From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8682E748E9 for ; Sun, 1 Oct 2023 10:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234838AbjJAKlL (ORCPT ); Sun, 1 Oct 2023 06:41:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234817AbjJAKlJ (ORCPT ); Sun, 1 Oct 2023 06:41:09 -0400 Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F314DC2 for ; Sun, 1 Oct 2023 03:41:05 -0700 (PDT) Received: by mail-ej1-x62e.google.com with SMTP id a640c23a62f3a-99c3c8adb27so2174764166b.1 for ; Sun, 01 Oct 2023 03:41:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696156864; x=1696761664; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=hd3IQ5VOgFAiZIrz9J6WO1XKlWIuJJ+vlxIzopklsp0=; b=HNpBruBrP9JzlDTLT3jwlvp35+N8Hanf9xRtUPYV0DY7jeb30+Ii6INq6fnq7Tu0pa bVZVKozzwlsDso3MmC6zlr9Qrq38VutlS+0M7WxtPd4c3gMawP9p+1CVZeRRxbLfTIUS VFNX825AQgiPejHc+sVReYHjcL6sXWelR0QMdfZ9G6nnrMaKensCGktv73rMvwF+SyVe 8l5NVP3lmmAQ/Rf5c57TdZquwVSsAYT7Trv2SXujbwhXE14YOSywCA6uRBTW3GCJAb2X XGIjYC+8Obf9gH2kixwVXt48pw33bN3RABMSJhdx0RW1qHkAa1CHKWWLywSVeF4Xon+H eAWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696156864; x=1696761664; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=hd3IQ5VOgFAiZIrz9J6WO1XKlWIuJJ+vlxIzopklsp0=; b=YSBwT1jakYK+9DsakEYyGtwiTzdiH85351DUWMt5APPJBNo69VYefc0J6i32fsO2Vg VxWTLBOCcnYVUcWerV4OxeEJEUNtnCbwgBllrENhQbsrBoZxXcfGzhh/2q3Wl9FYb3ok 53kYno8xq3KzKdxZEAXWDZ1/6ioHXvlk5Wkdp34mUFeFa6+VCg+qx2B2H94+aq5FXTOq mTuXvHSxAVJNW3/vy3xa+6rtjddAZUUzCYb+vSlVGPfA4p2M3lK6bYddicFANrL5O2Ph oBuw0cuGUsV1G70svI89Q5kSieOsJAEVuxqX3Gd3wl12dGCXP9Abc5dmIXfBbiYALvru R81w== X-Gm-Message-State: AOJu0YyS3kNad1PbRDonyfY27vo3XphH176b+GUcQAIEnSSrPaNFc+1/ FA3MJAPCWsZB+EowNZWd8qQETk/YFhlxwQ== X-Google-Smtp-Source: AGHT+IG9JZc6TmvZHbVpgjX2iUva5UEpfEXoJsk9uCuk4m2g+BHUY+ApqFLeLJsTAyFlG09evitVDA== X-Received: by 2002:a17:907:774f:b0:9ae:673a:88b9 with SMTP id kx15-20020a170907774f00b009ae673a88b9mr7550136ejc.22.1696156863846; Sun, 01 Oct 2023 03:41:03 -0700 (PDT) Received: from localhost.localdomain ([46.248.82.114]) by smtp.gmail.com with ESMTPSA id jx14-20020a170906ca4e00b0099caf5bed64sm15333657ejb.57.2023.10.01.03.41.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Oct 2023 03:41:03 -0700 (PDT) From: Uros Bizjak To: linux-kernel@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org Cc: Uros Bizjak , Will Deacon , Peter Zijlstra , Ingo Molnar , Boqun Feng , Mark Rutland Subject: [PATCH v2 1/3] locking/generic: Add generic support for sync_try_cmpxchg and its fallback Date: Sun, 1 Oct 2023 12:39:09 +0200 Message-ID: <20231001104053.9644-1-ubizjak@gmail.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Provide the generic sync_try_cmpxchg function from the raw_ prefixed version, also adding explicit instrumentation. The patch amends existing scripts to generate sync_try_cmpxchg locking primitive and its raw_sync_try_cmpxchg fallback, while leaving existing macros from try_cmpxchg family unchanged. The target can define its own arch_sync_try_cmpxchg to override the generic version of raw_sync_try_cmpxchg. This allows the target to generate more optimal assembly than the generic version. Additionally, the patch renames two scripts to better reflect whet they really do. Cc: Will Deacon Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Boqun Feng Cc: Mark Rutland Signed-off-by: Uros Bizjak --- v2: Improve commit description. --- include/linux/atomic/atomic-arch-fallback.h | 15 +++++++++- include/linux/atomic/atomic-instrumented.h | 10 ++++++- scripts/atomic/gen-atomic-fallback.sh | 33 +++++++++++---------- scripts/atomic/gen-atomic-instrumented.sh | 3 +- 4 files changed, 43 insertions(+), 18 deletions(-) diff --git a/include/linux/atomic/atomic-arch-fallback.h b/include/linux/atomic/atomic-arch-fallback.h index b83ef19da13d..5e95faa959c4 100644 --- a/include/linux/atomic/atomic-arch-fallback.h +++ b/include/linux/atomic/atomic-arch-fallback.h @@ -428,6 +428,19 @@ extern void raw_cmpxchg128_relaxed_not_implemented(void); #define raw_sync_cmpxchg arch_sync_cmpxchg +#ifdef arch_sync_try_cmpxchg +#define raw_sync_try_cmpxchg arch_sync_try_cmpxchg +#else +#define raw_sync_try_cmpxchg(_ptr, _oldp, _new) \ +({ \ + typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \ + ___r = raw_sync_cmpxchg((_ptr), ___o, (_new)); \ + if (unlikely(___r != ___o)) \ + *___op = ___r; \ + likely(___r == ___o); \ +}) +#endif + /** * raw_atomic_read() - atomic load with relaxed ordering * @v: pointer to atomic_t @@ -4649,4 +4662,4 @@ raw_atomic64_dec_if_positive(atomic64_t *v) } #endif /* _LINUX_ATOMIC_FALLBACK_H */ -// 2fdd6702823fa842f9cea57a002e6e4476ae780c +// eec048affea735b8464f58e6d96992101f8f85f1 diff --git a/include/linux/atomic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h index d401b406ef7c..54d7bbe0aeaa 100644 --- a/include/linux/atomic/atomic-instrumented.h +++ b/include/linux/atomic/atomic-instrumented.h @@ -4998,6 +4998,14 @@ atomic_long_dec_if_positive(atomic_long_t *v) raw_try_cmpxchg128_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \ }) +#define sync_try_cmpxchg(ptr, ...) \ +({ \ + typeof(ptr) __ai_ptr = (ptr); \ + kcsan_mb(); \ + instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \ + raw_sync_try_cmpxchg(__ai_ptr, __VA_ARGS__); \ +}) + #endif /* _LINUX_ATOMIC_INSTRUMENTED_H */ -// 1568f875fef72097413caab8339120c065a39aa4 +// 2cc4bc990fef44d3836ec108f11b610f3f438184 diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh index a45154cefa48..f80d69cfeb1f 100755 --- a/scripts/atomic/gen-atomic-fallback.sh +++ b/scripts/atomic/gen-atomic-fallback.sh @@ -223,14 +223,15 @@ gen_xchg_fallbacks() gen_try_cmpxchg_fallback() { + local prefix="$1"; shift local cmpxchg="$1"; shift; - local order="$1"; shift; + local suffix="$1"; shift; cat <