{"id":2229191,"url":"http://patchwork.ozlabs.org/api/1.1/covers/2229191/?format=json","web_url":"http://patchwork.ozlabs.org/project/rtc-linux/cover/20260427214127.406067-1-ynorov@nvidia.com/","project":{"id":9,"url":"http://patchwork.ozlabs.org/api/1.1/projects/9/?format=json","name":"Linux RTC development","link_name":"rtc-linux","list_id":"linux-rtc.vger.kernel.org","list_email":"linux-rtc@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260427214127.406067-1-ynorov@nvidia.com>","date":"2026-04-27T21:41:17","name":"[v2,0/9] bitfield: add FIELD_GET_SIGNED()","submitter":{"id":92516,"url":"http://patchwork.ozlabs.org/api/1.1/people/92516/?format=json","name":"Yury Norov","email":"ynorov@nvidia.com"},"mbox":"http://patchwork.ozlabs.org/project/rtc-linux/cover/20260427214127.406067-1-ynorov@nvidia.com/mbox/","series":[{"id":501729,"url":"http://patchwork.ozlabs.org/api/1.1/series/501729/?format=json","web_url":"http://patchwork.ozlabs.org/project/rtc-linux/list/?series=501729","date":"2026-04-27T21:41:17","name":"bitfield: add FIELD_GET_SIGNED()","version":2,"mbox":"http://patchwork.ozlabs.org/series/501729/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/covers/2229191/comments/","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-rtc@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256\n header.s=selector2 header.b=n7frwneL;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; helo=sea.lore.kernel.org;\n envelope-from=linux-rtc+bounces-6432-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com\n header.b=\"n7frwneL\"","smtp.subspace.kernel.org;\n arc=fail smtp.client-ip=52.101.53.60","smtp.subspace.kernel.org;\n dmarc=pass (p=reject dis=none) header.from=nvidia.com","smtp.subspace.kernel.org;\n spf=fail smtp.mailfrom=nvidia.com","dkim=none (message not signed)\n header.d=none;dmarc=none action=none header.from=nvidia.com;"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org [172.234.253.10])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g4H970GHyz1xrS\n\tfor ; Tue, 28 Apr 2026 07:42:35 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id CF744307E8B2\n\tfor ; Mon, 27 Apr 2026 21:41:40 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 1DEC33845B7;\n\tMon, 27 Apr 2026 21:41:40 +0000 (UTC)","from BL0PR03CU003.outbound.protection.outlook.com\n (mail-eastusazon11012060.outbound.protection.outlook.com [52.101.53.60])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 915ED2F7478;\n\tMon, 27 Apr 2026 21:41:38 +0000 (UTC)","from CY8PR12MB8300.namprd12.prod.outlook.com (2603:10b6:930:7d::16)\n by PH7PR12MB6418.namprd12.prod.outlook.com (2603:10b6:510:1fe::18) with\n Microsoft SMTP Server (version=TLS1_2,\n cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9870.16; Mon, 