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Subject[PATCH] ARM: Save/Restore 64-bit TTBR registers on LPAE suspend/resume
Date
From: Mahesh Sivasubramanian <msivasub@codeaurora.org>

LPAE enabled kernels use the 64-bit version of TTBR0 and TTBR1
registers. If we're running an LPAE kernel, fill the upper half
of TTBR0 with 0 because we're setting it to the idmap here (the
idmap is guaranteed to be < 4Gb) and fully restore TTBR1 instead
of just restoring the lower 32 bits. Failure to do so can cause
failures on resume from suspend when these registers are only
half restored.

Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
arch/arm/mm/proc-v7.S | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index c63d9bd..fb8b5e0 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -92,7 +92,7 @@ ENDPROC(cpu_v7_dcache_clean_area)

/* 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 * 9
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7_do_suspend)
stmfd sp!, {r4 - r10, lr}
@@ -101,13 +101,17 @@ ENTRY(cpu_v7_do_suspend)
stmia r0!, {r4 - r5}
#ifdef CONFIG_MMU
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
+#ifdef CONFIG_ARM_LPAE
+ mrrc p15, 1, r5, r7, c2 @ TTB 1
+#else
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
+#endif
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
- stmia r0, {r6 - r11}
+ stmia r0, {r5 - r11}
ldmfd sp!, {r4 - r10, pc}
ENDPROC(cpu_v7_do_suspend)

@@ -118,16 +122,19 @@ ENTRY(cpu_v7_do_resume)
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}
+ ldmia r0, {r5 - 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
+#ifdef CONFIG_ARM_LPAE
+ mcrr p15, 0, r1, ip, c2 @ TTB 0
+ mcrr p15, 1, r5, r7, c2 @ TTB 1
+#else
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
-#endif
mcr p15, 0, r1, c2, c0, 0 @ TTB 0
mcr p15, 0, r7, c2, c0, 1 @ TTB 1
+#endif
mcr p15, 0, r11, c2, c0, 2 @ TTB control register
ldr r4, =PRRR @ PRRR
ldr r5, =NMRR @ NMRR
--
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