[PATCH v10 4/7] PCI: add SR-IOV API for Physical Function driver

Yu Zhao
2009-02-20T06:54:45Z

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
drivers/pci/iov.c | 348 +++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/pci/pci.h | 3 +
include/linux/pci.h | 14 ++
3 files changed, 365 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 0b80437..8096fc9 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -13,6 +13,8 @@
#include <linux/delay.h>
#include "pci.h"

+#define VIRTFN_ID_LEN 8
+

static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn)
{
@@ -24,6 +26,319 @@ static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn)
*devfn = bdf & 0xff;
}

+static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
+{
+ int rc;
+ 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;
+
+ child->subordinate = busnr;
+ child->dev.parent = bus->bridge;
+ rc = pci_bus_add_child(child);
+ if (rc) {
+ pci_remove_bus(child);
+ return NULL;
+ }
+
+ return child;
+}
+
+static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
+{
+ struct pci_bus *child;
+
+ if (bus->number == busnr)
+ return;
+
+ child = pci_find_bus(pci_domain_nr(bus), busnr);
+ BUG_ON(!child);
+
+ if (list_empty(&child->devices))
+ pci_remove_bus(child);
+}
+
+static int virtfn_add(struct pci_dev *dev, int id, int reset)
+{
+ int i;
+ int rc;
+ u64 size;
+ u8 busnr, devfn;
+ char buf[VIRTFN_ID_LEN];
+ struct pci_dev *virtfn;
+ struct resource *res;
+ struct pci_sriov *iov = dev->sriov;
+
+ virtfn = alloc_pci_dev();
+ if (!virtfn)
+ return -ENOMEM;
+
+ virtfn_bdf(dev, id, &busnr, &devfn);
+ mutex_lock(&iov->pdev->sriov->lock);
+ virtfn->bus = virtfn_add_bus(dev->bus, busnr);
+ if (!virtfn->bus) {
+ kfree(virtfn);
+ mutex_unlock(&iov->pdev->sriov->lock);
+ return -ENOMEM;
+ }
+
+ virtfn->sysdata = dev->bus->sysdata;
+ virtfn->dev.parent = dev->dev.parent;
+ virtfn->dev.bus = dev->dev.bus;
+ virtfn->devfn = devfn;
+ virtfn->hdr_type = PCI_HEADER_TYPE_NORMAL;
+ virtfn->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
+ virtfn->error_state = pci_channel_io_normal;
+ virtfn->current_state = PCI_UNKNOWN;
+ virtfn->is_pcie = 1;
+ virtfn->pcie_type = PCI_EXP_TYPE_ENDPOINT;
+ virtfn->dma_mask = 0xffffffff;
+ virtfn->vendor = dev->vendor;
+ virtfn->subsystem_vendor = dev->subsystem_vendor;
+ virtfn->class = dev->class;
+ pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
+ pci_read_config_byte(virtfn, PCI_REVISION_ID, &virtfn->revision);
+ pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
+ &virtfn->subsystem_device);
+
+ dev_set_name(&virtfn->dev, "%04x:%02x:%02x.%d",
+ pci_domain_nr(virtfn->bus), busnr,
+ PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+ for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+ res = dev->resource + PCI_SRIOV_RESOURCES + i;
+ if (!res->parent)
+ continue;
+ virtfn->resource[i].name = pci_name(virtfn);
+ virtfn->resource[i].flags = res->flags;
+ size = resource_size(res);
+ do_div(size, iov->total);
+ 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_execute_reset_function(virtfn);
+
+ pci_device_add(virtfn, virtfn->bus);
+ mutex_unlock(&iov->pdev->sriov->lock);
+
+ virtfn->physfn = pci_dev_get(dev);
+
+ rc = pci_bus_add_device(virtfn);
+ if (rc)
+ goto failed1;
+ sprintf(buf, "%d", id);
+ rc = sysfs_create_link(&iov->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(&iov->dev.kobj, buf);
+failed1:
+ pci_dev_put(dev);
+ mutex_lock(&iov->pdev->sriov->lock);
+ pci_remove_bus_device(virtfn);
+ virtfn_remove_bus(dev->bus, busnr);
+ mutex_unlock(&iov->pdev->sriov->lock);
+
+ return rc;
+}
+
+static void virtfn_remove(struct pci_dev *dev, int id, int reset)
+{
+ u8 busnr, devfn;
+ char buf[VIRTFN_ID_LEN];
+ struct pci_bus *bus;
+ struct pci_dev *virtfn;
+ struct pci_sriov *iov = dev->sriov;
+
+ virtfn_bdf(dev, id, &busnr, &devfn);
