From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 B791AC0015E for ; Thu, 20 Jul 2023 17:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID: References:Mime-Version:In-Reply-To:Date:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=SkDMUssuPE/gvXsjKo2dcQKCiHgQ0XhB9er5JWr//Yk=; b=b0FF+1vPcJ2jjCv7NZC+eBB2UX NOSeHHPYQIuRCtfNWwvt/7Et9lJ7up4X50X/JSyu7X3aQ7ueDx5wR1TupErcEkLeWt7C4s5NM1323 m5gIHAN9uL1PFR/yZGCDwYWvb5Ec8yBpl1WK/EMF5LtB5zfXLIFEmq1ZMea1OrSc1MzMYHWwFXD5F zrgtIgR5pe1NDSaVrnLVfRCDjU2960DvGWoVZfOyV1T1owmFoDHw9z7Hmmi3JdToZd9TOtKbrL818 TFjOHqvCEwHq8ddqN6uzgQr9mJDYGkF91d2KC6Q2hYlkbM+ak7e3YYfy97mmbyaG8EXF2rQRVVsru zx9p8Q0Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qMXdO-00BoPQ-2U; Thu, 20 Jul 2023 17:40:14 +0000 Received: from mail-ed1-x549.google.com ([2a00:1450:4864:20::549]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qMXdH-00BoLn-2d for linux-arm-kernel@lists.infradead.org; Thu, 20 Jul 2023 17:40:09 +0000 Received: by mail-ed1-x549.google.com with SMTP id 4fb4d7f45d1cf-51e2497eeefso748170a12.3 for ; Thu, 20 Jul 2023 10:40:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689874803; x=1690479603; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=sBTD77nZvv18xeO6UXUxdZ0TBIDcYAZAkWaNswyfelY=; b=1yT9HCrQQBAuoPLZ7UGNCLsWKvdxdYuhPi2NOHvNyCTSGgIEes/2FWg7ihwLHAhBfR 1PeLv9ipNyiodNyHDDK6BSNY8lzNRKw8Oix+MqAbxNmnzi9yiavk+N7YHSIgr0bFHzPs 8jV8LZHfabUsgSYAepexYCKMLMQ+dZQBsP2w2FU868WrtZgu64b0q/VPbS+dyJeruvFn BleAB1+spyaED66wcjfeaBbfoPl03mU6B1mt1b7bDlMZWQrCquq9K2CxeCXPiKIQWf4k IKxjpvdbWrbdBgYYm3DhUM1180bxFCEzrpPPJVvTv1C44fNSmbNxAKCG5CH6A9gChutu jrtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689874803; x=1690479603; 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=sBTD77nZvv18xeO6UXUxdZ0TBIDcYAZAkWaNswyfelY=; b=ODqjRRxdgcz7y1EUut2lcIjbwGLEg5UizOkm5is41IQN0Rf/p59iZjDFICBEPgap9V r8UBfAfwtWcy/3cIn64M6HwuBO/jmK5NlCgCp/cIYAJt78QVrXPLgonfKb2a4n3ngRB8 FYOjhkdKsX9VA+p+J8oWEPh+NfAIREBJocBkNMy/Hiu93YyBU1blEMzeZk/pO/9NVXnh RXraCo05H2qLQWxyc/8Wvw3nB8wCM50xJMN4IaOwxphQr5hnlGK4ugs1SPFc6BN0/cYN eF3gSuT/iBpPgFzxyFBzjT/6R3D5PCCA2+DCC3McSnK7sr65zjyNabFnGehN9rgbeUdq JAiA== X-Gm-Message-State: ABy/qLbgfiqlCkT5U5hdW4KYFuSTjVJh7bkdCPNf+cQmlbmEJP1xMXMR R+wIxL9ldtDmGxuRj0QrNfMtmDNExII= X-Google-Smtp-Source: APBJJlFEpqXtUIUruBd5vPcsMxTpgg2Ahl+rkUC7d3QtocVPUnbq6OicKT0NEEeMZUKIzs8vBCw+aHOpe9o= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:c495:c29a:e275:1dfb]) (user=glider job=sendgmr) by 2002:a50:cc9c:0:b0:51d:e3e6:cc6b with SMTP id q28-20020a50cc9c000000b0051de3e6cc6bmr25395edi.6.1689874803086; Thu, 20 Jul 2023 10:40:03 -0700 (PDT) Date: Thu, 20 Jul 2023 19:39:52 +0200 In-Reply-To: <20230720173956.3674987-1-glider@google.com> Mime-Version: 1.0 References: <20230720173956.3674987-1-glider@google.com> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog Message-ID: <20230720173956.3674987-2-glider@google.com> Subject: [PATCH v4 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230720_104007_877468_D81A5706 X-CRM114-Status: GOOD ( 17.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Syed Nayyar Waris 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 Co-developed-by: Alexander Potapenko Signed-off-by: Alexander Potapenko --- v4: - Address comments by Andy Shevchenko and Yury Norov: - prevent passing values >= 64 to GENMASK() - fix commit authorship - change comments - check for unlikely(nbits==0) - drop unnecessary const declarations - fix kernel-doc comments - rename bitmap_{get,set}_value() to bitmap_{read,write}() --- include/linux/bitmap.h | 60 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 03644237e1efb..bc21c09a2e038 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_read(map, start, nbits) Read an nbits-sized value from + * map at start * bitmap_set_value8(map, value, start) Set 8bit value to map at start + * bitmap_write(map, value, start, nbits) Write an nbits-sized value to + * 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 +587,33 @@ static inline unsigned long bitmap_get_value8(const unsigned long *map, return (map[index] >> offset) & 0xFF; } +/** + * bitmap_read - read 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, up to BITS_PER_LONG + * + * Returns: value of nbits located at the @start bit offset within the @map + * memory region. + */ +static inline unsigned long bitmap_read(const unsigned long *map, + unsigned long start, + unsigned long nbits) +{ + size_t index = BIT_WORD(start); + unsigned long offset = start % BITS_PER_LONG; + unsigned long space = BITS_PER_LONG - offset; + unsigned long value_low, value_high; + + if (unlikely(!nbits)) + return 0; + if (space >= nbits) + return (map[index] >> offset) & GENMASK(nbits - 1, 0); + value_low = map[index] & BITMAP_FIRST_WORD_MASK(start); + value_high = 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 +630,35 @@ static inline void bitmap_set_value8(unsigned long *map, unsigned long value, map[index] |= value << offset; } +/** + * bitmap_write - write 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, up to BITS_PER_LONG + */ +static inline void bitmap_write(unsigned long *map, + unsigned long value, + unsigned long start, unsigned long nbits) +{ + size_t index = BIT_WORD(start); + unsigned long offset = start % BITS_PER_LONG; + unsigned long space = BITS_PER_LONG - offset; + + if (unlikely(!nbits)) + return; + value &= GENMASK(nbits - 1, 0); + if (space >= nbits) { + map[index] &= ~(GENMASK(nbits - 1, 0) << offset); + map[index] |= value << offset; + return; + } + map[index] &= ~BITMAP_FIRST_WORD_MASK(start); + map[index] |= value << offset; + map[index + 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits); + map[index + 1] |= (value >> space); +} + #endif /* __ASSEMBLY__ */ #endif /* __LINUX_BITMAP_H */ -- 2.41.0.487.g6d72f3e995-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel