[PATCH v2 1/9] x86, pci: Clean up comment about buggy MMIO config space access for AMD Fam10h CPUs.
From: Tomasz Nowicki <hidden>
Date: 2015-02-27 15:03:43
Also in:
linux-acpi, linux-pci, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
- fix typo - improve explanation - add reference to the related document Signed-off-by: Tomasz Nowicki <redacted> --- arch/x86/include/asm/pci_x86.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 164e3f8..eddf8f0 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h@@ -154,10 +154,13 @@ extern struct list_head pci_mmcfg_list; /* * AMD Fam10h CPUs are buggy, and cannot access MMIO config space - * on their northbrige except through the * %eax register. As such, you MUST - * NOT use normal IOMEM accesses, you need to only use the magic mmio-config + * on their northbridge except through the * %eax register. As such, you MUST + * NOT use normal IOMEM accesses, you need to only use the magic mmio_config_* * accessor functions. - * In fact just use pci_config_*, nothing else please. + * + * Please refer to the following doc: + * "BIOS and Kernel Developer's Guide (BKDG) For AMD Family 10h Processors", + * rev. 3.48, sec 2.11.1, "MMIO Configuration Coding Requirements". */ static inline unsigned char mmio_config_readb(void __iomem *pos) {
--
1.9.1