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/export.h>
13 #include <linux/string.h>
14 #include <linux/delay.h>
15 #include "pci.h"
16
17 #define VIRTFN_ID_LEN 17 /* "virtfn%u\0" for 2^32 - 1 */
18
pci_iov_virtfn_bus(struct pci_dev * dev,int vf_id)19 int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
20 {
21 if (!dev->is_physfn)
22 return -EINVAL;
23 return dev->bus->number + ((dev->devfn + dev->sriov->offset +
24 dev->sriov->stride * vf_id) >> 8);
25 }
26
pci_iov_virtfn_devfn(struct pci_dev * dev,int vf_id)27 int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
28 {
29 if (!dev->is_physfn)
30 return -EINVAL;
31 return (dev->devfn + dev->sriov->offset +
32 dev->sriov->stride * vf_id) & 0xff;
33 }
34 EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
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_sysfs_link(struct pci_dev * dev,struct pci_dev * virtfn,int id)137 int pci_iov_sysfs_link(struct pci_dev *dev,
138 struct pci_dev *virtfn, int id)
139 {
140 char buf[VIRTFN_ID_LEN];
141 int rc;
142
143 sprintf(buf, "virtfn%u", id);
144 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
145 if (rc)
146 goto failed;
147 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
148 if (rc)
149 goto failed1;
150
151 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
152
153 return 0;
154
155 failed1:
156 sysfs_remove_link(&dev->dev.kobj, buf);
157 failed:
158 return rc;
159 }
160
161 #ifdef CONFIG_PCI_MSI
sriov_vf_total_msix_show(struct device * dev,struct device_attribute * attr,char * buf)162 static ssize_t sriov_vf_total_msix_show(struct device *dev,
163 struct device_attribute *attr,
164 char *buf)
165 {
166 struct pci_dev *pdev = to_pci_dev(dev);
167 u32 vf_total_msix = 0;
168
169 device_lock(dev);
170 if (!pdev->driver || !pdev->driver->sriov_get_vf_total_msix)
171 goto unlock;
172
173 vf_total_msix = pdev->driver->sriov_get_vf_total_msix(pdev);
174 unlock:
175 device_unlock(dev);
176 return sysfs_emit(buf, "%u\n", vf_total_msix);
177 }
178 static DEVICE_ATTR_RO(sriov_vf_total_msix);
179
sriov_vf_msix_count_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)180 static ssize_t sriov_vf_msix_count_store(struct device *dev,
181 struct device_attribute *attr,
182 const char *buf, size_t count)
183 {
184 struct pci_dev *vf_dev = to_pci_dev(dev);
185 struct pci_dev *pdev = pci_physfn(vf_dev);
186 int val, ret;
187
188 ret = kstrtoint(buf, 0, &val);
189 if (ret)
190 return ret;
191
192 if (val < 0)
193 return -EINVAL;
194
195 device_lock(&pdev->dev);
196 if (!pdev->driver || !pdev->driver->sriov_set_msix_vec_count) {
197 ret = -EOPNOTSUPP;
198 goto err_pdev;
199 }
200
201 device_lock(&vf_dev->dev);
202 if (vf_dev->driver) {
203 /*
204 * A driver is already attached to this VF and has configured
205 * itself based on the current MSI-X vector count. Changing
206 * the vector size could mess up the driver, so block it.
