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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/pci/iov.c
Initial import
Diffstat (limited to 'drivers/pci/iov.c')
-rw-r--r--drivers/pci/iov.c762
1 files changed, 762 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
new file mode 100644
index 000000000..ee0ebff10
--- /dev/null
+++ b/drivers/pci/iov.c
@@ -0,0 +1,762 @@
+/*
+ * drivers/pci/iov.c
+ *
+ * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
+ *
+ * PCI Express I/O Virtualization (IOV) support.
+ * Single Root IOV 1.0
+ * Address Translation Service 1.0
+ */
+
+#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 and calculate the maximum number of bus
+ * numbers that could ever be required.
+ */
+static inline u8 virtfn_max_buses(struct pci_dev *dev)
+{
+ struct pci_sriov *iov = dev->sriov;
+ int nr_virtfn;
+ u8 max = 0;
+ int busnr;
+
+ for (nr_virtfn = 1; nr_virtfn <= iov->total_VFs; nr_virtfn++) {
+ pci_iov_set_numvfs(dev, nr_virtfn);
+ busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
+ if (busnr > max)
+ max = busnr;
+ }
+
+ return max;
+}
+
+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 int virtfn_add(struct pci_dev *dev, int id, int reset)
+{
+ 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;
+
+ mutex_lock(&iov->dev->sriov->lock);
+ 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;
+ pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
+ pci_setup_device(virtfn);
+ virtfn->dev.parent = dev->dev.parent;
+ virtfn->physfn = pci_dev_get(dev);
+ virtfn->is_virtfn = 1;
+ 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);
+ }
+
+ if (reset)
+ __pci_reset_function(virtfn);
+
+ pci_device_add(virtfn, virtfn->bus);
+ mutex_unlock(&iov->dev->sriov->lock);
+
+ pci_bus_add_device(virtfn);
+ 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);
+
+ return 0;
+
+failed2:
+ sysfs_remove_link(&dev->dev.kobj, buf);
+failed1:
+ pci_dev_put(dev);
+ mutex_lock(&iov->dev->sriov->lock);
+ pci_stop_and_remove_bus_device(virtfn);
+failed0:
+ virtfn_remove_bus(dev->bus, bus);
+failed:
+ mutex_unlock(&iov->dev->sriov->lock);
+
+ return rc;
+}
+
+static void virtfn_remove(struct pci_dev *dev, int id, int reset)
+{
+ char buf[VIRTFN_ID_LEN];
+ struct pci_dev *virtfn;
+ struct pci_sriov *iov = dev->sriov;
+
+ 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;
+
+ if (reset) {
+ device_release_driver(&virtfn->dev);
+ __pci_reset_function(virtfn);
+ }
+
+ 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");
+
+ mutex_lock(&iov->dev->sriov->lock);
+ pci_stop_and_remove_bus_device(virtfn);
+ virtfn_remove_bus(dev->bus, virtfn->bus);
+ mutex_unlock(&iov->dev->sriov->lock);
+
+ /* 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;
+}
+
+static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
+{
+ int rc;
+ int i, j;
+ int nres;
+ u16 offset, stride, initial;
+ struct resource *res;
+ struct pci_dev *pdev;
+ struct pci_sriov *iov = dev->sriov;
+ int bars = 0;
+ int bus;
+ int retval;
+
+ 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;
+
+ pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
+ pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
+ if (!offset || (nr_virtfn > 1 && !stride))
+ return -EIO;
+
+ 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) {
+ dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
+ return -ENOMEM;
+ }
+
+ iov->offset = offset;
+ iov->stride = stride;
+
+ bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
+ if (bus > dev->bus->busn_res.end) {
+ dev_err(&dev->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)) {
+ dev_err(&dev->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;
+ }
+
+ 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);
+
+ iov->initial_VFs = initial;
+ if (nr_virtfn < initial)
+ initial = nr_virtfn;
+
+ if ((retval = pcibios_sriov_enable(dev, initial))) {
+ dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n",
+ retval);
+ return retval;
+ }
+
+ for (i = 0; i < initial; i++) {
+ rc = virtfn_add(dev, i, 0);
+ if (rc)
+ goto failed;
+ }
+
+ kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
+ iov->num_VFs = nr_virtfn;
+
+ return 0;
+
+failed:
+ for (j = 0; j < i; j++)
+ virtfn_remove(dev, j, 0);
+
+ 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);
+ pci_iov_set_numvfs(dev, 0);
+ ssleep(1);
+ pci_cfg_access_unlock(dev);
+
+ if (iov->link != dev->devfn)
+ sysfs_remove_link(&dev->dev.kobj, "dep_link");
+
+ return rc;
+}
+
+int __weak pcibios_sriov_disable(struct pci_dev *pdev)
+{
+ return 0;
+}
+
+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++)
+ virtfn_remove(dev, i, 0);
+
+ pcibios_sriov_disable(dev);
+
+ 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);
+
+ 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, offset, stride;
+ struct pci_sriov *iov;
+ struct resource *res;
+ struct pci_dev *pdev;
+
+ if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
+ pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
+ return -ENODEV;
+
+ 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);
+ }
+
+ pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
+ if (!total)
+ return 0;
+
+ 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_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
+ pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
+ pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
+ if (!offset || (total > 1 && !stride))
+ return -EIO;
+
+ 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];
+ 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;
+ dev_info(&dev->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->offset = offset;
+ iov->stride = stride;
+ iov->pgsz = pgsz;
+ iov->self = dev;
+ 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;
+
+ mutex_init(&iov->lock);
+
+ dev->sriov = iov;
+ dev->is_physfn = 1;
+ iov->max_VF_buses = virtfn_max_buses(dev);
+
+ return 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);
+
+ mutex_destroy(&dev->sriov->lock);
+
+ 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;
+
+ 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_resource_bar - get position of the SR-IOV BAR
+ * @dev: the PCI device
+ * @resno: the resource number
+ *
+ * Returns position of the BAR encapsulated in the SR-IOV capability.
+ */
+int pci_iov_resource_bar(struct pci_dev *dev, int resno)
+{
+ if (resno < PCI_IOV_RESOURCES || resno > PCI_IOV_RESOURCE_END)
+ return 0;
+
+ BUG_ON(!dev->is_physfn);
+
+ return dev->sriov->pos + PCI_SRIOV_BAR +
+ 4 * (resno - PCI_IOV_RESOURCES);
+}
+
+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_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
+ */
+ pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
+
+ /* 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;
+ else
+ 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;
+
+ if (dev->sriov->driver_max_VFs)
+ return dev->sriov->driver_max_VFs;
+
+ return dev->sriov->total_VFs;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);