1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PCI Express I/O Virtualization (IOV) support
4 * Single Root IOV 1.0
5 * Address Translation Service 1.0
6 *
7 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
8 */
9
10 #include <linux/pci.h>
11 #include <linux/slab.h>
12 #include <linux/mutex.h>
13 #include <linux/export.h>
14 #include <linux/string.h>
15 #include <linux/delay.h>
16 #include "pci.h"
17
18 #define VIRTFN_ID_LEN 16
19
pci_iov_virtfn_bus(struct pci_dev * dev,int vf_id)20 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
21 {
22 if (!dev->is_physfn)
23 return -EINVAL;
24 return dev->bus->number + ((dev->devfn + dev->sriov->offset +
25 dev->sriov->stride * vf_id) >> 8);
26 }
27
pci_iov_virtfn_devfn(struct pci_dev * dev,int vf_id)28 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
29 {
30 if (!dev->is_physfn)
31 return -EINVAL;
32 return (dev->devfn + dev->sriov->offset +
33 dev->sriov->stride * vf_id) & 0xff;
34 }
35
36 /*
37 * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
38 * change when NumVFs changes.
39 *
40 * Update iov->offset and iov->stride when NumVFs is written.
41 */
pci_iov_set_numvfs(struct pci_dev * dev,int nr_virtfn)42 static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
43 {
44 struct pci_sriov *iov = dev->sriov;
45
46 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
47 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
48 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride);
49 }
50
51 /*
52 * The PF consumes one bus number. NumVFs, First VF Offset, and VF Stride
53 * determine how many additional bus numbers will be consumed by VFs.
54 *
55 * Iterate over all valid NumVFs, validate offset and stride, and calculate
56 * the maximum number of bus numbers that could ever be required.
57 */
compute_max_vf_buses(struct pci_dev * dev)58 static int compute_max_vf_buses(struct pci_dev *dev)
59 {
60 struct pci_sriov *iov = dev->sriov;
61 int nr_virtfn, busnr, rc = 0;
62
63 for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
64 pci_iov_set_numvfs(dev, nr_virtfn);
65 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
66 rc = -EIO;
67 goto out;
68 }
69
70 busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
71 if (busnr > iov->max_VF_buses)
72 iov->max_VF_buses = busnr;
73 }
74
75 out:
76 pci_iov_set_numvfs(dev, 0);
77 return rc;
78 }
79
virtfn_add_bus(struct pci_bus * bus,int busnr)80 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
81 {
82 struct pci_bus *child;
83
84 if (bus->number == busnr)
85 return bus;
86
87 child = pci_find_bus(pci_domain_nr(bus), busnr);
88 if (child)
89 return child;
90
91 child = pci_add_new_bus(bus, NULL, busnr);
92 if (!child)
93 return NULL;
94
95 pci_bus_insert_busn_res(child, busnr, busnr);
96
97 return child;
98 }
99
virtfn_remove_bus(struct pci_bus * physbus,struct pci_bus * virtbus)100 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
101 {
102 if (physbus != virtbus && list_empty(&virtbus->devices))
103 pci_remove_bus(virtbus);
104 }
105
pci_iov_resource_size(struct pci_dev * dev,int resno)106 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
107 {
108 if (!dev->is_physfn)
109 return 0;
110
111 return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
112 }
113
pci_read_vf_config_common(struct pci_dev * virtfn)114 static void pci_read_vf_config_common(struct pci_dev *virtfn)
115 {
116 struct pci_dev *physfn = virtfn->physfn;
117
118 /*
119 * Some config registers are the same across all associated VFs.
120 * Read them once from VF0 so we can skip reading them from the
121 * other VFs.
122 *
123 * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
124 * have the same Revision ID and Subsystem ID, but we assume they
125 * do.
126 */
127 pci_read_config_dword(virtfn, PCI_CLASS_REVISION,
128 &physfn->sriov->class);
129 pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
130 &physfn->sriov->hdr_type);
131 pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
132 &physfn->sriov->subsystem_vendor);
133 pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
134 &physfn->sriov->subsystem_device);
135 }
136
pci_iov_add_virtfn(struct pci_dev * dev,int id)137 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
138 {
139 int i;
140 int rc = -ENOMEM;
141 u64 size;
142 char buf[VIRTFN_ID_LEN];
143 struct pci_dev *virtfn;
144 struct resource *res;
145 struct pci_sriov *iov = dev->sriov;
146 struct pci_bus *bus;
147
148 bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
149 if (!bus)
150 goto failed;
151
152 virtfn = pci_alloc_dev(bus);
153 if (!virtfn)
154 goto failed0;
155
156 virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
157 virtfn->vendor = dev->vendor;
158 virtfn->device = iov->vf_device;
159 virtfn->is_virtfn = 1;
160 virtfn->physfn = pci_dev_get(dev);
161
162 if (id == 0)
163 pci_read_vf_config_common(virtfn);
164
165 rc = pci_setup_device(virtfn);
166 if (rc)
167 goto failed1;
168
169 virtfn->dev.parent = dev->dev.parent;
170 virtfn->multifunction = 0;
171
172 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
173 res = &dev->resource[i + PCI_IOV_RESOURCES];
174 if (!res->parent)
175 continue;
176 virtfn->resource[i].name = pci_name(virtfn);
177 virtfn->resource[i].flags = res->flags;
178 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
179 virtfn->resource[i].start = res->start + size * id;
180 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
181 rc = request_resource(res, &virtfn->resource[i]);
182 BUG_ON(rc);
183 }
184
185 pci_device_add(virtfn, virtfn->bus);
186
187 sprintf(buf, "virtfn%u", id);
188 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
189 if (rc)
190 goto failed1;
191 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
192 if (rc)
193 goto failed2;
194
195 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
196
197 pci_bus_add_device(virtfn);
198
199 return 0;
200
201 failed2:
202 sysfs_remove_link(&dev->dev.kobj, buf);
203 failed1:
204 pci_stop_and_remove_bus_device(virtfn);
205 pci_dev_put(dev);
206 failed0:
207 virtfn_remove_bus(dev->bus, bus);
208 failed:
209
210 return rc;
211 }
212
pci_iov_remove_virtfn(struct pci_dev * dev,int id)213 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
214 {
215 char buf[VIRTFN_ID_LEN];
216 struct pci_dev *virtfn;
217
218 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
219 pci_iov_virtfn_bus(dev, id),
220 pci_iov_virtfn_devfn(dev, id));
221 if (!virtfn)
222 return;
223
224 sprintf(buf, "virtfn%u", id);
225 sysfs_remove_link(&dev->dev.kobj, buf);
226 /*
227 * pci_stop_dev() could have been called for this virtfn already,
228 * so the directory for the virtfn may have been removed before.
229 * Double check to avoid spurious sysfs warnings.
230 */
231 if (virtfn->dev.kobj.sd)
232 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
233
234 pci_stop_and_remove_bus_device(virtfn);
235 virtfn_remove_bus(dev->bus, virtfn->bus);
236
237 /* balance pci_get_domain_bus_and_slot() */
238 pci_dev_put(virtfn);
239 pci_dev_put(dev);
240 }
241
sriov_totalvfs_show(struct device * dev,struct device_attribute * attr,char * buf)242 static ssize_t sriov_totalvfs_show(struct device *dev,
243 struct device_attribute *attr,
244 char *buf)
245 {
246 struct pci_dev *pdev = to_pci_dev(dev);
247
248 return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
249 }
250
sriov_numvfs_show(struct device * dev,struct device_attribute * attr,char * buf)251 static ssize_t sriov_numvfs_show(struct device *dev,
252 struct device_attribute *attr,
253 char *buf)
254 {
255 struct pci_dev *pdev = to_pci_dev(dev);
256 u16 num_vfs;
257
258 /* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
259 device_lock(&pdev->dev);
260 num_vfs = pdev->sriov->num_VFs;
261 device_unlock(&pdev->dev);
262
263 return sprintf(buf, "%u\n", num_vfs);
264 }
265
266 /*
267 * num_vfs > 0; number of VFs to enable
268 * num_vfs = 0; disable all VFs
269 *
270 * Note: SRIOV spec does not allow partial VF
271 * disable, so it's all or none.
272 */
sriov_numvfs_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)273 static ssize_t sriov_numvfs_store(struct device *dev,
274 struct device_attribute *attr,
275 const char *buf, size_t count)
276 {
277 struct pci_dev *pdev = to_pci_dev(dev);
278 int ret;
279 u16 num_vfs;
280
281 ret = kstrtou16(buf, 0, &num_vfs);
282 if (ret < 0)
283 return ret;
284
285 if (num_vfs > pci_sriov_get_totalvfs(pdev))
286 return -ERANGE;
287
288 device_lock(&pdev->dev);
289
290 if (num_vfs == pdev->sriov->num_VFs)
291 goto exit;
292
293 /* is PF driver loaded w/callback */
294 if (!pdev->driver || !pdev->driver->sriov_configure) {
295 pci_info(pdev, "Driver does not support SRIOV configuration via sysfs\n");
296 ret = -ENOENT;
297 goto exit;
298 }
299
300 if (num_vfs == 0) {
301 /* disable VFs */
302 ret = pdev->driver->sriov_configure(pdev, 0);
303 goto exit;
304 }
305
306 /* enable VFs */
307 if (pdev->sriov->num_VFs) {
308 pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
309 pdev->sriov->num_VFs, num_vfs);
310 ret = -EBUSY;
311 goto exit;
312 }
313
314 ret = pdev->driver->sriov_configure(pdev, num_vfs);
315 if (ret < 0)
316 goto exit;
317
318 if (ret != num_vfs)
319 pci_warn(pdev, "%d VFs requested; only %d enabled\n",
320 num_vfs, ret);
321
322 exit:
323 device_unlock(&pdev->dev);
324
325 if (ret < 0)
326 return ret;
327
328 return count;
329 }
330
sriov_offset_show(struct device * dev,struct device_attribute * attr,char * buf)331 static ssize_t sriov_offset_show(struct device *dev,
332 struct device_attribute *attr,
333 char *buf)
334 {
335 struct pci_dev *pdev = to_pci_dev(dev);
336
337 return sprintf(buf, "%u\n", pdev->sriov->offset);
338 }
339
sriov_stride_show(struct device * dev,struct device_attribute * attr,char * buf)340 static ssize_t sriov_stride_show(struct device *dev,
341 struct device_attribute *attr,
342 char *buf)
343 {
344 struct pci_dev *pdev = to_pci_dev(dev);
345
346 return sprintf(buf, "%u\n", pdev->sriov->stride);
347 }
348
sriov_vf_device_show(struct device * dev,struct device_attribute * attr,char * buf)349 static ssize_t sriov_vf_device_show(struct device *dev,
350 struct device_attribute *attr,
351 char *buf)
352 {
353 struct pci_dev *pdev = to_pci_dev(dev);
354
355 return sprintf(buf, "%x\n", pdev->sriov->vf_device);
356 }
357
sriov_drivers_autoprobe_show(struct device * dev,struct device_attribute * attr,char * buf)358 static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
359 struct device_attribute *attr,
360 char *buf)
361 {
362 struct pci_dev *pdev = to_pci_dev(dev);
363
364 return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe);
365 }
366
sriov_drivers_autoprobe_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)367 static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
368 struct device_attribute *attr,
369 const char *buf, size_t count)
370 {
371 struct pci_dev *pdev = to_pci_dev(dev);
372 bool drivers_autoprobe;
373
374 if (kstrtobool(buf, &drivers_autoprobe) < 0)
375 return -EINVAL;
376
377 pdev->sriov->drivers_autoprobe = drivers_autoprobe;
378
379 return count;
380 }
381
382 static DEVICE_ATTR_RO(sriov_totalvfs);
383 static DEVICE_ATTR_RW(sriov_numvfs);
384 static DEVICE_ATTR_RO(sriov_offset);
385 static DEVICE_ATTR_RO(sriov_stride);
386 static DEVICE_ATTR_RO(sriov_vf_device);
387 static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
388
389 static struct attribute *sriov_dev_attrs[] = {
390 &dev_attr_sriov_totalvfs.attr,
391 &dev_attr_sriov_numvfs.attr,
392 &dev_attr_sriov_offset.attr,
393 &dev_attr_sriov_stride.attr,
394 &dev_attr_sriov_vf_device.attr,
395 &dev_attr_sriov_drivers_autoprobe.attr,
396 NULL,
397 };
398
sriov_attrs_are_visible(struct kobject * kobj,struct attribute * a,int n)399 static umode_t sriov_attrs_are_visible(struct kobject *kobj,
400 struct attribute *a, int n)
401 {
402 struct device *dev = kobj_to_dev(kobj);
403
404 if (!dev_is_pf(dev))
405 return 0;
406
407 return a->mode;
408 }
409
410 const struct attribute_group sriov_dev_attr_group = {
411 .attrs = sriov_dev_attrs,
412 .is_visible = sriov_attrs_are_visible,
413 };
414
pcibios_sriov_enable(struct pci_dev * pdev,u16 num_vfs)415 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
416 {
417 return 0;
418 }
419
pcibios_sriov_disable(struct pci_dev * pdev)420 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
421 {
422 return 0;
423 }
424
sriov_add_vfs(struct pci_dev * dev,u16 num_vfs)425 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
426 {
427 unsigned int i;
428 int rc;
429
430 if (dev->no_vf_scan)
431 return 0;
432
433 for (i = 0; i < num_vfs; i++) {
434 rc = pci_iov_add_virtfn(dev, i);
435 if (rc)
436 goto failed;
437 }
438 return 0;
439 failed:
440 while (i--)
441 pci_iov_remove_virtfn(dev, i);
442
443 return rc;
444 }
445
sriov_enable(struct pci_dev * dev,int nr_virtfn)446 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
447 {
448 int rc;
449 int i;
450 int nres;
451 u16 initial;
452 struct resource *res;
453 struct pci_dev *pdev;
454 struct pci_sriov *iov = dev->sriov;
455 int bars = 0;
456 int bus;
457
458 if (!nr_virtfn)
459 return 0;
460
461 if (iov->num_VFs)
462 return -EINVAL;
463
464 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
465 if (initial > iov->total_VFs ||
466 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
467 return -EIO;
468
469 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
470 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
471 return -EINVAL;
472
473 nres = 0;
474 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
475 bars |= (1 << (i + PCI_IOV_RESOURCES));
476 res = &dev->resource[i + PCI_IOV_RESOURCES];
477 if (res->parent)
478 nres++;
479 }
480 if (nres != iov->nres) {
481 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
482 return -ENOMEM;
483 }
484
485 bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
486 if (bus > dev->bus->busn_res.end) {
487 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
488 nr_virtfn, bus, &dev->bus->busn_res);
489 return -ENOMEM;
490 }
491
492 if (pci_enable_resources(dev, bars)) {
493 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
494 return -ENOMEM;
495 }
496
497 if (iov->link != dev->devfn) {
498 pdev = pci_get_slot(dev->bus, iov->link);
499 if (!pdev)
500 return -ENODEV;
501
502 if (!pdev->is_physfn) {
503 pci_dev_put(pdev);
504 return -ENOSYS;
505 }
506
507 rc = sysfs_create_link(&dev->dev.kobj,
508 &pdev->dev.kobj, "dep_link");
509 pci_dev_put(pdev);
510 if (rc)
511 return rc;
512 }
513
514 iov->initial_VFs = initial;
515 if (nr_virtfn < initial)
516 initial = nr_virtfn;
517
518 rc = pcibios_sriov_enable(dev, initial);
519 if (rc) {
520 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
521 goto err_pcibios;
522 }
523
524 pci_iov_set_numvfs(dev, nr_virtfn);
525 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
526 pci_cfg_access_lock(dev);
527 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
528 msleep(100);
529 pci_cfg_access_unlock(dev);
530
531 rc = sriov_add_vfs(dev, initial);
532 if (rc)
533 goto err_pcibios;
534
535 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
536 iov->num_VFs = nr_virtfn;
537
538 return 0;
539
540 err_pcibios:
541 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
542 pci_cfg_access_lock(dev);
543 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
544 ssleep(1);
545 pci_cfg_access_unlock(dev);
546
547 pcibios_sriov_disable(dev);
548
549 if (iov->link != dev->devfn)
550 sysfs_remove_link(&dev->dev.kobj, "dep_link");
551
552 pci_iov_set_numvfs(dev, 0);
553 return rc;
554 }
555
sriov_del_vfs(struct pci_dev * dev)556 static void sriov_del_vfs(struct pci_dev *dev)
557 {
558 struct pci_sriov *iov = dev->sriov;
559 int i;
560
561 if (dev->no_vf_scan)
562 return;
563
564 for (i = 0; i < iov->num_VFs; i++)
565 pci_iov_remove_virtfn(dev, i);
566 }
567
sriov_disable(struct pci_dev * dev)568 static void sriov_disable(struct pci_dev *dev)
569 {
570 struct pci_sriov *iov = dev->sriov;
571
572 if (!iov->num_VFs)
573 return;
574
575 sriov_del_vfs(dev);
576 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
577 pci_cfg_access_lock(dev);
578 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
579 ssleep(1);
580 pci_cfg_access_unlock(dev);
581
582 pcibios_sriov_disable(dev);
583
584 if (iov->link != dev->devfn)
585 sysfs_remove_link(&dev->dev.kobj, "dep_link");
586
587 iov->num_VFs = 0;
588 pci_iov_set_numvfs(dev, 0);
589 }
590
sriov_init(struct pci_dev * dev,int pos)591 static int sriov_init(struct pci_dev *dev, int pos)
592 {
593 int i, bar64;
594 int rc;
595 int nres;
596 u32 pgsz;
597 u16 ctrl, total;
598 struct pci_sriov *iov;
599 struct resource *res;
600 struct pci_dev *pdev;
601
602 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
603 if (ctrl & PCI_SRIOV_CTRL_VFE) {
604 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
605 ssleep(1);
606 }
607
608 ctrl = 0;
609 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
610 if (pdev->is_physfn)
611 goto found;
612
613 pdev = NULL;
614 if (pci_ari_enabled(dev->bus))
615 ctrl |= PCI_SRIOV_CTRL_ARI;
616
617 found:
618 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
619
620 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
621 if (!total)
622 return 0;
623
624 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
625 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
626 pgsz &= ~((1 << i) - 1);
627 if (!pgsz)
628 return -EIO;
629
630 pgsz &= ~(pgsz - 1);
631 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
632
633 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
634 if (!iov)
635 return -ENOMEM;
636
637 nres = 0;
638 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
639 res = &dev->resource[i + PCI_IOV_RESOURCES];
640 /*
641 * If it is already FIXED, don't change it, something
642 * (perhaps EA or header fixups) wants it this way.