207 */
208 ret = -EBUSY;
209 goto err_dev;
210 }
211
212 ret = pdev->driver->sriov_set_msix_vec_count(vf_dev, val);
213
214 err_dev:
215 device_unlock(&vf_dev->dev);
216 err_pdev:
217 device_unlock(&pdev->dev);
218 return ret ? : count;
219 }
220 static DEVICE_ATTR_WO(sriov_vf_msix_count);
221 #endif
222
223 static struct attribute *sriov_vf_dev_attrs[] = {
224 #ifdef CONFIG_PCI_MSI
225 &dev_attr_sriov_vf_msix_count.attr,
226 #endif
227 NULL,
228 };
229
sriov_vf_attrs_are_visible(struct kobject * kobj,struct attribute * a,int n)230 static umode_t sriov_vf_attrs_are_visible(struct kobject *kobj,
231 struct attribute *a, int n)
232 {
233 struct device *dev = kobj_to_dev(kobj);
234 struct pci_dev *pdev = to_pci_dev(dev);
235
236 if (!pdev->is_virtfn)
237 return 0;
238
239 return a->mode;
240 }
241
242 const struct attribute_group sriov_vf_dev_attr_group = {
243 .attrs = sriov_vf_dev_attrs,
244 .is_visible = sriov_vf_attrs_are_visible,
245 };
246
pci_iov_add_virtfn(struct pci_dev * dev,int id)247 int pci_iov_add_virtfn(struct pci_dev *dev, int id)
248 {
249 int i;
250 int rc = -ENOMEM;
251 u64 size;
252 struct pci_dev *virtfn;
253 struct resource *res;
254 struct pci_sriov *iov = dev->sriov;
255 struct pci_bus *bus;
256
257 bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
258 if (!bus)
259 goto failed;
260
261 virtfn = pci_alloc_dev(bus);
262 if (!virtfn)
263 goto failed0;
264
265 virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
266 virtfn->vendor = dev->vendor;
267 virtfn->device = iov->vf_device;
268 virtfn->is_virtfn = 1;
269 virtfn->physfn = pci_dev_get(dev);
270 virtfn->no_command_memory = 1;
271
272 if (id == 0)
273 pci_read_vf_config_common(virtfn);
274
275 rc = pci_setup_device(virtfn);
276 if (rc)
277 goto failed1;
278
279 virtfn->dev.parent = dev->dev.parent;
280 virtfn->multifunction = 0;
281
282 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
283 res = &dev->resource[i + PCI_IOV_RESOURCES];
284 if (!res->parent)
285 continue;
286 virtfn->resource[i].name = pci_name(virtfn);
287 virtfn->resource[i].flags = res->flags;
288 size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
289 virtfn->resource[i].start = res->start + size * id;
290 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
291 rc = request_resource(res, &virtfn->resource[i]);
292 BUG_ON(rc);
293 }
294
295 pci_device_add(virtfn, virtfn->bus);
296 rc = pci_iov_sysfs_link(dev, virtfn, id);
297 if (rc)
298 goto failed1;
299
300 pci_bus_add_device(virtfn);
301
302 return 0;
303
304 failed1:
305 pci_stop_and_remove_bus_device(virtfn);
306 pci_dev_put(dev);
307 failed0:
308 virtfn_remove_bus(dev->bus, bus);
309 failed:
310
311 return rc;
312 }
313
pci_iov_remove_virtfn(struct pci_dev * dev,int id)314 void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
315 {
316 char buf[VIRTFN_ID_LEN];
317 struct pci_dev *virtfn;
318
319 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
320 pci_iov_virtfn_bus(dev, id),
321 pci_iov_virtfn_devfn(dev, id));
322 if (!virtfn)
323 return;
324
325 sprintf(buf, "virtfn%u", id);
326 sysfs_remove_link(&dev->dev.kobj, buf);
327 /*
328 * pci_stop_dev() could have been called for this virtfn already,
329 * so the directory for the virtfn may have been removed before.
330 * Double check to avoid spurious sysfs warnings.
331 */
332 if (virtfn->dev.kobj.sd)
333 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
334
335 pci_stop_and_remove_bus_device(virtfn);
336 virtfn_remove_bus(dev->bus, virtfn->bus);
337
338 /* balance pci_get_domain_bus_and_slot() */
339 pci_dev_put(virtfn);
340 pci_dev_put(dev);
341 }
342
sriov_totalvfs_show(struct device * dev,struct device_attribute * attr,char * buf)343 static ssize_t sriov_totalvfs_show(struct device *dev,
344 struct device_attribute *attr,
345 char *buf)
346 {
347 struct pci_dev *pdev = to_pci_dev(dev);
348
349 return sysfs_emit(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
350 }
351
sriov_numvfs_show(struct device * dev,struct device_attribute * attr,char * buf)352 static ssize_t sriov_numvfs_show(struct device *dev,
353 struct device_attribute *attr,
354 char *buf)
355 {
356 struct pci_dev *pdev = to_pci_dev(dev);
357 u16 num_vfs;
358
359 /* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
360 device_lock(&pdev->dev);
361 num_vfs = pdev->sriov->num_VFs;
362 device_unlock(&pdev->dev);
363
364 return sysfs_emit(buf, "%u\n", num_vfs);
365 }
366
367 /*
368 * num_vfs > 0; number of VFs to enable
369 * num_vfs = 0; disable all VFs
370 *
371 * Note: SRIOV spec does not allow partial VF
372 * disable, so it's all or none.
