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
19int 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
27int 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}
34EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);
35
36int pci_iov_vf_id(struct pci_dev *dev)
37{
38 struct pci_dev *pf;
39
40 if (!dev->is_virtfn)
41 return -EINVAL;
42
43 pf = pci_physfn(dev);
44 return (pci_dev_id(dev) - (pci_dev_id(dev: pf) + pf->sriov->offset)) /
45 pf->sriov->stride;
46}
47EXPORT_SYMBOL_GPL(pci_iov_vf_id);
48
49/**
50 * pci_iov_get_pf_drvdata - Return the drvdata of a PF
51 * @dev: VF pci_dev
52 * @pf_driver: Device driver required to own the PF
53 *
54 * This must be called from a context that ensures that a VF driver is attached.
55 * The value returned is invalid once the VF driver completes its remove()
56 * callback.
57 *
58 * Locking is achieved by the driver core. A VF driver cannot be probed until
59 * pci_enable_sriov() is called and pci_disable_sriov() does not return until
60 * all VF drivers have completed their remove().
61 *
62 * The PF driver must call pci_disable_sriov() before it begins to destroy the
63 * drvdata.
64 */
65void *pci_iov_get_pf_drvdata(struct pci_dev *dev, struct pci_driver *pf_driver)
66{
67 struct pci_dev *pf_dev;
68
69 if (!dev->is_virtfn)
70 return ERR_PTR(error: -EINVAL);
71 pf_dev = dev->physfn;
72 if (pf_dev->driver != pf_driver)
73 return ERR_PTR(error: -EINVAL);
74 return pci_get_drvdata(pdev: pf_dev);
75}
76EXPORT_SYMBOL_GPL(pci_iov_get_pf_drvdata);
77
78/*
79 * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may
80 * change when NumVFs changes.
81 *
82 * Update iov->offset and iov->stride when NumVFs is written.
83 */
84static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn)
85{
86 struct pci_sriov *iov = dev->sriov;
87
88 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_NUM_VF, val: nr_virtfn);
89 pci_read_config_word(dev, where: iov->pos + PCI_SRIOV_VF_OFFSET, val: &iov->offset);
90 pci_read_config_word(dev, where: iov->pos + PCI_SRIOV_VF_STRIDE, val: &iov->stride);
91}
92
93/*
94 * The PF consumes one bus number. NumVFs, First VF Offset, and VF Stride
95 * determine how many additional bus numbers will be consumed by VFs.
96 *
97 * Iterate over all valid NumVFs, validate offset and stride, and calculate
98 * the maximum number of bus numbers that could ever be required.
99 */
100static int compute_max_vf_buses(struct pci_dev *dev)
101{
102 struct pci_sriov *iov = dev->sriov;
103 int nr_virtfn, busnr, rc = 0;
104
105 for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) {
106 pci_iov_set_numvfs(dev, nr_virtfn);
107 if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) {
108 rc = -EIO;
109 goto out;
110 }
111
112 busnr = pci_iov_virtfn_bus(dev, vf_id: nr_virtfn - 1);
113 if (busnr > iov->max_VF_buses)
114 iov->max_VF_buses = busnr;
115 }
116
117out:
118 pci_iov_set_numvfs(dev, nr_virtfn: 0);
119 return rc;
120}
121
122static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
123{
124 struct pci_bus *child;
125
126 if (bus->number == busnr)
127 return bus;
128
129 child = pci_find_bus(domain: pci_domain_nr(bus), busnr);
130 if (child)
131 return child;
132
133 child = pci_add_new_bus(parent: bus, NULL, busnr);
134 if (!child)
135 return NULL;
136
137 pci_bus_insert_busn_res(b: child, bus: busnr, busmax: busnr);
138
139 return child;
140}
141
142static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
143{
144 if (physbus != virtbus && list_empty(head: &virtbus->devices))
145 pci_remove_bus(b: virtbus);
146}
147
148resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
149{
150 if (!dev->is_physfn)
151 return 0;
152
153 return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
154}
155
156static void pci_read_vf_config_common(struct pci_dev *virtfn)
157{
158 struct pci_dev *physfn = virtfn->physfn;
159
160 /*
161 * Some config registers are the same across all associated VFs.
162 * Read them once from VF0 so we can skip reading them from the
163 * other VFs.
164 *
165 * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to
166 * have the same Revision ID and Subsystem ID, but we assume they
167 * do.
