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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-09-01 09:59:28 +0300
committerard <ard.biesheuvel@linaro.org>2015-12-13 21:18:28 +0300
commit2937367b8a4b0d46ce3312cb997e4a240b02cf15 (patch)
tree44454d1cfd965482d661c92d17264d6affa77a6a /arch/arm/include/asm
parentf7d924894265794f447ea799dd853400749b5a22 (diff)
downloadlinux-2937367b8a4b0d46ce3312cb997e4a240b02cf15.tar.xz
ARM: add support for generic early_ioremap/early_memremap
This enables the generic early_ioremap implementation for ARM. It uses the fixmap region reserved for kmap. Since early_ioremap is only supported before paging_init(), and kmap is only supported afterwards, this is guaranteed not to cause any clashes. Tested-by: Ryan Harkin <ryan.harkin@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Diffstat (limited to 'arch/arm/include/asm')
-rw-r--r--arch/arm/include/asm/Kbuild1
-rw-r--r--arch/arm/include/asm/fixmap.h29
2 files changed, 29 insertions, 1 deletions
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index bd425302c97a..16da6380eb85 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -3,6 +3,7 @@
generic-y += bitsperlong.h
generic-y += cputime.h
generic-y += current.h
+generic-y += early_ioremap.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index 58cfe9f1a687..5c17d2dec777 100644
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -19,20 +19,47 @@ enum fixed_addresses {
FIX_TEXT_POKE0,
FIX_TEXT_POKE1,
- __end_of_fixed_addresses
+ __end_of_fixmap_region,
+
+ /*
+ * Share the kmap() region with early_ioremap(): this is guaranteed
+ * not to clash since early_ioremap() is only available before
+ * paging_init(), and kmap() only after.
+ */
+#define NR_FIX_BTMAPS 32
+#define FIX_BTMAPS_SLOTS 7
+#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+ FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+ FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+ __end_of_early_ioremap_region
};
+static const enum fixed_addresses __end_of_fixed_addresses =
+ __end_of_fixmap_region > __end_of_early_ioremap_region ?
+ __end_of_fixmap_region : __end_of_early_ioremap_region;
+
#define FIXMAP_PAGE_COMMON (L_PTE_YOUNG | L_PTE_PRESENT | L_PTE_XN | L_PTE_DIRTY)
#define FIXMAP_PAGE_NORMAL (FIXMAP_PAGE_COMMON | L_PTE_MT_WRITEBACK)
+#define FIXMAP_PAGE_RO (FIXMAP_PAGE_NORMAL | L_PTE_RDONLY)
/* Used by set_fixmap_(io|nocache), both meant for mapping a device */
#define FIXMAP_PAGE_IO (FIXMAP_PAGE_COMMON | L_PTE_MT_DEV_SHARED | L_PTE_SHARED)
#define FIXMAP_PAGE_NOCACHE FIXMAP_PAGE_IO
+#define __early_set_fixmap __set_fixmap
+
+#ifdef CONFIG_MMU
+
void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
void __init early_fixmap_init(void);
#include <asm-generic/fixmap.h>
+#else
+
+static inline void early_fixmap_init(void) { }
+
+#endif
#endif