mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 00:48:50 +00:00
e6eadc6787
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>
60 lines
1.6 KiB
C
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;
|
|
}
|