168 */
169 pci_read_config_dword(dev: virtfn, PCI_CLASS_REVISION,
170 val: &physfn->sriov->class);
171 pci_read_config_byte(dev: virtfn, PCI_HEADER_TYPE,
172 val: &physfn->sriov->hdr_type);
173 pci_read_config_word(dev: virtfn, PCI_SUBSYSTEM_VENDOR_ID,
174 val: &physfn->sriov->subsystem_vendor);
175 pci_read_config_word(dev: virtfn, PCI_SUBSYSTEM_ID,
176 val: &physfn->sriov->subsystem_device);
177}
178
179int pci_iov_sysfs_link(struct pci_dev *dev,
180 struct pci_dev *virtfn, int id)
181{
182 char buf[VIRTFN_ID_LEN];
183 int rc;
184
185 sprintf(buf, fmt: "virtfn%u", id);
186 rc = sysfs_create_link(kobj: &dev->dev.kobj, target: &virtfn->dev.kobj, name: buf);
187 if (rc)
188 goto failed;
189 rc = sysfs_create_link(kobj: &virtfn->dev.kobj, target: &dev->dev.kobj, name: "physfn");
190 if (rc)
191 goto failed1;
192
193 kobject_uevent(kobj: &virtfn->dev.kobj, action: KOBJ_CHANGE);
194
195 return 0;
196
197failed1:
198 sysfs_remove_link(kobj: &dev->dev.kobj, name: buf);
199failed:
200 return rc;
201}
202
203#ifdef CONFIG_PCI_MSI
204static ssize_t sriov_vf_total_msix_show(struct device *dev,
205 struct device_attribute *attr,
206 char *buf)
207{
208 struct pci_dev *pdev = to_pci_dev(dev);
209 u32 vf_total_msix = 0;
210
211 device_lock(dev);
212 if (!pdev->driver || !pdev->driver->sriov_get_vf_total_msix)
213 goto unlock;
214
215 vf_total_msix = pdev->driver->sriov_get_vf_total_msix(pdev);
216unlock:
217 device_unlock(dev);
218 return sysfs_emit(buf, fmt: "%u\n", vf_total_msix);
219}
220static DEVICE_ATTR_RO(sriov_vf_total_msix);
221
222static ssize_t sriov_vf_msix_count_store(struct device *dev,
223 struct device_attribute *attr,
224 const char *buf, size_t count)
225{
226 struct pci_dev *vf_dev = to_pci_dev(dev);
227 struct pci_dev *pdev = pci_physfn(dev: vf_dev);
228 int val, ret = 0;
229
230 if (kstrtoint(s: buf, base: 0, res: &val) < 0)
231 return -EINVAL;
232
233 if (val < 0)
234 return -EINVAL;
235
236 device_lock(dev: &pdev->dev);
237 if (!pdev->driver || !pdev->driver->sriov_set_msix_vec_count) {
238 ret = -EOPNOTSUPP;
239 goto err_pdev;
240 }
241
242 device_lock(dev: &vf_dev->dev);
243 if (vf_dev->driver) {
244 /*
245 * A driver is already attached to this VF and has configured
246 * itself based on the current MSI-X vector count. Changing
247 * the vector size could mess up the driver, so block it.
248 */
249 ret = -EBUSY;
250 goto err_dev;
251 }
252
253 ret = pdev->driver->sriov_set_msix_vec_count(vf_dev, val);
254
255err_dev:
256 device_unlock(dev: &vf_dev->dev);
257err_pdev:
258 device_unlock(dev: &pdev->dev);
259 return ret ? : count;
260}
261static DEVICE_ATTR_WO(sriov_vf_msix_count);
262#endif
263
264static struct attribute *sriov_vf_dev_attrs[] = {
265#ifdef CONFIG_PCI_MSI
266 &dev_attr_sriov_vf_msix_count.attr,
267#endif
268 NULL,
269};
270
271static umode_t sriov_vf_attrs_are_visible(struct kobject *kobj,
272 struct attribute *a, int n)
273{
274 struct device *dev = kobj_to_dev(kobj);
275 struct pci_dev *pdev = to_pci_dev(dev);
276
277 if (!pdev->is_virtfn)
278 return 0;
279
280 return a->mode;
281}
282
283const struct attribute_group sriov_vf_dev_attr_group = {
284 .attrs = sriov_vf_dev_attrs,
285 .is_visible = sriov_vf_attrs_are_visible,
286};
287
288int pci_iov_add_virtfn(struct pci_dev *dev, int id)
289{
290 int i;
291 int rc = -ENOMEM;
292 u64 size;
293 struct pci_dev *virtfn;
294 struct resource *res;
295 struct pci_sriov *iov = dev->sriov;
296 struct pci_bus *bus;
297
298 bus = virtfn_add_bus(bus: dev->bus, busnr: pci_iov_virtfn_bus(dev, vf_id: id));
299 if (!bus)
300 goto failed;
301
302 virtfn = pci_alloc_dev(bus);
303 if (!virtfn)
304 goto failed0;
305
306 virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
307 virtfn->vendor = dev->vendor;
308 virtfn->device = iov->vf_device;
309 virtfn->is_virtfn = 1;
310 virtfn->physfn = pci_dev_get(dev);
311 virtfn->no_command_memory = 1;
312
313 if (id == 0)
314 pci_read_vf_config_common(virtfn);
315
316 rc = pci_setup_device(dev: virtfn);
317 if (rc)
318 goto failed1;
319
320 virtfn->dev.parent = dev->dev.parent;
321 virtfn->multifunction = 0;
322
323 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
324 res = &dev->resource[i + PCI_IOV_RESOURCES];
325 if (!res->parent)
326 continue;
327 virtfn->resource[i].name = pci_name(pdev: virtfn);
328 virtfn->resource[i].flags = res->flags;
329 size = pci_iov_resource_size(dev, resno: i + PCI_IOV_RESOURCES);
330 virtfn->resource[i].start = res->start + size * id;
331 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
332 rc = request_resource(root: res, new: &virtfn->resource[i]);
333 BUG_ON(rc);
334 }
335
336 pci_device_add(dev: virtfn, bus: virtfn->bus);
337 rc = pci_iov_sysfs_link(dev, virtfn, id);
338 if (rc)
339 goto failed1;
340
341 pci_bus_add_device(dev: virtfn);
342
343 return 0;
344
345failed1:
346 pci_stop_and_remove_bus_device(dev: virtfn);
347 pci_dev_put(dev);
348failed0:
349 virtfn_remove_bus(physbus: dev->bus, virtbus: bus);
350failed:
351
352 return rc;
353}
354
355void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
356{
357 char buf[VIRTFN_ID_LEN];
358 struct pci_dev *virtfn;
359
360 virtfn = pci_get_domain_bus_and_slot(domain: pci_domain_nr(bus: dev->bus),
361 bus: pci_iov_virtfn_bus(dev, vf_id: id),
362 devfn: pci_iov_virtfn_devfn(dev, id));
363 if (!virtfn)
364 return;
365
366 sprintf(buf, fmt: "virtfn%u", id);
367 sysfs_remove_link(kobj: &dev->dev.kobj, name: buf);
368 /*
369 * pci_stop_dev() could have been called for this virtfn already,
370 * so the directory for the virtfn may have been removed before.
371 * Double check to avoid spurious sysfs warnings.
372 */
373 if (virtfn->dev.kobj.sd)
374 sysfs_remove_link(kobj: &virtfn->dev.kobj, name: "physfn");
375
376 pci_stop_and_remove_bus_device(dev: virtfn);
377 virtfn_remove_bus(physbus: dev->bus, virtbus: virtfn->bus);
378
379 /* balance pci_get_domain_bus_and_slot() */
380 pci_dev_put(dev: virtfn);
381 pci_dev_put(dev);
382}
383
384static ssize_t sriov_totalvfs_show(struct device *dev,
385 struct device_attribute *attr,
386 char *buf)
387{
388 struct pci_dev *pdev = to_pci_dev(dev);
389
390 return sysfs_emit(buf, fmt: "%u\n", pci_sriov_get_totalvfs(dev: pdev));
391}
392
393static ssize_t sriov_numvfs_show(struct device *dev,
394 struct device_attribute *attr,
395 char *buf)
396{
397 struct pci_dev *pdev = to_pci_dev(dev);
398 u16 num_vfs;
399
400 /* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
401 device_lock(dev: &pdev->dev);
402 num_vfs = pdev->sriov->num_VFs;
403 device_unlock(dev: &pdev->dev);
404
405 return sysfs_emit(buf, fmt: "%u\n", num_vfs);
406}
407
408/*
409 * num_vfs > 0; number of VFs to enable
410 * num_vfs = 0; disable all VFs
411 *
412 * Note: SRIOV spec does not allow partial VF
413 * disable, so it's all or none.
