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 12440C38159 for ; Wed, 18 Jan 2023 15:36:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230305AbjARPf5 (ORCPT ); Wed, 18 Jan 2023 10:35:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230320AbjARPfu (ORCPT ); Wed, 18 Jan 2023 10:35:50 -0500 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 869F211EA3; Wed, 18 Jan 2023 07:35:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1674056149; x=1705592149; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=V+7w/6DVh6oOTj/5Q6BI82PHATnPnRgB/JN4Ard83Dk=; b=Gz57egnTY6YYvqlojEwpjGrMBhV4JoVeqKWN6u8gYUt037QbG2cfm5L4 GnscKpY2cJlEC+u0BFtiv5lTlyH05XcpZeIGFBtX3mWP5QgiAVrijE7H0 yBRkLQsBmy7y396IZuGRu0Qz/89PlSDT9PHKJDoYna47pdBzTi3aL6KQH HdQPVFUsdVwDoKmTwZ/gHuwg55DllH6h8lTEFSJgyQIbrji8tBzrmVZEm lVQ2QCb8uEJvcp1+GlGS5aOJzQ/OYg+65HXarOgZbUt92144zIdo6oq66 MsPYvODbjMjuNlfX8veHhn4BA77mS/+JPU13yj6/ufzu5hdD/ElZyMC83 A==; X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="305381646" X-IronPort-AV: E=Sophos;i="5.97,226,1669104000"; d="scan'208";a="305381646" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2023 07:35:47 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10593"; a="833614590" X-IronPort-AV: E=Sophos;i="5.97,226,1669104000"; d="scan'208";a="833614590" Received: from lab-ah.igk.intel.com ([10.102.42.211]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2023 07:35:41 -0800 From: Andrzej Hajda To: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Andrzej Hajda , Arnd Bergmann , Rodrigo Vivi , Andrew Morton , Andy Shevchenko , Peter Zijlstra , Boqun Feng , Mark Rutland Subject: [PATCH v5 0/7] Introduce __xchg, non-atomic xchg Date: Wed, 18 Jan 2023 16:35:22 +0100 Message-Id: <20230118153529.57695-1-andrzej.hajda@intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org Hi all, The helper is tiny and there are advices we can live without it, so I want to present few arguments why it would be good to have it: 1. Code readability/simplification/number of lines: - decreases number of lines, - it often eliminates local variables, - for real examples see patches 3+. 2. Presence of similar helpers in other somehow related languages/libs: a) Rust[1]: 'replace' from std::mem module, there is also 'take' helper (__xchg(&x, 0)), which is the same as private helper in i915 - fetch_and_zero, see latest patch. b) C++ [2]: 'exchange' from utility header. If the idea is OK there are still 2 questions to answer: 1. Name of the helper, __xchg follows kernel conventions, but for me Rust names are also OK. 2. Where to put the helper: a) as in this patchset include/linux/non-atomic/xchg.h, proposed by Andy Shevchenko, b) include/linux/utils.h ? any better name? Some kind of container for simple helpers. All __xchg conversions were performed using cocci script, then manually adjusted if necessary. There is lot of places it can be used in, I have just chosen some of them. I can provide cocci script to detect others (not all), if necessary. Changes: v2: squashed all __xchg -> __arch_xchg t one patch (Arnd) v3: fixed alpha/xchg_local (lkp@intel.com) v4: adjusted indentation (Heiko) v5: added more __xchg conversions - patches 3-6, added tags [1]: https://doc.rust-lang.org/std/mem/index.html [2]: https://en.cppreference.com/w/cpp/header/utility Regards Andrzej Andrzej Hajda (7): arch: rename all internal names __xchg to __arch_xchg linux/include: add non-atomic version of xchg arch/*/uprobes: simplify arch_uretprobe_hijack_return_addr llist: simplify __llist_del_all io_uring: use __xchg if possible qed: use __xchg if possible drm/i915/gt: use __xchg instead of internal helper arch/alpha/include/asm/cmpxchg.h | 10 +++++----- arch/arc/include/asm/cmpxchg.h | 4 ++-- arch/arm/include/asm/cmpxchg.h | 7 ++++--- arch/arm/probes/uprobes/core.c | 8 ++------ arch/arm64/include/asm/cmpxchg.h | 7 +++---- arch/arm64/kernel/probes/uprobes.c | 9 ++------- arch/csky/kernel/probes/uprobes.c | 9 ++------- arch/hexagon/include/asm/cmpxchg.h | 10 +++++----- arch/ia64/include/asm/cmpxchg.h | 2 +- arch/ia64/include/uapi/asm/cmpxchg.h | 4 ++-- arch/loongarch/include/asm/cmpxchg.h | 4 ++-- arch/m68k/include/asm/cmpxchg.h | 6 +++--- arch/mips/include/asm/cmpxchg.h | 4 ++-- arch/mips/kernel/uprobes.c | 10 ++-------- arch/openrisc/include/asm/cmpxchg.h | 10 +++++----- arch/parisc/include/asm/cmpxchg.h | 4 ++-- arch/powerpc/include/asm/cmpxchg.h | 4 ++-- arch/powerpc/kernel/uprobes.c | 10 ++-------- arch/riscv/include/asm/atomic.h | 2 +- arch/riscv/include/asm/cmpxchg.h | 4 ++-- arch/riscv/kernel/probes/uprobes.c | 9 ++------- arch/s390/include/asm/cmpxchg.h | 8 ++++---- arch/s390/kernel/uprobes.c | 7 ++----- arch/sh/include/asm/cmpxchg.h | 4 ++-- arch/sparc/include/asm/cmpxchg_32.h | 4 ++-- arch/sparc/include/asm/cmpxchg_64.h | 6 +++--- arch/sparc/kernel/uprobes.c | 7 ++----- arch/xtensa/include/asm/cmpxchg.h | 4 ++-- drivers/gpu/drm/i915/gt/intel_engine_cs.c | 2 +- .../gpu/drm/i915/gt/intel_engine_heartbeat.c | 4 ++-- .../drm/i915/gt/intel_execlists_submission.c | 4 ++-- drivers/gpu/drm/i915/gt/intel_ggtt.c | 4 ++-- drivers/gpu/drm/i915/gt/intel_gsc.c | 2 +- drivers/gpu/drm/i915/gt/intel_gt.c | 4 ++-- drivers/gpu/drm/i915/gt/intel_gt_pm.c | 2 +- drivers/gpu/drm/i915/gt/intel_lrc.c | 6 +++--- drivers/gpu/drm/i915/gt/intel_migrate.c | 2 +- drivers/gpu/drm/i915/gt/intel_rc6.c | 2 +- drivers/gpu/drm/i915/gt/intel_rps.c | 2 +- drivers/gpu/drm/i915/gt/selftest_context.c | 2 +- .../drm/i915/gt/selftest_ring_submission.c | 2 +- drivers/gpu/drm/i915/gt/selftest_timeline.c | 2 +- drivers/gpu/drm/i915/gt/uc/intel_gsc_uc.c | 2 +- drivers/gpu/drm/i915/gt/uc/intel_uc.c | 2 +- drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 2 +- drivers/gpu/drm/i915/i915_utils.h | 1 + include/linux/llist.h | 6 ++---- include/linux/non-atomic/xchg.h | 19 +++++++++++++++++++ include/linux/qed/qed_chain.h | 19 +++++++------------ io_uring/io_uring.c | 7 ++----- io_uring/slist.h | 6 ++---- 51 files changed, 126 insertions(+), 155 deletions(-) create mode 100644 include/linux/non-atomic/xchg.h -- 2.34.1