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| author | Mark Rutland <mark.rutland@arm.com> | 2016-11-03 21:23:09 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-11-11 19:25:44 +0100 |
| commit | 623b476fc815464a0241ea7483da7b3580b7d8ac (patch) | |
| tree | 5bfda3f2e218b2dd884f28188def7ba73e8104ed /arch/arm64/mm | |
| parent | arm64: prep stack walkers for THREAD_INFO_IN_TASK (diff) | |
| download | linux-623b476fc815464a0241ea7483da7b3580b7d8ac.tar.xz linux-623b476fc815464a0241ea7483da7b3580b7d8ac.zip | |
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/mm')
| -rw-r--r-- | arch/arm64/mm/proc.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 352c73b6a59e..6a853a867d9e 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -70,11 +70,14 @@ ENTRY(cpu_do_suspend) mrs x8, mdscr_el1 mrs x9, oslsr_el1 mrs x10, sctlr_el1 + mrs x11, tpidr_el1 + mrs x12, sp_el0 stp x2, x3, [x0] stp x4, xzr, [x0, #16] stp x5, x6, [x0, #32] stp x7, x8, [x0, #48] stp x9, x10, [x0, #64] + stp x11, x12, [x0, #80] ret ENDPROC(cpu_do_suspend) @@ -90,6 +93,7 @@ ENTRY(cpu_do_resume) ldp x6, x8, [x0, #32] ldp x9, x10, [x0, #48] ldp x11, x12, [x0, #64] + ldp x13, x14, [x0, #80] msr tpidr_el0, x2 msr tpidrro_el0, x3 msr contextidr_el1, x4 @@ -112,6 +116,8 @@ ENTRY(cpu_do_resume) msr mdscr_el1, x10 msr sctlr_el1, x12 + msr tpidr_el1, x13 + msr sp_el0, x14 /* * Restore oslsr_el1 by writing oslar_el1 */ |