Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751502AbbLUMip (ORCPT ); Mon, 21 Dec 2015 07:38:45 -0500 Received: from foss.arm.com ([217.140.101.70]:48666 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145AbbLUMio (ORCPT ); Mon, 21 Dec 2015 07:38:44 -0500 Date: Mon, 21 Dec 2015 12:38:43 +0000 From: Will Deacon To: Andrew Pinski Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM64: Fix compiling with GCC 6 and Atomics enabled Message-ID: <20151221123843.GM23092@arm.com> References: <1450498655-3820-1-git-send-email-apinski@cavium.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1450498655-3820-1-git-send-email-apinski@cavium.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2053 Lines: 58 On Fri, Dec 18, 2015 at 08:17:35PM -0800, Andrew Pinski wrote: > The problem here is that GCC 6 and above emits .arch now > for each function so now the global .arch_extension has > no effect. This fixes the problem by putting > .arch_extension inside ARM64_LSE_ATOMIC_INSN so > it is enabled for each place where LSE is used. Hmm, this is going to affect arch/arm/ much more heavily than arch/arm64. .arch_extension is used for virt, mp and sec over there, and it may be tricky to isolate the actual instruction usage (at least, virt looks lost in kvm/arm.c). Why can't gas have an option to accept all instruction encodings that it knows about, inspite of any .arch directives? Will > Signed-off-by: Andrew Pinski > --- > arch/arm64/include/asm/lse.h | 4 +--- > 1 files changed, 1 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h > index 3de42d6..625601f 100644 > --- a/arch/arm64/include/asm/lse.h > +++ b/arch/arm64/include/asm/lse.h > @@ -17,8 +17,6 @@ > > #else /* __ASSEMBLER__ */ > > -__asm__(".arch_extension lse"); > - > /* Move the ll/sc atomics out-of-line */ > #define __LL_SC_INLINE > #define __LL_SC_PREFIX(x) __ll_sc_##x > @@ -29,7 +27,7 @@ __asm__(".arch_extension lse"); > > /* In-line patching at runtime */ > #define ARM64_LSE_ATOMIC_INSN(llsc, lse) \ > - ALTERNATIVE(llsc, lse, ARM64_HAS_LSE_ATOMICS) > + ALTERNATIVE(".arch_extension lse\n" llsc, lse, ARM64_HAS_LSE_ATOMICS) > > #endif /* __ASSEMBLER__ */ > #else /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */ > -- > 1.7.2.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/