[PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.
From: Ashok Raj
Date: Tue May 30 2017 - 13:37:47 EST
From: CQ Tang <cq.tang@xxxxxxxxx>
Requires: https://patchwork.kernel.org/patch/9593891
After a FLR, pci-states need to be restored. This patch saves PASID features
and PRI reqs cached.
To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
To: Joerg Roedel <joro@xxxxxxxxxx>
To: linux-pci@xxxxxxxxxxxxxxx
To: linux-kernel@xxxxxxxxxxxxxxx
Cc: Jean-Phillipe Brucker <jean-philippe.brucker@xxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: CQ Tang <cq.tang@xxxxxxxxx>
Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx>
---
drivers/pci/ats.c | 65 +++++++++++++++++++++++++++++++++++++------------
drivers/pci/pci.c | 3 +++
include/linux/pci-ats.h | 10 ++++++++
include/linux/pci.h | 6 +++++
4 files changed, 69 insertions(+), 15 deletions(-)
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 2126497..a769955 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -160,17 +160,16 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
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 +205,29 @@ void pci_disable_pri(struct pci_dev *pdev)
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;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+ if (!pos)
+ return;
+
+ if (!pdev->pri_enabled)
+ 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 +246,7 @@ int pci_reset_pri(struct pci_dev *pdev)
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 +276,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
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 +284,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
return -EINVAL;
control = PCI_PASID_CTRL_ENABLE | features;
+ pdev->pasid_features = features;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
@@ -305,6 +318,28 @@ void pci_disable_pasid(struct pci_dev *pdev)
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;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+ if (!pos)
+ return;
+
+ if (!pdev->pasid_enabled)
+ 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
*
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7904d02..c9a6510 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -28,6 +28,7 @@
#include <linux/pm_runtime.h>
#include <linux/pci_hotplug.h>
#include <linux/vmalloc.h>
+#include <linux/pci-ats.h>
#include <asm/setup.h>
#include <asm/dma.h>
#include <linux/aer.h>
@@ -1171,6 +1172,8 @@ void pci_restore_state(struct pci_dev *dev)
/* PCI Express register must be restored first */
pci_restore_pcie_state(dev);
+ pci_restore_pasid_state(dev);
+ pci_restore_pri_state(dev);
pci_restore_ats_state(dev);
pci_restore_vc_state(dev);
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 57e0b82..782fb8e 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -7,6 +7,7 @@
int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
void pci_disable_pri(struct pci_dev *pdev);
+void pci_restore_pri_state(struct pci_dev *pdev);
int pci_reset_pri(struct pci_dev *pdev);
#else /* CONFIG_PCI_PRI */
@@ -20,6 +21,10 @@ static inline void pci_disable_pri(struct pci_dev *pdev)
{
}
+static inline void pci_restore_pri_state(struct pci_dev *pdev)
+{
+}
+
static inline int pci_reset_pri(struct pci_dev *pdev)
{
return -ENODEV;
@@ -31,6 +36,7 @@ static inline int pci_reset_pri(struct pci_dev *pdev)
int pci_enable_pasid(struct pci_dev *pdev, int features);
void pci_disable_pasid(struct pci_dev *pdev);
+void pci_restore_pasid_state(struct pci_dev *pdev);
int pci_pasid_features(struct pci_dev *pdev);
int pci_max_pasids(struct pci_dev *pdev);
@@ -45,6 +51,10 @@ static inline void pci_disable_pasid(struct pci_dev *pdev)
{
}
+static inline void pci_restore_pasid_state(struct pci_dev *pdev)
+{
+}
+
static inline int pci_pasid_features(struct pci_dev *pdev)
{
return -EINVAL;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index bee980e..1ddb8e0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -395,6 +395,12 @@ struct pci_dev {
u8 ats_stu; /* ATS Smallest Translation Unit */
atomic_t ats_ref_cnt; /* number of VFs with ATS enabled */
#endif
+#ifdef CONFIG_PCI_PRI
+ u32 pri_reqs_alloc; /* Number of PRI requests allocated */
+#endif
+#ifdef CONFIG_PCI_PASID
+ u16 pasid_features;
+#endif
phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
size_t romlen; /* Length of ROM if it's not from the BAR */
char *driver_override; /* Driver name to force a match */
--
2.7.4