{"id":2224664,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2224664/?format=json","web_url":"http://patchwork.ozlabs.org/project/rtc-linux/patch/20260417173621.368914-2-ynorov@nvidia.com/","project":{"id":9,"url":"http://patchwork.ozlabs.org/api/1.2/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":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260417173621.368914-2-ynorov@nvidia.com>","list_archive_url":null,"date":"2026-04-17T17:36:12","name":"[1/9] bitfield: add FIELD_GET_SIGNED()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"21db05175a96381f5b0989c1fe62f4a88f7db29d","submitter":{"id":92516,"url":"http://patchwork.ozlabs.org/api/1.2/people/92516/?format=json","name":"Yury Norov","email":"ynorov@nvidia.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/rtc-linux/patch/20260417173621.368914-2-ynorov@nvidia.com/mbox/","series":[{"id":500382,"url":"http://patchwork.ozlabs.org/api/1.2/series/500382/?format=json","web_url":"http://patchwork.ozlabs.org/project/rtc-linux/list/?series=500382","date":"2026-04-17T17:36:11","name":"bitfield: add FIELD_GET_SIGNED()","version":1,"mbox":"http://patchwork.ozlabs.org/series/500382/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2224664/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2224664/checks/","tags":{},"related":[],"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=lqDUkyKe;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; 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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=ctnTpI2RNaqGdOP2b+kZbogh55OglPF3v2wXKLiOyIw=;\n b=lqDUkyKeIPYkbRGx8ItjIrAj4HDf4BxtycHsk8GY1cOpba2g9oSMKNClyPYkoX0DVIpwLm7T5CvdzHfyg2AAmeqiI+oZK1vC+dtcVRidVXW9WWhcq75f5kGJdq5f7wAlXPIKJzJ7k79RBO8GIeqg6cg5VrrUwMRFmo1GopnG+YWte9VHWpU0pXJn6LFFqyH9mPunLTeePLLGl6nLCDvpuZEcq3uqzwvcFDqMaEQn86QR4WPFb7SxN7PhDFdJCI5tXuvXqaNTNV9gUm/VZL0qYa6d711W4JARwPkDuimxki4Zmo9+LwQQ2cZ9BItOqXwIb02IExUJQ8xI5YHw8/V3Tg==","From":"Yury Norov ","To":"Thomas Gleixner , Ingo Molnar ,\n Borislav Petkov , Dave Hansen ,\n x86@kernel.org, \"H. Peter Anvin\" ,\n Andy Lutomirski , Peter Zijlstra ,\n Jonathan Cameron , David Lechner ,\n\t=?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 , linux-kernel@vger.kernel.org,\n linux-iio@vger.kernel.org, linux-wireless@vger.kernel.org,\n netdev@vger.kernel.org, linux-rtc@vger.kernel.org","Cc":"Yury Norov ","Subject":"[PATCH 1/9] bitfield: add FIELD_GET_SIGNED()","Date":"Fri, 17 Apr 2026 13:36:12 -0400","Message-ID":"<20260417173621.368914-2-ynorov@nvidia.com>","X-Mailer":"git-send-email 2.51.0","In-Reply-To":"<20260417173621.368914-1-ynorov@nvidia.com>","References":"<20260417173621.368914-1-ynorov@nvidia.com>","Content-Transfer-Encoding":"8bit","Content-Type":"text/plain","X-ClientProxiedBy":"BN0PR04CA0155.namprd04.prod.outlook.com\n (2603:10b6:408:eb::10) To CY8PR12MB8300.namprd12.prod.outlook.com\n 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","X-OriginatorOrg":"Nvidia.com","X-MS-Exchange-CrossTenant-Network-Message-Id":"\n 34b93e52-c9d7-4dff-c7f0-08de9ca7da02","X-MS-Exchange-CrossTenant-AuthSource":"CY8PR12MB8300.namprd12.prod.outlook.com","X-MS-Exchange-CrossTenant-AuthAs":"Internal","X-MS-Exchange-CrossTenant-OriginalArrivalTime":"17 Apr 2026 17:36:26.5109\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 Y1+iT6ksODVlWJSSwv2UJ8r/LIC1ctrCy44eDZQ8DrwfQdDJKcsOIaTMOcAWLeEP7lynyjB3bOrXPW4hjFA0CA==","X-MS-Exchange-Transport-CrossTenantHeadersStamped":"SA1PR12MB8744"},"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() macro, which is the more\nconvenient and compiles (on x86_64) to just a couple instructions:\nshl and sar.\n\nSigned-off-by: Yury Norov \n---\n include/linux/bitfield.h | 16 ++++++++++++++++\n 1 file changed, 16 insertions(+)","diff":"diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h\nindex 54aeeef1f0ec..35ef63972810 100644\n--- a/include/linux/bitfield.h\n+++ b/include/linux/bitfield.h\n@@ -178,6 +178,22 @@\n \t\t__FIELD_GET(_mask, _reg, \"FIELD_GET: \");\t\t\\\n \t})\n \n+/**\n+ * FIELD_GET_SIGNED() - extract a signed bitfield element\n+ * @mask: shifted mask defining the field's length and position\n+ * @reg: value of entire bitfield\n+ *\n+ * Returns the sign-extended field specified by @_mask from the\n+ * bitfield passed in as @_reg by masking and shifting it down.\n+ */\n+#define FIELD_GET_SIGNED(mask, reg)\t\t\t\t\t\\\n+\t({\t\t\t\t\t\t\t\t\\\n+\t\t__BF_FIELD_CHECK(mask, reg, 0U, \"FIELD_GET_SIGNED: \");\t\\\n+\t\t ((__signed_scalar_typeof(mask))((long long)(reg) <<\t\\\n+\t\t __builtin_clzll(mask) >> (__builtin_clzll(mask) +\t\\\n+\t\t\t\t\t\t__builtin_ctzll(mask))));\\\n+\t})\n+\n /**\n * FIELD_MODIFY() - modify a bitfield element\n * @_mask: shifted mask defining the field's length and position\n","prefixes":["1/9"]}