Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1091 insertions, 0 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
new file mode 100644
index 000000000..4afd4ee4f
--- /dev/null
+++ b/drivers/pci/iov.c
@@ -0,0 +1,1091 @@
+// 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/export.h>
+#include <linux/string.h>
+#include <linux/delay.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_sysfs_link(struct pci_dev *dev,
+		struct pci_dev *virtfn, int id)
+{
+	char buf[VIRTFN_ID_LEN];
+	int rc;
+
+	sprintf(buf, "virtfn%u", id);
+	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
+	if (rc)
+		goto failed;
+	rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
+	if (rc)
+		goto failed1;
+
+	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
+
+	return 0;
+
+failed1:
+	sysfs_remove_link(&dev->dev.kobj, buf);
+failed:
+	return rc;
+}
+
+int pci_iov_add_virtfn(struct pci_dev *dev, int id)
+{
+	int i;
+	int rc = -ENOMEM;
+	u64 size;
+	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);
+	virtfn->no_command_memory = 1;
+
+	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);
+	rc = pci_iov_sysfs_link(dev, virtfn, id);
+	if (rc)
+		goto failed1;
+
+	pci_bus_add_device(virtfn);
+
+	return 0;
+
+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);
+}
+
+static ssize_t sriov_totalvfs_show(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
+}
+
+static ssize_t sriov_numvfs_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	u16 num_vfs;
+
+	/* Serialize vs sriov_numvfs_store() so readers see valid num_VFs */
+	device_lock(&pdev->dev);
+	num_vfs = pdev->sriov->num_VFs;
+	device_unlock(&pdev->dev);
+
+	return sprintf(buf, "%u\n", num_vfs);
+}
+
+/*
+ * num_vfs > 0; number of VFs to enable
+ * num_vfs = 0; disable all VFs
+ *
+ * Note: SRIOV spec does not allow partial VF
+ *	 disable, so it's all or none.
+ */
+static ssize_t sriov_numvfs_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int ret;
+	u16 num_vfs;
+
+	ret = kstrtou16(buf, 0, &num_vfs);
+	if (ret < 0)
+		return ret;
+
+	if (num_vfs > pci_sriov_get_totalvfs(pdev))
+		return -ERANGE;
+
+	device_lock(&pdev->dev);
+
+	if (num_vfs == pdev->sriov->num_VFs)
+		goto exit;
+
+	/* is PF driver loaded w/callback */
+	if (!pdev->driver || !pdev->driver->sriov_configure) {
+		pci_info(pdev, "Driver does not support SRIOV configuration via sysfs\n");
+		ret = -ENOENT;
+		goto exit;
+	}
+
+	if (num_vfs == 0) {
+		/* disable VFs */
+		ret = pdev->driver->sriov_configure(pdev, 0);
+		goto exit;
+	}
+
+	/* enable VFs */
+	if (pdev->sriov->num_VFs) {
+		pci_warn(pdev, "%d VFs already enabled. Disable before enabling %d VFs\n",
+			 pdev->sriov->num_VFs, num_vfs);
+		ret = -EBUSY;
+		goto exit;
+	}
+
+	ret = pdev->driver->sriov_configure(pdev, num_vfs);
+	if (ret < 0)
+		goto exit;
+
+	if (ret != num_vfs)
+		pci_warn(pdev, "%d VFs requested; only %d enabled\n",
+			 num_vfs, ret);
+
+exit:
+	device_unlock(&pdev->dev);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t sriov_offset_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sprintf(buf, "%u\n", pdev->sriov->offset);
+}
+
+static ssize_t sriov_stride_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sprintf(buf, "%u\n", pdev->sriov->stride);
+}
+
+static ssize_t sriov_vf_device_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sprintf(buf, "%x\n", pdev->sriov->vf_device);
+}
+
+static ssize_t sriov_drivers_autoprobe_show(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe);
+}
+
+static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	bool drivers_autoprobe;
+
+	if (kstrtobool(buf, &drivers_autoprobe) < 0)
+		return -EINVAL;
+
+	pdev->sriov->drivers_autoprobe = drivers_autoprobe;
+
+	return count;
+}
+
+static DEVICE_ATTR_RO(sriov_totalvfs);
+static DEVICE_ATTR_RW(sriov_numvfs);
+static DEVICE_ATTR_RO(sriov_offset);
+static DEVICE_ATTR_RO(sriov_stride);
+static DEVICE_ATTR_RO(sriov_vf_device);
+static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
+
+static struct attribute *sriov_dev_attrs[] = {
+	&dev_attr_sriov_totalvfs.attr,
+	&dev_attr_sriov_numvfs.attr,
+	&dev_attr_sriov_offset.attr,
+	&dev_attr_sriov_stride.attr,
+	&dev_attr_sriov_vf_device.attr,
+	&dev_attr_sriov_drivers_autoprobe.attr,
+	NULL,
+};
+
+static umode_t sriov_attrs_are_visible(struct kobject *kobj,
+				       struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+
+	if (!dev_is_pf(dev))
+		return 0;
+
+	return a->mode;
+}
+
+const struct attribute_group sriov_dev_attr_group = {
+	.attrs = sriov_dev_attrs,
+	.is_visible = sriov_attrs_are_visible,
+};
+
+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_add_vfs(struct pci_dev *dev, u16 num_vfs)
+{
+	unsigned int i;
+	int rc;
+
+	if (dev->no_vf_scan)
+		return 0;
+
+	for (i = 0; i < num_vfs; i++) {
+		rc = pci_iov_add_virtfn(dev, i);
+		if (rc)
+			goto failed;
+	}
+	return 0;
+failed:
+	while (i--)
+		pci_iov_remove_virtfn(dev, i);
+
+	return rc;
+}
+
+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);
+
+	rc = sriov_add_vfs(dev, initial);
+	if (rc)
+		goto err_pcibios;
+
+	kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
+	iov->num_VFs = nr_virtfn;
+
+	return 0;
+
+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_del_vfs(struct pci_dev *dev)
+{
+	struct pci_sriov *iov = dev->sriov;
+	int i;
+
+	for (i = 0; i < iov->num_VFs; i++)
+		pci_iov_remove_virtfn(dev, i);
+}
+
+static void sriov_disable(struct pci_dev *dev)
+{
+	struct pci_sriov *iov = dev->sriov;
+
+	if (!iov->num_VFs)
+		return;
+
+	sriov_del_vfs(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);
+
+	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 = 0; i < PCI_SRIOV_NUM_BARS; i++)
+		pci_update_resource(dev, i + PCI_IOV_RESOURCES);
+
+	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, &region, 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);