From patchwork Tue Jun 4 10:51:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Devarsh Thakkar X-Patchwork-Id: 13685053 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 E9D02C25B78 for ; Tue, 4 Jun 2024 10:51:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D4C7510E446; Tue, 4 Jun 2024 10:51:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=ti.com header.i=@ti.com header.b="uYlZsMCp"; dkim-atps=neutral Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by gabe.freedesktop.org (Postfix) with ESMTPS id A7AFB10E446 for ; Tue, 4 Jun 2024 10:51:38 +0000 (UTC) Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 454ApPwF104288; Tue, 4 Jun 2024 05:51:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1717498285; bh=frKIkup1rya8/oIVCuozYgIkw2YiLenjI5YJiYQbdwo=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=uYlZsMCpO6BmzI29pbfN5isqhCyS6MeEhchQVcV9XC4rTasy+ZAw59O8daz0q6ovI +vNr8ES3x82DCSiLF7igMc2FtCk/ZSzL1DIV+qotCk9UdoR3zFD7yG6JFBqRWnAJtp ANAGafJqWWacz5LDW2wUyIeYB4jrg8Fb4gsjvZy4= Received: from DFLE108.ent.ti.com (dfle108.ent.ti.com [10.64.6.29]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 454ApP1o032028 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 4 Jun 2024 05:51:25 -0500 Received: from DFLE109.ent.ti.com (10.64.6.30) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 4 Jun 2024 05:51:25 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 4 Jun 2024 05:51:25 -0500 Received: from localhost (ti.dhcp.ti.com [172.24.227.95] (may be forged)) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 454ApOF8119625; Tue, 4 Jun 2024 05:51:25 -0500 From: Devarsh Thakkar To: , , , , , , , , , , , , , , CC: , , , , , , , , , , , , , , Subject: [PATCH v12 07/13] math.h: Add macros for rounding to closest value Date: Tue, 4 Jun 2024 16:21:24 +0530 Message-ID: <20240604105124.2253786-1-devarsht@ti.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20240604104001.2235082-1-devarsht@ti.com> References: <20240604104001.2235082-1-devarsht@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add below rounding related macros: round_closest_up(x, y) : Rounds x to closest multiple of y where y is a power of 2, with a preference to round up in case two nearest values are possible. round_closest_down(x, y) : Rounds x to closest multiple of y where y is a power of 2, with a preference to round down in case two nearest values are possible. roundclosest(x, y) : Rounds x to closest multiple of y, this macro should generally be used only when y is not multiple of 2 as otherwise round_closest* macros should be used which are much faster. Examples: * round_closest_up(17, 4) = 16 * round_closest_up(15, 4) = 16 * round_closest_up(14, 4) = 16 * round_closest_down(17, 4) = 16 * round_closest_down(15, 4) = 16 * round_closest_down(14, 4) = 12 * roundclosest(21, 5) = 20 * roundclosest(19, 5) = 20 * roundclosest(17, 5) = 15 Signed-off-by: Devarsh Thakkar Acked-by: Andy Shevchenko --- NOTE: This patch is inspired from the Mentor Graphics IPU driver [1] which uses similar macro locally and which is updated in further patch in the series to use this generic macro instead along with other drivers having similar requirements. Link: https://elixir.bootlin.com/linux/v6.8.9/source/drivers/gpu/ipu-v3/ipu-image-convert.c#L480 [1] V12: - Add Acked-by V11: - Fix commenting style per review comments and remove extra whitespace V10: - Update example comment to fix formatting issues as observed with html docs V9: - No change V8: - Add new macro to round to nearest value for non-multiple of 2 - Update commit message as suggested: V1->V6 (No change, patch introduced in V7) --- include/linux/math.h | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/include/linux/math.h b/include/linux/math.h index dd4152711de7..79e3dfda77fc 100644 --- a/include/linux/math.h +++ b/include/linux/math.h @@ -34,6 +34,52 @@ */ #define round_down(x, y) ((x) & ~__round_mask(x, y)) +/** + * round_closest_up - round closest to be multiple of specified value (which is + * power of 2) with preference to rounding up + * @x: the value to round + * @y: multiple to round closest to (must be a power of 2) + * + * Rounds @x to closest multiple of @y (which must be a power of 2). + * The value can be either rounded up or rounded down depending upon rounded + * value's closeness to the specified value. If there are two closest possible + * values, i.e. the difference between the specified value and it's rounded up + * and rounded down values is same then preference is given to rounded up + * value. + * + * To perform arbitrary rounding to closest value (not multiple of 2), use + * roundclosest(). + * + * Examples: + * * round_closest_up(17, 4) = 16 + * * round_closest_up(15, 4) = 16 + * * round_closest_up(14, 4) = 16 + */ +#define round_closest_up(x, y) round_down((x) + (y) / 2, (y)) + +/** + * round_closest_down - round closest to be multiple of specified value (which + * is power of 2) with preference to rounding down + * @x: the value to round + * @y: multiple to round closest to (must be a power of 2) + * + * Rounds @x to closest multiple of @y (which must be a power of 2). + * The value can be either rounded up or rounded down depending upon rounded + * value's closeness to the specified value. If there are two closest possible + * values, i.e. the difference between the specified value and it's rounded up + * and rounded down values is same then preference is given to rounded up + * value. + * + * To perform arbitrary rounding to closest value (not multiple of 2), use + * roundclosest(). + * + * Examples: + * * round_closest_down(17, 4) = 16 + * * round_closest_down(15, 4) = 16 + * * round_closest_down(14, 4) = 12 + */ +#define round_closest_down(x, y) round_up((x) - (y) / 2, (y)) + #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP #define DIV_ROUND_DOWN_ULL(ll, d) \ @@ -77,6 +123,23 @@ } \ ) +/** + * roundclosest - round to nearest multiple + * @x: the value to round + * @y: multiple to round nearest to + * + * Rounds @x to nearest multiple of @y. + * The rounded value can be greater than or less than @x depending + * upon it's nearness to @x. If @y will always be a power of 2, consider + * using the faster round_closest_up() or round_closest_down(). + * + * Examples: + * * roundclosest(21, 5) = 20 + * * roundclosest(19, 5) = 20 + * * roundclosest(17, 5) = 15 + */ +#define roundclosest(x, y) rounddown((x) + (y) / 2, (y)) + /* * Divide positive or negative dividend by positive or negative divisor * and round to closest integer. Result is undefined for negative