From: Will Deacon <will@kernel.org>
To: Tri Vo <trong@android.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Ard.Biesheuvel@arm.com, andrew.murray@arm.com,
Nathan Chancellor <natechancellor@gmail.com>,
Robin Murphy <robin.murphy@arm.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v5 05/10] arm64: atomics: Remove atomic_ll_sc compilation unit
Date: Thu, 29 Aug 2019 22:54:52 +0100 [thread overview]
Message-ID: <20190829215452.GC2404@brain-police> (raw)
In-Reply-To: <CANA+-vA8CcSKPU-0Pyaxd5YOprTzqAq9KAZ2Ta1pf-zNdNB3BA@mail.gmail.com>
On Thu, Aug 29, 2019 at 01:07:04PM -0700, Tri Vo wrote:
> On Thu, Aug 29, 2019 at 10:47 AM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
> >
> > On Thu, Aug 29, 2019 at 8:48 AM Will Deacon <will@kernel.org> wrote:
> > >
> > > From: Andrew Murray <andrew.murray@arm.com>
> > >
> > > We no longer fall back to out-of-line atomics on systems with
> > > CONFIG_ARM64_LSE_ATOMICS where ARM64_HAS_LSE_ATOMICS is not set.
> > >
> > > Remove the unused compilation unit which provided these symbols.
> > >
> > > Signed-off-by: Andrew Murray <andrew.murray@arm.com>
> > > Signed-off-by: Will Deacon <will@kernel.org>
> > > ---
> > > arch/arm64/lib/Makefile | 19 -------------------
> > > arch/arm64/lib/atomic_ll_sc.c | 3 ---
> > > 2 files changed, 22 deletions(-)
> > > delete mode 100644 arch/arm64/lib/atomic_ll_sc.c
> > >
> > > diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
> > > index 33c2a4abda04..f10809ef1690 100644
> > > --- a/arch/arm64/lib/Makefile
> > > +++ b/arch/arm64/lib/Makefile
> > > @@ -11,25 +11,6 @@ CFLAGS_REMOVE_xor-neon.o += -mgeneral-regs-only
> > > CFLAGS_xor-neon.o += -ffreestanding
> > > endif
> > >
> > > -# Tell the compiler to treat all general purpose registers (with the
> > > -# exception of the IP registers, which are already handled by the caller
> > > -# in case of a PLT) as callee-saved, which allows for efficient runtime
> > > -# patching of the bl instruction in the caller with an atomic instruction
> > > -# when supported by the CPU. Result and argument registers are handled
> > > -# correctly, based on the function prototype.
> > > -lib-$(CONFIG_ARM64_LSE_ATOMICS) += atomic_ll_sc.o
> > > -CFLAGS_atomic_ll_sc.o := -ffixed-x1 -ffixed-x2 \
> > > - -ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6 \
> > > - -ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \
> > > - -fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
> > > - -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
> > > - -fcall-saved-x18 -fomit-frame-pointer
> >
> > + Tri (who implemented support for -fcall-saved-x*, -ffixed-x* in
> > Clang). I won't be sad to see the use of these flags go.
>
> Nice! IMO these flags made the code hard to read.
Well, we didn't do it like that because it looked pretty ;)
Will
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next prev parent reply other threads:[~2019-08-29 21:55 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-29 15:48 [PATCH v5 00/10] arm64: avoid out-of-line ll/sc atomics Will Deacon
2019-08-29 15:48 ` [PATCH v5 01/10] jump_label: Don't warn on __exit jump entries Will Deacon
2019-08-29 15:48 ` [PATCH v5 02/10] arm64: Use correct ll/sc atomic constraints Will Deacon
2019-08-29 15:48 ` [PATCH v5 03/10] arm64: atomics: avoid out-of-line ll/sc atomics Will Deacon
2019-09-03 6:00 ` Nathan Chancellor
2019-09-03 6:39 ` Will Deacon
2019-09-03 14:31 ` Andrew Murray
2019-09-03 14:45 ` Will Deacon
2019-09-03 15:15 ` Andrew Murray
2019-09-03 15:31 ` Andrew Murray
2019-09-03 16:37 ` Will Deacon
2019-09-03 22:04 ` Andrew Murray
2019-09-03 22:35 ` Nick Desaulniers
[not found] ` <CANW9uyuRFtNKMnSwmHWt_RebJA1ADXdZfeDHc6=yaaFH2NsyWg@mail.gmail.com>
2019-09-03 22:53 ` Nick Desaulniers
2019-09-04 10:20 ` Will Deacon
2019-09-04 17:28 ` Nick Desaulniers
2019-09-05 11:25 ` Andrew Murray
2019-09-06 19:44 ` Nick Desaulniers
2019-08-29 15:48 ` [PATCH v5 04/10] arm64: avoid using hard-coded registers for LSE atomics Will Deacon
2019-08-29 15:48 ` [PATCH v5 05/10] arm64: atomics: Remove atomic_ll_sc compilation unit Will Deacon
2019-08-29 17:47 ` Nick Desaulniers
2019-08-29 20:07 ` Tri Vo
2019-08-29 21:54 ` Will Deacon [this message]
2019-08-29 15:48 ` [PATCH v5 06/10] arm64: lse: Remove unused 'alt_lse' assembly macro Will Deacon
2019-08-29 23:39 ` Andrew Murray
2019-08-29 15:48 ` [PATCH v5 07/10] arm64: asm: Kill 'asm/atomic_arch.h' Will Deacon
2019-08-29 23:43 ` Andrew Murray
2019-08-29 15:48 ` [PATCH v5 08/10] arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL Will Deacon
2019-08-29 23:44 ` Andrew Murray
2019-08-29 15:48 ` [PATCH v5 09/10] arm64: atomics: Undefine internal macros after use Will Deacon
2019-08-29 23:44 ` Andrew Murray
2019-08-29 15:48 ` [PATCH v5 10/10] arm64: atomics: Use K constraint when toolchain appears to support it Will Deacon
2019-08-29 16:54 ` Will Deacon
2019-08-29 17:45 ` Nick Desaulniers
2019-08-29 21:53 ` Will Deacon
2019-08-30 20:57 ` Nick Desaulniers
2019-08-30 0:08 ` Andrew Murray
2019-08-30 7:52 ` Will Deacon
2019-08-30 9:11 ` Andrew Murray
2019-08-30 10:17 ` Will Deacon
2019-08-30 11:57 ` Andrew Murray
2019-08-30 10:40 ` Mark Rutland
2019-08-30 11:53 ` Andrew Murray
2019-08-29 23:49 ` Andrew Murray
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