PCI: Restore PRI and PASID state after Function-Level Reset
After a Function-Level Reset, PCI states need to be restored. Save PASID
features and PRI reqs cached.
[bhelgaas: search for capability only if PRI/PASID were enabled]
Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 2126497..ad8ddbb 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -160,17 +160,16 @@
if (!pos)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
- if ((control & PCI_PRI_CTRL_ENABLE) ||
- !(status & PCI_PRI_STATUS_STOPPED))
+ if (!(status & PCI_PRI_STATUS_STOPPED))
return -EBUSY;
pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
reqs = min(max_requests, reqs);
+ pdev->pri_reqs_alloc = reqs;
pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
- control |= PCI_PRI_CTRL_ENABLE;
+ control = PCI_PRI_CTRL_ENABLE;
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
pdev->pri_enabled = 1;
@@ -206,6 +205,28 @@
EXPORT_SYMBOL_GPL(pci_disable_pri);
/**
+ * pci_restore_pri_state - Restore PRI
+ * @pdev: PCI device structure
+ */
+void pci_restore_pri_state(struct pci_dev *pdev)
+{
+ u16 control = PCI_PRI_CTRL_ENABLE;
+ u32 reqs = pdev->pri_reqs_alloc;
+ int pos;
+
+ if (!pdev->pri_enabled)
+ return;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+ if (!pos)
+ return;
+
+ pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
+ pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pri_state);
+
+/**
* pci_reset_pri - Resets device's PRI state
* @pdev: PCI device structure
*
@@ -224,12 +245,7 @@
if (!pos)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
- if (control & PCI_PRI_CTRL_ENABLE)
- return -EBUSY;
-
- control |= PCI_PRI_CTRL_RESET;
-
+ control = PCI_PRI_CTRL_RESET;
pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
return 0;
@@ -259,12 +275,7 @@
if (!pos)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control);
pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
-
- if (control & PCI_PASID_CTRL_ENABLE)
- return -EINVAL;
-
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
/* User wants to enable anything unsupported? */
@@ -272,6 +283,7 @@
return -EINVAL;
control = PCI_PASID_CTRL_ENABLE | features;
+ pdev->pasid_features = features;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
@@ -284,7 +296,6 @@
/**
* pci_disable_pasid - Disable the PASID capability
* @pdev: PCI device structure
- *
*/
void pci_disable_pasid(struct pci_dev *pdev)
{
@@ -305,6 +316,27 @@
EXPORT_SYMBOL_GPL(pci_disable_pasid);
/**
+ * pci_restore_pasid_state - Restore PASID capabilities
+ * @pdev: PCI device structure
+ */
+void pci_restore_pasid_state(struct pci_dev *pdev)
+{
+ u16 control;
+ int pos;
+
+ if (!pdev->pasid_enabled)
+ return;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+ if (!pos)
+ return;
+
+ control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
+ pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
+
+/**
* pci_pasid_features - Check which PASID features are supported
* @pdev: PCI device structure
*