diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/pci/iov.c | 884 |
1 files changed, 884 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c new file mode 100644 index 000000000..c3b0b10f9 --- /dev/null +++ b/drivers/pci/iov.c @@ -0,0 +1,884 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Express I/O Virtualization (IOV) support + * Single Root IOV 1.0 + * Address Translation Service 1.0 + * + * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com> + */ + +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/export.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/pci-ats.h> +#include "pci.h" + +#define VIRTFN_ID_LEN 16 + +int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id) +{ + if (!dev->is_physfn) + return -EINVAL; + return dev->bus->number + ((dev->devfn + dev->sriov->offset + + dev->sriov->stride * vf_id) >> 8); +} + +int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id) +{ + if (!dev->is_physfn) + return -EINVAL; + return (dev->devfn + dev->sriov->offset + + dev->sriov->stride * vf_id) & 0xff; +} + +/* + * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may + * change when NumVFs changes. + * + * Update iov->offset and iov->stride when NumVFs is written. + */ +static inline void pci_iov_set_numvfs(struct pci_dev *dev, int nr_virtfn) +{ + struct pci_sriov *iov = dev->sriov; + + pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn); + pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &iov->offset); + pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &iov->stride); +} + +/* + * The PF consumes one bus number. NumVFs, First VF Offset, and VF Stride + * determine how many additional bus numbers will be consumed by VFs. + * + * Iterate over all valid NumVFs, validate offset and stride, and calculate + * the maximum number of bus numbers that could ever be required. + */ +static int compute_max_vf_buses(struct pci_dev *dev) +{ + struct pci_sriov *iov = dev->sriov; + int nr_virtfn, busnr, rc = 0; + + for (nr_virtfn = iov->total_VFs; nr_virtfn; nr_virtfn--) { + pci_iov_set_numvfs(dev, nr_virtfn); + if (!iov->offset || (nr_virtfn > 1 && !iov->stride)) { + rc = -EIO; + goto out; + } + + busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1); + if (busnr > iov->max_VF_buses) + iov->max_VF_buses = busnr; + } + +out: + pci_iov_set_numvfs(dev, 0); + return rc; +} + +static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr) +{ + struct pci_bus *child; + + if (bus->number == busnr) + return bus; + + child = pci_find_bus(pci_domain_nr(bus), busnr); + if (child) + return child; + + child = pci_add_new_bus(bus, NULL, busnr); + if (!child) + return NULL; + + pci_bus_insert_busn_res(child, busnr, busnr); + + return child; +} + +static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus) +{ + if (physbus != virtbus && list_empty(&virtbus->devices)) + pci_remove_bus(virtbus); +} + +resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno) +{ + if (!dev->is_physfn) + return 0; + + return dev->sriov->barsz[resno - PCI_IOV_RESOURCES]; +} + +static void pci_read_vf_config_common(struct pci_dev *virtfn) +{ + struct pci_dev *physfn = virtfn->physfn; + + /* + * Some config registers are the same across all associated VFs. + * Read them once from VF0 so we can skip reading them from the + * other VFs. + * + * PCIe r4.0, sec 9.3.4.1, technically doesn't require all VFs to + * have the same Revision ID and Subsystem ID, but we assume they + * do. + */ + pci_read_config_dword(virtfn, PCI_CLASS_REVISION, + &physfn->sriov->class); + pci_read_config_byte(virtfn, PCI_HEADER_TYPE, + &physfn->sriov->hdr_type); + pci_read_config_word(virtfn, PCI_SUBSYSTEM_VENDOR_ID, + &physfn->sriov->subsystem_vendor); + pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID, + &physfn->sriov->subsystem_device); +} + +int pci_iov_add_virtfn(struct pci_dev *dev, int id) +{ + int i; + int rc = -ENOMEM; + u64 size; + char buf[VIRTFN_ID_LEN]; + struct pci_dev *virtfn; + struct resource *res; + struct pci_sriov *iov = dev->sriov; + struct pci_bus *bus; + + bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id)); + if (!bus) + goto failed; + + virtfn = pci_alloc_dev(bus); + if (!virtfn) + goto failed0; + + virtfn->devfn = pci_iov_virtfn_devfn(dev, id); + virtfn->vendor = dev->vendor; + virtfn->device = iov->vf_device; + virtfn->is_virtfn = 1; + virtfn->physfn = pci_dev_get(dev); + + if (id == 0) + pci_read_vf_config_common(virtfn); + + rc = pci_setup_device(virtfn); + if (rc) + goto failed1; + + virtfn->dev.parent = dev->dev.parent; + virtfn->multifunction = 0; + + for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { + res = &dev->resource[i + PCI_IOV_RESOURCES]; + if (!res->parent) + continue; + virtfn->resource[i].name = pci_name(virtfn); + virtfn->resource[i].flags = res->flags; + size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES); + virtfn->resource[i].start = res->start + size * id; + virtfn->resource[i].end = virtfn->resource[i].start + size - 1; + rc = request_resource(res, &virtfn->resource[i]); + BUG_ON(rc); + } + + pci_device_add(virtfn, virtfn->bus); + + sprintf(buf, "virtfn%u", id); + rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf); + if (rc) + goto failed1; + rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn"); + if (rc) + goto failed2; + + kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE); + + pci_bus_add_device(virtfn); + + return 0; + +failed2: + sysfs_remove_link(&dev->dev.kobj, buf); +failed1: + pci_stop_and_remove_bus_device(virtfn); + pci_dev_put(dev); +failed0: + virtfn_remove_bus(dev->bus, bus); +failed: + + return rc; +} + +void pci_iov_remove_virtfn(struct pci_dev *dev, int id) +{ + char buf[VIRTFN_ID_LEN]; + struct pci_dev *virtfn; + + virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), + pci_iov_virtfn_bus(dev, id), + pci_iov_virtfn_devfn(dev, id)); + if (!virtfn) + return; + + sprintf(buf, "virtfn%u", id); + sysfs_remove_link(&dev->dev.kobj, buf); + /* + * pci_stop_dev() could have been called for this virtfn already, + * so the directory for the virtfn may have been removed before. + * Double check to avoid spurious sysfs warnings. + */ + if (virtfn->dev.kobj.sd) + sysfs_remove_link(&virtfn->dev.kobj, "physfn"); + + pci_stop_and_remove_bus_device(virtfn); + virtfn_remove_bus(dev->bus, virtfn->bus); + + /* balance pci_get_domain_bus_and_slot() */ + pci_dev_put(virtfn); + pci_dev_put(dev); +} + +int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs) +{ + return 0; +} + +int __weak pcibios_sriov_disable(struct pci_dev *pdev) +{ + return 0; +} + +static int sriov_enable(struct pci_dev *dev, int nr_virtfn) +{ + int rc; + int i; + int nres; + u16 initial; + struct resource *res; + struct pci_dev *pdev; + struct pci_sriov *iov = dev->sriov; + int bars = 0; + int bus; + + if (!nr_virtfn) + return 0; + + if (iov->num_VFs) + return -EINVAL; + + pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial); + if (initial > iov->total_VFs || + (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total_VFs))) + return -EIO; + + if (nr_virtfn < 0 || nr_virtfn > iov->total_VFs || + (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial))) + return -EINVAL; + + nres = 0; + for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { + bars |= (1 << (i + PCI_IOV_RESOURCES)); + res = &dev->resource[i + PCI_IOV_RESOURCES]; + if (res->parent) + nres++; + } + if (nres != iov->nres) { + pci_err(dev, "not enough MMIO resources for SR-IOV\n"); + return -ENOMEM; + } + + bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1); + if (bus > dev->bus->busn_res.end) { + pci_err(dev, "can't enable %d VFs (bus %02x out of range of %pR)\n", + nr_virtfn, bus, &dev->bus->busn_res); + return -ENOMEM; + } + + if (pci_enable_resources(dev, bars)) { + pci_err(dev, "SR-IOV: IOV BARS not allocated\n"); + return -ENOMEM; + } + + if (iov->link != dev->devfn) { + pdev = pci_get_slot(dev->bus, iov->link); + if (!pdev) + return -ENODEV; + + if (!pdev->is_physfn) { + pci_dev_put(pdev); + return -ENOSYS; + } + + rc = sysfs_create_link(&dev->dev.kobj, + &pdev->dev.kobj, "dep_link"); + pci_dev_put(pdev); + if (rc) + return rc; + } + + iov->initial_VFs = initial; + if (nr_virtfn < initial) + initial = nr_virtfn; + + rc = pcibios_sriov_enable(dev, initial); + if (rc) { + pci_err(dev, "failure %d from pcibios_sriov_enable()\n", rc); + goto err_pcibios; + } + + pci_iov_set_numvfs(dev, nr_virtfn); + iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE; + pci_cfg_access_lock(dev); + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); + msleep(100); + pci_cfg_access_unlock(dev); + + for (i = 0; i < initial; i++) { + rc = pci_iov_add_virtfn(dev, i); + if (rc) + goto