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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57C30FF8875 for ; Thu, 30 Apr 2026 09:49:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uj6ei4wKT4j87OaAUFpQiZTdFA1aaakEUuv9evu/U9M=; b=Pu75zhc/k3KUdAinkz606gOx08 pSWc2/jfE1+jhhC82d+17/BAY9KVSdzmBfb4SDqj9q8G6ySE3UsS5u1zLs1qi+PcARAsQ82G0iRjx 1lv88kVia/sT8Q6vREyAYcNsQWXAPj9jNwX50n+K9JzWHuDElQm2CZN/bVaLFZbBrnSiMxBU8AGl9 6wZsdGv65qTPJNxj+pQb4joANcvHFZG9KJ+uXIomj1rTGVkhUK4u01sdgp09conAfNYhP9bTZUPzB IRxJo/XzP4e9N1B8F0ao+L0hHs7fDYVtbpHC5fbEVOljP9/e/OZ8rOfwCMtG9OdcC6zHC1zJotC9O NVqiWWNA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIO1D-000000057VF-3ex2; Thu, 30 Apr 2026 09:49:15 +0000 Received: from mail-centralusazlp170110009.outbound.protection.outlook.com ([2a01:111:f403:c111::9] helo=DM5PR21CU001.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIO13-000000057P0-1QlR; Thu, 30 Apr 2026 09:49:10 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=SBN00VniIMBc6O8BAq7DksOlk/tv0LJ7KpFtn7UkJ7H4Gm1Sw26BuqECIz68+Mn+Lyv341Qw+NAR5u01LjhfrUQjieh7IIetEL6jC1dtRQYirXj1xyeM/2LVSjLvvMMchdkXwGgZRPHSbLeY15Qg+g92iU6sxgFWCav1975t440IQewH60qzKCAKDkckiXTNHXvo9u+N3uxPhzGHVKkLbNBCZgTU0bJGuTV6lHjbiZifulV+33ERGx3DZvlMU/4PGNfjZAjThqsr+uuB35twgGzIwHsLSnmgZiCbbGNdtX/NYSKZ4liyelbrluZ8fIl7Ai+NZ1mfhh/JohF+frG1zA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=uj6ei4wKT4j87OaAUFpQiZTdFA1aaakEUuv9evu/U9M=; b=wpyAoNtdKCpkyv8hPq9VXwn1eM3p4NfU8ZUIjuzAjNWV+JEP0WWvf07H4lXtPN06MkWIvIcUHDNCaAJ28MrfB9JYTpDdI012W36JIBuqhjIFQoCrBzeooFKG3tPUg2lO6g3EhTAwkjiyWoChIEsLtz+dbcRxaVOarA1T2hprVdws6kLT6KL6YmiDV2K4t7Phv/8XdEcrRIm1jqYxcyVTkrt8sdiNkicP7DU8Avfkhk8ZvkxcYxv3Mn2OWKrEr6LMSfDaxHIjMck/CipTNvzFpl4WO0g9qZV6fKJQLkA9Ax/lhegNXs6Vz8Tv7R7avfzA7lJFD0Ho/BNE01u5eOOKJg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=kernel.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=uj6ei4wKT4j87OaAUFpQiZTdFA1aaakEUuv9evu/U9M=; b=q4EkGHzQ1UF8eNn4LRE2FzMP9jIPiIjVbWFRCFVES/3J89vku/kEHxuFeM2o9UgxzBMTUjzOCrSdfO6JsGXulPfY9pjGsjriA56GR5WuaPdFRAlqKYvu0HeTIwRGhozi+/09jFE7ZykPG/4EELPUvVTFWTuWA5VuP/tSntOiNGI= Received: from SA9PR13CA0176.namprd13.prod.outlook.com (2603:10b6:806:28::31) by BN7PPF9507C739C.namprd12.prod.outlook.com (2603:10b6:40f:fc02::6da) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9818.20; Thu, 30 Apr 2026 09:48:57 +0000 Received: from SA2PEPF0000150B.namprd04.prod.outlook.com (2603:10b6:806:28:cafe::c6) by SA9PR13CA0176.outlook.office365.com (2603:10b6:806:28::31) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9891.5 via Frontend Transport; Thu, 30 Apr 2026 09:48:56 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=satlexmb07.amd.com; pr=C Received: from satlexmb07.amd.com (165.204.84.17) by SA2PEPF0000150B.mail.protection.outlook.com (10.167.242.43) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9846.18 via Frontend Transport; Thu, 30 Apr 2026 09:48:56 +0000 Received: from BLRKPRNAYAK.amd.com (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Thu, 30 Apr 2026 04:48:51 -0500 From: K Prateek Nayak To: Thomas Gleixner , Ingo Molnar , "Peter Zijlstra" , Sebastian Andrzej Siewior , Catalin Marinas , "Will Deacon" CC: Darren Hart , Davidlohr Bueso , =?UTF-8?q?Andr=C3=A9=20Almeida?= , , , , , , K Prateek Nayak , Jisheng Zhang Subject: [PATCH v4 3/8] arm64/runtime-const: Introduce runtime_const_mask_32() Date: Thu, 30 Apr 2026 09:47:25 +0000 Message-ID: <20260430094730.31624-4-kprateek.nayak@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260430094730.31624-1-kprateek.nayak@amd.com> References: <20260430094730.31624-1-kprateek.nayak@amd.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: satlexmb08.amd.com (10.181.42.217) To satlexmb07.amd.com (10.181.42.216) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA2PEPF0000150B:EE_|BN7PPF9507C739C:EE_ X-MS-Office365-Filtering-Correlation-Id: 101cdfd2-5961-4fc3-c2dc-08dea69db283 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|36860700016|376014|7416014|82310400026|22082099003|56012099003|18002099003; X-Microsoft-Antispam-Message-Info: wHAdHYt7Ivhy9GdyKW9HKVvuixXpRduWuf54l0nAt7PqsGwl6d/Ku9wwtchHY8CuavFzafhod9BbxupJneKontTmJ+9qrpwedPSqC2eDXh3RuVDDVMuWstWP1VU6R5jcZ6nL5pPswu5RYbo+Pq/g0ogPvURdgRw6y4W6l6/XGlheasFihuSpa1J7Be/wf4WnivBtqUvx/HSEWrIprYaoTDfy61YgP+kQ5mOBVpZTCCeW/DUudEasYIA0850MN7PG/9fCvGuXo0yKeoSh/RclSZ0v5+b7vsF5nvZv7CUGSrtaK16C/pF4+3/sz5W9dsqb0Gz+vr3iVSqzPphrIw7fLVy259+N1U1Zo8q0eom5gcOk5i9IgK4Ot/1EZigeTfWsA38Tw25nnm+zLoHYR5B1IuuvNmdk8h4rcxstgrR+g8SE6K3nLXOf2Gu7FlNa7IIl1PemtEqAuMLrlwk0JQDwA/lKlQF7xrojq2cI7gpGMmHKbXd9en6rkWy13xmKtbaPqtGtjLqyhAiXjKRxoojwNXEjGRw0tzt1o5b5hTe1KVwg+i3NXQtSvCglPWNO+sQuWhQVALIcPsYan8UdwmVVfcg86k/ztpEfzWFNy1shLGvlTh6k2fpEzTQkSAxEdSouF21g7DF1CuXMb7yXmxWpX6EbfKMFB7UdAVgR9Cy7jk6g1v3zLnDI9zmWPtCldNCRh3Q1XPOfhUNpQN49Zl1fuoeDnl80iqQN88IbvTCLLf3kLLaUP5WkkQYRAg3L+H898doAoeSAm4XvcMWwrTS2oQ== X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(1800799024)(36860700016)(376014)(7416014)(82310400026)(22082099003)(56012099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: XBgyZuWsSqI58QXFfRWZ+hMoDTARFqFCTvOo6OMD736CMBSKJ25eFNnswKn7zqp7WQsLCodc0ATRsZiu80Uu/zt7QRd3UG9KJwVuegp0LMjfik9hOQ82tdizEfjhhlnoBKQ881uIShmArslZLwhZLwfrkSvPY5IhCzhW7S6UaahtPXsSp3I5zx4VWF8hP/zGQyennUNKXvboacL8F8HyQnmyjvMn6BaTep3Lpe1etoq23vMJQn3kD5ROaWxTBTrMQPmieZ9EPsRtC0DgvTe881F3cpK78QpS6MV+99Qutkxolh9v9xs6uFfXI6Mh4oYESsi8AqdHaLVQhvcrV0CLhPCKrYvqmrhMuKbL8Q/dW+ipFqMXtQJXJZ1OZT0aNcnMceE55jyRRUfCHN58sv2HJr+MOGZ+6QyUU/D+5q05wZPFfrtxG4Pld5AqQm0gIBUP X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Apr 2026 09:48:56.7611 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 101cdfd2-5961-4fc3-c2dc-08dea69db283 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SA2PEPF0000150B.