From mboxrd@z Thu Jan 1 00:00:00 1970 From: hanjun.guo@linaro.org (Hanjun Guo) Date: Tue, 26 May 2015 20:49:15 +0800 Subject: [PATCH 02/11] x86, pci: Clean up comment about buggy MMIO config space access for AMD Fam10h CPUs. In-Reply-To: <1432644564-24746-1-git-send-email-hanjun.guo@linaro.org> References: <1432644564-24746-1-git-send-email-hanjun.guo@linaro.org> Message-ID: <1432644564-24746-3-git-send-email-hanjun.guo@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Tomasz Nowicki - fix typo - improve explanation - add reference to the related document Signed-off-by: Tomasz Nowicki Signed-off-by: Hanjun Guo Tested-by: Suravee Suthikulpanit --- 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