From patchwork Thu May 30 17:12:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Devarsh Thakkar X-Patchwork-Id: 800383 Received: from fllv0016.ext.ti.com (fllv0016.ext.ti.com [198.47.19.142]) (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 AB97447A6A; Thu, 30 May 2024 17:12:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.142 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717089170; cv=none; b=cNDXpHtu2eGwitdHUIx5u5q8NDtW4/mgPpDeTkP9JKN/WHhhWssOpNzf4xGgLJ0Hae4Oa+zv4OD06P9XOSQvBTgxK6NUJUqXuZf7P8GfVCe09RJrPhEVTO+wnWH1iZBr/ey5g4VfD5lZ2F11fqwESiOuMMjVG42sKeBhciJS0dg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717089170; c=relaxed/simple; bh=LDZdp5aUZDzJRQFxyUmVWtBdJDRZWdCHtHshkVP8rzc=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=pzyVPhHeDI2ZRSGWH66lvA4EhMhsJjS2fNeI2/35DnAqxw+XNbDhcwRwDtimESfpgLNIlDQlZq8Q1qwVJveCDNfr69pYW5ObOC5rffrRgDWOtVNSHg7+NJhhtrRZqQe45ocp+sqOHy5n0ULfl1eKfdAtlK5WMHbMFkpVkiFuveM= 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=UydH+mEx; arc=none smtp.client-ip=198.47.19.142 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="UydH+mEx" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 44UHCRCg026237; Thu, 30 May 2024 12:12:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1717089147; bh=3aNzr9uceqg3pOicXXuyXGK/Y+G9kDvzv2RfMYKcupU=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=UydH+mExLY4K4NTEty6agejlBOLfVB80LF3G2auLiJTi6Wrjho9N5eaQdWokVRmmN ePPCH38pfLEjcR9PspOBxP4G6BjE0oAR0HJ4CuzDaSHdQlmRYRaYQDdhp7S5sHlccN wG2xIWw+Zckf0g3jhI0xgIcHHy4NONQlq5QfgyQ4= Received: from DFLE104.ent.ti.com (dfle104.ent.ti.com [10.64.6.25]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 44UHCRYl025196 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 30 May 2024 12:12:27 -0500 Received: from DFLE100.ent.ti.com (10.64.6.21) by DFLE104.ent.ti.com (10.64.6.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 30 May 2024 12:12:26 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DFLE100.ent.ti.com (10.64.6.21) 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; Thu, 30 May 2024 12:12:26 -0500 Received: from localhost (ti.dhcp.ti.com [172.24.227.95] (may be forged)) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 44UHCQgu056152; Thu, 30 May 2024 12:12:26 -0500 From: Devarsh Thakkar To: , , , , , , , , , , , , , , CC: , , , , , , , , , , , , , , Subject: [PATCH v10 06/11] math.h: Add macros for rounding to closest value Date: Thu, 30 May 2024 22:42:25 +0530 Message-ID: <20240530171225.2749312-1-devarsht@ti.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20240530165925.2715837-1-devarsht@ti.com> References: <20240530165925.2715837-1-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 --- 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 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 | 72 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/include/linux/math.h b/include/linux/math.h index dd4152711de7..1f6177191b66 100644 --- a/include/linux/math.h +++ b/include/linux/math.h @@ -34,6 +34,58 @@ */ #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 +129,26 @@ } \ ) +/** + * 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