4 * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
6 * PCI Express I/O Virtualization (IOV) support.
8 * Address Translation Service 1.0
11 #include <linux/pci.h>
12 #include <linux/slab.h>
13 #include <linux/mutex.h>
14 #include <linux/export.h>
15 #include <linux/string.h>
16 #include <linux/delay.h>
17 #include <linux/pci-ats.h>
20 #define VIRTFN_ID_LEN 16
22 static inline u8 virtfn_bus(struct pci_dev *dev, int id)
24 return dev->bus->number + ((dev->devfn + dev->sriov->offset +
25 dev->sriov->stride * id) >> 8);
28 static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
30 return (dev->devfn + dev->sriov->offset +
31 dev->sriov->stride * id) & 0xff;
34 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
36 struct pci_bus *child;
38 if (bus->number == busnr)
41 child = pci_find_bus(pci_domain_nr(bus), busnr);
45 child = pci_add_new_bus(bus, NULL, busnr);
49 pci_bus_insert_busn_res(child, busnr, busnr);
54 static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
56 if (physbus != virtbus && list_empty(&virtbus->devices))
57 pci_remove_bus(virtbus);
60 static int virtfn_add(struct pci_dev *dev, int id, int reset)
65 char buf[VIRTFN_ID_LEN];
66 struct pci_dev *virtfn;
68 struct pci_sriov *iov = dev->sriov;
71 mutex_lock(&iov->dev->sriov->lock);
72 bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
76 virtfn = pci_alloc_dev(bus);
80 virtfn->devfn = virtfn_devfn(dev, id);
81 virtfn->vendor = dev->vendor;
82 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
83 pci_setup_device(virtfn);
84 virtfn->dev.parent = dev->dev.parent;
85 virtfn->physfn = pci_dev_get(dev);
86 virtfn->is_virtfn = 1;
87 virtfn->multifunction = 0;
89 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
90 res = dev->resource + PCI_IOV_RESOURCES + i;
93 virtfn->resource[i].name = pci_name(virtfn);
94 virtfn->resource[i].flags = res->flags;
95 size = resource_size(res);
96 do_div(size, iov->total_VFs);
97 virtfn->resource[i].start = res->start + size * id;
98 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
99 rc = request_resource(res, &virtfn->resource[i]);
104 __pci_reset_function(virtfn);
106 pci_device_add(virtfn, virtfn->bus);
107 mutex_unlock(&iov->dev->sriov->lock);
109 pci_bus_add_device(virtfn);
110 sprintf(buf, "virtfn%u", id);
111 rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
114 rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
118 kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
123 sysfs_remove_link(&dev->dev.kobj, buf);
126 mutex_lock(&iov->dev->sriov->lock);
127 pci_stop_and_remove_bus_device(virtfn);
129 virtfn_remove_bus(dev->bus, bus);
131 mutex_unlock(&iov->dev->sriov->lock);
136 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
138 char buf[VIRTFN_ID_LEN];
139 struct pci_dev *virtfn;
140 struct pci_sriov *iov = dev->sriov;
142 virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
144 virtfn_devfn(dev, id));
149 device_release_driver(&virtfn->dev);
150 __pci_reset_function(virtfn);
153 sprintf(buf, "virtfn%u", id);
154 sysfs_remove_link(&dev->dev.kobj, buf);
156 * pci_stop_dev() could have been called for this virtfn already,
157 * so the directory for the virtfn may have been removed before.
158 * Double check to avoid spurious sysfs warnings.
160 if (virtfn->dev.kobj.sd)
161 sysfs_remove_link(&virtfn->dev.kobj, "physfn");
163 mutex_lock(&iov->dev->sriov->lock);
164 pci_stop_and_remove_bus_device(virtfn);
165 virtfn_remove_bus(dev->bus, virtfn->bus);
166 mutex_unlock(&iov->dev->sriov->lock);
168 /* balance pci_get_domain_bus_and_slot() */
173 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
178 u16 offset, stride, initial;
179 struct resource *res;
180 struct pci_dev *pdev;
181 struct pci_sriov *iov = dev->sriov;
191 pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
192 if (initial > iov->total_VFs ||
193 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs)))
196 if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs ||
197 (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
200 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
201 pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
202 if (!offset || (nr_virtfn > 1 && !stride))
206 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
207 bars |= (1 << (i + PCI_IOV_RESOURCES));
208 res = dev->resource + PCI_IOV_RESOURCES + i;
212 if (nres != iov->nres) {
213 dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
217 iov->offset = offset;
218 iov->stride = stride;
220 bus = virtfn_bus(dev, nr_virtfn - 1);
221 if (bus > dev->bus->busn_res.end) {
222 dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
223 nr_virtfn, bus, &dev->bus->busn_res);
227 if (pci_enable_resources(dev, bars)) {
228 dev_err(&dev->dev, "SR-IOV: IOV BARS not allocated\n");
232 if (iov->link != dev->devfn) {
233 pdev = pci_get_slot(dev->bus, iov->link);
237 if (!pdev->is_physfn) {
242 rc = sysfs_create_link(&dev->dev.kobj,
243 &pdev->dev.kobj, "dep_link");
249 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
250 iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
251 pci_cfg_access_lock(dev);
252 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
254 pci_cfg_access_unlock(dev);
256 iov->initial_VFs = initial;
257 if (nr_virtfn < initial)
260 for (i = 0; i < initial; i++) {
261 rc = virtfn_add(dev, i, 0);
266 kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
267 iov->num_VFs = nr_virtfn;
272 for (j = 0; j < i; j++)
273 virtfn_remove(dev, j, 0);
275 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
276 pci_cfg_access_lock(dev);
277 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
278 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, 0);
280 pci_cfg_access_unlock(dev);
282 if (iov->link != dev->devfn)
283 sysfs_remove_link(&dev->dev.kobj, "dep_link");
288 static void sriov_disable(struct pci_dev *dev)
291 struct pci_sriov *iov = dev->sriov;
296 for (i = 0; i < iov->num_VFs; i++)
297 virtfn_remove(dev, i, 0);
299 iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
300 pci_cfg_access_lock(dev);
301 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
303 pci_cfg_access_unlock(dev);
305 if (iov->link != dev->devfn)
306 sysfs_remove_link(&dev->dev.kobj, "dep_link");
309 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, 0);
312 static int sriov_init(struct pci_dev *dev, int pos)
318 u16 ctrl, total, offset, stride;
319 struct pci_sriov *iov;
320 struct resource *res;
321 struct pci_dev *pdev;
323 if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
324 pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
327 pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
328 if (ctrl & PCI_SRIOV_CTRL_VFE) {
329 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
333 pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
338 list_for_each_entry(pdev, &dev->bus->devices, bus_list)
343 if (pci_ari_enabled(dev->bus))
344 ctrl |= PCI_SRIOV_CTRL_ARI;
347 pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
348 pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
349 pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
350 pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
351 if (!offset || (total > 1 && !stride))
354 pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
355 i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
356 pgsz &= ~((1 << i) - 1);
361 pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
364 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
365 res = dev->resource + PCI_IOV_RESOURCES + i;
366 i += __pci_read_base(dev, pci_bar_unknown, res,
367 pos + PCI_SRIOV_BAR + i * 4);
370 if (resource_size(res) & (PAGE_SIZE - 1)) {
374 res->end = res->start + resource_size(res) * total - 1;
378 iov = kzalloc(sizeof(*iov), GFP_KERNEL);
387 iov->total_VFs = total;
388 iov->offset = offset;
389 iov->stride = stride;
392 pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
393 pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
394 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
395 iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link);
398 iov->dev = pci_dev_get(pdev);
402 mutex_init(&iov->lock);
410 for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
411 res = dev->resource + PCI_IOV_RESOURCES + i;
418 static void sriov_release(struct pci_dev *dev)
420 BUG_ON(dev->sriov->num_VFs);
422 if (dev != dev->sriov->dev)
423 pci_dev_put(dev->sriov->dev);
425 mutex_destroy(&dev->sriov->lock);
431 static void sriov_restore_state(struct pci_dev *dev)
435 struct pci_sriov *iov = dev->sriov;
437 pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
438 if (ctrl & PCI_SRIOV_CTRL_VFE)
441 for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++)
442 pci_update_resource(dev, i);
444 pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
445 pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->num_VFs);
446 pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
447 if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
452 * pci_iov_init - initialize the IOV capability
453 * @dev: the PCI device
455 * Returns 0 on success, or negative on failure.
457 int pci_iov_init(struct pci_dev *dev)
461 if (!pci_is_pcie(dev))
464 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
466 return sriov_init(dev, pos);
472 * pci_iov_release - release resources used by the IOV capability
473 * @dev: the PCI device
475 void pci_iov_release(struct pci_dev *dev)
482 * pci_iov_resource_bar - get position of the SR-IOV BAR
483 * @dev: the PCI device
484 * @resno: the resource number
486 * Returns position of the BAR encapsulated in the SR-IOV capability.
