From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomasz.nowicki@linaro.org (Tomasz Nowicki) Date: Wed, 11 Mar 2015 15:12:41 +0100 Subject: [PATCH v4 1/9] x86, pci: Clean up comment about buggy MMIO config space access for AMD Fam10h CPUs. In-Reply-To: <1426083169-8698-1-git-send-email-tomasz.nowicki@linaro.org> References: <1426083169-8698-1-git-send-email-tomasz.nowicki@linaro.org> Message-ID: <1426083169-8698-2-git-send-email-tomasz.nowicki@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org - fix typo - improve explanation - add reference to the related document Signed-off-by: Tomasz Nowicki --- 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 fa1195d..d024f4d 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -152,10 +152,13 @@ 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