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPF9507C739C X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260430_024906_376075_737FBB9A X-CRM114-Status: GOOD ( 11.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Futex hash computation requires a mask operation with read-only after init data that will be converted to a runtime constant in the subsequent commit. Introduce runtime_const_mask_32 to further optimize the mask operation in the futex hash computation hot path. GCC generates a: movz w1, #lo16, lsl #0 // w1 = bits [15:0] movk w1, #hi16, lsl #16 // w1 = full 32-bit value and w0, w0, w1 // w0 = w0 & w1 pattern to tackle arbitrary 32-bit masks and the same was also suggested by Claude which is implemented here. The final (__ret & mask) operation is intentiaonally placed outside of asm block to allow compilers to further optimize it if possible. __runtime_fixup_ptr() already patches a "movz, + movk lsl #16" sequence which has been reused to patch the same sequence for __runtime_fixup_mask(). Assisted-by: Claude:claude-sonnet-4-5 Signed-off-by: K Prateek Nayak --- changelog v3..v4: o Reverted back to using __ret as the macro variable to prevent collision with local varaibles at callsite. (Sashiko) o Separated out the & operation to prevent any confusion with operator precedence id "val" is an expression. (Sashiko) --- arch/arm64/include/asm/runtime-const.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/arm64/include/asm/runtime-const.h b/arch/arm64/include/asm/runtime-const.h index 838145bc289d2..1db4faac8c373 100644 --- a/arch/arm64/include/asm/runtime-const.h +++ b/arch/arm64/include/asm/runtime-const.h @@ -36,6 +36,18 @@ :"r" (0u+(val))); \ __ret; }) +#define runtime_const_mask_32(val, sym) ({ \ + unsigned long __ret; \ + asm_inline("1:\t" \ + "movz %w0, #0xcdef\n\t" \ + "movk %w0, #0x89ab, lsl #16\n\t" \ + ".pushsection runtime_mask_" #sym ",\"a\"\n\t" \ + ".long 1b - .\n\t" \ + ".popsection" \ + :"=r" (__ret)); \ + __ret &= val; /* Allow compiler to optimize & op. */ \ + __ret; }) + #define runtime_const_init(type, sym) do { \ extern s32 __start_runtime_##type##_##sym[]; \ extern s32 __stop_runtime_##type##_##sym[]; \ @@ -73,6 +85,13 @@ static inline void __runtime_fixup_shift(void *where, unsigned long val) aarch64_insn_patch_text_nosync(p, insn); } +static inline void __runtime_fixup_mask(void *where, unsigned long val) +{ + __le32 *p = where; + __runtime_fixup_16(p, val); + __runtime_fixup_16(p+1, val >> 16); +} + static inline void runtime_const_fixup(void (*fn)(void *, unsigned long), unsigned long val, s32 *start, s32 *end) { -- 2.34.1