488 int pci_iov_resource_bar(struct pci_dev *dev, int resno)
490 if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
493 BUG_ON(!dev->is_physfn);
495 return dev->sriov->pos + PCI_SRIOV_BAR +
496 4 * (resno - PCI_IOV_RESOURCES);
500 * pci_sriov_resource_alignment - get resource alignment for VF BAR
501 * @dev: the PCI device
502 * @resno: the resource number
504 * Returns the alignment of the VF BAR found in the SR-IOV capability.
505 * This is not the same as the resource size which is defined as
506 * the VF BAR size multiplied by the number of VFs. The alignment
507 * is just the VF BAR size.
509 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
512 int reg = pci_iov_resource_bar(dev, resno);
517 __pci_read_base(dev, pci_bar_unknown, &tmp, reg);
518 return resource_alignment(&tmp);
522 * pci_restore_iov_state - restore the state of the IOV capability
523 * @dev: the PCI device
525 void pci_restore_iov_state(struct pci_dev *dev)
528 sriov_restore_state(dev);
532 * pci_iov_bus_range - find bus range used by Virtual Function
535 * Returns max number of buses (exclude current one) used by Virtual
538 int pci_iov_bus_range(struct pci_bus *bus)
544 list_for_each_entry(dev, &bus->devices, bus_list) {
547 busnr = virtfn_bus(dev, dev->sriov->total_VFs - 1);
552 return max ? max - bus->number : 0;
556 * pci_enable_sriov - enable the SR-IOV capability
557 * @dev: the PCI device
558 * @nr_virtfn: number of virtual functions to enable
560 * Returns 0 on success, or negative on failure.
562 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
569 return sriov_enable(dev, nr_virtfn);
571 EXPORT_SYMBOL_GPL(pci_enable_sriov);
574 * pci_disable_sriov - disable the SR-IOV capability
575 * @dev: the PCI device
577 void pci_disable_sriov(struct pci_dev *dev)
586 EXPORT_SYMBOL_GPL(pci_disable_sriov);
589 * pci_num_vf - return number of VFs associated with a PF device_release_driver
590 * @dev: the PCI device
592 * Returns number of VFs, or 0 if SR-IOV is not enabled.
594 int pci_num_vf(struct pci_dev *dev)
599 return dev->sriov->num_VFs;
601 EXPORT_SYMBOL_GPL(pci_num_vf);
604 * pci_vfs_assigned - returns number of VFs are assigned to a guest
605 * @dev: the PCI device
607 * Returns number of VFs belonging to this device that are assigned to a guest.
608 * If device is not a physical function returns 0.
610 int pci_vfs_assigned(struct pci_dev *dev)
612 struct pci_dev *vfdev;
613 unsigned int vfs_assigned = 0;
614 unsigned short dev_id;
616 /* only search if we are a PF */
621 * determine the device ID for the VFs, the vendor ID will be the
622 * same as the PF so there is no need to check for that one
624 pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
626 /* loop through all the VFs to see if we own any that are assigned */
627 vfdev = pci_get_device(dev->vendor, dev_id, NULL);
630 * It is considered assigned if it is a virtual function with
631 * our dev as the physical function and the assigned bit is set
633 if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
634 pci_is_dev_assigned(vfdev))
637 vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
642 EXPORT_SYMBOL_GPL(pci_vfs_assigned);
645 * pci_sriov_set_totalvfs -- reduce the TotalVFs available
646 * @dev: the PCI PF device
647 * @numvfs: number that should be used for TotalVFs supported
649 * Should be called from PF driver's probe routine with
650 * device's mutex held.
652 * Returns 0 if PF is an SRIOV-capable device and
653 * value of numvfs valid. If not a PF return -ENOSYS;
654 * if numvfs is invalid return -EINVAL;
655 * if VFs already enabled, return -EBUSY.
657 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
661 if (numvfs > dev->sriov->total_VFs)
664 /* Shouldn't change if VFs already enabled */
665 if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
668 dev->sriov->driver_max_VFs = numvfs;
672 EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
675 * pci_sriov_get_totalvfs -- get total VFs supported on this device
676 * @dev: the PCI PF device
678 * For a PCIe device with SRIOV support, return the PCIe
679 * SRIOV capability value of TotalVFs or the value of driver_max_VFs
680 * if the driver reduced it. Otherwise 0.
682 int pci_sriov_get_totalvfs(struct pci_dev *dev)
687 if (dev->sriov->driver_max_VFs)
688 return dev->sriov->driver_max_VFs;
690 return dev->sriov->total_VFs;
692 EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);