+ bus = pci_find_bus(pci_domain_nr(dev->bus), busnr);
+ if (!bus)
+ return;
+
+ virtfn = pci_get_slot(bus, devfn);
+ if (!virtfn)
+ return;
+
+ pci_dev_put(virtfn);
+
+ if (reset) {
+ device_release_driver(&virtfn->dev);
+ pci_execute_reset_function(virtfn);
+ }
+
+ sprintf(buf, "%d", id);
+ sysfs_remove_link(&iov->dev.kobj, buf);
+ sysfs_remove_link(&virtfn->dev.kobj, "physfn");
+
+ mutex_lock(&iov->pdev->sriov->lock);
+ pci_remove_bus_device(virtfn);
+ virtfn_remove_bus(dev->bus, busnr);
+ mutex_unlock(&iov->pdev->sriov->lock);
+
+ pci_dev_put(dev);
+}
+
+static void sriov_release_dev(struct device *dev)
+{
+ struct pci_sriov *iov = container_of(dev, struct pci_sriov, dev);
+
+ iov->nr_virtfn = 0;
+}
+
+static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
+{
+ int rc;
+ int i, j;
+ int nres;
+ u8 busnr, devfn;
+ u16 offset, stride, initial;
+ struct resource *res;
+ struct pci_dev *link;
+ struct pci_sriov *iov = dev->sriov;
+
+ if (!nr_virtfn)
+ return 0;
+
+ if (iov->nr_virtfn)
+ return -EINVAL;
+
+ pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
+ if (initial > iov->total ||
+ (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
+ return -EIO;
+
+ if (nr_virtfn < 0 || nr_virtfn > iov->total ||
+ (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
+ return -EINVAL;
+
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
+ 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++) {
+ res = dev->resource + PCI_SRIOV_RESOURCES + i;
+ if (!res->parent)
+ continue;
+ nres++;
+ }
+ if (nres != iov->nres) {
+ dev_err(&dev->dev, "no enough MMIO for SR-IOV\n");
+ return -ENOMEM;
+ }
+
+ iov->offset = offset;
+ iov->stride = stride;
+
+ virtfn_bdf(dev, nr_virtfn - 1, &busnr, &devfn);
+ if (busnr > dev->bus->subordinate) {
+ dev_err(&dev->dev, "no enough bus range for SR-IOV\n");
+ return -ENOMEM;
+ }
+
+ memset(&iov->dev, 0, sizeof(iov->dev));
+ strcpy(iov->dev.bus_id, "virtfn");
+ iov->dev.parent = &dev->dev;
+ iov->dev.release = sriov_release_dev;
+ rc = device_register(&iov->dev);
+ if (rc)
+ return rc;
+
+ if (iov->link != dev->devfn) {
+ rc = -ENODEV;
+ list_for_each_entry(link, &dev->bus->devices, bus_list) {
+ if (link->sriov && link->devfn == iov->link)
+ rc = sysfs_create_link(&iov->dev.kobj,
+ &link->dev.kobj, "dep_link");
+ }
+ if (rc)
+ goto failed1;
+ }
+
+ iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
+ pci_block_user_cfg_access(dev);
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+ msleep(100);
+ pci_unblock_user_cfg_access(dev);
+
+ iov->initial = initial;
+ if (nr_virtfn < initial)
+ initial = nr_virtfn;
+
+ for (i = 0; i < initial; i++) {
+ rc = virtfn_add(dev, i, 0);
+ if (rc)
+ goto failed2;
+ }
+
+ kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
+ iov->nr_virtfn = nr_virtfn;
+
+ return 0;
+
+failed2:
+ for (j = 0; j < i; j++)
+ virtfn_remove(dev, j, 0);
+
+ iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+ pci_block_user_cfg_access(dev);
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+ ssleep(1);
+ pci_unblock_user_cfg_access(dev);
+
+ if (iov->link != dev->devfn)
+ sysfs_remove_link(&iov->dev.kobj, "dep_link");
+failed1:
+ device_unregister(&iov->dev);
+
+ return rc;
+}
+
+static void sriov_disable(struct pci_dev *dev)
+{
+ int i;
+ struct pci_sriov *iov = dev->sriov;
+
+ if (!iov->nr_virtfn)
+ return;
+
+ for (i = 0; i < iov->nr_virtfn; i++)
+ virtfn_remove(dev, i, 0);
+
+ iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+ pci_block_user_cfg_access(dev);
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+ ssleep(1);
+ pci_unblock_user_cfg_access(dev);
+
+ if (iov->link != dev->devfn)
+ sysfs_remove_link(&iov->dev.kobj, "dep_link");
+ device_unregister(&iov->dev);
+}
+
static int sriov_init(struct pci_dev *dev, int pos)
{
int i;
@@ -129,6 +444,8 @@ failed:

