From patchwork Fri May 31 17:11:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Devarsh Thakkar X-Patchwork-Id: 800762 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 9533A1761B9; Fri, 31 May 2024 17:11:55 +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=1717175517; cv=none; b=OoeOQJt1XQjKhrW89P4v8gZRT7Z9tNIF7pk98Mxmz7oX82UIiMxZR90dsy2VuPlTkIYjwA+HwCJi3sIiLTwr2h/JS09KofSIqD3+8Bp+pH6dxfFFAOY+6bEtdEbIUsxr/oWFrziwi8YIWBiFkGeeSMEoQsZHFpFw3qaZADSE93A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717175517; c=relaxed/simple; bh=a5x88MXbVCLXCAiju4n5+46kR3pspDVGqzq8PBXWolk=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qEvs4h6s3RPKqoz4QwJ02tEMMH6PHAxvJfRdTGNWrKH3QYC5ia70rwJQOvVFusd6pJCmXK4zQQZmWjacQn+iY+p62d3TYdG8vckEIkI1lmKB7LwJtuUA6GQqe029O6ih0Tq3VrgmQbDHTkboMEeQcsygIfhyCnt78yNHHTwnmDs= 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=uTEqqbiz; 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="uTEqqbiz" Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 44VHBcTw055970; Fri, 31 May 2024 12:11:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1717175498; bh=hw2Yrj4LcxBZgFZdTy8i462oQh9qD794bEc0WFHu3n0=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=uTEqqbizltqzZzbHUqqJyLSoJYe4geJv2fzCxbufFRUseKFkfPe31uh4ILbZXUNxC QERhrxgRF06GdCJvKU08Y3iMh6cKQHTihGG7L5cRyGgYC3OaJo638nKUoOaPsYt18E gK7IsCLD+bKe/myHEzMYBymY4eZ0pwTmuuWodNu4= Received: from DFLE110.ent.ti.com (dfle110.ent.ti.com [10.64.6.31]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 44VHBca9022944 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 31 May 2024 12:11:38 -0500 Received: from DFLE113.ent.ti.com (10.64.6.34) by DFLE110.ent.ti.com (10.64.6.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Fri, 31 May 2024 12:11:38 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DFLE113.ent.ti.com (10.64.6.34) 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; Fri, 31 May 2024 12:11:38 -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 44VHBbwC050138; Fri, 31 May 2024 12:11:38 -0500 From: Devarsh Thakkar To: , , , , , , , , , , , , , , CC: , , , , , , , , , , , , , , Subject: [PATCH v11 06/11] math.h: Add macros for rounding to closest value Date: Fri, 31 May 2024 22:41:36 +0530 Message-ID: <20240531171136.1293905-1-devarsht@ti.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20240531170229.1270828-1-devarsht@ti.com> References: <20240531170229.1270828-1-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 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. [1]: https://elixir.bootlin.com/linux/v6.8.9/source/drivers/gpu/ipu-v3/ipu-image-convert.c#L480 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