commit 0efea0006335a2425b1a12a2ad35efad626fe353
author Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Thu Nov 05 12:05:11 2009 +0900
committer Jesse Barnes <jbarnes@virtuousgeek.org> Fri Nov 06 13:59:02 2009 -0800
tree d139b06a32665ec1227c06f1c0a14b21e3c0d654
parent 1e5ad9679016275d422e36b12a98b0927d76f556

PCI: cache PCIe capability offset

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

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 623086f..54b9f15 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -692,6 +692,7 @@
 	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

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c31ac..233b3a0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -218,6 +218,7 @@
 	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 */