643 */
644 if (res->flags & IORESOURCE_PCI_FIXED)
645 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
646 else
647 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
648 pos + PCI_SRIOV_BAR + i * 4);
649 if (!res->flags)
650 continue;
651 if (resource_size(res) & (PAGE_SIZE - 1)) {
652 rc = -EIO;
653 goto failed;
654 }
655 iov->barsz[i] = resource_size(res);
656 res->end = res->start + resource_size(res) * total - 1;
657 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
658 i, res, i, total);
659 i += bar64;
660 nres++;
661 }
662
663 iov->pos = pos;
664 iov->nres = nres;
665 iov->ctrl = ctrl;
666 iov->total_VFs = total;
667 iov->driver_max_VFs = total;
668 pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
669 iov->pgsz = pgsz;
670 iov->self = dev;
671 iov->drivers_autoprobe = true;
672 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
673 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
674 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
675 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
676
677 if (pdev)
678 iov->dev = pci_dev_get(pdev);
679 else
680 iov->dev = dev;
681
682 dev->sriov = iov;
683 dev->is_physfn = 1;
684 rc = compute_max_vf_buses(dev);
685 if (rc)
686 goto fail_max_buses;
687
688 return 0;
689
690 fail_max_buses:
691 dev->sriov = NULL;
692 dev->is_physfn = 0;
693 failed:
694 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
695 res = &dev->resource[i + PCI_IOV_RESOURCES];
696 res->flags = 0;
697 }
698
699 kfree(iov);
700 return rc;
701 }
702
sriov_release(struct pci_dev * dev)703 static void sriov_release(struct pci_dev *dev)
704 {
705 BUG_ON(dev->sriov->num_VFs);
706
707 if (dev != dev->sriov->dev)
708 pci_dev_put(dev->sriov->dev);
709
710 kfree(dev->sriov);
711 dev->sriov = NULL;
712 }
713
sriov_restore_state(struct pci_dev * dev)714 static void sriov_restore_state(struct pci_dev *dev)
715 {
716 int i;
717 u16 ctrl;
718 struct pci_sriov *iov = dev->sriov;
719
720 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
721 if (ctrl & PCI_SRIOV_CTRL_VFE)
722 return;
723
724 /*
725 * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
726 * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
727 */
728 ctrl &= ~PCI_SRIOV_CTRL_ARI;
729 ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
730 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
731
732 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
733 pci_update_resource(dev, i + PCI_IOV_RESOURCES);
734
735 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
736 pci_iov_set_numvfs(dev, iov->num_VFs);
737 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
738 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
739 msleep(100);
740 }
741
742 /**
743 * pci_iov_init - initialize the IOV capability
744 * @dev: the PCI device
745 *
746 * Returns 0 on success, or negative on failure.
747 */
pci_iov_init(struct pci_dev * dev)748 int pci_iov_init(struct pci_dev *dev)
749 {
750 int pos;
751
752 if (!pci_is_pcie(dev))
753 return -ENODEV;
754
755 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
756 if (pos)
757 return sriov_init(dev, pos);
758
759 return -ENODEV;
760 }
761
762 /**
763 * pci_iov_release - release resources used by the IOV capability
764 * @dev: the PCI device
765 */
pci_iov_release(struct pci_dev * dev)766 void pci_iov_release(struct pci_dev *dev)
767 {
768 if (dev->is_physfn)
769 sriov_release(dev);
770 }
771
772 /**
773 * pci_iov_remove - clean up SR-IOV state after PF driver is detached
774 * @dev: the PCI device
775 */
pci_iov_remove(struct pci_dev * dev)776 void pci_iov_remove(struct pci_dev *dev)
777 {
778 struct pci_sriov *iov = dev->sriov;
779
780 if (!dev->is_physfn)
781 return;
782
783 iov->driver_max_VFs = iov->total_VFs;
784 if (iov->num_VFs)
785 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
786 }
787
788 /**
789 * pci_iov_update_resource - update a VF BAR
790 * @dev: the PCI device
791 * @resno: the resource number
792 *
793 * Update a VF BAR in the SR-IOV capability of a PF.
794 */
pci_iov_update_resource(struct pci_dev * dev,int resno)795 void pci_iov_update_resource(struct pci_dev *dev, int resno)
796 {
797 struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
798 struct resource *res = dev->resource + resno;
799 int vf_bar = resno - PCI_IOV_RESOURCES;
800 struct pci_bus_region region;
801 u16 cmd;
802 u32 new;
803 int reg;
804
805 /*
806 * The generic pci_restore_bars() path calls this for all devices,
807 * including VFs and non-SR-IOV devices. If this is not a PF, we
808 * have nothing to do.
809 */
810 if (!iov)
811 return;
812
813 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
814 if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
815 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
816 vf_bar, res);
817 return;
818 }
819
820 /*
821 * Ignore unimplemented BARs, unused resource slots for 64-bit
822 * BARs, and non-movable resources, e.g., those described via
823 * Enhanced Allocation.