414 */
415static ssize_t sriov_numvfs_store(struct device *dev,
416 struct device_attribute *attr,
417 const char *buf, size_t count)
418{
419 struct pci_dev *pdev = to_pci_dev(dev);
420 int ret = 0;
421 u16 num_vfs;
422
423 if (kstrtou16(s: buf, base: 0, res: &num_vfs) < 0)
424 return -EINVAL;
425
426 if (num_vfs > pci_sriov_get_totalvfs(dev: pdev))
427 return -ERANGE;
428
429 device_lock(dev: &pdev->dev);
430
431 if (num_vfs == pdev->sriov->num_VFs)
432 goto exit;
433
434 /* is PF driver loaded */
435 if (!pdev->driver) {
436 pci_info(pdev, "no driver bound to device; cannot configure SR-IOV\n");
437 ret = -ENOENT;
438 goto exit;
439 }
440
441 /* is PF driver loaded w/callback */
442 if (!pdev->driver->sriov_configure) {
443 pci_info(pdev, "driver does not support SR-IOV configuration via sysfs\n");
444 ret = -ENOENT;
445 goto exit;
446 }
447
448 if (num_vfs == 0) {
449 /* disable VFs */
450 ret = pdev->driver->sriov_configure(pdev, 0);
451 goto exit;
452 }
453
454 /* enable VFs */
455 if (pdev->sriov->num_VFs) {
456 pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
457 pdev->sriov->num_VFs, num_vfs);
458 ret = -EBUSY;
459 goto exit;
460 }
461
462 ret = pdev->driver->sriov_configure(pdev, num_vfs);
463 if (ret < 0)
464 goto exit;
465
466 if (ret != num_vfs)
467 pci_warn(pdev, "%d VFs requested; only %d enabled\n",
468 num_vfs, ret);
469
470exit:
471 device_unlock(dev: &pdev->dev);
472
473 if (ret < 0)
474 return ret;
475
476 return count;
477}
478
479static ssize_t sriov_offset_show(struct device *dev,
480 struct device_attribute *attr,
481 char *buf)
482{
483 struct pci_dev *pdev = to_pci_dev(dev);
484
485 return sysfs_emit(buf, fmt: "%u\n", pdev->sriov->offset);
486}
487
488static ssize_t sriov_stride_show(struct device *dev,
489 struct device_attribute *attr,
490 char *buf)
491{
492 struct pci_dev *pdev = to_pci_dev(dev);
493
494 return sysfs_emit(buf, fmt: "%u\n", pdev->sriov->stride);
495}
496
497static ssize_t sriov_vf_device_show(struct device *dev,
498 struct device_attribute *attr,
499 char *buf)
500{
501 struct pci_dev *pdev = to_pci_dev(dev);
502
503 return sysfs_emit(buf, fmt: "%x\n", pdev->sriov->vf_device);
504}
505
506static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
507 struct device_attribute *attr,
508 char *buf)
509{
510 struct pci_dev *pdev = to_pci_dev(dev);
511
512 return sysfs_emit(buf, fmt: "%u\n", pdev->sriov->drivers_autoprobe);
513}
514
515static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
516 struct device_attribute *attr,
517 const char *buf, size_t count)
518{
519 struct pci_dev *pdev = to_pci_dev(dev);
520 bool drivers_autoprobe;
521
522 if (kstrtobool(s: buf, res: &drivers_autoprobe) < 0)
523 return -EINVAL;
524
525 pdev->sriov->drivers_autoprobe = drivers_autoprobe;
526
527 return count;
528}
529
530static DEVICE_ATTR_RO(sriov_totalvfs);
531static DEVICE_ATTR_RW(sriov_numvfs);
532static DEVICE_ATTR_RO(sriov_offset);
533static DEVICE_ATTR_RO(sriov_stride);
534static DEVICE_ATTR_RO(sriov_vf_device);
535static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
536
537static struct attribute *sriov_pf_dev_attrs[] = {
538 &dev_attr_sriov_totalvfs.attr,
539 &dev_attr_sriov_numvfs.attr,
540 &dev_attr_sriov_offset.attr,
541 &dev_attr_sriov_stride.attr,
542 &dev_attr_sriov_vf_device.attr,
543 &dev_attr_sriov_drivers_autoprobe.attr,
544#ifdef CONFIG_PCI_MSI
545 &dev_attr_sriov_vf_total_msix.attr,
546#endif
547 NULL,
548};
549
550static umode_t sriov_pf_attrs_are_visible(struct kobject *kobj,
551 struct attribute *a, int n)
552{
553 struct device *dev = kobj_to_dev(kobj);
554
555 if (!dev_is_pf(dev))
556 return 0;
557
558 return a->mode;
559}
560
561const struct attribute_group sriov_pf_dev_attr_group = {
562 .attrs = sriov_pf_dev_attrs,
563 .is_visible = sriov_pf_attrs_are_visible,
564};
565
566int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
567{
568 return 0;
569}
570
571int __weak pcibios_sriov_disable(struct pci_dev *pdev)
572{
573 return 0;
574}
575
576static int sriov_add_vfs(struct pci_dev *dev, u16 num_vfs)
577{
578 unsigned int i;
579 int rc;
580
581 if (dev->no_vf_scan)
582 return 0;
583
584 for (i = 0; i < num_vfs; i++) {
585 rc = pci_iov_add_virtfn(dev, id: i);
586 if (rc)
587 goto failed;
588 }
589 return 0;
590failed:
591 while (i--)
592 pci_iov_remove_virtfn(dev, id: i);
593
594 return rc;
595}
596
597static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
598{
599 int rc;
600 int i;
601 int nres;
602 u16 initial;
603 struct resource *res;
604 struct pci_dev *pdev;
605 struct pci_sriov *iov = dev->sriov;
606 int bars = 0;
607 int bus;
608
609 if (!nr_virtfn)
610 return 0;
611
612 if (iov->num_VFs)
613 return -EINVAL;
614
615 pci_read_config_word(dev, where: iov->pos + PCI_SRIOV_INITIAL_VF, val: &initial);