27 Apr\n 2026 21:41:31 +0000","from CY8PR12MB8300.namprd12.prod.outlook.com\n ([fe80::ce75:8187:3ac3:c5de]) by CY8PR12MB8300.namprd12.prod.outlook.com\n ([fe80::ce75:8187:3ac3:c5de%3]) with mapi id 15.20.9870.013; Mon, 27 Apr 2026\n 21:41:30 +0000"],"ARC-Seal":["i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1777326100; cv=fail;\n b=J6hKd9jWDn03UywdTGLpEhmjjY4HU8HjEjJ6y/ZBq2aAGaWnPc5hq3gXm+T5YSq0p/xsx14eaGFD474Cy87FOtAAyGhkFmLLEzfVN00PGd/1ViWd5Se3xsHBxb5iAf1mF3y6ecvMh58yhOcuPem56JZv2ZoSlWx1Fg0UHBj1zh0=","i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none;\n b=AVhVEN/HFekaAgxbjIRZlrY66V0u37QQ+9rSICwI3mphEb/Ad7rqFzhNJ0+mYeEU8ZBaXXOAqo0+deoDMBF3m8jA5yCh2+by3zE15uPPK11nVPo4K4DCNgCiNoyt3fNt7GyNi1VgnasO3y9FQsleR5V6fjsHvDs6DgPIkoMyoDUiFhy/LHjwReJUbqouU7znT1fCBdlt2C7wrkd40WzS9EXcv8DGzokzyqDvPlvHSWlZLUBY89YJlWiHlig3NeFAKGFJSXkvMcjGA3CosLyYHRzlrXXy09GnS01Jeg/11SX4jSVZo/mIaTusWViq+raCqdLWz1Ia+eHPZgWUPUHVRA=="],"ARC-Message-Signature":["i=2; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1777326100; c=relaxed/simple;\n\tbh=CJ/w796/sId5bFX6fy91k8t8qwCwiSrNvgYIfTJMn2U=;\n\th=From:To:Cc:Subject:Date:Message-ID:Content-Type:MIME-Version;\n b=Jv73alQOtpDxk1soMndgkAO1ul8sZxjKp06mzOARp4Cr+4iI5p8ouQNLf9OpVud5aE+Y5atAm54Ew/1nV7UdN04snk2K0ytCl6BaXLKdzVdNcZjN3+qSLAf4zw6Tx8tEpGgzGp+J7oFw3gh8nzQYeL5dFHQZ3RuBe37memYJ9Rw=","i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com;\n s=arcselector10001;\n 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;\n bh=6VI3prW45uS7UDhQzpJciRTUD/E5Q6YgdyWox644+tA=;\n b=iDfXh9oWJkjGbr7FP7VSR1OWAlvJNcOy2RL09nfYx89bxZNHAN65GL0X7b1+CdlDaah2u+L2uOuHDx29D6tIIdCrcZwE0CpVNqJAVWFO2fRHiG3G54iVY9wlGcm1sV1X/x20dDDapNSCTAvUUJ674HlI8hk3R/4VBwROJDafTBv6m4bzdLtTlqLzby6KgStjLQQ58ZOWOqxf+j8/wbeeYtW62eEy8pUz3W6Aehjj1rqUwyQLsH8k1h+GNCSJMVKspcaVX4sI07VepIQ9Ftmp66JLrSbwLDjz3WVFQCxk6imnzaAYWnlJurYqJEymcKnRnwxgHkaamEnRQa5C1vQ8kA=="],"ARC-Authentication-Results":["i=2; smtp.subspace.kernel.org;\n dmarc=pass (p=reject dis=none) header.from=nvidia.com;\n spf=fail smtp.mailfrom=nvidia.com;\n dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com\n header.b=n7frwneL; arc=fail smtp.client-ip=52.101.53.60","i=1; mx.microsoft.com 1; spf=pass\n smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com;\n dkim=pass header.d=nvidia.com; arc=none"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com;\n s=selector2;\n h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;\n bh=6VI3prW45uS7UDhQzpJciRTUD/E5Q6YgdyWox644+tA=;\n b=n7frwneLOLCYuhcXPcXRLj8X5cCT/mUOY9x+FbAemmgnvyiPHx4IszsnHS1fxIlC6PGKqKw/Ji/ZSrsPqIwalA4PtHbYjChW/2Rz9hEo5NwDBAI6ZwrX37hpk7rcZFq1b1Z2ZI7+gxzsjJaIQC6m+ODGXr7ZbKMfItPwBjdw/+6WT9UL5K/FQAa39EKCN5ylpeqBUtBvIyMQL88nWF/glKuvEeUzw3BsSjT6rNU4HFpIjjxO2Lw/4BVLcS3z/B5zKhUlA/jEbn628do0xrzQ48MUokI+kcjkun91aW2Ri4EYKHPnXF0hzJCB2Pk10j5wgHJhgGsiYr7pWmKYgpHODw==","From":"Yury Norov ","To":"Thomas Gleixner , Ingo Molnar ,\n Borislav Petkov , Dave Hansen ,\n \"H. Peter Anvin\" , Andy Lutomirski ,\n Peter Zijlstra , Jonathan Cameron ,\n David Lechner ,\n Johannes Berg ,\n David Laight ,\n =?utf-8?q?Nuno_S=C3=A1?