xref: /kernel/linux/linux-6.6/drivers/pci/iov.c (revision 62306a36)
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(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(-EINVAL);
71	pf_dev = dev->physfn;
72	if (pf_dev->driver != pf_driver)
73		return ERR_PTR(-EINVAL);
74	return pci_get_drvdata(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, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
89	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset);
90	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &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, 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, 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(pci_domain_nr(bus), busnr);
130	if (child)
131		return child;
132
133	child = pci_add_new_bus(bus, NULL, busnr);
134	if (!child)
135		return NULL;
136
137	pci_bus_insert_busn_res(child, busnr, 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(&virtbus->devices))
145		pci_remove_bus(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(virtfn, PCI_CLASS_REVISION,
170			      &physfn->sriov->class);
171	pci_read_config_byte(virtfn, PCI_HEADER_TYPE,
172			     &physfn->sriov->hdr_type);
173	pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID,
174			     &physfn->sriov->subsystem_vendor);
175	pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
176			     &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, "virtfn%u", id);
186	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
187	if (rc)
188		goto failed;
189	rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
190	if (rc)
191		goto failed1;
192
193	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
194
195	return 0;
196
197failed1:
198	sysfs_remove_link(&dev->dev.kobj, 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, "%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(vf_dev);
228	int val, ret = 0;
229
230	if (kstrtoint(buf, 0, &val) < 0)
231		return -EINVAL;
232
233	if (val < 0)
234		return -EINVAL;
235
236	device_lock(&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(&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(&vf_dev->dev);
257err_pdev:
258	device_unlock(&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(dev->bus, pci_iov_virtfn_bus(dev, 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(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(virtfn);
328		virtfn->resource[i].flags = res->flags;
329		size = pci_iov_resource_size(dev, 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(res, &virtfn->resource[i]);
333		BUG_ON(rc);
334	}
335
336	pci_device_add(virtfn, virtfn->bus);
337	rc = pci_iov_sysfs_link(dev, virtfn, id);
338	if (rc)
339		goto failed1;
340
341	pci_bus_add_device(virtfn);
342
343	return 0;
344
345failed1:
346	pci_stop_and_remove_bus_device(virtfn);
347	pci_dev_put(dev);
348failed0:
349	virtfn_remove_bus(dev->bus, 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(pci_domain_nr(dev->bus),
361					     pci_iov_virtfn_bus(dev, id),
362					     pci_iov_virtfn_devfn(dev, id));
363	if (!virtfn)
364		return;
365
366	sprintf(buf, "virtfn%u", id);
367	sysfs_remove_link(&dev->dev.kobj, 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(&virtfn->dev.kobj, "physfn");
375
376	pci_stop_and_remove_bus_device(virtfn);
377	virtfn_remove_bus(dev->bus, virtfn->bus);
378
379	/* balance pci_get_domain_bus_and_slot() */
380	pci_dev_put(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, "%u\n", pci_sriov_get_totalvfs(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(&pdev->dev);
402	num_vfs = pdev->sriov->num_VFs;
403	device_unlock(&pdev->dev);
404
405	return sysfs_emit(buf, "%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(buf, 0, &num_vfs) < 0)
424		return -EINVAL;
425
426	if (num_vfs > pci_sriov_get_totalvfs(pdev))
427		return -ERANGE;
428
429	device_lock(&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(&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, "%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, "%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, "%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, "%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(buf, &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, i);
586		if (rc)
587			goto failed;
588	}
589	return 0;
590failed:
591	while (i--)
592		pci_iov_remove_virtfn(dev, 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, iov->pos + PCI_SRIOV_INITIAL_VF, &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, 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, 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(dev->bus, iov->link);
650		if (!pdev)
651			return -ENODEV;
652
653		if (!pdev->is_physfn) {
654			pci_dev_put(pdev);
655			return -ENOSYS;
656		}
657
658		rc = sysfs_create_link(&dev->dev.kobj,
659					&pdev->dev.kobj, "dep_link");
660		pci_dev_put(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(dev, 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, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
679	msleep(100);
680	pci_cfg_access_unlock(dev);
681
682	rc = sriov_add_vfs(dev, initial);
683	if (rc)
684		goto err_pcibios;
685
686	kobject_uevent(&dev->dev.kobj, 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, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
695	ssleep(1);
696	pci_cfg_access_unlock(dev);
697
698	pcibios_sriov_disable(dev);
699
700	if (iov->link != dev->devfn)
701		sysfs_remove_link(&dev->dev.kobj, "dep_link");
702
703	pci_iov_set_numvfs(dev, 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, 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, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
727	ssleep(1);
728	pci_cfg_access_unlock(dev);
729
730	pcibios_sriov_disable(dev);
731
732	if (iov->link != dev->devfn)
733		sysfs_remove_link(&dev->dev.kobj, "dep_link");
734
735	iov->num_VFs = 0;
736	pci_iov_set_numvfs(dev, 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, pos + PCI_SRIOV_CTRL, &ctrl);
751	if (ctrl & PCI_SRIOV_CTRL_VFE) {
752		pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
753		ssleep(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(dev->bus))
763		ctrl |= PCI_SRIOV_CTRL_ARI;
764
765found:
766	pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
767
768	pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
769	if (!total)
770		return 0;
771
772	pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &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, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
780
781	iov = kzalloc(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, pci_bar_unknown, res,
796						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, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
817	iov->pgsz = pgsz;
818	iov->self = dev;
819	iov->drivers_autoprobe = true;
820	pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
821	pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &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(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(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->sriov->dev);
857
858	kfree(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, iov->pos + PCI_SRIOV_CTRL, &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, iov->pos + PCI_SRIOV_CTRL, ctrl);
879
880	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
881		pci_update_resource(dev, i + PCI_IOV_RESOURCES);
882
883	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
884	pci_iov_set_numvfs(dev, iov->num_VFs);
885	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
886	if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
887		msleep(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, iov->pos + PCI_SRIOV_CTRL, &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(dev->bus, &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, reg, new);
988	if (res->flags & IORESOURCE_MEM_64) {
989		new = region.start >> 16 >> 16;
990		pci_write_config_dword(dev, reg + 4, 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(dev->vendor, 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(vfdev))
1138			vfs_assigned++;
1139
1140		vfdev = pci_get_device(dev->vendor, dev_id, 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