Messages in this thread Patch in this message | | | From | Mark Rutland <> | Subject | [PATCHv2 10/14] arm64: assembler: allow adr_this_cpu to use the stack pointer | Date | Tue, 15 Aug 2017 13:50:45 +0100 |
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From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Given that adr_this_cpu already requires a temp register in addition to the destination register, tweak the instruction sequence so that sp may be used as well.
This will simplify switching to per-cpu stacks in subsequent patches. While this limits the range of adr_this_cpu, to +/-4GiB, we don't currently use adr_this_cpu in modules, and this is not problematic for the main kernel image.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [Mark: add more commit text] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/assembler.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 610a420..2f2bd51 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -230,12 +230,18 @@ .endm /* - * @dst: Result of per_cpu(sym, smp_processor_id()) + * @dst: Result of per_cpu(sym, smp_processor_id()), can be SP for + * non-module code * @sym: The name of the per-cpu variable * @tmp: scratch register */ .macro adr_this_cpu, dst, sym, tmp +#ifndef MODULE + adrp \tmp, \sym + add \dst, \tmp, #:lo12:\sym +#else adr_l \dst, \sym +#endif mrs \tmp, tpidr_el1 add \dst, \dst, \tmp .endm -- 1.9.1
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