From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Previously most resizable BAR interfaces (pci_rebar_get_possible_sizes(),
pci_rebar_set_size(), etc) as well as pci_restore_state() searched config
space for a Resizable BAR capability. Most devices don't have such a
capability, so this is wasted effort, especially for pci_restore_state().
Search for a Resizable BAR capability once at enumeration-time and cache
the offset so we don't have to search every time we need it. No functional
change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/pci.c | 9 +++++++--
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 1 +
include/linux/pci.h | 1 +
4 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 503376bf7e75..cf2632080a94 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1872,7 +1872,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev)
unsigned int pos, nbars, i;
u32 ctrl;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+ pos = pdev->rebar_cap;
if (!pos)
return;
@@ -3719,6 +3719,11 @@ void pci_acs_init(struct pci_dev *dev)
pci_enable_acs(dev);
}
+void pci_rebar_init(struct pci_dev *pdev)
+{
+ pdev->rebar_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+}
+
/**
* pci_rebar_find_pos - find position of resize ctrl reg for BAR
* @pdev: PCI device
@@ -3733,7 +3738,7 @@ static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
unsigned int pos, nbars, i;
u32 ctrl;
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+ pos = pdev->rebar_cap;
if (!pos)
return -ENOTSUPP;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 01e51db8d285..d7b46ddfd6d2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -799,6 +799,7 @@ static inline int acpi_get_rc_resources(struct device *dev, const char *hid,
}
#endif
+void pci_rebar_init(struct pci_dev *pdev);
int pci_rebar_get_current_size(struct pci_dev *pdev, int bar);
int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size);
static inline u64 pci_rebar_size_to_bytes(int size)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b6536ed599c3..24dd3dcfd223 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2564,6 +2564,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
pci_rcec_init(dev); /* Root Complex Event Collector */
pci_doe_init(dev); /* Data Object Exchange */
pci_tph_init(dev); /* TLP Processing Hints */
+ pci_rebar_init(dev); /* Resizable BAR */
pcie_report_downtraining(dev);
pci_init_reset_methods(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 47b31ad724fa..9e5bbd996c83 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -353,6 +353,7 @@ struct pci_dev {
struct pci_dev *rcec; /* Associated RCEC device */
#endif
u32 devcap; /* PCIe Device Capabilities */
+ u16 rebar_cap; /* Resizable BAR capability offset */
u8 pcie_cap; /* PCIe capability offset */
u8 msi_cap; /* MSI capability offset */
u8 msix_cap; /* MSI-X capability offset */
--
2.34.1
