520
521 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
522 pci_iov_set_numvfs(dev, iov->num_VFs);
523 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
524 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
525 msleep(100);
526 }
527
528 /**
529 * pci_iov_init - initialize the IOV capability
530 * @dev: the PCI device
531 *
532 * Returns 0 on success, or negative on failure.
533 */
pci_iov_init(struct pci_dev * dev)534 int pci_iov_init(struct pci_dev *dev)
535 {
536 int pos;
537
538 if (!pci_is_pcie(dev))
539 return -ENODEV;
540
541 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
542 if (pos)
543 return sriov_init(dev, pos);
544
545 return -ENODEV;
546 }
547
548 /**
549 * pci_iov_release - release resources used by the IOV capability
550 * @dev: the PCI device
551 */
pci_iov_release(struct pci_dev * dev)552 void pci_iov_release(struct pci_dev *dev)
553 {
554 if (dev->is_physfn)
555 sriov_release(dev);
556 }
557
558 /**
559 * pci_iov_update_resource - update a VF BAR
560 * @dev: the PCI device
561 * @resno: the resource number
562 *
563 * Update a VF BAR in the SR-IOV capability of a PF.
564 */
pci_iov_update_resource(struct pci_dev * dev,int resno)565 void pci_iov_update_resource(struct pci_dev *dev, int resno)
566 {
567 struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
568 struct resource *res = dev->resource + resno;
569 int vf_bar = resno - PCI_IOV_RESOURCES;
570 struct pci_bus_region region;
571 u16 cmd;
572 u32 new;
573 int reg;
574
575 /*
576 * The generic pci_restore_bars() path calls this for all devices,
577 * including VFs and non-SR-IOV devices. If this is not a PF, we
578 * have nothing to do.
579 */
580 if (!iov)
581 return;
582
583 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
584 if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
585 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
586 vf_bar, res);
587 return;
588 }
589
590 /*
591 * Ignore unimplemented BARs, unused resource slots for 64-bit
592 * BARs, and non-movable resources, e.g., those described via
593 * Enhanced Allocation.
594 */
595 if (!res->flags)
596 return;
597
598 if (res->flags & IORESOURCE_UNSET)
599 return;
600
601 if (res->flags & IORESOURCE_PCI_FIXED)
602 return;
603
604 pcibios_resource_to_bus(dev->bus, ®ion, res);
605 new = region.start;
606 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
607
608 reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
609 pci_write_config_dword(dev, reg, new);
610 if (res->flags & IORESOURCE_MEM_64) {
611 new = region.start >> 16 >> 16;
612 pci_write_config_dword(dev, reg + 4, new);
613 }
614 }
615
pcibios_iov_resource_alignment(struct pci_dev * dev,int resno)616 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
617 int resno)
618 {
619 return pci_iov_resource_size(dev, resno);
620 }
621
622 /**
623 * pci_sriov_resource_alignment - get resource alignment for VF BAR
624 * @dev: the PCI device
625 * @resno: the resource number
626 *
627 * Returns the alignment of the VF BAR found in the SR-IOV capability.
628 * This is not the same as the resource size which is defined as
629 * the VF BAR size multiplied by the number of VFs. The alignment
630 * is just the VF BAR size.
631 */
pci_sriov_resource_alignment(struct pci_dev * dev,int resno)632 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
633 {
634 return pcibios_iov_resource_alignment(dev, resno);
635 }
636
637 /**
638 * pci_restore_iov_state - restore the state of the IOV capability
639 * @dev: the PCI device
640 */
pci_restore_iov_state(struct pci_dev * dev)641 void pci_restore_iov_state(struct pci_dev *dev)
642 {
643 if (dev->is_physfn)
644 sriov_restore_state(dev);
645 }
646
647 /**
648 * pci_iov_bus_range - find bus range used by Virtual Function
649 * @bus: the PCI bus
650 *
651 * Returns max number of buses (exclude current one) used by Virtual
652 * Functions.
653 */
pci_iov_bus_range(struct pci_bus * bus)654 int pci_iov_bus_range(struct pci_bus *bus)
655 {
656 int max = 0;
657 struct pci_dev *dev;
658
659 list_for_each_entry(dev, &bus->devices, bus_list) {
660 if (!dev->is_physfn)
661 continue;
662 if (dev->sriov->max_VF_buses > max)
663 max = dev->sriov->max_VF_buses;
664 }
665
666 return max ? max - bus->number : 0;
667 }
668
669 /**
670 * pci_enable_sriov - enable the SR-IOV capability
671 * @dev: the PCI device
672 * @nr_virtfn: number of virtual functions to enable
673 *
674 * Returns 0 on success, or negative on failure.
