From patchwork Mon Aug 26 15:08:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Devarsh Thakkar X-Patchwork-Id: 13778023 Received: from fllv0015.ext.ti.com (fllv0015.ext.ti.com [198.47.19.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 363ED18BC24; Mon, 26 Aug 2024 15:08:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.141 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724684926; cv=none; b=YcMkUvK03S/iKiKFPj6nD64EclR82NYgfPThZ91LrENT7WH5GJ9zoAlysDlW2R/zWqh8EqOnBfTvgn7aYy0Dk0TOKgrruoqoel3uFOPAkFFliUC6mwjfcWfdF0RIRfijxzxe4C8mQaFbAv2tqzDHkpdMzFIXkPwGIPEAZg7QBO4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724684926; c=relaxed/simple; bh=YJIkUeRLu2Kr/WqRzxWJExQWPxmfHyiG0Bgnp9y7yyk=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=k69ucGUx80aEnNCey/FBL0ba9geIioGgWnFf902Hd5VzNw8WABmkUzyGTnY6HR+c4PR4v8TPKPPcinWXbI6y62kyKWS5Qbs8EmVRYoQLi3g3CQuNjD5uxZGtFk1mAVhgCqxS5sUVQEb4zfPDQVU8oy0Y+HULy4F7XUiNfRSQQN4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=JD9AU/B5; arc=none smtp.client-ip=198.47.19.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="JD9AU/B5" Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 47QF8QFG078703; Mon, 26 Aug 2024 10:08:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1724684906; bh=InOaQ/oT4jDIyfmOlh93amRUx7UWvjLOJkSpc/qJSO8=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=JD9AU/B5GijX8jmT9o5Ld0HQTH8vIb0TkEJr+ExqCQQQVVx0lyIQlURqAksWfaqqq LECLWqGjhWmvuyQA2AFaifoVpNuDi3f92ZbS/5/UXP0n/cNlClWBTSklUDvn4AGCT5 55DOb7pQF7HS3Yx5zmxQDihcoJljNvP9bb3pCNTs= Received: from DLEE115.ent.ti.com (dlee115.ent.ti.com [157.170.170.26]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 47QF8Q5w115122 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 26 Aug 2024 10:08:26 -0500 Received: from DLEE103.ent.ti.com (157.170.170.33) by DLEE115.ent.ti.com (157.170.170.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Mon, 26 Aug 2024 10:08:25 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DLEE103.ent.ti.com (157.170.170.33) 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; Mon, 26 Aug 2024 10:08:25 -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 47QF8OeO100787; Mon, 26 Aug 2024 10:08:25 -0500 From: Devarsh Thakkar To: , , , , , CC: , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 1/6] math.h: Add macros for rounding to the closest value Date: Mon, 26 Aug 2024 20:38:17 +0530 Message-ID: <20240826150822.4057164-2-devarsht@ti.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20240826150822.4057164-1-devarsht@ti.com> References: <20240826150822.4057164-1-devarsht@ti.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Add below rounding related macros: round_closest_up(x, y) : Rounds x to the 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 the 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 the 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] Past discussions and alignment on this: https://lore.kernel.org/all/7e3ad816-6a2a-4e02-9b41-03a8562812ad@ti.com/#r https://lore.kernel.org/all/ZkISG6p1tn9Do-xY@smile.fi.intel.com/#r https://lore.kernel.org/all/ZlTt-YWzyRyhmT9n@smile.fi.intel.com/ https://lore.kernel.org/all/ZmHDWeuezCEgj20m@smile.fi.intel.com/ https://lore.kernel.org/all/ZloMFfGKLry6EWNL@smile.fi.intel.com/ Changelog: V2: - Fix grammar in macro description - Update roundclosest macro to use roundup to avoid overflow scenario --- include/linux/math.h | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/include/linux/math.h b/include/linux/math.h index f5f18dc3616b..b59a02a007d7 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 the 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 the closest multiple of @y (which must be a power of 2). + * The value can be rounded up or rounded down depending on the rounded + * value's closeness to the specified value. Also, there can be two closest + * values, i.e. the difference between the specified value and its rounded-up + * and rounded-down values could be the same. In that case, the rounded-up + * value is preferred. + * + * To perform arbitrary rounding to the 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 the 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 the closest multiple of @y (which must be a power of 2). + * The value can be rounded up or rounded down depending on the rounded + * value's closeness to the specified value. Also, there can be two closest + * values, i.e. the difference between the specified value and its rounded-up + * and rounded-down values could be the same. In that case, the rounded-down + * value is preferred. + * + * To perform arbitrary rounding to the 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 the nearest multiple + * @x: the value to round + * @y: multiple to round nearest to + * + * Rounds @x to the nearest multiple of @y. + * The rounded value can be greater or less than @x depending + * upon its nearness to @x. If @y is always 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) roundup((x) - (y) / 2, (y)) + /* * Divide positive or negative dividend by positive or negative divisor * and round to closest integer. Result is undefined for negative