From patchwork Mon Aug 12 14:36:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11089979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CE5ED6C5 for ; Mon, 12 Aug 2019 14:37:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD75927F2B for ; Mon, 12 Aug 2019 14:37:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B149127F98; Mon, 12 Aug 2019 14:37:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1791727F2B for ; Mon, 12 Aug 2019 14:37:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Zf3D4BjvNC88TfQHu4eEiCxSPGgSdsedGk17xKjOp4M=; b=dPMmkgRWTx6P03 Zl5jL5lwsySlr37rH4divTjRdM2XmaPJywOpzIkq8ybREoizRS4HGKKpi1sONriL9XggJ6NNRAE1b 3yNiHYQ2P+Yb6aXGUc7v1TDUVviUFNmHq/gqqfBIKZznj0HdB2fmcYeMdPoYNwBZZ74ydAvW5xIU2 rYN4OP3Wt3iYDvDFNWT44HaLiS4vtcKivsvo3yegxewWFJf48hC4XGBqXV5wVxlraUEv6GbJdvvY3 tt4bP7np2lVfloYtkqwKX7QbA4p2OV/UqqFO5bckyaSmtXZrUOrpcKcgeroY8QDwChSHJdJ7evCv2 EFB3R64JmyZcd1KMW6PQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hxBRb-0004AR-75; Mon, 12 Aug 2019 14:37:07 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hxBR7-0003jg-Df for linux-arm-kernel@lists.infradead.org; Mon, 12 Aug 2019 14:36:39 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0FC8D174E; Mon, 12 Aug 2019 07:36:37 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 756D83F718; Mon, 12 Aug 2019 07:36:35 -0700 (PDT) From: Andrew Murray To: Catalin Marinas , Will Deacon , Peter Zijlstra , Ard.Biesheuvel@arm.com Subject: [PATCH v3 2/5] arm64: Use correct ll/sc atomic constraints Date: Mon, 12 Aug 2019 15:36:22 +0100 Message-Id: <20190812143625.42745-3-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190812143625.42745-1-andrew.murray@arm.com> References: <20190812143625.42745-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190812_073637_560439_83F4334A X-CRM114-Status: GOOD ( 11.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Boqun Feng , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP For many of the ll/sc atomic operations we use the 'I' machine constraint regardless to the instruction used - this may not be optimal. Let's add an additional parameter to the ATOMIC_xx macros that allows the caller to specify an appropriate machine constraint. Let's also improve __CMPXCHG_CASE by replacing the 'K' constraint with a caller provided constraint. Please note that whilst we would like to use the 'K' constraint on 32 bit operations, we choose not to provide any constraint to avoid a GCC bug which results in a build error. Earlier versions of GCC (no later than 8.1.0) appear to incorrectly handle the 'K' constraint for the value 4294967295. Signed-off-by: Andrew Murray --- arch/arm64/include/asm/atomic_ll_sc.h | 89 ++++++++++++++------------- 1 file changed, 47 insertions(+), 42 deletions(-) diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index c8c850bc3dfb..4ebff769f3ed 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -26,7 +26,7 @@ * (the optimize attribute silently ignores these options). */ -#define ATOMIC_OP(op, asm_op) \ +#define ATOMIC_OP(op, asm_op, constraint) \ __LL_SC_INLINE void \ __LL_SC_PREFIX(arch_atomic_##op(int i, atomic_t *v)) \ { \ @@ -40,11 +40,11 @@ __LL_SC_PREFIX(arch_atomic_##op(int i, atomic_t *v)) \ " stxr %w1, %w0, %2\n" \ " cbnz %w1, 1b" \ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i)); \ + : #constraint "r" (i)); \ } \ __LL_SC_EXPORT(arch_atomic_##op); -#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \ +#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\ __LL_SC_INLINE int \ __LL_SC_PREFIX(arch_atomic_##op##_return##name(int i, atomic_t *v)) \ { \ @@ -59,14 +59,14 @@ __LL_SC_PREFIX(arch_atomic_##op##_return##name(int i, atomic_t *v)) \ " cbnz %w1, 1b\n" \ " " #mb \ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i) \ + : #constraint "r" (i) \ : cl); \ \ return result; \ } \ __LL_SC_EXPORT(arch_atomic_##op##_return##name); -#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \ +#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint) \ __LL_SC_INLINE int \ __LL_SC_PREFIX(arch_atomic_fetch_##op##name(int i, atomic_t *v)) \ { \ @@ -81,7 +81,7 @@ __LL_SC_PREFIX(arch_atomic_fetch_##op##name(int i, atomic_t *v)) \ " cbnz %w2, 1b\n" \ " " #mb \ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i) \ + : #constraint "r" (i) \ : cl); \ \ return result; \ @@ -99,8 +99,8 @@ __LL_SC_EXPORT(arch_atomic_fetch_##op##name); ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__) -ATOMIC_OPS(add, add) -ATOMIC_OPS(sub, sub) +ATOMIC_OPS(add, add, I) +ATOMIC_OPS(sub, sub, J) #undef ATOMIC_OPS #define ATOMIC_OPS(...) \ @@ -110,17 +110,17 @@ ATOMIC_OPS(sub, sub) ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__) -ATOMIC_OPS(and, and) -ATOMIC_OPS(andnot, bic) -ATOMIC_OPS(or, orr) -ATOMIC_OPS(xor, eor) +ATOMIC_OPS(and, and, K) +ATOMIC_OPS(andnot, bic, ) +ATOMIC_OPS(or, orr, K) +ATOMIC_OPS(xor, eor, K) #undef