[PATCH v12 2/8] PCI: restore saved SR-IOV state

[Yu Zhao]

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

Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>
---
 drivers/pci/iov.c |   29 +++++++++++++++++++++++++++++
 drivers/pci/pci.c |    1 +
 drivers/pci/pci.h |    4 ++++
 3 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 66cc414..b121e47 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);
+}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2eba2a5..8e21912 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -773,6 +773,7 @@ pci_restore_state(struct pci_dev *dev)
 	}
 	pci_restore_pcix_state(dev);
 	pci_restore_msi_state(dev);
+	pci_restore_iov_state(dev);
 
 	return 0;
 }
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 196be5e..efd79a2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -216,6 +216,7 @@ extern int pci_iov_init(struct pci_dev *dev);
 extern void pci_iov_release(struct pci_dev *dev);
 extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 				enum pci_bar_type *type);
+extern void pci_restore_iov_state(struct pci_dev *dev);
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
@@ -230,6 +231,9 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 {
 	return 0;
 }
+static inline void pci_restore_iov_state(struct pci_dev *dev)
+{
+}
 #endif /* CONFIG_PCI_IOV */
 
 #endif /* DRIVERS_PCI_H */
-- 
1.5.6.4

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