PCI: restore saved SR-IOV state

Restore the volatile registers in the SR-IOV capability after the
D3->D0 transition.

Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 66cc414ed15f..b121e47402fa 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -129,6 +129,25 @@ static void sriov_release(struct pci_dev *dev)
         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_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
@@ -180,3 +199,13 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno,
         return dev->sriov->pos + PCI_SRIOV_BAR +
                 4 * (resno - PCI_IOV_RESOURCES);
 }
+
+/**
+ * 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);
+}