616 if (initial > iov->total_VFs ||
617 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
618 return -EIO;
619
620 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
621 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
622 return -EINVAL;
623
624 nres = 0;
625 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
626 bars |= (1 << (i + PCI_IOV_RESOURCES));
627 res = &dev->resource[i + PCI_IOV_RESOURCES];
628 if (res->parent)
629 nres++;
630 }
631 if (nres != iov->nres) {
632 pci_err(dev, "not enough MMIO resources for SR-IOV\n");
633 return -ENOMEM;
634 }
635
636 bus = pci_iov_virtfn_bus(dev, vf_id: nr_virtfn - 1);
637 if (bus > dev->bus->busn_res.end) {
638 pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
639 nr_virtfn, bus, &dev->bus->busn_res);
640 return -ENOMEM;
641 }
642
643 if (pci_enable_resources(dev, mask: bars)) {
644 pci_err(dev, "SR-IOV: IOV BARS not allocated\n");
645 return -ENOMEM;
646 }
647
648 if (iov->link != dev->devfn) {
649 pdev = pci_get_slot(bus: dev->bus, devfn: iov->link);
650 if (!pdev)
651 return -ENODEV;
652
653 if (!pdev->is_physfn) {
654 pci_dev_put(dev: pdev);
655 return -ENOSYS;
656 }
657
658 rc = sysfs_create_link(kobj: &dev->dev.kobj,
659 target: &pdev->dev.kobj, name: "dep_link");
660 pci_dev_put(dev: pdev);
661 if (rc)
662 return rc;
663 }
664
665 iov->initial_VFs = initial;
666 if (nr_virtfn < initial)
667 initial = nr_virtfn;
668
669 rc = pcibios_sriov_enable(pdev: dev, num_vfs: initial);
670 if (rc) {
671 pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc);
672 goto err_pcibios;
673 }
674
675 pci_iov_set_numvfs(dev, nr_virtfn);
676 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
677 pci_cfg_access_lock(dev);
678 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: iov->ctrl);
679 msleep(msecs: 100);
680 pci_cfg_access_unlock(dev);
681
682 rc = sriov_add_vfs(dev, num_vfs: initial);
683 if (rc)
684 goto err_pcibios;
685
686 kobject_uevent(kobj: &dev->dev.kobj, action: KOBJ_CHANGE);
687 iov->num_VFs = nr_virtfn;
688
689 return 0;
690
691err_pcibios:
692 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
693 pci_cfg_access_lock(dev);
694 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: iov->ctrl);
695 ssleep(seconds: 1);
696 pci_cfg_access_unlock(dev);
697
698 pcibios_sriov_disable(pdev: dev);
699
700 if (iov->link != dev->devfn)
701 sysfs_remove_link(kobj: &dev->dev.kobj, name: "dep_link");
702
703 pci_iov_set_numvfs(dev, nr_virtfn: 0);
704 return rc;
705}
706
707static void sriov_del_vfs(struct pci_dev *dev)
708{
709 struct pci_sriov *iov = dev->sriov;
710 int i;
711
712 for (i = 0; i < iov->num_VFs; i++)
713 pci_iov_remove_virtfn(dev, id: i);
714}
715
716static void sriov_disable(struct pci_dev *dev)
717{
718 struct pci_sriov *iov = dev->sriov;
719
720 if (!iov->num_VFs)
721 return;
722
723 sriov_del_vfs(dev);
724 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
725 pci_cfg_access_lock(dev);
726 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: iov->ctrl);
727 ssleep(seconds: 1);
728 pci_cfg_access_unlock(dev);
729
730 pcibios_sriov_disable(pdev: dev);
731
732 if (iov->link != dev->devfn)
733 sysfs_remove_link(kobj: &dev->dev.kobj, name: "dep_link");
734
735 iov->num_VFs = 0;
736 pci_iov_set_numvfs(dev, nr_virtfn: 0);
737}
738
739static int sriov_init(struct pci_dev *dev, int pos)
740{
741 int i, bar64;
742 int rc;
743 int nres;
744 u32 pgsz;
745 u16 ctrl, total;
746 struct pci_sriov *iov;
747 struct resource *res;
748 struct pci_dev *pdev;
749
750 pci_read_config_word(dev, where: pos + PCI_SRIOV_CTRL, val: &ctrl);
751 if (ctrl & PCI_SRIOV_CTRL_VFE) {
752 pci_write_config_word(dev, where: pos + PCI_SRIOV_CTRL, val: 0);
753 ssleep(seconds: 1);
754 }
755
756 ctrl = 0;
757 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
758 if (pdev->is_physfn)
759 goto found;
760
761 pdev = NULL;
762 if (pci_ari_enabled(bus: dev->bus))
763 ctrl |= PCI_SRIOV_CTRL_ARI;
764
765found:
766 pci_write_config_word(dev, where: pos + PCI_SRIOV_CTRL, val: ctrl);
767
768 pci_read_config_word(dev, where: pos + PCI_SRIOV_TOTAL_VF, val: &total);
769 if (!total)
770 return 0;
771
772 pci_read_config_dword(dev, where: pos + PCI_SRIOV_SUP_PGSIZE, val: &pgsz);
773 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
774 pgsz &= ~((1 << i) - 1);
775 if (!pgsz)
776 return -EIO;
777
778 pgsz &= ~(pgsz - 1);
779 pci_write_config_dword(dev, where: pos + PCI_SRIOV_SYS_PGSIZE, val: pgsz);
780
781 iov = kzalloc(size: sizeof(*iov), GFP_KERNEL);
782 if (!iov)
783 return -ENOMEM;
784
785 nres = 0;
786 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
787 res = &dev->resource[i + PCI_IOV_RESOURCES];
788 /*
789 * If it is already FIXED, don't change it, something
790 * (perhaps EA or header fixups) wants it this way.
