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authorKyösti Mälkki <kyosti.malkki@gmail.com>2019-03-11 18:26:01 +0200
committerPatrick Georgi <pgeorgi@google.com>2019-03-14 11:36:09 +0000
commit3af6aa10f7a439e97a5f7d159336b4a207a97c21 (patch)
tree37f521bf43fe3f50237ac19ac5da9d65a69255e8
parent125c9cf98cba524d3f8259bc34dc4c3f515403b4 (diff)
downloadcoreboot-3af6aa10f7a439e97a5f7d159336b4a207a97c21.tar.xz
arch/x86: Optimise PCI IO config accessor
By design only 'reg' parameter can have the two least- significant bits set. As 'reg' is often a constant, '0xCFC + (reg & 3)' resolves to an immediate value already at buildtime, unlike (addr & 3) which depends of a constant (but non-immediate) value of 'dev' in ramstage. Change-Id: I6e729fe800c92b1ce4994ad2b4203072fa75a958 Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/31754 Reviewed-by: Nico Huber <nico.h@gmx.de> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
-rw-r--r--src/arch/x86/include/arch/pci_io_cfg.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/src/arch/x86/include/arch/pci_io_cfg.h b/src/arch/x86/include/arch/pci_io_cfg.h
index 317c50a3fc..6c88b3cf5e 100644
--- a/src/arch/x86/include/arch/pci_io_cfg.h
+++ b/src/arch/x86/include/arch/pci_io_cfg.h
@@ -34,7 +34,7 @@ uint8_t pci_io_read_config8(pci_devfn_t dev, uint16_t reg)
{
uint32_t addr = pci_io_encode_addr(dev, reg);
outl(0x80000000 | (addr & ~3), 0xCF8);
- return inb(0xCFC + (addr & 3));
+ return inb(0xCFC + (reg & 3));
}
static __always_inline
@@ -42,7 +42,7 @@ uint16_t pci_io_read_config16(pci_devfn_t dev, uint16_t reg)
{
uint32_t addr = pci_io_encode_addr(dev, reg);
outl(0x80000000 | (addr & ~3), 0xCF8);
- return inw(0xCFC + (addr & 2));
+ return inw(0xCFC + (reg & 2));
}
static __always_inline
@@ -58,7 +58,7 @@ void pci_io_write_config8(pci_devfn_t dev, uint16_t reg, uint8_t value)
{
uint32_t addr = pci_io_encode_addr(dev, reg);
outl(0x80000000 | (addr & ~3), 0xCF8);
- outb(value, 0xCFC + (addr & 3));
+ outb(value, 0xCFC + (reg & 3));
}
static __always_inline
@@ -66,7 +66,7 @@ void pci_io_write_config16(pci_devfn_t dev, uint16_t reg, uint16_t value)
{
uint32_t addr = pci_io_encode_addr(dev, reg);
outl(0x80000000 | (addr & ~3), 0xCF8);
- outw(value, 0xCFC + (addr & 2));
+ outw(value, 0xCFC + (reg & 2));
}
static __always_inline