373 */
sriov_numvfs_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)374 static ssize_t sriov_numvfs_store(struct device *dev,
375 struct device_attribute *attr,
376 const char *buf, size_t count)
377 {
378 struct pci_dev *pdev = to_pci_dev(dev);
379 int ret;
380 u16 num_vfs;
381
382 ret = kstrtou16(buf, 0, &num_vfs);
383 if (ret < 0)
384 return ret;
385
386 if (num_vfs > pci_sriov_get_totalvfs(pdev))
387 return -ERANGE;
388
389 device_lock(&pdev->dev);
390
391 if (num_vfs == pdev->sriov->num_VFs)
392 goto exit;
393
394 /* is PF driver loaded */
395 if (!pdev->driver) {
396 pci_info(pdev, "no driver bound to device; cannot configure SR-IOV\n");
397 ret = -ENOENT;
398 goto exit;
399 }
400
401 /* is PF driver loaded w/callback */
402 if (!pdev->driver->sriov_configure) {
403 pci_info(pdev, "driver does not support SR-IOV configuration via sysfs\n");
404 ret = -ENOENT;
405 goto exit;
406 }
407
408 if (num_vfs == 0) {
409 /* disable VFs */
410 ret = pdev->driver->sriov_configure(pdev, 0);
411 goto exit;
412 }
413
414 /* enable VFs */
415 if (pdev->sriov->num_VFs) {
416 pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
417 pdev->sriov->num_VFs, num_vfs);
418 ret = -EBUSY;
419 goto exit;
420 }
421
422 ret = pdev->driver->sriov_configure(pdev, num_vfs);
423 if (ret < 0)
424 goto exit;
425
426 if (ret != num_vfs)
427 pci_warn(pdev, "%d VFs requested; only %d enabled\n",
428 num_vfs, ret);
429
430 exit:
431 device_unlock(&pdev->dev);
432
433 if (ret < 0)
434 return ret;
435
436 return count;
437 }
438
sriov_offset_show(struct device * dev,struct device_attribute * attr,char * buf)439 static ssize_t sriov_offset_show(struct device *dev,
440 struct device_attribute *attr,
441 char *buf)
442 {
443 struct pci_dev *pdev = to_pci_dev(dev);
444
445 return sysfs_emit(buf, "%u\n", pdev->sriov->offset);
446 }
447
sriov_stride_show(struct device * dev,struct device_attribute * attr,char * buf)448 static ssize_t sriov_stride_show(struct device *dev,
449 struct device_attribute *attr,
450 char *buf)
451 {
452 struct pci_dev *pdev = to_pci_dev(dev);
453
454 return sysfs_emit(buf, "%u\n", pdev->sriov->stride);
455 }
456
sriov_vf_device_show(struct device * dev,struct device_attribute * attr,char * buf)457 static ssize_t sriov_vf_device_show(struct device *dev,
458 struct device_attribute *attr,
459 char *buf)
460 {
461 struct pci_dev *pdev = to_pci_dev(dev);
462
463 return sysfs_emit(buf, "%x\n", pdev->sriov->vf_device);
464 }
465
sriov_drivers_autoprobe_show(struct device * dev,struct device_attribute * attr,char * buf)466 static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
467 struct device_attribute *attr,
468 char *buf)
469 {
470 struct pci_dev *pdev = to_pci_dev(dev);
471
472 return sysfs_emit(buf, "%u\n", pdev->sriov->drivers_autoprobe);
473 }
474
sriov_drivers_autoprobe_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)475 static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
476 struct device_attribute *attr,
477 const char *buf, size_t count)
478 {
479 struct pci_dev *pdev = to_pci_dev(dev);
480 bool drivers_autoprobe;
481
482 if (kstrtobool(buf, &drivers_autoprobe) < 0)
483 return -EINVAL;
484
485 pdev->sriov->drivers_autoprobe = drivers_autoprobe;
486
487 return count;
488 }
489
490 static DEVICE_ATTR_RO(sriov_totalvfs);
491 static DEVICE_ATTR_RW(sriov_numvfs);
