[PATCH v2 1/7] PCI: Keep the ACS capability offset in device

Rajat Jain
2020-06-30T04:50:27Z

Currently this is being looked up at a number of places. Read and store it
once at bootup so that it can be used by all later.

Signed-off-by: Rajat Jain <rajatja@google.com>
---
v2: Commit log cosmetic changes

drivers/pci/p2pdma.c | 2 +-
drivers/pci/pci.c | 21 +++++++++++++++++----
drivers/pci/pci.h | 2 +-
drivers/pci/probe.c | 2 +-
drivers/pci/quirks.c | 8 ++++----
include/linux/pci.h | 1 +
6 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index e8e444eeb1cd2..f29a48f8fa594 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 ce096272f52b1..d2ff987585855 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -51,6 +51,7 @@ EXPORT_SYMBOL(pci_pci_problems);

unsigned int pci_pm_d3_delay;

+static void pci_enable_acs(struct pci_dev *dev);
static void pci_pme_list_scan(struct work_struct *work);

static LIST_HEAD(pci_pme_list);
@@ -3284,7 +3285,7 @@ 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;
@@ -3310,7 +3311,7 @@ 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;

@@ -3336,7 +3337,7 @@ 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 +3363,7 @@ 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;

@@ -3487,6 +3488,18 @@ bool pci_acs_path_enabled(struct pci_dev *start,
return true;
}

+/**
+ * pci_acs_init - Initialize 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
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6d3f758671064..12fb79fbe29d3 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 2f66988cea257..6d87066a5ecc5 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 812bfc32ecb82..b341628e47527 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 c79d83304e529..a26be5332bba6 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 */
--
2.27.0.212.ge8ba1cc988-goog