PCI: cache PCIe capability offset (0efea000) · Commits · 戴 / test

There are a lot of codes that searches PCI express capability offset in the PCI configuration space using pci_find_capability(). Caching it in the struct pci_dev will reduce unncecessary search. This patch adds an additional 'pcie_cap' fields into struct pci_dev, which is initialized at pci device scan time (in set_pcie_port_type()). Signed-off-by:

Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by:

Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/probe.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -692,6 +692,7 @@ static void set_pcie_port_type(struct pci_dev *pdev)
		if (!pos)
		return;
		pdev->is_pcie = 1;
		pdev->pcie_cap = pos;
		pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
		pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
		}

include/linux/pci.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -218,6 +218,7 @@ struct pci_dev {
		unsigned int class; /* 3 bytes: (base,sub,prog-if) */
		u8 revision; /* PCI revision, low byte of class word */
		u8 hdr_type; /* PCI header type (`multi' flag masked out) */
		u8 pcie_cap; /* PCI-E capability offset */
		u8 pcie_type; /* PCI-E device/port type */
		u8 rom_base_reg; /* which config register controls the ROM */
		u8 pin; /* which interrupt pin this device uses */

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