791 */
792 if (res->flags & IORESOURCE_PCI_FIXED)
793 bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
794 else
795 bar64 = __pci_read_base(dev, type: pci_bar_unknown, res,
796 reg: pos + PCI_SRIOV_BAR + i * 4);
797 if (!res->flags)
798 continue;
799 if (resource_size(res) & (PAGE_SIZE - 1)) {
800 rc = -EIO;
801 goto failed;
802 }
803 iov->barsz[i] = resource_size(res);
804 res->end = res->start + resource_size(res) * total - 1;
805 pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
806 i, res, i, total);
807 i += bar64;
808 nres++;
809 }
810
811 iov->pos = pos;
812 iov->nres = nres;
813 iov->ctrl = ctrl;
814 iov->total_VFs = total;
815 iov->driver_max_VFs = total;
816 pci_read_config_word(dev, where: pos + PCI_SRIOV_VF_DID, val: &iov->vf_device);
817 iov->pgsz = pgsz;
818 iov->self = dev;
819 iov->drivers_autoprobe = true;
820 pci_read_config_dword(dev, where: pos + PCI_SRIOV_CAP, val: &iov->cap);
821 pci_read_config_byte(dev, where: pos + PCI_SRIOV_FUNC_LINK, val: &iov->link);
822 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
823 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
824
825 if (pdev)
826 iov->dev = pci_dev_get(dev: pdev);
827 else
828 iov->dev = dev;
829
830 dev->sriov = iov;
831 dev->is_physfn = 1;
832 rc = compute_max_vf_buses(dev);
833 if (rc)
834 goto fail_max_buses;
835
836 return 0;
837
838fail_max_buses:
839 dev->sriov = NULL;
840 dev->is_physfn = 0;
841failed:
842 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
843 res = &dev->resource[i + PCI_IOV_RESOURCES];
844 res->flags = 0;
845 }
846
847 kfree(objp: iov);
848 return rc;
849}
850
851static void sriov_release(struct pci_dev *dev)
852{
853 BUG_ON(dev->sriov->num_VFs);
854
855 if (dev != dev->sriov->dev)
856 pci_dev_put(dev: dev->sriov->dev);
857
858 kfree(objp: dev->sriov);
859 dev->sriov = NULL;
860}
861
862static void sriov_restore_state(struct pci_dev *dev)
863{
864 int i;
865 u16 ctrl;
866 struct pci_sriov *iov = dev->sriov;
867
868 pci_read_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: &ctrl);
869 if (ctrl & PCI_SRIOV_CTRL_VFE)
870 return;
871
872 /*
873 * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because
874 * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI.
875 */
876 ctrl &= ~PCI_SRIOV_CTRL_ARI;
877 ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI;
878 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: ctrl);
879
880 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
881 pci_update_resource(dev, resno: i + PCI_IOV_RESOURCES);
882
883 pci_write_config_dword(dev, where: iov->pos + PCI_SRIOV_SYS_PGSIZE, val: iov->pgsz);
884 pci_iov_set_numvfs(dev, nr_virtfn: iov->num_VFs);
885 pci_write_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: iov->ctrl);
886 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
887 msleep(msecs: 100);
888}
889
890/**
891 * pci_iov_init - initialize the IOV capability
892 * @dev: the PCI device
893 *
894 * Returns 0 on success, or negative on failure.
