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| author | Tomasz Nowicki <tomasz.nowicki@linaro.org> | 2015-05-26 20:49:15 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-12-10 19:38:06 -0600 |
| commit | 21461775f3d173dedec27a0402d426ba422d80a1 (patch) | |
| tree | fab34b6461867bf2db8b5cf1c3595a7107b88546 /arch/x86/include/asm/pci_x86.h | |
| parent | 4066df6345f5b3bacdf7944c4d9a839f1eef5773 (diff) | |
| download | linux-0-day-21461775f3d173dedec27a0402d426ba422d80a1.tar.gz linux-0-day-21461775f3d173dedec27a0402d426ba422d80a1.tar.xz | |
x86/PCI: Clarify AMD Fam10h config access restrictions comment
Clarify the comment about AMD Fam10h config access restrictions, fix typos,
and add a reference to the specification.
[bhelgaas: streamline]
Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Diffstat (limited to 'arch/x86/include/asm/pci_x86.h')
| -rw-r--r-- | arch/x86/include/asm/pci_x86.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h index fa1195dae4254..46873fbd44e1b 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -151,11 +151,11 @@ extern struct list_head pci_mmcfg_list; #define PCI_MMCFG_BUS_OFFSET(bus) ((bus) << 20) /* - * 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 - * accessor functions. - * In fact just use pci_config_*, nothing else please. + * On AMD Fam10h CPUs, all PCI MMIO configuration space accesses must use + * %eax. No other source or target registers may be used. The following + * mmio_config_* accessors enforce this. See "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) { |