Messages in this thread Patch in this message | | | From | Minchan Kim <> | Subject | [PATCH v1 1/3] arm: mm: reordering memory type table | Date | Mon, 17 Sep 2018 09:44:49 +0900 |
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To use bit 5 in page table as L_PTE_SPECIAL, we need a room for that. It seems we don't need 4 bits for the memory type with ARMv6+. If it's true, let's reorder bits to make bit 5 free.
We will use the bit for L_PTE_SPECIAL in next patch.
A note from Catalin " > Anyway, on ARMv7 or ARMv6+LPAE, the non-shared device gets mapped to > shared device in hardware. Looking through the arm32 code, it seems that > MT_DEVICE_NONSHARED is used by arch/arm/mach-shmobile/setup-r8a7779.c > and IIUC that's a v7 platform (R-Car H1, Cortex-A9). I think the above > should be defined to L_PTE_MT_DEV_SHARED, unless I miss any place where > DEV_NONSHARED is relevant on ARMv6 (adding Simon to confirm on shmbile). "
Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Simon Horman <horms@verge.net.au> Signed-off-by: Minchan Kim <minchan@kernel.org> --- arch/arm/include/asm/pgtable-2level.h | 19 +++++++++++++++---- arch/arm/mm/proc-macros.S | 4 ++-- 2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h index 92fd2c8a9af0..514b13c27b43 100644 --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -164,14 +164,25 @@ #define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */ #define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */ #define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */ +#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */ +#define L_PTE_MT_VECTORS (_AT(pteval_t, 0x05) << 2) /* 0101 */ #define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */ #define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */ -#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */ -#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */ +#if defined(CONFIG_CPU_V7) || defined (CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) +/* + * On ARMv7 or ARMv6+LPAE, the non-shared device gets mapped to + * shared device in hardware. + */ +#define L_PTE_MT_DEV_NONSHARED L_PTE_MT_DEV_SHARED +#define L_PTE_MT_DEV_WC L_PTE_MT_BUFFERABLE +#define L_PTE_MT_DEV_CACHED L_PTE_MT_WRITEBACK +#define L_PTE_MT_MASK (_AT(pteval_t, 0x07) << 2) +#else #define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */ #define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */ -#define L_PTE_MT_VECTORS (_AT(pteval_t, 0x0f) << 2) /* 1111 */ -#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2) +#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */ +#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2) +#endif #ifndef __ASSEMBLY__ diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S index 81d0efb055c6..367a89d5aeca 100644 --- a/arch/arm/mm/proc-macros.S +++ b/arch/arm/mm/proc-macros.S @@ -138,7 +138,7 @@ .long PTE_CACHEABLE @ L_PTE_MT_WRITETHROUGH .long PTE_CACHEABLE | PTE_BUFFERABLE @ L_PTE_MT_WRITEBACK .long PTE_BUFFERABLE @ L_PTE_MT_DEV_SHARED - .long 0x00 @ unused + .long PTE_CACHEABLE | PTE_BUFFERABLE | PTE_EXT_APX @ L_PTE_MT_VECTORS .long 0x00 @ L_PTE_MT_MINICACHE (not present) .long PTE_EXT_TEX(1) | PTE_CACHEABLE | PTE_BUFFERABLE @ L_PTE_MT_WRITEALLOC .long 0x00 @ unused @@ -148,7 +148,7 @@ .long PTE_EXT_TEX(2) @ L_PTE_MT_DEV_NONSHARED .long 0x00 @ unused .long 0x00 @ unused - .long PTE_CACHEABLE | PTE_BUFFERABLE | PTE_EXT_APX @ L_PTE_MT_VECTORS + .long 0x00 @ unused .endm .macro armv6_set_pte_ext pfx -- 2.19.0.397.gdd90340f6a-goog
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