linux/arch/arm/kernel/suspend.c
Will Deacon e6eadc6787 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 <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>
2011-12-06 14:04:14 +00:00

60 lines
1.6 KiB
C

#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>
extern int __cpu_suspend(unsigned long, int (*)(unsigned long));
extern void cpu_resume_mmu(void);
/*
* This is called by __cpu_suspend() to save the state, and do whatever
* flushing is required to ensure that when the CPU goes to sleep we have
* the necessary data available when the caches are not searched.
*/
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(idmap_pgd);
*ptr++ = sp;
*ptr++ = virt_to_phys(cpu_do_resume);
cpu_do_suspend(ptr);
flush_cache_all();
outer_clean_range(*save_ptr, *save_ptr + ptrsz);
outer_clean_range(virt_to_phys(save_ptr),
virt_to_phys(save_ptr) + sizeof(*save_ptr));
}
/*
* Hide the first two arguments to __cpu_suspend - these are an implementation
* detail which platform code shouldn't have to know about.
*/
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
struct mm_struct *mm = current->active_mm;
int ret;
if (!idmap_pgd)
return -EINVAL;
/*
* Provide a temporary page table with an identity mapping for
* the MMU-enable code, required for resuming. On successful
* resume (indicated by a zero return code), we need to switch
* back to the correct page tables.
*/
ret = __cpu_suspend(arg, fn);
if (ret == 0) {
cpu_switch_mm(mm->pgd, mm);
local_flush_tlb_all();
}
return ret;
}