ATOMIC_OPS #undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP -#define ATOMIC64_OP(op, asm_op) \ +#define ATOMIC64_OP(op, asm_op, constraint) \ __LL_SC_INLINE void \ __LL_SC_PREFIX(arch_atomic64_##op(s64 i, atomic64_t *v)) \ { \ @@ -134,11 +134,11 @@ __LL_SC_PREFIX(arch_atomic64_##op(s64 i, atomic64_t *v)) \ " stxr %w1, %0, %2\n" \ " cbnz %w1, 1b" \ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i)); \ + : #constraint "r" (i)); \ } \ __LL_SC_EXPORT(arch_atomic64_##op); -#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \ +#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\ __LL_SC_INLINE s64 \ __LL_SC_PREFIX(arch_atomic64_##op##_return##name(s64 i, atomic64_t *v))\ { \ @@ -153,14 +153,14 @@ __LL_SC_PREFIX(arch_atomic64_##op##_return##name(s64 i, atomic64_t *v))\ " cbnz %w1, 1b\n" \ " " #mb \ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i) \ + : #constraint "r" (i) \ : cl); \ \ return result; \ } \ __LL_SC_EXPORT(arch_atomic64_##op##_return##name); -#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \ +#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint)\ __LL_SC_INLINE s64 \ __LL_SC_PREFIX(arch_atomic64_fetch_##op##name(s64 i, atomic64_t *v)) \ { \ @@ -175,7 +175,7 @@ __LL_SC_PREFIX(arch_atomic64_fetch_##op##name(s64 i, atomic64_t *v)) \ " cbnz %w2, 1b\n" \ " " #mb \ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \ - : "Ir" (i) \ + : #constraint "r" (i) \ : cl); \ \ return result; \ @@ -193,8 +193,8 @@ __LL_SC_EXPORT(arch_atomic64_fetch_##op##name); ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__) -ATOMIC64_OPS(add, add) -ATOMIC64_OPS(sub, sub) +ATOMIC64_OPS(add, add, I) +ATOMIC64_OPS(sub, sub, J) #undef ATOMIC64_OPS #define ATOMIC64_OPS(...) \ @@ -204,10 +204,10 @@ ATOMIC64_OPS(sub, sub) ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__) -ATOMIC64_OPS(and, and) -ATOMIC64_OPS(andnot, bic) -ATOMIC64_OPS(or, orr) -ATOMIC64_OPS(xor, eor) +ATOMIC64_OPS(and, and, K) +ATOMIC64_OPS(andnot, bic, ) +ATOMIC64_OPS(or, orr, K) +ATOMIC64_OPS(xor, eor, K) #undef ATOMIC64_OPS #undef ATOMIC64_FETCH_OP @@ -237,7 +237,7 @@ __LL_SC_PREFIX(arch_atomic64_dec_if_positive(atomic64_t *v)) } __LL_SC_EXPORT(arch_atomic64_dec_if_positive); -#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl) \ +#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl, constraint) \ __LL_SC_INLINE u##sz \ __LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \ unsigned long old, \ @@ -265,29 +265,34 @@ __LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \ "2:" \ : [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \ [v] "+Q" (*(u##sz *)ptr) \ - : [old] "Kr" (old), [new] "r" (new) \ + : [old] #constraint "r" (old), [new] "r" (new) \ : cl); \ \ return oldval; \ } \ __LL_SC_EXPORT(__cmpxchg_case_##name##sz); -__CMPXCHG_CASE(w, b, , 8, , , , ) -__CMPXCHG_CASE(w, h, , 16, , , , ) -__CMPXCHG_CASE(w, , , 32, , , , ) -__CMPXCHG_CASE( , , , 64, , , , ) -__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory") -__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory") -__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory") -__CMPXCHG_CASE( , , acq_, 64, , a, , "memory") -__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory") -__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory") -__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory") -__CMPXCHG_CASE( , , rel_, 64, , , l, "memory") -__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory") -__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory") -__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory") -__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory") +/* + * Earlier versions of GCC (no later than 8.1.0) appear to incorrectly + * handle the 'K' constraint for the value 4294967295 - thus we use no + * constraint for 32 bit operations. + */ +__CMPXCHG_CASE(w, b, , 8, , , , , ) +__CMPXCHG_CASE(w, h, , 16, , , , , ) +__CMPXCHG_CASE(w, , , 32, , , , , ) +__CMPXCHG_CASE( , , , 64, , , , , L) +__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory", ) +__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory", ) +__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory", ) +__CMPXCHG_CASE( , , acq_, 64, , a, , "memory", L) +__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory", ) +__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory", ) +__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory", ) +__CMPXCHG_CASE( , , rel_, 64, , , l, "memory", L) +__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory", ) +__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory", ) +__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory", ) +__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory", L) #undef __CMPXCHG_CASE