= ,\n Andy Shevchenko , Ping-Ke Shih ,\n Richard Cochran ,\n Andrew Lunn , \"David S. Miller\" ,\n Eric Dumazet , Jakub Kicinski ,\n Paolo Abeni ,\n Alexandre Belloni ,\n Yury Norov ,\n Rasmus Villemoes ,\n Hans de Goede , Linus Walleij ,\n Sakari Ailus ,\n Salah Triki , Achim Gratz ,\n Ben Collins , x86@kernel.org,\n linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,\n linux-wireless@vger.kernel.org, netdev@vger.kernel.org,\n linux-rtc@vger.kernel.org","Cc":"Yury Norov ","Subject":"[PATCH v2 0/9] bitfield: add FIELD_GET_SIGNED()","Date":"Mon, 27 Apr 2026 17:41:17 -0400","Message-ID":"<20260427214127.406067-1-ynorov@nvidia.com>","X-Mailer":"git-send-email 2.51.0","Content-Transfer-Encoding":"8bit","Content-Type":"text/plain","X-ClientProxiedBy":"BN0PR10CA0016.namprd10.prod.outlook.com\n (2603:10b6:408:143::23) To CY8PR12MB8300.namprd12.prod.outlook.com\n (2603:10b6:930:7d::16)","Precedence":"bulk","X-Mailing-List":"linux-rtc@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","X-MS-PublicTrafficType":"Email","X-MS-TrafficTypeDiagnostic":"CY8PR12MB8300:EE_|PH7PR12MB6418:EE_","X-MS-Office365-Filtering-Correlation-Id":"788ccc81-2ce7-4434-34cd-08dea4a5be86","X-MS-Exchange-SenderADCheck":"1","X-MS-Exchange-AntiSpam-Relay":"0","X-Microsoft-Antispam":"\n\tBCL:0;ARA:13230040|376014|7416014|366016|1800799024|10070799003|921020|18002099003|56012099003;","X-Microsoft-Antispam-Message-Info":"\n\tw8hx4DZCHco2qx4/DOPjBLx5RwUHJOafn3wpYtw8LYC5UTN5SIUJZEG8gaJjJFaUBqfzuAmNS1Cs+GAgwwDW6enIwffsrPApnRVXx4mNUGmEM6VPfOLHOEFaIpdzFQC6wwNKCmpqhprJHQEusyzxoB/UTinF9U7igRGV9dMy8U1rK5nUz/4GPbaVUF8wh4aEww1HeiM8/mV14/O9MjAeg1j8tDpAZoXvE9UYsJAiZw1g51+uhM6nbRcmmPAmOrIrBZ/TQ9+w/t6wJjCbYIaVcHWlXeYy+34rZbjPh5nyzAKafLw5SlzUpnrnCYmAXg0C1ZkSuoHOkXV5HuXG6cVCziTCXVL6dwdpBqWUphKZiZjUNiU6Qvlu+XSu5K5i/6v6PFN1PMsc0sYpluujhmVTplfbyt5BhbbFxkN4zq3bK7S6Q8mhXoqkKDidyJMzIlqEaJf28zE4QkVfgeQWnFmoopPnakJHRsakqxpi4rrKcFt5Pcbg638ZIHtrKs3fT/htVtrNlHMNfjG/8XZ0NEfCGprivoIGb3pH4wqb+knHbvpmAoHW9IQQI/lo4LaXCzzJ9Qkpw011XqLhyX6pQZJqBXECySB/63XvdxmIW77Fo6PHPX1SWCR8GEUzggVMLOuf5vvWPJeeweZ+zfz0YagI179TaC6vSaDybVGv3NeYnZKU4F8hXKkVTM/0WRCV6vNZgWQ7sZcI+Ov7hCcFNc8GPMLtPuTiJ55er0shHDC/JgcUFd/o5SGWIfSPOkcy3nJHG02/KocGUye5GiIUxG293g==","X-Forefront-Antispam-Report":"\n\tCIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CY8PR12MB8300.