824 */
825 if (!res->flags)
826 return;
827
828 if (res->flags & IORESOURCE_UNSET)
829 return;
830
831 if (res->flags & IORESOURCE_PCI_FIXED)
832 return;
833
834 pcibios_resource_to_bus(dev->bus, ®ion, res);
835 new = region.start;
836 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
837
838 reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
839 pci_write_config_dword(dev, reg, new);
840 if (res->flags & IORESOURCE_MEM_64) {
841 new = region.start >> 16 >> 16;
842 pci_write_config_dword(dev, reg + 4, new);
843 }
844 }
845
pcibios_iov_resource_alignment(struct pci_dev * dev,int resno)846 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
847 int resno)
848 {
849 return pci_iov_resource_size(dev, resno);
850 }
851
852 /**
853 * pci_sriov_resource_alignment - get resource alignment for VF BAR
854 * @dev: the PCI device
855 * @resno: the resource number
856 *
857 * Returns the alignment of the VF BAR found in the SR-IOV capability.
858 * This is not the same as the resource size which is defined as
859 * the VF BAR size multiplied by the number of VFs. The alignment
860 * is just the VF BAR size.
861 */
pci_sriov_resource_alignment(struct pci_dev * dev,int resno)862 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
863 {
864 return pcibios_iov_resource_alignment(dev, resno);
865 }
866
867 /**
868 * pci_restore_iov_state - restore the state of the IOV capability
869 * @dev: the PCI device
870 */
pci_restore_iov_state(struct pci_dev * dev)871 void pci_restore_iov_state(struct pci_dev *dev)
872 {
873 if (dev->is_physfn)
874 sriov_restore_state(dev);
875 }
876
877 /**
878 * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
879 * @dev: the PCI device
880 * @auto_probe: set VF drivers auto probe flag
881 */
pci_vf_drivers_autoprobe(struct pci_dev * dev,bool auto_probe)882 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
883 {
884 if (dev->is_physfn)
885 dev->sriov->drivers_autoprobe = auto_probe;
886 }
887
888 /**
889 * pci_iov_bus_range - find bus range used by Virtual Function
890 * @bus: the PCI bus
891 *
892 * Returns max number of buses (exclude current one) used by Virtual
893 * Functions.
894 */
pci_iov_bus_range(struct pci_bus * bus)895 int pci_iov_bus_range(struct pci_bus *bus)
896 {
897 int max = 0;
898 struct pci_dev *dev;
899
900 list_for_each_entry(dev, &bus->devices, bus_list) {
901 if (!dev->is_physfn)
902 continue;
903 if (dev->sriov->max_VF_buses > max)
904 max = dev->sriov->max_VF_buses;
905 }
906
907 return max ? max - bus->number : 0;
908 }
909
910 /**
911 * pci_enable_sriov - enable the SR-IOV capability
912 * @dev: the PCI device
913 * @nr_virtfn: number of virtual functions to enable
914 *
915 * Returns 0 on success, or negative on failure.
916 */
pci_enable_sriov(struct pci_dev * dev,int nr_virtfn)917 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
918 {
919 might_sleep();
920
921 if (!dev->is_physfn)
922 return -ENOSYS;
923
924 return sriov_enable(dev, nr_virtfn);
925 }
926 EXPORT_SYMBOL_GPL(pci_enable_sriov);
927
928 /**
929 * pci_disable_sriov - disable the SR-IOV capability
930 * @dev: the PCI device
931 */
pci_disable_sriov(struct pci_dev * dev)932 void pci_disable_sriov(struct pci_dev *dev)
933 {
934 might_sleep();
935
936 if (!dev->is_physfn)
937 return;
938
939 sriov_disable(dev);
940 }
941 EXPORT_SYMBOL_GPL(pci_disable_sriov);
942
943 /**
944 * pci_num_vf - return number of VFs associated with a PF device_release_driver
945 * @dev: the PCI device
946 *
947 * Returns number of VFs, or 0 if SR-IOV is not enabled.
948 */
pci_num_vf(struct pci_dev * dev)949 int pci_num_vf(struct pci_dev *dev)
950 {
951 if (!dev->is_physfn)
952 return 0;
953
954 return dev->sriov->num_VFs;
955 }
956 EXPORT_SYMBOL_GPL(pci_num_vf);
957
958 /**
959 * pci_vfs_assigned - returns number of VFs are assigned to a guest
960 * @dev: the PCI device
961 *
962 * Returns number of VFs belonging to this device that are assigned to a guest.
963 * If device is not a physical function returns 0.
964 */
pci_vfs_assigned(struct pci_dev * dev)965 int pci_vfs_assigned(struct pci_dev *dev)
966 {
967 struct pci_dev *vfdev;
968 unsigned int vfs_assigned = 0;
969 unsigned short dev_id;
970
971 /* only search if we are a PF */
972 if (!dev->is_physfn)
973 return 0;
974
975 /*
976 * determine the device ID for the VFs, the vendor ID will be the
977 * same as the PF so there is no need to check for that one
978 */
979 dev_id = dev->sriov->vf_device;
980
981 /* loop through all the VFs to see if we own any that are assigned */
982 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
983 while (vfdev) {
984 /*
985 * It is considered assigned if it is a virtual function with
986 * our dev as the physical function and the assigned bit is set
987 */
988 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
989 pci_is_dev_assigned(vfdev))
990 vfs_assigned++;
991
992 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
993 }
994
995 return vfs_assigned;
996 }
997 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
998
999 /**
1000 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
1001 * @dev: the PCI PF device
1002 * @numvfs: number that should be used for TotalVFs supported
1003 *
1004 * Should be called from PF driver's probe routine with
1005 * device's mutex held.
1006 *
1007 * Returns 0 if PF is an SRIOV-capable device and
1008 * value of numvfs valid. If not a PF return -ENOSYS;
1009 * if numvfs is invalid return -EINVAL;
1010 * if VFs already enabled, return -EBUSY.
1011 */
pci_sriov_set_totalvfs(struct pci_dev * dev,u16 numvfs)1012 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
1013 {
1014 if (!dev->is_physfn)
1015 return -ENOSYS;
1016
1017 if (numvfs > dev->sriov->total_VFs)
1018 return -EINVAL;
1019
1020 /* Shouldn't change if VFs already enabled */
1021 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
1022 return -EBUSY;
1023
1024 dev->sriov->driver_max_VFs = numvfs;
1025 return 0;
1026 }
1027 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
1028
1029 /**
1030 * pci_sriov_get_totalvfs -- get total VFs supported on this device
1031 * @dev: the PCI PF device
1032 *
1033 * For a PCIe device with SRIOV support, return the PCIe
1034 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
1035 * if the driver reduced it. Otherwise 0.
1036 */
pci_sriov_get_totalvfs(struct pci_dev * dev)1037 int pci_sriov_get_totalvfs(struct pci_dev *dev)
1038 {
1039 if (!dev->is_physfn)
1040 return 0;
1041
1042 return dev->sriov->driver_max_VFs;
1043 }
1044 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
1045
1046 /**
1047 * pci_sriov_configure_simple - helper to configure SR-IOV
1048 * @dev: the PCI device
1049 * @nr_virtfn: number of virtual functions to enable, 0 to disable
1050 *
1051 * Enable or disable SR-IOV for devices that don't require any PF setup
1052 * before enabling SR-IOV. Return value is negative on error, or number of
1053 * VFs allocated on success.
1054 */
pci_sriov_configure_simple(struct pci_dev * dev,int nr_virtfn)1055 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
1056 {
1057 int rc;
1058
1059 might_sleep();
1060
1061 if (!dev->is_physfn)
1062 return -ENODEV;
1063
1064 if (pci_vfs_assigned(dev)) {
1065 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
1066 return -EPERM;
1067 }
1068
1069 if (nr_virtfn == 0) {
1070 sriov_disable(dev);
1071 return 0;
1072 }
1073
1074 rc = sriov_enable(dev, nr_virtfn);
1075 if (rc < 0)
1076 return rc;
1077
1078 return nr_virtfn;
1079 }
1080 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);
1081