From 623b476fc815464a0241ea7483da7b3580b7d8ac Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 Nov 2016 20:23:09 +0000 Subject: [PATCH] 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 --- arch/arm64/include/asm/suspend.h | 2 +- arch/arm64/kernel/sleep.S | 3 --- arch/arm64/kernel/suspend.c | 6 ------ arch/arm64/mm/proc.S | 6 ++++++ 4 files changed, 7 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h index b8a313fd7a09..de5600f40adf 100644 --- a/arch/arm64/include/asm/suspend.h +++ b/arch/arm64/include/asm/suspend.h @@ -1,7 +1,7 @@ #ifndef __ASM_SUSPEND_H #define __ASM_SUSPEND_H -#define NR_CTX_REGS 10 +#define NR_CTX_REGS 12 #define NR_CALLEE_SAVED_REGS 12 /* 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 */ diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index bb0cd787a9d3..1e3be9064cfa 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -46,12 +46,6 @@ void notrace __cpu_suspend_exit(void) */ cpu_uninstall_idmap(); - /* - * Restore per-cpu offset before any kernel - * subsystem relying on it has a chance to run. - */ - set_my_cpu_offset(per_cpu_offset(cpu)); - /* * PSTATE was not saved over suspend/resume, re-enable any detected * features that might not have been set correctly. 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 */ -- 2.20.1