[PATCH] mmu: move MAP_RO definition into global mmu.h header

[Ahmad Fatoum <a.fatoum@barebox.org>]

To allow generic code to remap memory as read-only, let's add the
definition to the global header.

On platforms other than ARM, mapping R/O will just be cached R/W.

Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>
---
 arch/Kconfig              | 3 +++
 arch/arm/Kconfig          | 1 +
 arch/arm/cpu/mmu-common.c | 4 ++--
 arch/arm/cpu/mmu-common.h | 3 +--
 arch/arm/cpu/mmu_32.c     | 4 ++--
 arch/arm/cpu/mmu_64.c     | 2 +-
 include/mmu.h             | 6 ++++++
 7 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index ca9aa25a9c4b..3daba5239740 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -62,6 +62,9 @@ config ARCH_DMA_DEFAULT_COHERENT
 config ARCH_HAS_DMA_WRITE_COMBINE
 	bool
 
+config ARCH_HAS_RO_MAPPINGS
+	bool
+
 config ARCH_HAS_ASAN_FIBER_API
 	bool
 
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5123e9b1402c..d9b1f5de1fa7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -17,6 +17,7 @@ config ARM
 	select HAVE_ARCH_BOOTM_OFTREE
 	select HW_HAS_PCI
 	select ARCH_HAS_DMA_WRITE_COMBINE
+	select ARCH_HAS_RO_MAPPINGS
 	select HAVE_EFI_LOADER if MMU # for payload unaligned accesses
 	default y
 
diff --git a/arch/arm/cpu/mmu-common.c b/arch/arm/cpu/mmu-common.c
index a1431c0ff461..6db85fa9c7d4 100644
--- a/arch/arm/cpu/mmu-common.c
+++ b/arch/arm/cpu/mmu-common.c
@@ -22,7 +22,7 @@ const char *map_type_tostr(maptype_t map_type)
 
 	switch (map_type) {
 	case ARCH_MAP_CACHED_RWX:	return "RWX";
-	case ARCH_MAP_CACHED_RO:	return "RO";
+	case MAP_RO:			return "RO";
 	case MAP_CACHED:		return "CACHED";
 	case MAP_UNCACHED:		return "UNCACHED";
 	case MAP_CODE:			return "CODE";
@@ -158,7 +158,7 @@ static void mmu_remap_memory_banks(void)
 	}
 
 	remap_range((void *)code_start, code_size, MAP_CODE);
-	remap_range((void *)rodata_start, rodata_size, ARCH_MAP_CACHED_RO);
+	remap_range((void *)rodata_start, rodata_size, MAP_RO);
 
 	setup_trap_pages();
 }
diff --git a/arch/arm/cpu/mmu-common.h b/arch/arm/cpu/mmu-common.h
index a111e15a21b4..39332d8f5a98 100644
--- a/arch/arm/cpu/mmu-common.h
+++ b/arch/arm/cpu/mmu-common.h
@@ -12,7 +12,6 @@
 #include <linux/bits.h>
 
 #define ARCH_MAP_CACHED_RWX	MAP_ARCH(2)
-#define ARCH_MAP_CACHED_RO	MAP_ARCH(3)
 
 #define ARCH_MAP_FLAG_PAGEWISE	BIT(31)
 
@@ -32,7 +31,7 @@ static inline maptype_t arm_mmu_maybe_skip_permissions(maptype_t map_type)
 	switch (map_type & MAP_TYPE_MASK) {
 	case MAP_CODE:
 	case MAP_CACHED:
-	case ARCH_MAP_CACHED_RO:
+	case MAP_RO:
 		return ARCH_MAP_CACHED_RWX;
 	default:
 		return map_type;
diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
index 912d14e8cf82..d41ebcfb7fe4 100644
--- a/arch/arm/cpu/mmu_32.c
+++ b/arch/arm/cpu/mmu_32.c
@@ -304,7 +304,7 @@ static uint32_t get_pte_flags(maptype_t map_type)
 		switch (map_type & MAP_TYPE_MASK) {
 		case ARCH_MAP_CACHED_RWX:
 			return PTE_FLAGS_CACHED_V7_RWX;
-		case ARCH_MAP_CACHED_RO:
+		case MAP_RO:
 			return PTE_FLAGS_CACHED_RO_V7;
 		case MAP_CACHED:
 			return PTE_FLAGS_CACHED_V7;
@@ -320,7 +320,7 @@ static uint32_t get_pte_flags(maptype_t map_type)
 		}
 	} else {
 		switch (map_type & MAP_TYPE_MASK) {
-		case ARCH_MAP_CACHED_RO:
+		case MAP_RO:
 		case MAP_CODE:
 			return PTE_FLAGS_CACHED_RO_V4;
 		case ARCH_MAP_CACHED_RWX:
diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
index 56c6a21f2b2a..006b2b29478f 100644
--- a/arch/arm/cpu/mmu_64.c
+++ b/arch/arm/cpu/mmu_64.c
@@ -159,7 +159,7 @@ static unsigned long get_pte_attrs(maptype_t map_type)
 		return attrs_xn() | MEM_ALLOC_WRITECOMBINE;
 	case MAP_CODE:
 		return CACHED_MEM | PTE_BLOCK_RO;
-	case ARCH_MAP_CACHED_RO:
+	case MAP_RO:
 		return attrs_xn() | CACHED_MEM | PTE_BLOCK_RO;
 	case ARCH_MAP_CACHED_RWX:
 		return CACHED_MEM;
diff --git a/include/mmu.h b/include/mmu.h
index f79619808829..7d87885a5cb4 100644
--- a/include/mmu.h
+++ b/include/mmu.h
@@ -16,6 +16,12 @@
 #define MAP_WRITECOMBINE	MAP_UNCACHED
 #endif
 
+#ifdef CONFIG_ARCH_HAS_RO_MAPPINGS
+#define MAP_RO			5
+#else
+#define MAP_RO			MAP_CACHED
+#endif
+
 #define MAP_TYPE_MASK	0xFFFF
 #define MAP_ARCH(x)	((u16)~(x))
 
-- 
2.47.3