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ARM: pm: no need to save/restore context ID register

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There is no need to save and restore the context ID register on ARMv6
and ARMv7 with a temporary page table as we write the context ID
register when we switch back to the real page tables for the thread.

Moreover, the temporary page tables do not contain any non-global
mappings, so the context ID value should not be used.  To be safe,
initialize the register to a reserved context ID value.

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 2011-08-28 10:30:34 +01:00
parent de8e71ca4f
commit 1aede681ac
2 changed files with 22 additions and 24 deletions
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33
arch/arm/mm/proc-v6.S
View File

@ -128,19 +128,18 @@ ENTRY(cpu_v6_set_pte_ext)
/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
.globl cpu_v6_suspend_size
.equ cpu_v6_suspend_size, 4 * 7
.equ cpu_v6_suspend_size, 4 * 6
#ifdef CONFIG_PM_SLEEP
ENTRY(cpu_v6_do_suspend)
stmfd sp!, {r4 - r10, lr}
stmfd sp!, {r4 - r9, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 1 @ Context ID
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ Translation table base 1
mrc p15, 0, r8, c1, c0, 1 @ auxiliary control register
mrc p15, 0, r9, c1, c0, 2 @ co-processor access control
mrc p15, 0, r10, c1, c0, 0 @ control register
stmia r0, {r4 - r10}
ldmfd sp!, {r4- r10, pc}
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
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
stmia r0, {r4 - r9}
ldmfd sp!, {r4- r9, pc}
ENDPROC(cpu_v6_do_suspend)
ENTRY(cpu_v6_do_resume)
@ -149,19 +148,19 @@ ENTRY(cpu_v6_do_resume)
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c7, c15, 0 @ clean+invalidate cache
mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
ldmia r0, {r4 - r10}
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0, {r4 - r9}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c13, c0, 1 @ Context ID
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
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, r7, c2, c0, 1 @ Translation table base 1
mcr p15, 0, r8, c1, c0, 1 @ auxiliary control register
mcr p15, 0, r9, c1, c0, 2 @ co-processor access control
mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
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, r10 @ control register
mov r0, r9 @ control register
b cpu_resume_mmu
ENDPROC(cpu_v6_do_resume)
#endif

13
arch/arm/mm/proc-v7.S
View File

@ -217,14 +217,13 @@ ENDPROC(cpu_v7_set_pte_ext)
/* Suspend/resume support: derived from arch/arm/mach-s5pv210/sleep.S */
.globl cpu_v7_suspend_size
.equ cpu_v7_suspend_size, 4 * 8
.equ cpu_v7_suspend_size, 4 * 7
#ifdef CONFIG_PM_SLEEP
ENTRY(cpu_v7_do_suspend)
stmfd sp!, {r4 - r10, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 1 @ Context ID
mrc p15, 0, r6, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r6}
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
mrc p15, 0, r8, c1, c0, 0 @ Control register
@ -238,10 +237,10 @@ 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
ldmia r0!, {r4 - r6}
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, 1 @ Context ID
mcr p15, 0, r6, c13, c0, 3 @ User r/o thread ID
mcr p15, 0, r5, c13, c0, 3 @ User r/o thread ID
ldmia r0, {r6 - r10}
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)