This patch defines _PAGE_CACHE_WT and its relevant macros, which now use the PA3/7 slot in the PAT MSR. pat_init() is also changed to set the WT memory type to the PA3/7 slot in the PAT MSR. Signed-off-by: Toshi Kani <toshi.kani@xxxxxx> --- arch/x86/include/asm/pgtable_types.h | 5 +++++ arch/x86/mm/pat.c | 8 ++++---- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 03d40da..7b905cb 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -132,6 +132,7 @@ #define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) #define _PAGE_CACHE_WB (0) #define _PAGE_CACHE_WC (_PAGE_PWT) +#define _PAGE_CACHE_WT (_PAGE_PCD | _PAGE_PWT) #define _PAGE_CACHE_UC_MINUS (_PAGE_PCD) #define _PAGE_CACHE_UC (_PAGE_CACHE_UC_MINUS) @@ -159,6 +160,7 @@ #define __PAGE_KERNEL_RX (__PAGE_KERNEL_EXEC & ~_PAGE_RW) #define __PAGE_KERNEL_EXEC_NOCACHE (__PAGE_KERNEL_EXEC | _PAGE_CACHE_UC) #define __PAGE_KERNEL_WC (__PAGE_KERNEL | _PAGE_CACHE_WC) +#define __PAGE_KERNEL_WT (__PAGE_KERNEL | _PAGE_CACHE_WT) #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC) #define __PAGE_KERNEL_UC_MINUS (__PAGE_KERNEL | _PAGE_CACHE_UC_MINUS) #define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER) @@ -172,12 +174,14 @@ #define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE | _PAGE_IOMAP) #define __PAGE_KERNEL_IO_UC_MINUS (__PAGE_KERNEL_UC_MINUS | _PAGE_IOMAP) #define __PAGE_KERNEL_IO_WC (__PAGE_KERNEL_WC | _PAGE_IOMAP) +#define __PAGE_KERNEL_IO_WT (__PAGE_KERNEL_WT | _PAGE_IOMAP) #define PAGE_KERNEL __pgprot(__PAGE_KERNEL) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) #define PAGE_KERNEL_RX __pgprot(__PAGE_KERNEL_RX) #define PAGE_KERNEL_WC __pgprot(__PAGE_KERNEL_WC) +#define PAGE_KERNEL_WT __pgprot(__PAGE_KERNEL_WT) #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE) #define PAGE_KERNEL_UC_MINUS __pgprot(__PAGE_KERNEL_UC_MINUS) #define PAGE_KERNEL_EXEC_NOCACHE __pgprot(__PAGE_KERNEL_EXEC_NOCACHE) @@ -192,6 +196,7 @@ #define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE) #define PAGE_KERNEL_IO_UC_MINUS __pgprot(__PAGE_KERNEL_IO_UC_MINUS) #define PAGE_KERNEL_IO_WC __pgprot(__PAGE_KERNEL_IO_WC) +#define PAGE_KERNEL_IO_WT __pgprot(__PAGE_KERNEL_IO_WT) /* xwr */ #define __P000 PAGE_NONE diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index c3567a5..176d4d6 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -101,7 +101,7 @@ void pat_init(void) } } - /* Set PWT to Write-Combining. All other bits stay the same */ + /* Set PWT to Write-Combining, and PCD|PWT to Write-Through. */ /* * PTE encoding used in Linux: * PAT @@ -111,11 +111,11 @@ void pat_init(void) * 000 WB _PAGE_CACHE_WB * 001 WC _PAGE_CACHE_WC * 010 UC- _PAGE_CACHE_UC_MINUS - * 011 UC _PAGE_CACHE_UC + * 011 WT _PAGE_CACHE_WT * PAT bit unused */ - pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | - PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); + pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, WT) | + PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, WT); /* Boot CPU check */ if (!boot_pat_state) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>