895 */
896int pci_iov_init(struct pci_dev *dev)
897{
898 int pos;
899
900 if (!pci_is_pcie(dev))
901 return -ENODEV;
902
903 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
904 if (pos)
905 return sriov_init(dev, pos);
906
907 return -ENODEV;
908}
909
910/**
911 * pci_iov_release - release resources used by the IOV capability
912 * @dev: the PCI device
913 */
914void pci_iov_release(struct pci_dev *dev)
915{
916 if (dev->is_physfn)
917 sriov_release(dev);
918}
919
920/**
921 * pci_iov_remove - clean up SR-IOV state after PF driver is detached
922 * @dev: the PCI device
923 */
924void pci_iov_remove(struct pci_dev *dev)
925{
926 struct pci_sriov *iov = dev->sriov;
927
928 if (!dev->is_physfn)
929 return;
930
931 iov->driver_max_VFs = iov->total_VFs;
932 if (iov->num_VFs)
933 pci_warn(dev, "driver left SR-IOV enabled after remove\n");
934}
935
936/**
937 * pci_iov_update_resource - update a VF BAR
938 * @dev: the PCI device
939 * @resno: the resource number
940 *
941 * Update a VF BAR in the SR-IOV capability of a PF.
942 */
943void pci_iov_update_resource(struct pci_dev *dev, int resno)
944{
945 struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
946 struct resource *res = dev->resource + resno;
947 int vf_bar = resno - PCI_IOV_RESOURCES;
948 struct pci_bus_region region;
949 u16 cmd;
950 u32 new;
951 int reg;
952
953 /*
954 * The generic pci_restore_bars() path calls this for all devices,
955 * including VFs and non-SR-IOV devices. If this is not a PF, we
956 * have nothing to do.
957 */
958 if (!iov)
959 return;
960
961 pci_read_config_word(dev, where: iov->pos + PCI_SRIOV_CTRL, val: &cmd);
962 if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) {
963 dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n",
964 vf_bar, res);
965 return;
966 }
967
968 /*
969 * Ignore unimplemented BARs, unused resource slots for 64-bit
970 * BARs, and non-movable resources, e.g., those described via
971 * Enhanced Allocation.
972 */
973 if (!res->flags)
974 return;
975
976 if (res->flags & IORESOURCE_UNSET)
977 return;
978
979 if (res->flags & IORESOURCE_PCI_FIXED)
980 return;
981
982 pcibios_resource_to_bus(bus: dev->bus, region: &region, res);
983 new = region.start;
984 new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
985
986 reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
987 pci_write_config_dword(dev, where: reg, val: new);
988 if (res->flags & IORESOURCE_MEM_64) {
989 new = region.start >> 16 >> 16;
990 pci_write_config_dword(dev, where: reg + 4, val: new);
991 }
992}
993
994resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
995 int resno)
996{
997 return pci_iov_resource_size(dev, resno);
998}
999
1000/**
1001 * pci_sriov_resource_alignment - get resource alignment for VF BAR
1002 * @dev: the PCI device
1003 * @resno: the resource number
1004 *
1005 * Returns the alignment of the VF BAR found in the SR-IOV capability.
1006 * This is not the same as the resource size which is defined as
1007 * the VF BAR size multiplied by the number of VFs. The alignment
1008 * is just the VF BAR size.
1009 */
1010resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
1011{
1012 return pcibios_iov_resource_alignment(dev, resno);
1013}
1014
1015/**
1016 * pci_restore_iov_state - restore the state of the IOV capability
1017 * @dev: the PCI device
1018 */
1019void pci_restore_iov_state(struct pci_dev *dev)
1020{
1021 if (dev->is_physfn)
1022 sriov_restore_state(dev);
1023}
1024
1025/**
1026 * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs
1027 * @dev: the PCI device
1028 * @auto_probe: set VF drivers auto probe flag
1029 */
1030void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
1031{
1032 if (dev->is_physfn)
1033 dev->sriov->drivers_autoprobe = auto_probe;
1034}
1035
1036/**
1037 * pci_iov_bus_range - find bus range used by Virtual Function
1038 * @bus: the PCI bus
1039 *
1040 * Returns max number of buses (exclude current one) used by Virtual
1041 * Functions.
1042 */
1043int pci_iov_bus_range(struct pci_bus *bus)
1044{
1045 int max = 0;
1046 struct pci_dev *dev;
1047
1048 list_for_each_entry(dev, &bus->devices, bus_list) {
1049 if (!dev->is_physfn)
1050 continue;
1051 if (dev->sriov->max_VF_buses > max)
1052 max = dev->sriov->max_VF_buses;
1053 }
1054
1055 return max ? max - bus->number : 0;
1056}
1057
1058/**
1059 * pci_enable_sriov - enable the SR-IOV capability
1060 * @dev: the PCI device
1061 * @nr_virtfn: number of virtual functions to enable
1062 *
1063 * Returns 0 on success, or negative on failure.