675 */
pci_enable_sriov(struct pci_dev * dev,int nr_virtfn)676 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
677 {
678 might_sleep();
679
680 if (!dev->is_physfn)
681 return -ENOSYS;
682
683 return sriov_enable(dev, nr_virtfn);
684 }
685 EXPORT_SYMBOL_GPL(pci_enable_sriov);
686
687 /**
688 * pci_disable_sriov - disable the SR-IOV capability
689 * @dev: the PCI device
690 */
pci_disable_sriov(struct pci_dev * dev)691 void pci_disable_sriov(struct pci_dev *dev)
692 {
693 might_sleep();
694
695 if (!dev->is_physfn)
696 return;
697
698 sriov_disable(dev);
699 }
700 EXPORT_SYMBOL_GPL(pci_disable_sriov);
701
702 /**
703 * pci_num_vf - return number of VFs associated with a PF device_release_driver
704 * @dev: the PCI device
705 *
706 * Returns number of VFs, or 0 if SR-IOV is not enabled.
707 */
pci_num_vf(struct pci_dev * dev)708 int pci_num_vf(struct pci_dev *dev)
709 {
710 if (!dev->is_physfn)
711 return 0;
712
713 return dev->sriov->num_VFs;
714 }
715 EXPORT_SYMBOL_GPL(pci_num_vf);
716
717 /**
718 * pci_vfs_assigned - returns number of VFs are assigned to a guest
719 * @dev: the PCI device
720 *
721 * Returns number of VFs belonging to this device that are assigned to a guest.
722 * If device is not a physical function returns 0.
723 */
pci_vfs_assigned(struct pci_dev * dev)724 int pci_vfs_assigned(struct pci_dev *dev)
725 {
726 struct pci_dev *vfdev;
727 unsigned int vfs_assigned = 0;
728 unsigned short dev_id;
729
730 /* only search if we are a PF */
731 if (!dev->is_physfn)
732 return 0;
733
734 /*
735 * determine the device ID for the VFs, the vendor ID will be the
736 * same as the PF so there is no need to check for that one
737 */
738 pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
739
740 /* loop through all the VFs to see if we own any that are assigned */
741 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
742 while (vfdev) {
743 /*
744 * It is considered assigned if it is a virtual function with
745 * our dev as the physical function and the assigned bit is set
746 */
747 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
748 pci_is_dev_assigned(vfdev))
749 vfs_assigned++;
750
751 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
752 }
753
754 return vfs_assigned;
755 }
756 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
757
758 /**
759 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
760 * @dev: the PCI PF device
761 * @numvfs: number that should be used for TotalVFs supported
762 *
763 * Should be called from PF driver's probe routine with
764 * device's mutex held.
765 *
766 * Returns 0 if PF is an SRIOV-capable device and
767 * value of numvfs valid. If not a PF return -ENOSYS;
768 * if numvfs is invalid return -EINVAL;
769 * if VFs already enabled, return -EBUSY.
770 */
pci_sriov_set_totalvfs(struct pci_dev * dev,u16 numvfs)771 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
772 {
773 if (!dev->is_physfn)
774 return -ENOSYS;
775 if (numvfs > dev->sriov->total_VFs)
776 return -EINVAL;
777
778 /* Shouldn't change if VFs already enabled */
779 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
780 return -EBUSY;
781 else
782 dev->sriov->driver_max_VFs = numvfs;
783
784 return 0;
785 }
786 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
787
788 /**
789 * pci_sriov_get_totalvfs -- get total VFs supported on this device
790 * @dev: the PCI PF device
791 *
792 * For a PCIe device with SRIOV support, return the PCIe
793 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
794 * if the driver reduced it. Otherwise 0.
795 */
pci_sriov_get_totalvfs(struct pci_dev * dev)796 int pci_sriov_get_totalvfs(struct pci_dev *dev)
797 {
798 if (!dev->is_physfn)
799 return 0;
800
801 if (dev->sriov->driver_max_VFs)
802 return dev->sriov->driver_max_VFs;
803
804 return dev->sriov->total_VFs;
805 }
806 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
807