From b3181a8474fc165fd53362aa60ce68d561fb26d4 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 Nov 2016 20:23:09 +0000 Subject: BACKPORT: 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 Tested-by: Laura Abbott Cc: James Morse Cc: Lorenzo Pieralisi Cc: Will Deacon Signed-off-by: Catalin Marinas (cherry picked from commit 623b476fc815464a0241ea7483da7b3580b7d8ac) Signed-off-by: Amit Pundir --- arch/arm64/mm/proc.S | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm64/mm') diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index c2adb0cb952a..32682be978e0 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 */ -- cgit v1.2.3