From 2937367b8a4b0d46ce3312cb997e4a240b02cf15 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 1 Sep 2015 08:59:28 +0200 Subject: 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 Reviewed-by: Matt Fleming Signed-off-by: Ard Biesheuvel --- arch/arm/include/asm/fixmap.h | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'arch/arm/include/asm/fixmap.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 +#else + +static inline void early_fixmap_init(void) { } + +#endif #endif -- cgit