ARM: mm: Add strongly ordered descriptor support.

On certain architectures, there might be a need to mark certain
addresses with strongly ordered memory attributes to avoid ordering
issues at the interconnect level.

On OMAP4, the asynchronous bridge buffers can only be drained
with strongly ordered accesses and hence the need to mark the
memory strongly ordered.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Woodruff Richard <r-woodruff2@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>

diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index d2fedb5aeb1f381d74dbdfd29516fbbfd0ea4e13..b36f3654bf54ebcc9e1c9617663c706d81bcfd97 100644 (file)
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -29,6 +29,7 @@ struct map_desc {
 #define MT_MEMORY_NONCACHED    11
 #define MT_MEMORY_DTCM         12
 #define MT_MEMORY_ITCM         13
+#define MT_MEMORY_SO           14
 
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 5750704e02718b9247704021a0832f161bcbaf3b..f1956b27ae5a27e5ba7f41d30adad53f922ed5d2 100644 (file)
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -232,6 +232,9 @@ extern pgprot_t             pgprot_kernel;
 #define pgprot_writecombine(prot) \
        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
 
+#define pgprot_stronglyordered(prot) \
+       __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
+
 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 #define pgprot_dmacoherent(prot) \
        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 594d677b92c883c25c4d5051bcc635394984b6f6..ea9c9f3e48bffbbe966d17abd6cfb286151f8a0c 100644 (file)
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -273,6 +273,14 @@ static struct mem_type mem_types[] = {
                .prot_l1   = PMD_TYPE_TABLE,
                .domain    = DOMAIN_KERNEL,
        },
+       [MT_MEMORY_SO] = {
+               .prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+                               L_PTE_MT_UNCACHED,
+               .prot_l1   = PMD_TYPE_TABLE,
+               .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S |
+                               PMD_SECT_UNCACHED | PMD_SECT_XN,
+               .domain    = DOMAIN_KERNEL,
+       },
 };
 
 const struct mem_type *get_mem_type(unsigned int type)