492 static DEVICE_ATTR_RO(sriov_offset);
493 static DEVICE_ATTR_RO(sriov_stride);
494 static DEVICE_ATTR_RO(sriov_vf_device);
495 static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
496
497 static struct attribute *sriov_pf_dev_attrs[] = {
498 &dev_attr_sriov_totalvfs.attr,
499 &dev_attr_sriov_numvfs.attr,
500 &dev_attr_sriov_offset.attr,
501 &dev_attr_sriov_stride.attr,
502 &dev_attr_sriov_vf_device.attr,
503 &dev_attr_sriov_drivers_autoprobe.attr,
504 #ifdef CONFIG_PCI_MSI
505 &dev_attr_sriov_vf_total_msix.attr,
506 #endif
507 NULL,
508 };
509
sriov_pf_attrs_are_visible(struct kobject * kobj,struct attribute * a,int n)510 static umode_t sriov_pf_attrs_are_visible(struct kobject *kobj,
511 struct attribute *a, int n)
512 {
513 struct device *dev = kobj_to_dev(kobj);
514
515 if (!dev_is_pf(dev))
516 return 0;
517
518 return a->mode;
519 }
520
521 const struct attribute_group sriov_pf_dev_attr_group = {
522 .attrs = sriov_pf_dev_attrs,
523 .is_visible = sriov_pf_attrs_are_visible,
524 };
525
pcibios_sriov_enable(struct pci_dev * pdev,u16 num_vfs)526 int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
527 {
528 return 0;
529 }
530
pcibios_sriov_disable(struct pci_dev * pdev)531 int __weak pcibios_sriov_disable(struct pci_dev *pdev)
532 {
533 return 0;
534 }
535
sriov_add_vfs(struct pci_dev * dev,u16 num_vfs)536 static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
537 {
538 unsigned int i;
539 int rc;
540
541 if (dev->no_vf_scan)
542 return 0;
543
544 for (i = 0; i < num_vfs; i++) {
545 rc = pci_iov_add_virtfn(dev, i);
546 if (rc)
547 goto failed;
548 }
549 return 0;
550 failed:
551 while (i--)
552 pci_iov_remove_virtfn(dev, i);
553
554 return rc;
555 }
556
sriov_enable(struct pci_dev * dev,int nr_virtfn)557 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
558 {
559 int rc;
560 int i;
561 int nres;
562 u16 initial;
563 struct resource *res;
564 struct pci_dev *pdev;
565 struct pci_sriov *iov = dev->sriov;
566 int bars = 0;
567 int bus;
568
569 if (!nr_virtfn)
570 return 0;
571
572 if (iov->num_VFs)
573 return -EINVAL;
574
575 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
576 if (initial > iov->total_VFs ||
577 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
578 return -EIO;
579
580 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
581 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
582 return -EINVAL;
583
584 nres = 0;
585 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
586 bars |= (1 << (i + PCI_IOV_RESOURCES));
587 res = &dev->resource[i + PCI_IOV_RESOURCES];
588 if (res->parent)
589 nres++;
590 }
591 if (nres != iov->nres) {
592 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
593 return -ENOMEM;
594 }
595
596 bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
597 if (bus > dev->bus->busn_res.end) {
598 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
599 nr_virtfn, bus, &dev->bus->busn_res);
600 return -ENOMEM;
601 }
602
603 if (pci_enable_resources(dev, bars)) {
604 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
605 return -ENOMEM;
606 }
607
608 if (iov->link != dev->devfn) {
609 pdev = pci_get_slot(dev->bus, iov->link);
610 if (!pdev)
611 return -ENODEV;
612
613 if (!pdev->is_physfn) {
614 pci_dev_put(pdev);
615 return -ENOSYS;
616 }
617
618 rc = sysfs_create_link(&dev->dev.kobj,
619 &pdev->dev.kobj, "dep_link");
