ARM: pm: preallocate a page table for suspend/resume

Preallocate a page table and setup an identity mapping for the MMU
enable code.  This means we don't have to "borrow" a page table to
do this, avoiding complexities with L2 cache coherency.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-08-26 20:28:52 +01:00
parent f5fa68d967
commit e8ce0eb5e2
11 changed files with 62 additions and 72 deletions

View file

@ -1,22 +1,7 @@
#ifndef __ASM_ARM_SUSPEND_H
#define __ASM_ARM_SUSPEND_H
#include <asm/memory.h>
#include <asm/tlbflush.h>
extern void cpu_resume(void);
/*
* Hide the first two arguments to __cpu_suspend - these are an implementation
* detail which platform code shouldn't have to know about.
*/
static inline int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
extern int __cpu_suspend(int, long, unsigned long,
int (*)(unsigned long));
int ret = __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn);
flush_tlb_all();
return ret;
}
extern int cpu_suspend(unsigned long, int (*)(unsigned long));
#endif

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@ -29,7 +29,7 @@ obj-$(CONFIG_MODULES) += armksyms.o module.o
obj-$(CONFIG_ARTHUR) += arthur.o
obj-$(CONFIG_ISA_DMA) += dma-isa.o
obj-$(CONFIG_PCI) += bios32.o isa.o
obj-$(CONFIG_PM_SLEEP) += sleep.o
obj-$(CONFIG_PM_SLEEP) += sleep.o suspend.o
obj-$(CONFIG_HAVE_SCHED_CLOCK) += sched_clock.o
obj-$(CONFIG_SMP) += smp.o smp_tlb.o
obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o

View file

@ -27,7 +27,7 @@ ENTRY(__cpu_suspend)
sub sp, sp, r5 @ allocate CPU state on stack
mov r0, sp @ save pointer to CPU save block
add ip, ip, r1 @ convert resume fn to phys
stmfd sp!, {r1, r6, ip} @ save v:p, virt SP, phys resume fn
stmfd sp!, {r6, ip} @ save virt SP, phys resume fn
ldr r5, =sleep_save_sp
add r6, sp, r1 @ convert SP to phys
stmfd sp!, {r2, r3} @ save suspend func arg and pointer
@ -60,7 +60,7 @@ ENDPROC(__cpu_suspend)
.ltorg
cpu_suspend_abort:
ldmia sp!, {r1 - r3} @ pop v:p, virt SP, phys resume fn
ldmia sp!, {r2 - r3} @ pop virt SP, phys resume fn
teq r0, #0
moveq r0, #1 @ force non-zero value
mov sp, r2
@ -74,28 +74,19 @@ ENDPROC(cpu_suspend_abort)
* r3 = L1 section flags
*/
ENTRY(cpu_resume_mmu)
adr r4, cpu_resume_turn_mmu_on
mov r4, r4, lsr #20
orr r3, r3, r4, lsl #20
ldr r5, [r2, r4, lsl #2] @ save old mapping
str r3, [r2, r4, lsl #2] @ setup 1:1 mapping for mmu code
sub r2, r2, r1
ldr r3, =cpu_resume_after_mmu
bic r1, r0, #CR_C @ ensure D-cache is disabled
b cpu_resume_turn_mmu_on
ENDPROC(cpu_resume_mmu)
.ltorg
.align 5
cpu_resume_turn_mmu_on:
mcr p15, 0, r1, c1, c0, 0 @ turn on MMU, I-cache, etc
mrc p15, 0, r1, c0, c0, 0 @ read id reg
mov r1, r1
mov r1, r1
ENTRY(cpu_resume_turn_mmu_on)
mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc
mrc p15, 0, r0, c0, c0, 0 @ read id reg
mov r0, r0
mov r0, r0
mov pc, r3 @ jump to virtual address
ENDPROC(cpu_resume_turn_mmu_on)
cpu_resume_after_mmu:
str r5, [r2, r4, lsl #2] @ restore old mapping
mcr p15, 0, r0, c1, c0, 0 @ turn on D-cache
bl cpu_init @ restore the und/abt/irq banked regs
mov r0, #0 @ return zero on success
ldmfd sp!, {r4 - r11, pc}
@ -121,11 +112,11 @@ ENTRY(cpu_resume)
ldr r0, sleep_save_sp @ stack phys addr
#endif
setmode PSR_I_BIT | PSR_F_BIT | SVC_MODE, r1 @ set SVC, irqs off
@ load v:p, stack, resume fn
ARM( ldmia r0!, {r1, sp, pc} )
THUMB( ldmia r0!, {r1, r2, r3} )
THUMB( mov sp, r2 )
THUMB( bx r3 )
@ load stack, resume fn
ARM( ldmia r0!, {sp, pc} )
THUMB( ldmia r0!, {r2, r3} )
THUMB( mov sp, r2 )
THUMB( bx r3 )
ENDPROC(cpu_resume)
sleep_save_sp:

