PCI: Cache ACS capability offset in device
Currently the ACS capability is being looked up at a number of places. Read
and store it once at enumeration so that it can be used by all later. No
functional change intended.
Link: https://lore.kernel.org/r/20200707224604.3737893-2-rajatja@google.com
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index e8e444e..f29a48f 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -253,7 +253,7 @@ static int pci_bridge_has_acs_redir(struct pci_dev *pdev)
int pos;
u16 ctrl;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
+ pos = pdev->acs_cap;
if (!pos)
return 0;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index eec625f..73a8627 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -831,7 +831,7 @@ static void pci_disable_acs_redir(struct pci_dev *dev)
if (!pci_dev_specific_disable_acs_redir(dev))
return;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ pos = dev->acs_cap;
if (!pos) {
pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n");
return;
@@ -857,7 +857,7 @@ static void pci_std_enable_acs(struct pci_dev *dev)
u16 cap;
u16 ctrl;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ pos = dev->acs_cap;
if (!pos)
return;
@@ -883,7 +883,7 @@ static void pci_std_enable_acs(struct pci_dev *dev)
* pci_enable_acs - enable ACS if hardware support it
* @dev: the PCI device
*/
-void pci_enable_acs(struct pci_dev *dev)
+static void pci_enable_acs(struct pci_dev *dev)
{
if (!pci_acs_enable)
goto disable_acs_redir;
@@ -3362,7 +3362,7 @@ static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
int pos;
u16 cap, ctrl;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
+ pos = pdev->acs_cap;
if (!pos)
return false;
@@ -3488,6 +3488,18 @@ bool pci_acs_path_enabled(struct pci_dev *start,
}
/**
+ * pci_acs_init - Initialize ACS if hardware supports it
+ * @dev: the PCI device
+ */
+void pci_acs_init(struct pci_dev *dev)
+{
+ dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+
+ if (dev->acs_cap)
+ pci_enable_acs(dev);
+}
+
+/**
* pci_rebar_find_pos - find position of resize ctrl reg for BAR
* @pdev: PCI device
* @bar: BAR to find
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6d3f758..12fb79f 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -532,7 +532,7 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
return resource_alignment(res);
}
-void pci_enable_acs(struct pci_dev *dev);
+void pci_acs_init(struct pci_dev *dev);
#ifdef CONFIG_PCI_QUIRKS
int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
int pci_dev_specific_enable_acs(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2f66988..6d87066 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2390,7 +2390,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
pci_ats_init(dev); /* Address Translation Services */
pci_pri_init(dev); /* Page Request Interface */
pci_pasid_init(dev); /* Process Address Space ID */
- pci_enable_acs(dev); /* Enable ACS P2P upstream forwarding */
+ pci_acs_init(dev); /* Access Control Services */
pci_ptm_init(dev); /* Precision Time Measurement */
pci_aer_init(dev); /* Advanced Error Reporting */
pci_dpc_init(dev); /* Downstream Port Containment */
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 812bfc3..b341628 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4653,7 +4653,7 @@ static int pci_quirk_intel_spt_pch_acs(struct pci_dev *dev, u16 acs_flags)
if (!pci_quirk_intel_spt_pch_acs_match(dev))
return -ENOTTY;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ pos = dev->acs_cap;
if (!pos)
return -ENOTTY;
@@ -4961,7 +4961,7 @@ static int pci_quirk_enable_intel_spt_pch_acs(struct pci_dev *dev)
if (!pci_quirk_intel_spt_pch_acs_match(dev))
return -ENOTTY;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ pos = dev->acs_cap;
if (!pos)
return -ENOTTY;
@@ -4988,7 +4988,7 @@ static int pci_quirk_disable_intel_spt_pch_acs_redir(struct pci_dev *dev)
if (!pci_quirk_intel_spt_pch_acs_match(dev))
return -ENOTTY;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ pos = dev->acs_cap;
if (!pos)
return -ENOTTY;
@@ -5355,7 +5355,7 @@ int pci_idt_bus_quirk(struct pci_bus *bus, int devfn, u32 *l, int timeout)
bool found;
struct pci_dev *bridge = bus->self;
- pos = pci_find_ext_capability(bridge, PCI_EXT_CAP_ID_ACS);
+ pos = bridge->acs_cap;
/* Disable ACS SV before initial config reads */
if (pos) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c79d833..a26be53 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -486,6 +486,7 @@ struct pci_dev {
#ifdef CONFIG_PCI_P2PDMA
struct pci_p2pdma *p2pdma;
#endif
+ u16 acs_cap; /* ACS Capability offset */
phys_addr_t rom; /* Physical address if not from BAR */
size_t romlen; /* Length if not from BAR */
char *driver_override; /* Driver name to force a match */