620 pci_dev_put(pdev);
621 if (rc)
622 return rc;
623 }
624
625 iov->initial_VFs = initial;
626 if (nr_virtfn < initial)
627 initial = nr_virtfn;
628
629 rc = pcibios_sriov_enable(dev, initial);
630 if (rc) {
631 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
632 goto err_pcibios;
633 }
634
635 pci_iov_set_numvfs(dev, nr_virtfn);
636 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
637 pci_cfg_access_lock(dev);
638 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
639 msleep(100);
640 pci_cfg_access_unlock(dev);
641
642 rc = sriov_add_vfs(dev, initial);
643 if (rc)
644 goto err_pcibios;
645
646 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
647 iov->num_VFs = nr_virtfn;
648
649 return 0;
650
651 err_pcibios:
652 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
653 pci_cfg_access_lock(dev);
654 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
655 ssleep(1);
656 pci_cfg_access_unlock(dev);
657
658 pcibios_sriov_disable(dev);
659
660 if (iov->link != dev->devfn)
661 sysfs_remove_link(&dev->dev.kobj, "dep_link");
662
663 pci_iov_set_numvfs(dev, 0);
664 return rc;
665 }
666
sriov_del_vfs(struct pci_dev * dev)667 static void sriov_del_vfs(struct pci_dev *dev)
668 {
669 struct pci_sriov *iov = dev->sriov;
670 int i;
671
672 for (i = 0; i < iov->num_VFs; i++)
673 pci_iov_remove_virtfn(dev, i);
674 }
675
sriov_disable(struct pci_dev * dev)676 static void sriov_disable(struct pci_dev *dev)
677 {
678 struct pci_sriov *iov = dev->sriov;
679
680 if (!iov->num_VFs)
681 return;
682
683 sriov_del_vfs(dev);
684 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
685 pci_cfg_access_lock(dev);
686 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
687 ssleep(1);
688 pci_cfg_access_unlock(dev);
689
690 pcibios_sriov_disable(dev);
691
692 if (iov->link != dev->devfn)
693 sysfs_remove_link(&dev->dev.kobj, "dep_link");
694
695 iov->num_VFs = 0;
696 pci_iov_set_numvfs(dev, 0);
697 }
698
sriov_init(struct pci_dev * dev,int pos)699 static int sriov_init(struct pci_dev *dev, int pos)
700 {
701 int i, bar64;
702 int rc;
703 int nres;
704 u32 pgsz;
705 u16 ctrl, total;
706 struct pci_sriov *iov;
707 struct resource *res;
708 struct pci_dev *pdev;
709
710 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
711 if (ctrl & PCI_SRIOV_CTRL_VFE) {
712 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
713 ssleep(1);
714 }
715
716 ctrl = 0;
717 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
718 if (pdev->is_physfn)
719 goto found;
720
721 pdev = NULL;
722 if (pci_ari_enabled(dev->bus))
723 ctrl |= PCI_SRIOV_CTRL_ARI;
724
725 found:
726 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
727
728 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
729 if (!total)
730 return 0;
731
732 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
733 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
734 pgsz &= ~((1 << i) - 1);
735 if (!pgsz)
736 return -EIO;
737
738 pgsz &= ~(pgsz - 1);
739 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
740
741 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
742 if (!iov)
743 return -ENOMEM;
744
745 nres = 0;
746 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
747 res = &dev->resource[i + PCI_IOV_RESOURCES];
748 /*
749 * If it is already FIXED, don't change it, something
750 * (perhaps EA or header fixups) wants it this way.
