diff options
| author | Cyril Chemparathy <cyril@ti.com> | 2012-07-21 21:55:04 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2013-05-30 17:02:15 +0200 |
| commit | 4756dcbfd37819a8359d3c69a22be2ee41666d0f (patch) | |
| tree | a9c172f6940e607b9c0c9a3bd7393bf0cc03e940 /arch/arm/include | |
| parent | ARM: LPAE: factor out T1SZ and TTBR1 computations (diff) | |
| download | linux-4756dcbfd37819a8359d3c69a22be2ee41666d0f.tar.xz linux-4756dcbfd37819a8359d3c69a22be2ee41666d0f.zip | |
ARM: LPAE: accomodate >32-bit addresses for page table base
This patch redefines the early boot time use of the R4 register to steal a few
low order bits (ARCH_PGD_SHIFT bits) on LPAE systems. This allows for up to
38-bit physical addresses.
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Subash Patel <subash.rp@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/memory.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 57870ab313c5..e506088a7678 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -18,6 +18,8 @@ #include <linux/types.h> #include <linux/sizes.h> +#include <asm/cache.h> + #ifdef CONFIG_NEED_MACH_MEMORY_H #include <mach/memory.h> #endif @@ -141,6 +143,20 @@ #define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page))) #define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys))) +/* + * Minimum guaranted alignment in pgd_alloc(). The page table pointers passed + * around in head.S and proc-*.S are shifted by this amount, in order to + * leave spare high bits for systems with physical address extension. This + * does not fully accomodate the 40-bit addressing capability of ARM LPAE, but + * gives us about 38-bits or so. + */ +#ifdef CONFIG_ARM_LPAE +#define ARCH_PGD_SHIFT L1_CACHE_SHIFT +#else +#define ARCH_PGD_SHIFT 0 +#endif +#define ARCH_PGD_MASK ((1 << ARCH_PGD_SHIFT) - 1) + #ifndef __ASSEMBLY__ /* |