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-rw-r--r--arch/arm/mm/mmu.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 9b36c5cb5e9f..aa424e1da8a1 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -243,6 +243,10 @@ static struct mem_type mem_types[] = {
.prot_sect = PMD_TYPE_SECT,
.domain = DOMAIN_KERNEL,
},
+ [MT_MEMORY_NONCACHED] = {
+ .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
+ .domain = DOMAIN_KERNEL,
+ },
};
const struct mem_type *get_mem_type(unsigned int type)
@@ -406,9 +410,28 @@ static void __init build_mem_type_table(void)
kern_pgprot |= L_PTE_SHARED;
vecs_pgprot |= L_PTE_SHARED;
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
+ mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
#endif
}
+ /*
+ * Non-cacheable Normal - intended for memory areas that must
+ * not cause dirty cache line writebacks when used
+ */
+ if (cpu_arch >= CPU_ARCH_ARMv6) {
+ if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
+ /* Non-cacheable Normal is XCB = 001 */
+ mem_types[MT_MEMORY_NONCACHED].prot_sect |=
+ PMD_SECT_BUFFERED;
+ } else {
+ /* For both ARMv6 and non-TEX-remapping ARMv7 */
+ mem_types[MT_MEMORY_NONCACHED].prot_sect |=
+ PMD_SECT_TEX(1);
+ }
+ } else {
+ mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
+ }
+
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
protection_map[i] = __pgprot(v | user_pgprot);