751 */
752 if (res->flags & IORESOURCE_PCI_FIXED)
753 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
754 else
755 bar64 = __pci_read_base(dev, pci_bar_unknown, res,
756 pos + PCI_SRIOV_BAR + i * 4);
757 if (!res->flags)
758 continue;
759 if (resource_size(res) & (PAGE_SIZE - 1)) {
760 rc = -EIO;
761 goto failed;
762 }
763 iov->barsz[i] = resource_size(res);
764 res->end = res->start + resource_size(res) * total - 1;
765 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
766 i, res, i, total);
767 i += bar64;
768 nres++;
769 }
770
771 iov->pos = pos;
772 iov->nres = nres;
773 iov->ctrl = ctrl;
774 iov->total_VFs = total;
775 iov->driver_max_VFs = total;
776 pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
777 iov->pgsz = pgsz;
778 iov->self = dev;
779 iov->drivers_autoprobe = true;
780 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
781 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
782 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
783 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
784
785 if (pdev)
786 iov->dev = pci_dev_get(pdev);
787 else
788 iov->dev = dev;
789
790 dev->sriov = iov;
791 dev->is_physfn = 1;
792 rc = compute_max_vf_buses(dev);
793 if (rc)
794 goto fail_max_buses;
795
796 return 0;
797
798 fail_max_buses:
799 dev->sriov = NULL;
800 dev->is_physfn = 0;
801 failed:
802 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
803 res = &dev->resource[i + PCI_IOV_RESOURCES];
804 res->flags = 0;
805 }
806
807 kfree(iov);
808 return rc;
809 }
810
sriov_release(struct pci_dev * dev)811 static void sriov_release(struct pci_dev *dev)
812 {
813 BUG_ON(dev->sriov->num_VFs);
814
815 if (dev != dev->sriov->dev)
816 pci_dev_put(dev->sriov->dev);
817
818 kfree(dev->sriov);
819 dev->sriov = NULL;
820 }
821
sriov_restore_state(struct pci_dev * dev)822 static void sriov_restore_state(struct pci_dev *dev)
823 {
824 int i;
825 u16 ctrl;
826 struct pci_sriov *iov = dev->sriov;
827
828 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
829 if (ctrl & PCI_SRIOV_CTRL_VFE)
830 return;
831
832 /*
833 * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
834 * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
835 */
836 ctrl &= ~PCI_SRIOV_CTRL_ARI;
837 ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
838 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
839
840 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
841 pci_update_resource(dev, i + PCI_IOV_RESOURCES);
842
843 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
844 pci_iov_set_numvfs(dev, iov->num_VFs);
845 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
846 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
847 msleep(100);
848 }
849
850 /**
851 * pci_iov_init - initialize the IOV capability
852 * @dev: the PCI device
853 *
854 * Returns 0 on success, or negative on failure.
855 */
pci_iov_init(struct pci_dev * dev)856 int pci_iov_init(struct pci_dev *dev)
857 {
858 int pos;
859
860 if (!pci_is_pcie(dev))
861 return -ENODEV;
862
863 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
864 if (pos)
865 return sriov_init(dev, pos);
866
867 return -ENODEV;
868 }
869
870 /**
871 * pci_iov_release - release resources used by the IOV capability
872 * @dev: the PCI device
873 */
pci_iov_release(struct pci_dev * dev)874 void pci_iov_release(struct pci_dev *dev)
875 {
876 if (dev->is_physfn)
877 sriov_release(dev);
878 }
879
880 /**
881 * pci_iov_remove - clean up SR-IOV state after PF driver is detached
882 * @dev: the PCI device
883 */
pci_iov_remove(struct pci_dev * dev)884 void pci_iov_remove(struct pci_dev *dev)
885 {
886 struct pci_sriov *iov = dev->sriov;
887
888 if (!dev->is_physfn)
889 return;
890
891 iov->driver_max_VFs = iov->total_VFs;
892 if (iov->num_VFs)
893 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
894 }
895
896 /**
897 * pci_iov_update_resource - update a VF BAR
898 * @dev: the PCI device
899 * @resno: the resource number
900 *
901 * Update a VF BAR in the SR-IOV capability of a PF.
902 */
pci_iov_update_resource(struct pci_dev * dev,int resno)903 void pci_iov_update_resource(struct pci_dev *dev, int resno)
904 {
905 struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
906 struct resource *res = dev->resource + resno;
907 int vf_bar = resno - PCI_IOV_RESOURCES;
908 struct pci_bus_region region;
909 u16 cmd;
910 u32 new;
911 int reg;
912
913 /*
914 * The generic pci_restore_bars() path calls this for all devices,
915 * including VFs and non-SR-IOV devices. If this is not a PF, we
916 * have nothing to do.
917 */
918 if (!iov)
919 return;
920
921 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd);
922 if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
923 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
924 vf_bar, res);
925 return;
926 }
927
928 /*
929 * Ignore unimplemented BARs, unused resource slots for 64-bit
930 * BARs, and non-movable resources, e.g., those described via
931 * Enhanced Allocation.
932 */
933 if (!res->flags)
934 return;
935
936 if (res->flags & IORESOURCE_UNSET)
937 return;
938
939 if (res->flags & IORESOURCE_PCI_FIXED)
940 return;
941
942 pcibios_resource_to_bus(dev->bus, ®ion, res);
943 new = region.start;
944 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
945
946 reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
947 pci_write_config_dword(dev, reg, new);
948 if (res->flags & IORESOURCE_MEM_64) {
949 new = region.start >> 16 >> 16;
950 pci_write_config_dword(dev, reg + 4, new);
951 }
952 }
953
pcibios_iov_resource_alignment(struct pci_dev * dev,int resno)954 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
955 int resno)
956 {
957 return pci_iov_resource_size(dev, resno);
958 }
959
960 /**
961 * pci_sriov_resource_alignment - get resource alignment for VF BAR
962 * @dev: the PCI device
963 * @resno: the resource number
964 *
965 * Returns the alignment of the VF BAR found in the SR-IOV capability.
966 * This is not the same as the resource size which is defined as
967 * the VF BAR size multiplied by the number of VFs. The alignment
968 * is just the VF BAR size.
969 */
pci_sriov_resource_alignment(struct pci_dev * dev,int resno)970 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
971 {
972 return pcibios_iov_resource_alignment(dev, resno);
973 }
974
975 /**
976 * pci_restore_iov_state - restore the state of the IOV capability
977 * @dev: the PCI device
978 */
pci_restore_iov_state(struct pci_dev * dev)979 void pci_restore_iov_state(struct pci_dev *dev)
980 {
981 if (dev->is_physfn)
982 sriov_restore_state(dev);
983 }
984
985 /**
986 * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
987 * @dev: the PCI device
988 * @auto_probe: set VF drivers auto probe flag
989 */
pci_vf_drivers_autoprobe(struct pci_dev * dev,bool auto_probe)990 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
991 {
992 if (dev->is_physfn)
993 dev->sriov->drivers_autoprobe = auto_probe;
994 }
995
996 /**
997 * pci_iov_bus_range - find bus range used by Virtual Function
998 * @bus: the PCI bus
999 *
1000 * Returns max number of buses (exclude current one) used by Virtual
1001 * Functions.
1002 */
pci_iov_bus_range(struct pci_bus * bus)1003 int pci_iov_bus_range(struct pci_bus *bus)
1004 {
1005 int max = 0;
1006 struct pci_dev *dev;
1007
1008 list_for_each_entry(dev, &bus->devices, bus_list) {
1009 if (!dev->is_physfn)
1010 continue;
1011 if (dev->sriov->max_VF_buses > max)
1012 max = dev->sriov->max_VF_buses;
1013 }
1014
1015 return max ? max - bus->number : 0;
1016 }
1017
1018 /**
1019 * pci_enable_sriov - enable the SR-IOV capability
1020 * @dev: the PCI device
1021 * @nr_virtfn: number of virtual functions to enable
1022 *
1023 * Returns 0 on success, or negative on failure.
1024 */
pci_enable_sriov(struct pci_dev * dev,int nr_virtfn)1025 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
1026 {
1027 might_sleep();
1028
1029 if (!dev->is_physfn)
1030 return -ENOSYS;
1031
1032 return sriov_enable(dev, nr_virtfn);
1033 }
1034 EXPORT_SYMBOL_GPL(pci_enable_sriov);
1035
1036 /**
1037 * pci_disable_sriov - disable the SR-IOV capability
1038 * @dev: the PCI device
1039 */
pci_disable_sriov(struct pci_dev * dev)1040 void pci_disable_sriov(struct pci_dev *dev)
1041 {
1042 might_sleep();
1043
1044 if (!dev->is_physfn)
1045 return;
1046
1047 sriov_disable(dev);
1048 }
1049 EXPORT_SYMBOL_GPL(pci_disable_sriov);
1050
1051 /**
1052 * pci_num_vf - return number of VFs associated with a PF device_release_driver
1053 * @dev: the PCI device
1054 *
1055 * Returns number of VFs, or 0 if SR-IOV is not enabled.
