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/kernel/vmlinux.lds.S | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/arm/kernel/vmlinux.lds.S') diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 20b3041e0860..f76e75548670 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -13,6 +13,12 @@ *(.proc.info.init) \ VMLINUX_SYMBOL(__proc_info_end) = .; +#define IDMAP_TEXT \ + ALIGN_FUNCTION(); \ + VMLINUX_SYMBOL(__idmap_text_start) = .; \ + *(.idmap.text) \ + VMLINUX_SYMBOL(__idmap_text_end) = .; + #ifdef CONFIG_HOTPLUG_CPU #define ARM_CPU_DISCARD(x) #define ARM_CPU_KEEP(x) x @@ -92,6 +98,7 @@ SECTIONS SCHED_TEXT LOCK_TEXT KPROBES_TEXT + IDMAP_TEXT #ifdef CONFIG_MMU *(.fixup) #endif -- cgit