Messages in this thread |  | | Date | Mon, 14 Aug 2017 18:13:39 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH 10/14] arm64: assembler: allow adr_this_cpu to use the stack pointer |
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On Mon, Aug 07, 2017 at 07:36:01PM +0100, Mark Rutland wrote: > 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 | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h > index 610a420..4775af5 100644 > --- a/arch/arm64/include/asm/assembler.h > +++ b/arch/arm64/include/asm/assembler.h > @@ -235,7 +235,8 @@ > * @tmp: scratch register > */ > .macro adr_this_cpu, dst, sym, tmp > - adr_l \dst, \sym > + adrp \tmp, \sym > + add \dst, \tmp, #:lo12:\sym > mrs \tmp, tpidr_el1 > add \dst, \dst, \tmp > .endm
Nitpick: it may be worth adding an #ifndef MODULE around these macros, together with a comment, just in case. There are other macros in this file like adr_l which are used in modules (crypto).
-- Catalin
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