diff options
| author | Steven Capper <steve.capper@linaro.org> | 2014-07-18 17:16:15 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-07-24 15:27:08 +0200 |
| commit | ded9477984690d026e46dd75e8157392cea3f13f (patch) | |
| tree | 8faee3f6c299d1979290ce459687cf51c7e91e4c /arch/arm/include/asm/pgtable-3level-hwdef.h | |
| parent | ARM: 8108/1: mm: Introduce {pte,pmd}_isset and {pte,pmd}_isclear (diff) | |
| download | linux-ded9477984690d026e46dd75e8157392cea3f13f.tar.xz linux-ded9477984690d026e46dd75e8157392cea3f13f.zip | |
ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE
For LPAE, we have the following means for encoding writable or dirty
ptes:
L_PTE_DIRTY L_PTE_RDONLY
!pte_dirty && !pte_write 0 1
!pte_dirty && pte_write 0 1
pte_dirty && !pte_write 1 1
pte_dirty && pte_write 1 0
So we can't distinguish between writeable clean ptes and read only
ptes. This can cause problems with ptes being incorrectly flagged as
read only when they are writeable but not dirty.
This patch renumbers L_PTE_RDONLY from AP[2] to a software bit #58,
and adds additional logic to set AP[2] whenever the pte is read only
or not dirty. That way we can distinguish between clean writeable ptes
and read only ptes.
HugeTLB pages will use this new logic automatically.
We need to add some logic to Transparent HugePages to ensure that they
correctly interpret the revised pgprot permissions (L_PTE_RDONLY has
moved and no longer matches PMD_SECT_AP2). In the process of revising
THP, the names of the PMD software bits have been prefixed with L_ to
make them easier to distinguish from their hardware bit counterparts.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/pgtable-3level-hwdef.h')
| -rw-r--r-- | arch/arm/include/asm/pgtable-3level-hwdef.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h index 626989fec4d3..9fd61c72a33a 100644 --- a/arch/arm/include/asm/pgtable-3level-hwdef.h +++ b/arch/arm/include/asm/pgtable-3level-hwdef.h @@ -43,7 +43,7 @@ #define PMD_SECT_BUFFERABLE (_AT(pmdval_t, 1) << 2) #define PMD_SECT_CACHEABLE (_AT(pmdval_t, 1) << 3) #define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */ -#define PMD_SECT_RDONLY (_AT(pmdval_t, 1) << 7) /* AP[2] */ +#define PMD_SECT_AP2 (_AT(pmdval_t, 1) << 7) /* read only */ #define PMD_SECT_S (_AT(pmdval_t, 3) << 8) #define PMD_SECT_AF (_AT(pmdval_t, 1) << 10) #define PMD_SECT_nG (_AT(pmdval_t, 1) << 11) @@ -72,6 +72,7 @@ #define PTE_TABLE_BIT (_AT(pteval_t, 1) << 1) #define PTE_BUFFERABLE (_AT(pteval_t, 1) << 2) /* AttrIndx[0] */ #define PTE_CACHEABLE (_AT(pteval_t, 1) << 3) /* AttrIndx[1] */ +#define PTE_AP2 (_AT(pteval_t, 1) << 7) /* AP[2] */ #define PTE_EXT_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */ #define PTE_EXT_AF (_AT(pteval_t, 1) << 10) /* Access Flag */ #define PTE_EXT_NG (_AT(pteval_t, 1) << 11) /* nG */ |