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.
Change-Id: Ifbf5f2b379f6f10c0c74c6e53e3e027c45339dcf
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>
Git-commit: 623b476fc815464a0241ea7483da7b3580b7d8ac
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/arch/arm64/include/asm/suspend.h b/arch/arm64/include/asm/suspend.h
index b8a313f..de5600f 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 1bec41b..df67652 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -125,9 +125,6 @@
/* 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 bb0cd78..1e3be90 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -47,12 +47,6 @@
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 61330c9..8d21250 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -116,11 +116,14 @@
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)
@@ -136,6 +139,7 @@
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
@@ -158,6 +162,8 @@
msr mdscr_el1, x10
msr sctlr_el1, x12
+ msr tpidr_el1, x13
+ msr sp_el0, x14
/*
* Restore oslsr_el1 by writing oslar_el1
*/