static void sriov_release(struct pci_dev *dev)
{
+ BUG_ON(dev->sriov->nr_virtfn);
+
if (dev == dev->sriov->pdev)
mutex_destroy(&dev->sriov->lock);
else
@@ -152,6 +469,7 @@ static void sriov_restore_state(struct pci_dev *dev)
pci_update_resource(dev, i);

pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
msleep(100);
@@ -242,3 +560,33 @@ int pci_iov_bus_range(struct pci_bus *bus)

return max ? max - bus->number : 0;
}
+
+/**
+ * pci_enable_sriov - enable the SR-IOV capability
+ * @dev: the PCI device
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
+{
+ might_sleep();
+
+ if (!dev->sriov)
+ return -ENODEV;
+
+ 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->sriov)
+ sriov_disable(dev);
+}
+EXPORT_SYMBOL_GPL(pci_disable_sriov);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 2cf32f5..9bbf868 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -202,6 +202,8 @@ struct pci_sriov {
u32 cap; /* SR-IOV Capabilities */
u16 ctrl; /* SR-IOV Control */
u16 total; /* total VFs associated with the PF */
+ u16 initial; /* initial VFs associated with the PF */
+ u16 nr_virtfn; /* number of VFs available */
u16 offset; /* first VF Routing ID offset */
u16 stride; /* following VF stride */
u32 pgsz; /* page size for BAR alignment */
@@ -209,6 +211,7 @@ struct pci_sriov {
struct pci_dev *pdev; /* lowest numbered PF */
struct pci_dev *self; /* this PF */
struct mutex lock; /* lock for VF bus */
+ struct device dev;
};

#ifdef CONFIG_PCI_IOV
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f4d740e..3a24ff5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -278,6 +278,7 @@ struct pci_dev {
#endif
struct pci_vpd *vpd;
struct pci_sriov *sriov; /* SR-IOV capability related */
+ struct pci_dev *physfn; /* Physical Function the device belongs to */
};

extern struct pci_dev *alloc_pci_dev(void);
@@ -1202,5 +1203,18 @@ int pci_ext_cfg_avail(struct pci_dev *dev);

void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);

+#ifdef CONFIG_PCI_IOV
+extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
+extern void pci_disable_sriov(struct pci_dev *dev);
+#else
+static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
+{
+ return -ENODEV;
+}
+static inline void pci_disable_sriov(struct pci_dev *dev)
+{
+}
+#endif
+
#endif /* __KERNEL__ */
#endif /* LINUX_PCI_H */
--
1.6.1