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ARM: suspend: fix CPU suspend code for !CONFIG_MMU configurations 

The ARM CPU suspend code can be selected even for a !CONFIG_MMU
configuration. The resulting kernel will not compile and, even if it did,
would access undefined co-processor registers when executing.

This patch fixes the v6 and v7 CPU suspend code for the nommu case.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Jonathan Austin <jonathan.austin@arm.com>
CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> (commit_signer:1/3=33%)
CC: Santosh Shilimkar <santosh.shilimkar@ti.com> (commit_signer:1/3=33%)
CC: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
This commit is contained in:
Will Deacon 2012-02-23 13:51:38 +00:00 committed by Jonathan Austin
parent c4a1f032ed
commit aa1aadc330
3 changed files with 50 additions and 34 deletions
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64
arch/arm/kernel/suspend.c
View File

@ -10,6 +10,42 @@
extern int __cpu_suspend(unsigned long, int (*)(unsigned long));
extern void cpu_resume_mmu(void);
#ifdef CONFIG_MMU
/*
* 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_bp_all();
local_flush_tlb_all();
}
return ret;
}
#else
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
return __cpu_suspend(arg, fn);
}
#define idmap_pgd NULL
#endif
/*
* 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
@ -46,31 +82,3 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
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_bp_all();
local_flush_tlb_all();
}
return ret;
}

6
arch/arm/mm/proc-v6.S
View File

@ -140,8 +140,10 @@ ENTRY(cpu_v6_set_pte_ext)
ENTRY(cpu_v6_do_suspend)
stmfd sp!, {r4 - r9, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
#ifdef CONFIG_MMU
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
#endif
mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register
mrc p15, 0, r8, c1, c0, 2 @ co-processor access control
mrc p15, 0, r9, c1, c0, 0 @ control register
@ -158,14 +160,16 @@ ENTRY(cpu_v6_do_resume)
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0, {r4 - r9}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
#ifdef CONFIG_MMU
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
mcr p15, 0, r1, c2, c0, 0 @ Translation table base 0
mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
mcr p15, 0, ip, c2, c0, 2 @ TTB control register
#endif
mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register
mcr p15, 0, r8, c1, c0, 2 @ co-processor access control
mcr p15, 0, ip, c2, c0, 2 @ TTB control register
mcr p15, 0, ip, c7, c5, 4 @ ISB
mov r0, r9 @ control register
b cpu_resume_mmu

14
arch/arm/mm/proc-v7.S
View File

@ -98,9 +98,11 @@ ENTRY(cpu_v7_do_suspend)
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
#ifdef CONFIG_MMU
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
mrc p15, 0, r11, c2, c0, 2 @ TTB control register
#endif
mrc p15, 0, r8, c1, c0, 0 @ Control register
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
@ -110,13 +112,14 @@ ENDPROC(cpu_v7_do_suspend)
ENTRY(cpu_v7_do_resume)
mov ip, #0
mcr p15, 0, ip, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0!, {r4 - r5}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c13, c0, 3 @ User r/o thread ID
ldmia r0, {r6 - r11}
#ifdef CONFIG_MMU
mcr p15, 0, ip, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
#ifndef CONFIG_ARM_LPAE
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
@ -125,14 +128,15 @@ ENTRY(cpu_v7_do_resume)
mcr p15, 0, r1, c2, c0, 0 @ TTB 0
mcr p15, 0, r7, c2, c0, 1 @ TTB 1
mcr p15, 0, r11, c2, c0, 2 @ TTB control register
mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
teq r4, r9 @ Is it already set?
mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
mcr p15, 0, r10, c1, c0, 2 @ Co-processor access control
ldr r4, =PRRR @ PRRR
ldr r5, =NMRR @ NMRR
mcr p15, 0, r4, c10, c2, 0 @ write PRRR
mcr p15, 0, r5, c10, c2, 1 @ write NMRR
#endif /* CONFIG_MMU */
mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
teq r4, r9 @ Is it already set?
mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
mcr p15, 0, r10, c1, c0, 2 @ Co-processor access control
isb
dsb
mov r0, r8 @ control register