From e6eadc67873d5f363c864cd7723104e7d47dcb44 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 15 Nov 2011 11:11:19 +0000 Subject: [PATCH] ARM: suspend: use idmap_pgd instead of suspend_pgd The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped in order to re-enable the MMU when coming out of suspend. Currently, this is accomplished by maintaining a suspend_pgd with the relevant mapping put in place at init time. This patch replaces the use of suspend_pgd with the new idmap_pgd. cpu_resume_mmu is placed in the .idmap.text section so that it is included in the identity map. Reviewed-by: Catalin Marinas Acked-by: Dave Martin Tested-by: Lorenzo Pieralisi Signed-off-by: Will Deacon --- arch/arm/kernel/sleep.S | 2 ++ arch/arm/kernel/suspend.c | 18 +++--------------- 2 files changed, 5 insertions(+), 15 deletions(-) diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 020e99c845e7..9e64231c8cfe 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -54,6 +54,7 @@ ENDPROC(cpu_suspend_abort) * r0 = control register value */ .align 5 + .pushsection .idmap.text,"ax" ENTRY(cpu_resume_mmu) ldr r3, =cpu_resume_after_mmu mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc @@ -62,6 +63,7 @@ ENTRY(cpu_resume_mmu) mov r0, r0 mov pc, r3 @ jump to virtual address ENDPROC(cpu_resume_mmu) + .popsection cpu_resume_after_mmu: bl cpu_init @ restore the und/abt/irq banked regs mov r0, #0 @ return zero on success diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c index 93a22d282c16..1794cc3b0f18 100644 --- a/arch/arm/kernel/suspend.c +++ b/arch/arm/kernel/suspend.c @@ -1,13 +1,12 @@ #include +#include #include #include #include #include #include -static pgd_t *suspend_pgd; - extern int __cpu_suspend(unsigned long, int (*)(unsigned long)); extern void cpu_resume_mmu(void); @@ -21,7 +20,7 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) *save_ptr = virt_to_phys(ptr); /* This must correspond to the LDM in cpu_resume() assembly */ - *ptr++ = virt_to_phys(suspend_pgd); + *ptr++ = virt_to_phys(idmap_pgd); *ptr++ = sp; *ptr++ = virt_to_phys(cpu_do_resume); @@ -42,7 +41,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) struct mm_struct *mm = current->active_mm; int ret; - if (!suspend_pgd) + if (!idmap_pgd) return -EINVAL; /* @@ -59,14 +58,3 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) return ret; } - -static int __init cpu_suspend_init(void) -{ - suspend_pgd = pgd_alloc(&init_mm); - if (suspend_pgd) { - unsigned long addr = virt_to_phys(cpu_resume_mmu); - identity_mapping_add(suspend_pgd, addr, addr + SECTION_SIZE); - } - return suspend_pgd ? 0 : -ENOMEM; -} -core_initcall(cpu_suspend_init);