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(366016)(1800799024)(10070799003)(921020)(18002099003)(56012099003);DIR:OUT;SFP:1101;","X-MS-Exchange-AntiSpam-MessageData-ChunkCount":"1","X-MS-Exchange-AntiSpam-MessageData-0":"\n moIcAq4YMbHuVN4v0/Gf0c5dbzNCPPvoJVhPJlsmS0dbcY7LOOIyvpG1DQyUPRLQA9pPApZaFFTjfUl8lgsrc8igHDuMMcqHE20eGH+wgFFKpKfNqyTYLq63jaM2kHRku+N9weKXX9GGZD9vW0V+aF6jzn9UGc6HFY/TTwctgCLN428WWK+RitH7KUXCnS/Q0pRmkHjKSS+ypT5uYB2UXLuauXQpOvQWs+NrStbmqL33azky8WvuDLsogXqpHwq0QXpb1yadCP7FyFsQBWM+d0kq7o58AfynRlhG/BJriUMy7zBA4yTj1Cop+xWRMU6287cLxXvE0LYb/DhfVIdzyULntrTHuULOG8Mr5w2bwe8IjauFljMytJU2/uxWIZiE1HyKOYBtymsId7qIfEXw/1LQalIqM000VGpNxgQZVMGL0b/qkLshLixLW9q5ljjnZOZGF6rn3+MEVzzYmFDu7crBk6YhuMyFG62SF4ZePdk7k/0uCkboCKFe7VtPVKI5YxjvyzRZLb/Ys8aq2xgXAj6XT5Xan4ebc5G3ezc7piaIoHVSmdrhG7lndxAhR3pynZo301gZF8Lu0HF0bZLsmIEyOfkIl6wouIDdjDxP2Tmzdt6Dl+64um2XCfnEI65nLbqlYOVfbSJlGq2cimKdVNoKMT6y1FW6UvwyVsKgE4a52+jAfEoDUZX/5YTf0myEkoiE5Ycp9q51R04tuXb1HwbOTOcC2DN9vB3q3aj/nw+X8VtJEsVesnBFUkHmQ2Dy2iuVDuHgmgu6lUO4zJDReOf40kfF7TyQq+NExkdY6Dj/urevN2t28CPHrZqlrkNSiGJgkaWNRSPk6RKpc8KX92Im0+YewVbcNFx04BbZF8BkeALNPdjnu+SgP35oi/y1Nu/dTjUjJxeIsMgkNgj+eeoaaUsui8nbXrp1oz/15Qn4P6hozEWipqwEfC2ZBAW0tVcmXGIFqvWYn2XS0dERbbEB1jmhndKE4rDKdZIGOdXFcXbS/LaJ9O5aP1PxP+Rl7QQiW1dO5bIpV/X8ezYypzWGEBjN7Rcx69miyBvr/OUoq3wX3lKCTekp+xA7OwcIQ7UPsP5+fNtOIWldA4gtnnjJhrRV8qP3qtlXGbzbNO43k076rsJ8EeS663pOKmukLQ/flkFfzG53dJ9tY07KNtfFRpikXTOgGfq8rvN3liiJKoDhvqvPiVjiWw8aXKbqXMarj4rYfry+WghiZTRTzN2fwUchtWDZoLLZoD+CEDFz1b+o2bN0bCzXp2S8ZFpu1L7TKvluANc37H+MvgNipJfdXMGNSBAi+yQLs1P8lGl1cTbRn7Ks13oHZFxGHe6YTs6V/t4usQu4YuW9ElBUiRGRO2rGkaDxi3/myE/OZMd1kItB/11eKPX91HP0aCQ53IUOez1e2MV01nTPoYdFHG2PoLl9NLmG+54FUTgXh0jzbv9T6zpBgqq8xhpQVpI9VO10gprT3bXkOzLY+JDMyQGzqJbd9iQyaW2WqGOWuPzymTN+zDbAm9fGK8pmPuC9m7X6pDEtu3ad7AzzdEdTS9KYDnRGBBrFKx8OOVvy+ywesVdCaHTDEyfZ44JNDu38AkagtrzrpupYoWU4QfGwV35kWuVaJ64NytO87vaY1VGGotisenK6dAtoVH5lePtTWJlx0+BLdpmeFHy6Oa1jaAsqnKWydJnxIB9g22AgZNYe+LcLyNE6/TJZcNz96dmqBQHcvRgcmkLU9IigapPGs3cdFmMdbIKVB5lnCbjffcaOFxNiB5TKCn4r5S7ElxjT","X-OriginatorOrg":"Nvidia.com","X-MS-Exchange-CrossTenant-Network-Message-Id":"\n 788ccc81-2ce7-4434-34cd-08dea4a5be86","X-MS-Exchange-CrossTenant-AuthSource":"CY8PR12MB8300.namprd12.prod.outlook.com","X-MS-Exchange-CrossTenant-AuthAs":"Internal","X-MS-Exchange-CrossTenant-OriginalArrivalTime":"27 Apr 2026 21:41:30.8527\n (UTC)","X-MS-Exchange-CrossTenant-FromEntityHeader":"Hosted","X-MS-Exchange-CrossTenant-Id":"43083d15-7273-40c1-b7db-39efd9ccc17a","X-MS-Exchange-CrossTenant-MailboxType":"HOSTED","X-MS-Exchange-CrossTenant-UserPrincipalName":"\n lBx+sbaiozfGkjrGZALAeHrXVo9O5FVk9Db89K8tyeq36gjhLu84KgOLRxO3kkfvHRtBKlEPQhUclpGd9/BTzA==","X-MS-Exchange-Transport-CrossTenantHeadersStamped":"PH7PR12MB6418"},"content":"The bitfields are designed in assumption that fields contain unsigned\ninteger values, thus extracting the values from the field implies\nzero-extending.