diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2021-11-25 10:26:44 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-12-06 12:49:17 +0100 |
| commit | 7b9896c352073156a325c3bb0dc4c46e06e2a468 (patch) | |
| tree | a9e6e3be8a6a2b91a147f3e9ae82dfb7fbd860e5 /arch/arm/kernel/sleep.S | |
| parent | 4e918ab13eaf40f19938659cb5a22c93172778a8 (diff) | |
ARM: percpu: add SMP_ON_UP support
Permit the use of the TPIDRPRW system register for carrying the per-CPU
offset in generic SMP configurations that also target non-SMP capable
ARMv6 cores. This uses the SMP_ON_UP code patching framework to turn all
TPIDRPRW accesses into reads/writes of entry #0 in the __per_cpu_offset
array.
While at it, switch over some existing direct TPIDRPRW accesses in asm
code to invocations of a new helper that is patched in the same way when
necessary.
Note that CPU_V6+SMP without SMP_ON_UP results in a kernel that does not
boot on v6 CPUs without SMP extensions, so add this dependency to
Kconfig as well.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Diffstat (limited to 'arch/arm/kernel/sleep.S')
| -rw-r--r-- | arch/arm/kernel/sleep.S | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 803b51e5cba0..f909baf17912 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -71,9 +71,7 @@ ENTRY(__cpu_suspend) @ Run the suspend code from the overflow stack so we don't have to rely @ on vmalloc-to-phys conversions anywhere in the arch suspend code. @ The original SP value captured in R5 will be restored on the way out. - mov_l r6, overflow_stack_ptr @ Base pointer - mrc p15, 0, r7, c13, c0, 4 @ Get per-CPU offset - ldr sp, [r6, r7] @ Address of this CPU's overflow stack + ldr_this_cpu sp, overflow_stack_ptr, r6, r7 #endif add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn sub sp, sp, r4 @ allocate CPU state on stack |