diff options
Diffstat (limited to 'arch/arm/include/asm/pgtable-2level.h')
| -rw-r--r-- | arch/arm/include/asm/pgtable-2level.h | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h index bfd662e49..aeddd28b3 100644 --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -129,7 +129,36 @@ /* * These are the memory types, defined to be compatible with - * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB + * pre-ARMv6 CPUs cacheable and bufferable bits: n/a,n/a,C,B + * ARMv6+ without TEX remapping, they are a table index. + * ARMv6+ with TEX remapping, they correspond to n/a,TEX(0),C,B + * + * MT type Pre-ARMv6 ARMv6+ type / cacheable status + * UNCACHED Uncached Strongly ordered + * BUFFERABLE Bufferable Normal memory / non-cacheable + * WRITETHROUGH Writethrough Normal memory / write through + * WRITEBACK Writeback Normal memory / write back, read alloc + * MINICACHE Minicache N/A + * WRITEALLOC Writeback Normal memory / write back, write alloc + * DEV_SHARED Uncached Device memory (shared) + * DEV_NONSHARED Uncached Device memory (non-shared) + * DEV_WC Bufferable Normal memory / non-cacheable + * DEV_CACHED Writeback Normal memory / write back, read alloc + * VECTORS Variable Normal memory / variable + * + * All normal memory mappings have the following properties: + * - reads can be repeated with no side effects + * - repeated reads return the last value written + * - reads can fetch additional locations without side effects + * - writes can be repeated (in certain cases) with no side effects + * - writes can be merged before accessing the target + * - unaligned accesses can be supported + * + * All device mappings have the following properties: + * - no access speculation + * - no repetition (eg, on return from an exception) + * - number, order and size of accesses are maintained + * - unaligned accesses are "unpredictable" */ #define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */ #define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */ |