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ARM: suspend: use idmap_pgd instead of suspend_pgd

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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 <catalin.marinas@arm.com>
Acked-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2011-11-15 11:11:19 +00:00
parent 8903826d0c
commit e6eadc6787
2 changed files with 5 additions and 15 deletions
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2
arch/arm/kernel/sleep.S
View File

@ -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

18
arch/arm/kernel/suspend.c
View File

@ -1,13 +1,12 @@
#include <linux/init.h>
#include <asm/idmap.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/memory.h>
#include <asm/suspend.h>
#include <asm/tlbflush.h>
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);