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-rw-r--r--arch/arm/mm/mmu.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 25d9a11eb61..a713e40e1f1 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -211,6 +211,12 @@ static struct mem_type mem_types[] = {
PMD_SECT_TEX(1),
.domain = DOMAIN_IO,
},
+ [MT_DEVICE_WC] = { /* ioremap_wc */
+ .prot_pte = PROT_PTE_DEVICE,
+ .prot_l1 = PMD_TYPE_TABLE,
+ .prot_sect = PROT_SECT_DEVICE,
+ .domain = DOMAIN_IO,
+ },
[MT_CACHECLEAN] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
@@ -273,6 +279,20 @@ static void __init build_mem_type_table(void)
}
/*
+ * On non-Xscale3 ARMv5-and-older systems, use CB=01
+ * (Uncached/Buffered) for ioremap_wc() mappings. On XScale3
+ * and ARMv6+, use TEXCB=00100 mappings (Inner/Outer Uncacheable
+ * in xsc3 parlance, Uncached Normal in ARMv6 parlance).
+ */
+ if (cpu_is_xsc3() || cpu_arch >= CPU_ARCH_ARMv6) {
+ mem_types[MT_DEVICE_WC].prot_pte_ext |= PTE_EXT_TEX(1);
+ mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
+ } else {
+ mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_BUFFERABLE;
+ mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
+ }
+
+ /*
* ARMv5 and lower, bit 4 must be set for page tables.
* (was: cache "update-able on write" bit on ARM610)
* However, Xscale cores require this bit to be cleared.