From nobody Mon Feb 9 10:24:45 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E2DAEB64DC for ; Mon, 17 Jul 2023 11:37:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230195AbjGQLhY (ORCPT ); Mon, 17 Jul 2023 07:37:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230169AbjGQLhT (ORCPT ); Mon, 17 Jul 2023 07:37:19 -0400 Received: from mail-ed1-x549.google.com (mail-ed1-x549.google.com [IPv6:2a00:1450:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8BBBBF for ; Mon, 17 Jul 2023 04:37:17 -0700 (PDT) Received: by mail-ed1-x549.google.com with SMTP id 4fb4d7f45d1cf-51e278a3a2dso2963097a12.3 for ; Mon, 17 Jul 2023 04:37:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689593836; x=1692185836; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=FGuCnRoGjtuxCyYZwSXlSd4VQfcsRWWQdyiV1Wnie4Q=; b=lOGtagPBwApVjfpfXneYZBu8MWYD1OliVo2uXXUvPFvV6+APoIbAw6+/k3YWQj3eId ++zdOrcTldnSRQnleASyL9AkS3sHtgDNjCJqdxPyeYFLbcNbm7H47WMPCrL025NnVhlV G1Qol0TNu5t6DU2yoyQVV2/M6YY2bbB1S6KNkkNOFhBw/Gi3exXLENY44qDhbiI+qFGh XTOGJBYScj/gFqOpJMAG1/JvF8wnIW5CuArTM2y25y2u8rr7pO8KA2XD2gxTxG4FbLph Yo+NTPG4cWlDz+nePnG/bgJtDwcLrzw/IHDxEArbQPROIOahGhUPuqygOW0gEksJ4t/k Sb+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689593836; x=1692185836; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=FGuCnRoGjtuxCyYZwSXlSd4VQfcsRWWQdyiV1Wnie4Q=; b=NHyjQM2ejPJiIBl/l4pJ9XcuK23hDk2cGV/X0flQGqtHXdrJm5cV22wHQ9c4i7fKjX r9PmCCME+SMGXAvmS1y39FEQU47z7uy2u3c4ZVLfy5q36bOs20dls1iPinJ6NntKrhIl juR8OA5LMY0Gxgeg8Wlj07duxZID41YBeuuM9jMwpGNCZe7F6npq4azMwtaK2XwXDEEF pbSwUyPKTXCCxb9RjgytKDNsjUUvu1zWaMKahw9DMn5G5ZSpbS+dmWY4a2s6HmKs1hhX Xp/RaGTkOPf8q6Us6gKNGyoWCXFvl5FLRpfDTon18yUhHz7VtwBX0thc/YjSo8jU1Z++ WekQ== X-Gm-Message-State: ABy/qLbhiupnYWHk834VLrIaTHUT/96cV8LvnrwJoU7LBRZQDD+3wU6t 7jPoxaJ86vUp6cf6nHOcblk4PZTPnYc= X-Google-Smtp-Source: APBJJlHU2OTCIg2LzbafyDqppv2wF6RJFGQojMIqEPAOBlxykPEq695ChnJkW5pC2kh2TPi2Dbwzn/+SnnY= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:3b6e:8102:6db8:d83f]) (user=glider job=sendgmr) by 2002:a50:c310:0:b0:51b:ee9e:aad2 with SMTP id a16-20020a50c310000000b0051bee9eaad2mr66529edb.0.1689593835900; Mon, 17 Jul 2023 04:37:15 -0700 (PDT) Date: Mon, 17 Jul 2023 13:37:04 +0200 In-Reply-To: <20230717113709.328671-1-glider@google.com> Mime-Version: 1.0 References: <20230717113709.328671-1-glider@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230717113709.328671-2-glider@google.com> Subject: [PATCH v3 1/5] lib/bitmap: add bitmap_{set,get}_value() From: Alexander Potapenko To: glider@google.com, catalin.marinas@arm.com, will@kernel.org, pcc@google.com, andreyknvl@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, yury.norov@gmail.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, eugenis@google.com, syednwaris@gmail.com, william.gray@linaro.org, Arnd Bergmann Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The two new functions allow setting/getting values of length up to BITS_PER_LONG bits at arbitrary position in the bitmap. The code was taken from "bitops: Introduce the for_each_set_clump macro" by Syed Nayyar Waris with a couple of minor changes: - instead of using roundup(), which adds an unnecessary dependency on , we calculate space as BITS_PER_LONG-offset; - indentation is reduced by not using else-clauses (suggested by checkpatch for bitmap_get_value()) Cc: Arnd Bergmann Signed-off-by: Syed Nayyar Waris Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/lkml/fe12eedf3666f4af5138de0e70b67a07c7f40338= .1592224129.git.syednwaris@gmail.com/ Suggested-by: Yury Norov Signed-off-by: Alexander Potapenko --- include/linux/bitmap.h | 57 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 03644237e1efb..4559366084988 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -76,7 +76,11 @@ struct device; * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32= [] dst * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64= [] dst * bitmap_get_value8(map, start) Get 8bit value from map at= start + * bitmap_get_value(map, start, nbits) Get bit value of size 'nbi= ts' + * from map at start * bitmap_set_value8(map, value, start) Set 8bit value to map at s= tart + * bitmap_set_value(map, value, start, nbits) Set bit value of size 'nbi= ts' + * of map at start * * Note, bitmap_zero() and bitmap_fill() operate over the region of * unsigned longs, that is, bits behind bitmap till the unsigned long @@ -583,6 +587,31 @@ static inline unsigned long bitmap_get_value8(const un= signed long *map, return (map[index] >> offset) & 0xFF; } =20 +/** + * bitmap_get_value - get a value of n-bits from the memory region + * @map: address to the bitmap memory region + * @start: bit offset of the n-bit value + * @nbits: size of value in bits + * + * Returns value of nbits located at the @start bit offset within the @map + * memory region. + */ +static inline unsigned long bitmap_get_value(const unsigned long *map, + unsigned long start, + unsigned long nbits) +{ + const size_t index =3D BIT_WORD(start); + const unsigned long offset =3D start % BITS_PER_LONG; + const unsigned long space =3D BITS_PER_LONG - offset; + unsigned long value_low, value_high; + + if (space >=3D nbits) + return (map[index] >> offset) & GENMASK(nbits - 1, 0); + value_low =3D map[index] & BITMAP_FIRST_WORD_MASK(start); + value_high =3D map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits); + return (value_low >> offset) | (value_high << space); +} + /** * bitmap_set_value8 - set an 8-bit value within a memory region * @map: address to the bitmap memory region @@ -599,6 +628,34 @@ static inline void bitmap_set_value8(unsigned long *ma= p, unsigned long value, map[index] |=3D value << offset; } =20 +/** + * bitmap_set_value - set n-bit value within a memory region + * @map: address to the bitmap memory region + * @value: value of nbits + * @start: bit offset of the n-bit value + * @nbits: size of value in bits + */ +static inline void bitmap_set_value(unsigned long *map, + unsigned long value, + unsigned long start, unsigned long nbits) +{ + const size_t index =3D BIT_WORD(start); + const unsigned long offset =3D start % BITS_PER_LONG; + const unsigned long space =3D BITS_PER_LONG - offset; + + value &=3D GENMASK(nbits - 1, 0); + + if (space >=3D nbits) { + map[index] &=3D ~(GENMASK(nbits + offset - 1, offset)); + map[index] |=3D value << offset; + return; + } + map[index] &=3D ~BITMAP_FIRST_WORD_MASK(start); + map[index] |=3D value << offset; + map[index + 1] &=3D ~BITMAP_LAST_WORD_MASK(start + nbits); + map[index + 1] |=3D (value >> space); +} + #endif /* __ASSEMBLY__ */ =20 #endif /* __LINUX_BITMAP_H */ --=20 2.41.0.255.g8b1d071c50-goog