PCI/ATS: Cache PASID Capability offset
Previously each PASID interface searched for the PASID Capability. Cache
the capability offset the first time we use it instead of searching each
time.
[bhelgaas: commit log, reorder patch to later, call pci_pasid_init() from
pci_init_capabilities()]
Link: https://lore.kernel.org/r/4957778959fa34eab3e8b3065d1951989c61cb0f.1567029860.git.sathyanarayanan.kuppuswamy@linux.intel.com
Link: https://lore.kernel.org/r/20190905193146.90250-6-helgaas@kernel.org
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index c97e862..d5ac808 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -322,6 +322,11 @@
#endif /* CONFIG_PCI_PRI */
#ifdef CONFIG_PCI_PASID
+void pci_pasid_init(struct pci_dev *pdev)
+{
+ pdev->pasid_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+}
+
/**
* pci_enable_pasid - Enable the PASID capability
* @pdev: PCI device structure
@@ -334,7 +339,7 @@
int pci_enable_pasid(struct pci_dev *pdev, int features)
{
u16 control, supported;
- int pos;
+ int pasid = pdev->pasid_cap;
/*
* VFs must not implement the PASID Capability, but if a PF
@@ -352,11 +357,10 @@
if (!pdev->eetlp_prefix_path)
return -EINVAL;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
- if (!pos)
+ if (!pasid)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+ pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
/* User wants to enable anything unsupported? */
@@ -366,7 +370,7 @@
control = PCI_PASID_CTRL_ENABLE | features;
pdev->pasid_features = features;
- pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+ pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
pdev->pasid_enabled = 1;
@@ -381,7 +385,7 @@
void pci_disable_pasid(struct pci_dev *pdev)
{
u16 control = 0;
- int pos;
+ int pasid = pdev->pasid_cap;
/* VFs share the PF PASID configuration */
if (pdev->is_virtfn)
@@ -390,11 +394,10 @@
if (WARN_ON(!pdev->pasid_enabled))
return;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
- if (!pos)
+ if (!pasid)
return;
- pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+ pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
pdev->pasid_enabled = 0;
}
@@ -407,7 +410,7 @@
void pci_restore_pasid_state(struct pci_dev *pdev)
{
u16 control;
- int pos;
+ int pasid = pdev->pasid_cap;
if (pdev->is_virtfn)
return;
@@ -415,12 +418,11 @@
if (!pdev->pasid_enabled)
return;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
- if (!pos)
+ if (!pasid)
return;
control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
- pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+ pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
}
EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
@@ -437,16 +439,15 @@
int pci_pasid_features(struct pci_dev *pdev)
{
u16 supported;
- int pos;
+ int pasid = pdev->pasid_cap;
if (pdev->is_virtfn)
pdev = pci_physfn(pdev);
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
- if (!pos)
+ if (!pasid)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+ pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
@@ -466,16 +467,15 @@
int pci_max_pasids(struct pci_dev *pdev)
{
u16 supported;
- int pos;
+ int pasid = pdev->pasid_cap;
if (pdev->is_virtfn)
pdev = pci_physfn(pdev);
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
- if (!pos)
+ if (!pasid)
return -EINVAL;
- pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+ pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index aa08cd3..ae84d28b 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -462,6 +462,12 @@
static inline void pci_pri_init(struct pci_dev *dev) { }
#endif
+#ifdef CONFIG_PCI_PASID
+void pci_pasid_init(struct pci_dev *dev);
+#else
+static inline void pci_pasid_init(struct pci_dev *dev) { }
+#endif
+
#ifdef CONFIG_PCI_IOV
int pci_iov_init(struct pci_dev *dev);
void pci_iov_release(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index d145165..df2b778 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2327,6 +2327,9 @@
/* Page Request Interface */
pci_pri_init(dev);
+ /* Process Address Space ID */
+ pci_pasid_init(dev);
+
/* Enable ACS P2P upstream forwarding */
pci_enable_acs(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e7770d9..6542100 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -458,6 +458,7 @@
u32 pri_reqs_alloc; /* Number of PRI requests allocated */
#endif
#ifdef CONFIG_PCI_PASID
+ u16 pasid_cap; /* PASID Capability offset */
u16 pasid_features;
#endif
#ifdef CONFIG_PCI_P2PDMA