48
arch/arm/kernel/suspend.c Normal file
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@ -0,0 +1,48 @@
#include <linux/init.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(int, long, unsigned long, int (*)(unsigned long));
extern void cpu_resume_turn_mmu_on(void);
/*
* 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 (!suspend_pgd)
return -EINVAL;
/*
* Temporarily switch the page tables to our suspend page
* tables, which contain the temporary identity mapping
* required for resuming.
*/
cpu_switch_mm(suspend_pgd, mm);
ret = __cpu_suspend(0, PHYS_OFFSET - PAGE_OFFSET, arg, fn);
cpu_switch_mm(mm->pgd, mm);
local_flush_tlb_all();
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_turn_mmu_on);
identity_mapping_add(suspend_pgd, addr, addr + SECTION_SIZE);
}
return suspend_pgd ? 0 : -ENOMEM;
}
core_initcall(cpu_suspend_init);

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@ -400,10 +400,6 @@ ENTRY(cpu_arm920_do_resume)
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
mcr p15, 0, r6, c2, c0, 0 @ TTB address
mov r0, r7 @ control register
mov r2, r6, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, =PMD_TYPE_SECT | PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | PMD_BIT4 | PMD_SECT_AP_WRITE
b cpu_resume_mmu
ENDPROC(cpu_arm920_do_resume)
#endif

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@ -415,10 +415,6 @@ ENTRY(cpu_arm926_do_resume)
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
mcr p15, 0, r6, c2, c0, 0 @ TTB address
mov r0, r7 @ control register
mov r2, r6, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, =PMD_TYPE_SECT | PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | PMD_BIT4 | PMD_SECT_AP_WRITE
b cpu_resume_mmu
ENDPROC(cpu_arm926_do_resume)
#endif

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@ -192,10 +192,6 @@ ENTRY(cpu_sa1100_do_resume)
mcr p15, 0, r5, c2, c0, 0 @ translation table base addr
mcr p15, 0, r6, c13, c0, 0 @ PID
mov r0, r7 @ control register
mov r2, r5, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, =PMD_TYPE_SECT | PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | PMD_SECT_AP_WRITE
b cpu_resume_mmu
ENDPROC(cpu_sa1100_do_resume)
#endif

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@ -161,14 +161,8 @@ ENTRY(cpu_v6_do_resume)
mcr p15, 0, ip, c2, c0, 2 @ TTB control register
mcr p15, 0, ip, c7, c5, 4 @ ISB
mov r0, r11 @ control register
mov r2, r7, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, cpu_resume_l1_flags
b cpu_resume_mmu
ENDPROC(cpu_v6_do_resume)
cpu_resume_l1_flags:
ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_FLAGS_SMP)
ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_FLAGS_UP)
#endif
string cpu_v6_name, "ARMv6-compatible processor"

View file

@ -259,14 +259,8 @@ ENTRY(cpu_v7_do_resume)
isb
dsb
mov r0, r9 @ control register
mov r2, r7, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, cpu_resume_l1_flags
b cpu_resume_mmu
ENDPROC(cpu_v7_do_resume)
cpu_resume_l1_flags:
ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_FLAGS_SMP)
ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_FLAGS_UP)
#endif
__CPUINIT

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@ -435,13 +435,7 @@ ENTRY(cpu_xsc3_do_resume)
mcr p15, 0, r7, c3, c0, 0 @ domain ID
mcr p15, 0, r8, c2, c0, 0 @ translation table base addr
mcr p15, 0, r9, c1, c0, 1 @ auxiliary control reg
@ temporarily map resume_turn_on_mmu into the page table,
@ otherwise prefetch abort occurs after MMU is turned on
mov r0, r10 @ control register
mov r2, r8, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, =0x542e @ section flags
b cpu_resume_mmu
ENDPROC(cpu_xsc3_do_resume)
#endif

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@ -548,10 +548,6 @@ ENTRY(cpu_xscale_do_resume)
mcr p15, 0, r8, c2, c0, 0 @ translation table base addr
mcr p15, 0, r9, c1, c1, 0 @ auxiliary control reg
mov r0, r10 @ control register
mov r2, r8, lsr #14 @ get TTB0 base
mov r2, r2, lsl #14
ldr r3, =PMD_TYPE_SECT | PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | PMD_SECT_AP_WRITE
b cpu_resume_mmu
ENDPROC(cpu_xscale_do_resume)
#endif