\n\nSome drivers need to sign-extend their fields, and currently do it like:\n\n\tdc_re += sign_extend32(FIELD_GET(0xfff000, tmp), 11);\n\tdc_im += sign_extend32(FIELD_GET(0xfff, tmp), 11);\n\nIt's error-prone because it relies on user to provide the correct\nindex of the most significant bit and proper 32 vs 64 function flavor.\n\nThus, introduce a FIELD_GET_SIGNED(). With the new API, the above\nsnippet turns into the more convenient:\n\n\tdc_re += FIELD_GET_SIGNED(0xfff000, tmp);\n\tdc_im += FIELD_GET_SIGNED(0xfff, tmp);\n\nIt compiles (on x86_64) into just a couple instructions: shl and sar.\nWhen the mask includes MSB, the '<< __builtin_clzll(mask)' part becomes\na NOP, and the compiler only emits a single sar:\n\n long long foo(long long reg)\n {\n 10: f3 0f 1e fa endbr64\n return FIELD_GET_SIGNED(GENMASK_ULL(63, 60), reg);\n 14: 48 89 f8 mov %rdi,%rax\n 17: 48 c1 f8 3c sar $0x3c,%rax\n }\n\n32-bit code generation is equally well. On arm32:\n\n long long foo(long long reg)\n {\n return FIELD_GET_SIGNED(0x00f00000ULL, reg);\n }\n\ngenerates:\n\n foo(long long):\n lsls r1, r0, #8\n asrs r0, r1, #28\n asrs r1, r1, #31\n bx lr\n\nImmutable branch:\n\nhttps://github.com/norov/linux/pull/new/fgsv2\n\nv1: https://lore.kernel.org/all/20260417173621.368914-1-ynorov@nvidia.com/\nv2:\n - more examples of the new API and code generation (Andy, David);\n - fix #7 FIELD_GET() / FIELD_GET_SIGNED() typo (Ping-Ke);\n - re-indent the macro (Andy, Peter);\n\nYury Norov (9):\n bitfield: add FIELD_GET_SIGNED()\n x86/extable: switch to using FIELD_GET_SIGNED()\n iio: intel_dc_ti_adc: switch to using FIELD_GET_SIGNED()\n iio: magnetometer: yas530: switch to using FIELD_GET_SIGNED()\n iio: pressure: bmp280: switch to using FIELD_GET_SIGNED()\n iio: mcp9600: switch to using FIELD_GET_SIGNED()\n wifi: rtw89: switch to using FIELD_GET_SIGNED()\n rtc: rv3032: switch to using FIELD_GET_SIGNED()\n ptp: switch to using FIELD_GET_SIGNED()\n\n arch/x86/include/asm/extable_fixup_types.h | 13 ++++---------\n arch/x86/mm/extable.c | 2 +-\n drivers/iio/adc/intel_dc_ti_adc.c | 4 ++--\n drivers/iio/magnetometer/yamaha-yas530.c | 12 ++++++------\n drivers/iio/pressure/bmp280-core.c | 2 +-\n drivers/iio/temperature/mcp9600.c | 2 +-\n .../net/wireless/realtek/rtw89/rtw8852a_rfk.c | 4 ++--\n .../net/wireless/realtek/rtw89/rtw8852b_common.c | 4 ++--\n .../net/wireless/realtek/rtw89/rtw8852b_rfk.c | 4 ++--\n drivers/net/wireless/realtek/rtw89/rtw8852c.c | 4 ++--\n drivers/ptp/ptp_fc3.c | 4 ++--\n drivers/rtc/rtc-rv3032.c | 2 +-\n include/linux/bitfield.h | 16 ++++++++++++++++\n 13 files changed, 42 insertions(+), 31 deletions(-)"}