From 8903826d0cd99aed9267e792d38284cf3092042b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 30 Sep 2011 11:43:29 +0100 Subject: ARM: idmap: populate identity map pgd at init time using .init.text When disabling and re-enabling the MMU, it is necessary to take out an identity mapping for the code that manipulates the SCTLR in order to avoid it disappearing from under our feet. This is useful when soft rebooting and returning from CPU suspend. This patch allocates a set of page tables during boot and populates them with an identity mapping for the .idmap.text section. This means that users of the identity map do not need to manage their own pgd and can instead annotate their functions with __idmap or, in the case of assembly code, place them in the correct section. Acked-by: Dave Martin Reviewed-by: Catalin Marinas Tested-by: Lorenzo Pieralisi Signed-off-by: Will Deacon --- arch/arm/include/asm/idmap.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 arch/arm/include/asm/idmap.h (limited to 'arch/arm/include/asm/idmap.h') diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h new file mode 100644 index 000000000000..62e3d19c9ad7 --- /dev/null +++ b/arch/arm/include/asm/idmap.h @@ -0,0 +1,17 @@ +#ifndef __ASM_IDMAP_H +#define __ASM_IDMAP_H + +#include +#include + +/* Tag a function as requiring to be executed via an identity mapping. */ +#define __idmap __section(.idmap.text) noinline notrace + +extern pgd_t *idmap_pgd; + +void identity_mapping_add(pgd_t *, unsigned long, unsigned long); +void identity_mapping_del(pgd_t *, unsigned long, unsigned long); + +void setup_mm_for_reboot(void); + +#endif /* __ASM_IDMAP_H */ -- cgit