1056 */
pci_num_vf(struct pci_dev * dev)1057 int pci_num_vf(struct pci_dev *dev)
1058 {
1059 if (!dev->is_physfn)
1060 return 0;
1061
1062 return dev->sriov->num_VFs;
1063 }
1064 EXPORT_SYMBOL_GPL(pci_num_vf);
1065
1066 /**
1067 * pci_vfs_assigned - returns number of VFs are assigned to a guest
1068 * @dev: the PCI device
1069 *
1070 * Returns number of VFs belonging to this device that are assigned to a guest.
1071 * If device is not a physical function returns 0.
1072 */
pci_vfs_assigned(struct pci_dev * dev)1073 int pci_vfs_assigned(struct pci_dev *dev)
1074 {
1075 struct pci_dev *vfdev;
1076 unsigned int vfs_assigned = 0;
1077 unsigned short dev_id;
1078
1079 /* only search if we are a PF */
1080 if (!dev->is_physfn)
1081 return 0;
1082
1083 /*
1084 * determine the device ID for the VFs, the vendor ID will be the
1085 * same as the PF so there is no need to check for that one
1086 */
1087 dev_id = dev->sriov->vf_device;
1088
1089 /* loop through all the VFs to see if we own any that are assigned */
1090 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
1091 while (vfdev) {
1092 /*
1093 * It is considered assigned if it is a virtual function with
1094 * our dev as the physical function and the assigned bit is set
1095 */
1096 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
1097 pci_is_dev_assigned(vfdev))
1098 vfs_assigned++;
1099
1100 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
1101 }
1102
1103 return vfs_assigned;
1104 }
1105 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
1106
1107 /**
1108 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
1109 * @dev: the PCI PF device
1110 * @numvfs: number that should be used for TotalVFs supported
1111 *
1112 * Should be called from PF driver's probe routine with
1113 * device's mutex held.
1114 *
1115 * Returns 0 if PF is an SRIOV-capable device and
1116 * value of numvfs valid. If not a PF return -ENOSYS;
1117 * if numvfs is invalid return -EINVAL;
1118 * if VFs already enabled, return -EBUSY.
1119 */
pci_sriov_set_totalvfs(struct pci_dev * dev,u16 numvfs)1120 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
1121 {
1122 if (!dev->is_physfn)
1123 return -ENOSYS;
1124
1125 if (numvfs > dev->sriov->total_VFs)
1126 return -EINVAL;
1127
1128 /* Shouldn't change if VFs already enabled */
1129 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
1130 return -EBUSY;
1131
1132 dev->sriov->driver_max_VFs = numvfs;
1133 return 0;
1134 }
1135 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
1136
1137 /**
1138 * pci_sriov_get_totalvfs -- get total VFs supported on this device
1139 * @dev: the PCI PF device
1140 *
1141 * For a PCIe device with SRIOV support, return the PCIe
1142 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
1143 * if the driver reduced it. Otherwise 0.
1144 */
pci_sriov_get_totalvfs(struct pci_dev * dev)1145 int pci_sriov_get_totalvfs(struct pci_dev *dev)
1146 {
1147 if (!dev->is_physfn)
1148 return 0;
1149
1150 return dev->sriov->driver_max_VFs;
1151 }
1152 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
1153
1154 /**
1155 * pci_sriov_configure_simple - helper to configure SR-IOV
1156 * @dev: the PCI device
1157 * @nr_virtfn: number of virtual functions to enable, 0 to disable
1158 *
1159 * Enable or disable SR-IOV for devices that don't require any PF setup
1160 * before enabling SR-IOV. Return value is negative on error, or number of
1161 * VFs allocated on success.
1162 */
pci_sriov_configure_simple(struct pci_dev * dev,int nr_virtfn)1163 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
1164 {
1165 int rc;
1166
1167 might_sleep();
1168
1169 if (!dev->is_physfn)
1170 return -ENODEV;
1171
1172 if (pci_vfs_assigned(dev)) {
1173 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
1174 return -EPERM;
1175 }
1176
1177 if (nr_virtfn == 0) {
1178 sriov_disable(dev);
1179 return 0;
1180 }
1181
1182 rc = sriov_enable(dev, nr_virtfn);
1183 if (rc < 0)
1184 return rc;
1185
1186 return nr_virtfn;
1187 }
1188 EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);
1189