failed; + } + + kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE); + iov->num_VFs = nr_virtfn; + + return 0; + +failed: + while (i--) + pci_iov_remove_virtfn(dev, i); + +err_pcibios: + iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE); + pci_cfg_access_lock(dev); + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); + ssleep(1); + pci_cfg_access_unlock(dev); + + pcibios_sriov_disable(dev); + + if (iov->link != dev->devfn) + sysfs_remove_link(&dev->dev.kobj, "dep_link"); + + pci_iov_set_numvfs(dev, 0); + return rc; +} + +static void sriov_disable(struct pci_dev *dev) +{ + int i; + struct pci_sriov *iov = dev->sriov; + + if (!iov->num_VFs) + return; + + for (i = 0; i < iov->num_VFs; i++) + pci_iov_remove_virtfn(dev, i); + + iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE); + pci_cfg_access_lock(dev); + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); + ssleep(1); + pci_cfg_access_unlock(dev); + + pcibios_sriov_disable(dev); + + if (iov->link != dev->devfn) + sysfs_remove_link(&dev->dev.kobj, "dep_link"); + + iov->num_VFs = 0; + pci_iov_set_numvfs(dev, 0); +} + +static int sriov_init(struct pci_dev *dev, int pos) +{ + int i, bar64; + int rc; + int nres; + u32 pgsz; + u16 ctrl, total; + struct pci_sriov *iov; + struct resource *res; + struct pci_dev *pdev; + + pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl); + if (ctrl & PCI_SRIOV_CTRL_VFE) { + pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0); + ssleep(1); + } + + ctrl = 0; + list_for_each_entry(pdev, &dev->bus->devices, bus_list) + if (pdev->is_physfn) + goto found; + + pdev = NULL; + if (pci_ari_enabled(dev->bus)) + ctrl |= PCI_SRIOV_CTRL_ARI; + +found: + pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); + + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); + if (!total) + return 0; + + pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz); + i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0; + pgsz &= ~((1 << i) - 1); + if (!pgsz) + return -EIO; + + pgsz &= ~(pgsz - 1); + pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz); + + iov = kzalloc(sizeof(*iov), GFP_KERNEL); + if (!iov) + return -ENOMEM; + + nres = 0; + for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { + res = &dev->resource[i + PCI_IOV_RESOURCES]; + /* + * If it is already FIXED, don't change it, something + * (perhaps EA or header fixups) wants it this way. + */ + if (res->flags & IORESOURCE_PCI_FIXED) + bar64 = (res->flags & IORESOURCE_MEM_64) ? 1 : 0; + else + bar64 = __pci_read_base(dev, pci_bar_unknown, res, + pos + PCI_SRIOV_BAR + i * 4); + if (!res->flags) + continue; + if (resource_size(res) & (PAGE_SIZE - 1)) { + rc = -EIO; + goto failed; + } + iov->barsz[i] = resource_size(res); + res->end = res->start + resource_size(res) * total - 1; + pci_info(dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n", + i, res, i, total); + i += bar64; + nres++; + } + + iov->pos = pos; + iov->nres = nres; + iov->ctrl = ctrl; + iov->total_VFs = total; + iov->driver_max_VFs = total; + pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device); + iov->pgsz = pgsz; + iov->self = dev; + iov->drivers_autoprobe = true; + pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap); + pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link); + if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) + iov->link = PCI_DEVFN(PCI_SLOT(dev->devfn), iov->link); + + if (pdev) + iov->dev = pci_dev_get(pdev); + else + iov->dev = dev; + + dev->sriov = iov; + dev->is_physfn = 1; + rc = compute_max_vf_buses(dev); + if (rc) + goto fail_max_buses; + + return 0; + +fail_max_buses: + dev->sriov = NULL; + dev->is_physfn = 0; +failed: + for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { + res = &dev->resource[i + PCI_IOV_RESOURCES]; + res->flags = 0; + } + + kfree(iov); + return rc; +} + +static void sriov_release(struct pci_dev *dev) +{ + BUG_ON(dev->sriov->num_VFs); + + if (dev != dev->sriov->dev) + pci_dev_put(dev->sriov->dev); + + kfree(dev->sriov); + dev->sriov = NULL; +} + +static void sriov_restore_state(struct pci_dev *dev) +{ + int i; + u16 ctrl; + struct pci_sriov *iov = dev->sriov; + + pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl); + if (ctrl & PCI_SRIOV_CTRL_VFE) + return; + + /* + * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because + * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI. + */ + ctrl &= ~PCI_SRIOV_CTRL_ARI; + ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI; + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl); + + for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) + pci_update_resource(dev, i); + + pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz); + pci_iov_set_numvfs(dev, iov->num_VFs); + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl); + if (iov->ctrl & PCI_SRIOV_CTRL_VFE) + msleep(100); +} + +/** + * pci_iov_init - initialize the IOV capability + * @dev: the PCI device + * + * Returns 0 on success, or negative on failure. + */ +int pci_iov_init(struct pci_dev *dev) +{ + int pos; + + if (!pci_is_pcie(dev)) + return -ENODEV; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV); + if (pos) + return sriov_init(dev, pos); + + return -ENODEV; +} + +/** + * pci_iov_release - release resources used by the IOV capability + * @dev: the PCI device + */ +void pci_iov_release(struct pci_dev *dev) +{ + if (dev->is_physfn) + sriov_release(dev); +} + +/** + * pci_iov_remove - clean up SR-IOV state after PF driver is detached + * @dev: the PCI device + */ +void pci_iov_remove(struct pci_dev *dev) +{ + struct pci_sriov *iov = dev->sriov; + + if (!dev->is_physfn) + return; + + iov->driver_max_VFs = iov->total_VFs; + if (iov->num_VFs) + pci_warn(dev, "driver left SR-IOV enabled after remove\n"); +} + +/** + * pci_iov_update_resource - update a VF BAR + * @dev: the PCI device + * @resno: the resource number + * + * Update a VF BAR in the SR-IOV capability of a PF. + */ +void pci_iov_update_resource(struct pci_dev *dev, int resno) +{ + struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL; + struct resource *res = dev->resource + resno; + int vf_bar = resno - PCI_IOV_RESOURCES; + struct pci_bus_region region; + u16 cmd; + u32 new; + int reg; + + /* + * The generic pci_restore_bars() path calls this for all devices, + * including VFs and non-SR-IOV devices. If this is not a PF, we + * have nothing to do. + */ + if (!iov) + return; + + pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd); + if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) { + dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n", + vf_bar, res); + return; + } + + /* + * Ignore unimplemented BARs, unused resource slots for 64-bit + * BARs, and non-movable resources, e.g., those described via + * Enhanced Allocation. + */ + if (!res->flags) + return; + + if (res->flags & IORESOURCE_UNSET) + return; + + if (res->flags & IORESOURCE_PCI_FIXED) + return; + + pcibios_resource_to_bus(dev->bus, ®ion, res); + new = region.start; + new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK; + + reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar; + pci_write_config_dword(dev, reg, new); + if (res->flags & IORESOURCE_MEM_64) { + new = region.start >> 16 >> 16; + pci_write_config_dword(dev, reg + 4, new); + } +} + +resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev, + int resno) +{ + return pci_iov_resource_size(dev, resno); +} + +/** + * pci_sriov_resource_alignment - get resource alignment for VF BAR + * @dev: the PCI device + * @resno: the resource number + * + * Returns the alignment of the VF BAR found in the SR-IOV capability. + * This is not the same as the resource size which is defined as + * the VF BAR size multiplied by the number of VFs. The alignment + * is just the VF BAR size. + */ +resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno) +{ + return pcibios_iov_resource_alignment(dev, resno); +} + +/** + * pci_restore_iov_state - restore the state of the IOV capability + * @dev: the PCI device + */ +void pci_restore_iov_state(struct pci_dev *dev) +{ + if (dev->is_physfn) + sriov_restore_state(dev); +} + +/** + * pci_vf_drivers_autoprobe - set PF property drivers_autoprobe for VFs + * @dev: the PCI device + * @auto_probe: set VF drivers auto probe flag + */ +void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe) +{ + if (dev->is_physfn) + dev->sriov->drivers_autoprobe = auto_probe; +} + +/** + * pci_iov_bus_range - find bus range used by Virtual Function + * @bus: the PCI bus + * + * Returns max number of buses (exclude current one) used by Virtual + * Functions. + */ +int pci_iov_bus_range(struct pci_bus *bus) +{ + int max = 0; + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (!dev->is_physfn) + continue; + if (dev->sriov->max_VF_buses > max) + max = dev->sriov->max_VF_buses; + } + + return max ? max - bus->number : 0; +} + +/** + * pci_enable_sriov - enable the SR-IOV capability + * @dev: the PCI device + * @nr_virtfn: number of virtual functions to enable + * + * Returns 0 on success, or negative on failure. + */ +int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn) +{ + might_sleep(); + + if (!dev->is_physfn) + return -ENOSYS; + + return sriov_enable(dev, nr_virtfn); +} +EXPORT_SYMBOL_GPL(pci_enable_sriov); + +/** + * pci_disable_sriov - disable the SR-IOV capability + * @dev: the PCI device + */ +void pci_disable_sriov(struct pci_dev *dev) +{ + might_sleep(); + + if (!dev->is_physfn) + return; + + sriov_disable(dev); +} +EXPORT_SYMBOL_GPL(pci_disable_sriov); + +/** + * pci_num_vf - return number of VFs associated with a PF device_release_driver + * @dev: the PCI device + * + * Returns number of VFs, or 0 if SR-IOV is not enabled. + */ +int pci_num_vf(struct pci_dev *dev) +{ + if (!dev->is_physfn) + return 0; + + return dev->sriov->num_VFs; +} +EXPORT_SYMBOL_GPL(pci_num_vf); + +/** + * pci_vfs_assigned - returns number of VFs are assigned to a guest + * @dev: the PCI device + * + * Returns number of VFs belonging to this device that are assigned to a guest. + * If device is not a physical function returns 0. + */ +int pci_vfs_assigned(struct pci_dev *dev) +{ + struct pci_dev *vfdev; + unsigned int vfs_assigned = 0; + unsigned short dev_id; + + /* only search if we are a PF */ + if (!dev->is_physfn) + return 0; + + /* + * determine the device ID for the VFs, the vendor ID will be the + * same as the PF so there is no need to check for that one + */ + dev_id = dev->sriov->vf_device; + + /* loop through all the VFs to see if we own any that are assigned */ + vfdev = pci_get_device(dev->vendor, dev_id, NULL); + while (vfdev) { + /* + * It is considered assigned if it is a virtual function with + * our dev as the physical function and the assigned bit is set + */ + if (vfdev->is_virtfn && (vfdev->physfn == dev) && + pci_is_dev_assigned(vfdev)) + vfs_assigned++; + + vfdev = pci_get_device(dev->vendor, dev_id, vfdev); + } + + return vfs_assigned; +} +EXPORT_SYMBOL_GPL(pci_vfs_assigned); + +/** + * pci_sriov_set_totalvfs -- reduce the TotalVFs available + * @dev: the PCI PF device + * @numvfs: number that should be used for TotalVFs supported + * + * Should be called from PF driver's probe routine with + * device's mutex held. + * + * Returns 0 if PF is an SRIOV-capable device and + * value of numvfs valid. If not a PF return -ENOSYS; + * if numvfs is invalid return -EINVAL; + * if VFs already enabled, return -EBUSY. + */ +int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs) +{ + if (!dev->is_physfn) + return -ENOSYS; + + if (numvfs > dev->sriov->total_VFs) + return -EINVAL; + + /* Shouldn't change if VFs already enabled */ + if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE) + return -EBUSY; + + dev->sriov->driver_max_VFs = numvfs; + return 0; +} +EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs); + +/** + * pci_sriov_get_totalvfs -- get total VFs supported on this device + * @dev: the PCI PF device + * + * For a PCIe device with SRIOV support, return the PCIe + * SRIOV capability value of TotalVFs or the value of driver_max_VFs + * if the driver reduced it. Otherwise 0. + */ +int pci_sriov_get_totalvfs(struct pci_dev *dev) +{ + if (!dev->is_physfn) + return 0; + + return dev->sriov->driver_max_VFs; +} +EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs); + +/** + * pci_sriov_configure_simple - helper to configure SR-IOV + * @dev: the PCI device + * @nr_virtfn: number of virtual functions to enable, 0 to disable + * + * Enable or disable SR-IOV for devices that don't require any PF setup + * before enabling SR-IOV. Return value is negative on error, or number of + * VFs allocated on success. + */ +int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn) +{ + int rc; + + might_sleep(); + + if (!dev->is_physfn) + return -ENODEV; + + if (pci_vfs_assigned(dev)) { + pci_warn(dev, "Cannot modify SR-IOV while VFs are assigned\n"); + return -EPERM; + } + + if (nr_virtfn == 0) { + sriov_disable(dev); + return 0; + } + + rc = sriov_enable(dev, nr_virtfn); + if (rc < 0) + return rc; + + return nr_virtfn; +} +EXPORT_SYMBOL_GPL(pci_sriov_configure_simple); |