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authorMark Rutland <mark.rutland@arm.com>2016-11-03 23:23:09 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2016-11-11 21:25:44 +0300
commit623b476fc815464a0241ea7483da7b3580b7d8ac (patch)
tree5bfda3f2e218b2dd884f28188def7ba73e8104ed /arch/arm64/kernel/sleep.S
parent9bbd4c56b0b642f04396da378296e68096d5afca (diff)
downloadlinux-623b476fc815464a0241ea7483da7b3580b7d8ac.tar.xz
arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx
When returning from idle, we rely on the fact that thread_info lives at the end of the kernel stack, and restore this by masking the saved stack pointer. Subsequent patches will sever the relationship between the stack and thread_info, and to cater for this we must save/restore sp_el0 explicitly, storing it in cpu_suspend_ctx. As cpu_suspend_ctx must be doubleword aligned, this leaves us with an extra slot in cpu_suspend_ctx. We can use this to save/restore tpidr_el1 in the same way, which simplifies the code, avoiding pointer chasing on the restore path (as we no longer need to load thread_info::cpu followed by the relevant slot in __per_cpu_offset based on this). This patch stashes both registers in cpu_suspend_ctx. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/sleep.S')
-rw-r--r--arch/arm64/kernel/sleep.S3
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 1bec41b5fda3..df67652e46f0 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -125,9 +125,6 @@ ENTRY(_cpu_resume)
/* load sp from context */
ldr x2, [x0, #CPU_CTX_SP]
mov sp, x2
- /* save thread_info */
- and x2, x2, #~(THREAD_SIZE - 1)
- msr sp_el0, x2
/*
* cpu_do_resume expects x0 to contain context address pointer
*/