1064 */
1065int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
1066{
1067 might_sleep();
1068
1069 if (!dev->is_physfn)
1070 return -ENOSYS;
1071
1072 return sriov_enable(dev, nr_virtfn);
1073}
1074EXPORT_SYMBOL_GPL(pci_enable_sriov);
1075
1076/**
1077 * pci_disable_sriov - disable the SR-IOV capability
1078 * @dev: the PCI device
1079 */
1080void pci_disable_sriov(struct pci_dev *dev)
1081{
1082 might_sleep();
1083
1084 if (!dev->is_physfn)
1085 return;
1086
1087 sriov_disable(dev);
1088}
1089EXPORT_SYMBOL_GPL(pci_disable_sriov);
1090
1091/**
1092 * pci_num_vf - return number of VFs associated with a PF device_release_driver
1093 * @dev: the PCI device
1094 *
1095 * Returns number of VFs, or 0 if SR-IOV is not enabled.
1096 */
1097int pci_num_vf(struct pci_dev *dev)
1098{
1099 if (!dev->is_physfn)
1100 return 0;
1101
1102 return dev->sriov->num_VFs;
1103}
1104EXPORT_SYMBOL_GPL(pci_num_vf);
1105
1106/**
1107 * pci_vfs_assigned - returns number of VFs are assigned to a guest
1108 * @dev: the PCI device
1109 *
1110 * Returns number of VFs belonging to this device that are assigned to a guest.
1111 * If device is not a physical function returns 0.
1112 */
1113int pci_vfs_assigned(struct pci_dev *dev)
1114{
1115 struct pci_dev *vfdev;
1116 unsigned int vfs_assigned = 0;
1117 unsigned short dev_id;
1118
1119 /* only search if we are a PF */
1120 if (!dev->is_physfn)
1121 return 0;
1122
1123 /*
1124 * determine the device ID for the VFs, the vendor ID will be the
1125 * same as the PF so there is no need to check for that one
1126 */
1127 dev_id = dev->sriov->vf_device;
1128
1129 /* loop through all the VFs to see if we own any that are assigned */
1130 vfdev = pci_get_device(vendor: dev->vendor, device: dev_id, NULL);
1131 while (vfdev) {
1132 /*
1133 * It is considered assigned if it is a virtual function with
1134 * our dev as the physical function and the assigned bit is set
1135 */
1136 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
1137 pci_is_dev_assigned(pdev: vfdev))
1138 vfs_assigned++;
1139
1140 vfdev = pci_get_device(vendor: dev->vendor, device: dev_id, from: vfdev);
1141 }
1142
1143 return vfs_assigned;
1144}
1145EXPORT_SYMBOL_GPL(pci_vfs_assigned);
1146
1147/**
1148 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
1149 * @dev: the PCI PF device
1150 * @numvfs: number that should be used for TotalVFs supported
1151 *
1152 * Should be called from PF driver's probe routine with
1153 * device's mutex held.
1154 *
1155 * Returns 0 if PF is an SRIOV-capable device and
1156 * value of numvfs valid. If not a PF return -ENOSYS;
1157 * if numvfs is invalid return -EINVAL;
1158 * if VFs already enabled, return -EBUSY.
1159 */
1160int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
1161{
1162 if (!dev->is_physfn)
1163 return -ENOSYS;
1164
1165 if (numvfs > dev->sriov->total_VFs)
1166 return -EINVAL;
1167
1168 /* Shouldn't change if VFs already enabled */
1169 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
1170 return -EBUSY;
1171
1172 dev->sriov->driver_max_VFs = numvfs;
1173 return 0;
1174}
1175EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
1176
1177/**
1178 * pci_sriov_get_totalvfs -- get total VFs supported on this device
1179 * @dev: the PCI PF device
1180 *
1181 * For a PCIe device with SRIOV support, return the PCIe
1182 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
1183 * if the driver reduced it. Otherwise 0.
1184 */
1185int pci_sriov_get_totalvfs(struct pci_dev *dev)
1186{
1187 if (!dev->is_physfn)
1188 return 0;
1189
1190 return dev->sriov->driver_max_VFs;
1191}
1192EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
1193
1194/**
1195 * pci_sriov_configure_simple - helper to configure SR-IOV
1196 * @dev: the PCI device
1197 * @nr_virtfn: number of virtual functions to enable, 0 to disable
1198 *
1199 * Enable or disable SR-IOV for devices that don't require any PF setup
1200 * before enabling SR-IOV. Return value is negative on error, or number of
1201 * VFs allocated on success.
1202 */
1203int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn)
1204{
1205 int rc;
1206
1207 might_sleep();
1208
1209 if (!dev->is_physfn)
1210 return -ENODEV;
1211
1212 if (pci_vfs_assigned(dev)) {
1213 pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n");
1214 return -EPERM;
1215 }
1216
1217 if (nr_virtfn == 0) {
1218 sriov_disable(dev);
1219 return 0;
1220 }
1221
1222 rc = sriov_enable(dev, nr_virtfn);
1223 if (rc < 0)
1224 return rc;
1225
1226 return nr_virtfn;
1227}
1228EXPORT_SYMBOL_GPL(pci_sriov_configure_simple);
1229

source code of linux/drivers/pci/iov.c