It will make sense to store the pcie_devcap2 value in the pci_dev
structure instead of reading Device Capabilities 2 Register multiple
times. Add pci_init_devcap2() to get the pcie_devcap2 value, then
use cached pcie_devcap2 in the needed place.
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
---
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 4 +---
drivers/pci/pci.c | 8 +++-----
drivers/pci/probe.c | 18 ++++++++++++------
include/linux/pci.h | 2 ++
4 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 6264bc6..7896c96 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -6303,7 +6303,6 @@ static int cxgb4_iov_configure(struct pci_dev *pdev, int num_vfs)
struct pci_dev *pbridge;
struct port_info *pi;
char name[IFNAMSIZ];
- u32 devcap2;
u16 flags;
/* If we want to instantiate Virtual Functions, then our
@@ -6313,10 +6312,9 @@ static int cxgb4_iov_configure(struct pci_dev *pdev, int num_vfs)
*/
pbridge = pdev->bus->self;
pcie_capability_read_word(pbridge, PCI_EXP_FLAGS, &flags);
- pcie_capability_read_dword(pbridge, PCI_EXP_DEVCAP2, &devcap2);
if ((flags & PCI_EXP_FLAGS_VERS) < 2 ||
- !(devcap2 & PCI_EXP_DEVCAP2_ARI)) {
+ !(pbridge->pcie_devcap2 & PCI_EXP_DEVCAP2_ARI)) {
/* Our parent bridge does not support ARI so issue a
* warning and skip instantiating the VFs. They
* won't be reachable.
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 68ccd77..11103bb 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3690,7 +3690,7 @@ int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
{
struct pci_bus *bus = dev->bus;
struct pci_dev *bridge;
- u32 cap, ctl2;
+ u32 ctl2;
if (!pci_is_pcie(dev))
return -EINVAL;
@@ -3714,19 +3714,17 @@ int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask)
while (bus->parent) {
bridge = bus->self;
- pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
-
switch (pci_pcie_type(bridge)) {
/* Ensure switch ports support AtomicOp routing */
case PCI_EXP_TYPE_UPSTREAM:
case PCI_EXP_TYPE_DOWNSTREAM:
- if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
+ if (!(bridge->pcie_devcap2 & PCI_EXP_DEVCAP2_ATOMIC_ROUTE))
return -EINVAL;
break;
/* Ensure root port supports all the sizes we care about */
case PCI_EXP_TYPE_ROOT_PORT:
- if ((cap & cap_mask) != cap_mask)
+ if ((bridge->pcie_devcap2 & cap_mask) != cap_mask)
return -EINVAL;
break;
}
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7963ab2..b9942cc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2093,7 +2093,7 @@ static void pci_configure_ltr(struct pci_dev *dev)
#ifdef CONFIG_PCIEASPM
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
struct pci_dev *bridge;
- u32 cap, ctl;
+ u32 ctl;
if (!pci_is_pcie(dev))
return;
@@ -2101,8 +2101,7 @@ static void pci_configure_ltr(struct pci_dev *dev)
/* Read L1 PM substate capabilities */
dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
- pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
- if (!(cap & PCI_EXP_DEVCAP2_LTR))
+ if (!(dev->pcie_devcap2 & PCI_EXP_DEVCAP2_LTR))
return;
pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl);
@@ -2142,13 +2141,11 @@ static void pci_configure_eetlp_prefix(struct pci_dev *dev)
#ifdef CONFIG_PCI_PASID
struct pci_dev *bridge;
int pcie_type;
- u32 cap;
if (!pci_is_pcie(dev))
return;
- pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
- if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX))
+ if (!(dev->pcie_devcap2 & PCI_EXP_DEVCAP2_EE_PREFIX))
return;
pcie_type = pci_pcie_type(dev);
@@ -2376,6 +2373,14 @@ void pcie_report_downtraining(struct pci_dev *dev)
__pcie_print_link_status(dev, false);
}
+static void pci_init_devcap2(struct pci_dev *dev)
+{
+ if (!pci_is_pcie(dev))
+ return;
+
+ pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &dev->pcie_devcap2);
+}
+
static void pci_init_capabilities(struct pci_dev *dev)
{
pci_ea_init(dev); /* Enhanced Allocation */
@@ -2452,6 +2457,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
int ret;
+ pci_init_devcap2(dev);
pci_configure_device(dev);
device_initialize(&dev->dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 555a3ac..2965620 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -341,6 +341,8 @@ struct pci_dev {
u8 pin; /* Interrupt pin this device uses */
u16 pcie_flags_reg; /* Cached PCIe Capabilities Register */
u32 pcie_devcap; /* Cached Device Capabilities Register */
+ u32 pcie_devcap2; /* Cached Device Capabilities 2
+ Register */
unsigned long *dma_alias_mask;/* Mask of enabled devfn aliases */
struct pci_driver *driver; /* Driver bound to this device */
--
2.7.4
