Change in ...coreboot[master]: arch/x86: Fix PCI IO config accessor

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/31847 )

Change subject: arch/x86: Fix PCI IO config accessor
......................................................................

arch/x86: Fix PCI IO config accessor

In case PCI_IO_CFG_EXT=n parameter 'reg' was not
properly truncated to 8 bits and it would overflow
to dev.fn part of the register.

A similar thing could happen with 'dev' but that
value originates from PCI_DEV() macro unlike 'reg'.

Change-Id: Id2888e07fc0f2b182b4633a747c1786e5c560678
Signed-off-by: Kyösti Mälkki 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31847
Reviewed-by: Nico Huber 
Tested-by: build bot (Jenkins) 
---
M src/arch/x86/include/arch/pci_io_cfg.h
1 file changed, 15 insertions(+), 12 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved

diff --git a/src/arch/x86/include/arch/pci_io_cfg.h b/src/arch/x86/include/arch/pci_io_cfg.h
index 6c88b3c..1e6934a 100644
--- a/src/arch/x86/include/arch/pci_io_cfg.h
+++ b/src/arch/x86/include/arch/pci_io_cfg.h
@@ -21,19 +21,22 @@
 static __always_inline
 uint32_t pci_io_encode_addr(pci_devfn_t dev, uint16_t reg)
 {
-	if (CONFIG(PCI_IO_CFG_EXT)) {
-		// seg == 0
-		return dev >> 4 | (reg & 0xff) | ((reg & 0xf00) << 16);
-	} else {
-		return dev >> 4 | reg;
-	}
+	uint32_t addr = 1 << 31;
+
+	addr |= dev >> 4;
+	addr |= reg & 0xfc;
+
+	if (CONFIG(PCI_IO_CFG_EXT))
+		addr |= (reg & 0xf00) << 16;
+
+	return addr;
 }

static __always_inline
 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);
+	outl(addr, 0xCF8);
    return inb(0xCFC + (reg & 3));
 }

@@ -41,7 +44,7 @@
 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);
+	outl(addr, 0xCF8);
    return inw(0xCFC + (reg & 2));
 }

@@ -49,7 +52,7 @@
 uint32_t pci_io_read_config32(pci_devfn_t dev, uint16_t reg)
 {
    uint32_t addr = pci_io_encode_addr(dev, reg);
-	outl(0x80000000 | (addr & ~3), 0xCF8);
+	outl(addr, 0xCF8);
    return inl(0xCFC);
 }

@@ -57,7 +60,7 @@
 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);
+	outl(addr, 0xCF8);
    outb(value, 0xCFC + (reg & 3));
 }

@@ -65,7 +68,7 @@
 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);
+	outl(addr, 0xCF8);
    outw(value, 0xCFC + (reg & 2));
 }

@@ -73,7 +76,7 @@
 void pci_io_write_config32(pci_devfn_t dev, uint16_t reg, uint32_t value)
 {
    uint32_t addr = pci_io_encode_addr(dev, reg);
-	outl(0x80000000 | (addr & ~3), 0xCF8);
+	outl(addr, 0xCF8);
    outl(value, 0xCFC);
 }