From patchwork Fri Apr 24 12:24:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Syed Nayyar Waris X-Patchwork-Id: 11507725 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 606D013B2 for ; Fri, 24 Apr 2020 12:24:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4740A21775 for ; Fri, 24 Apr 2020 12:24:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MEAAr4dy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727105AbgDXMYU (ORCPT ); Fri, 24 Apr 2020 08:24:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728361AbgDXMYT (ORCPT ); Fri, 24 Apr 2020 08:24:19 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B869C09B045; Fri, 24 Apr 2020 05:24:19 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id 18so3502396pfv.8; Fri, 24 Apr 2020 05:24:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=EZWTGR2wDApXn1qZCOfO8QQ0qwLL2b6F+ahGlWVDubE=; b=MEAAr4dysjyXTujdAdFnc96D2y8DQPhLqk17tYm4NicOHg94yLN+enU9TZcefycxMF xfu00/TW/q9DwhPW9mM7rxfO+YnvVnoMQ7HeauwHNXNV/IkclWHKTOYTOPNP/tI/1X7U pse4CKlZA7Evyu/NdxJajLTMTcJd0PpCTx9TpqC15jGa0THgjX0TAuVCPB78Dc3e9zX1 PVPTGAYshT5/u7XcppcHY397NnqPNtVGn0VKENS9ZDRZzdfG5VT5idkD7muoAaTEFp4G b2MarLjwHM6XT7ZWwOhVX8ekN6g6HfnmJKu61VgAeH2s+qVXTs23ZVQhKgWRWIeoIZ9V 1TQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=EZWTGR2wDApXn1qZCOfO8QQ0qwLL2b6F+ahGlWVDubE=; b=iHC8hxwZ+WCErLwN6TbFklgIXqzaIxmjVCMsJDwXDLAajTdCYui5zP3D1itgfnAHLt 4xDkr7DKA1pOtVsrUk2yT+gCFzzYr0VCQRUn7tdO65iqxvAbDLAyIRplxhCdXVhKj+T6 WaHSd4lik820eqBsDFDrf73CD/SkjhonyyL7yshX/GxvUTSTgAy7ODT0DUsJgFnpdedG SetPYdFiW5ae+D0Hu0cslPaHH8xivUjL48fkuRLSSRWxY8QourApR7m3Mjuhox1+bx8R kpzbsCGQhP7ZL0tMN0rgweZo2ysyPaphwRL1v7vAzVpoULVWGJvA96DZ5mXmsQ1kn9SP XkXQ== X-Gm-Message-State: AGi0PuaHSNr+F/WFbp4Nt6cyrVM9D/2A1G2wYjWccx+qhCFOhzh3sk0v m1S7oBg1T8NzCpS98S/Nen8= X-Google-Smtp-Source: APiQypJ/bDxFy3P4vG/L+xY5hQN6UgcBmpz0Oy4ArCtE5VFPb+XAJMmVLhzSVnO2QcZz5nZQ6W4blg== X-Received: by 2002:a62:b611:: with SMTP id j17mr9266856pff.214.1587731058449; Fri, 24 Apr 2020 05:24:18 -0700 (PDT) Received: from syed ([106.223.101.26]) by smtp.gmail.com with ESMTPSA id g9sm4845622pgj.89.2020.04.24.05.24.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Apr 2020 05:24:17 -0700 (PDT) Date: Fri, 24 Apr 2020 17:54:07 +0530 From: Syed Nayyar Waris To: akpm@linux-foundation.org Cc: andriy.shevchenko@linux.intel.com, vilhelm.gray@gmail.com, michal.simek@xilinx.com, arnd@arndb.de, rrichter@marvell.com, linus.walleij@linaro.org, bgolaszewski@baylibre.com, yamada.masahiro@socionext.com, rui.zhang@intel.com, daniel.lezcano@linaro.org, amit.kucheria@verdurent.com, linux-arch@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH 0/6] Introduce the for_each_set_clump macro Message-ID: <20200424122407.GA5523@syed> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This patchset introduces a new generic version of for_each_set_clump. The previous version of for_each_set_clump8 used a fixed size 8-bit clump, but the new generic version can work with clump of any size but less than or equal to BITS_PER_LONG. The patchset utilizes the new macro in several GPIO drivers. The earlier 8-bit for_each_set_clump8 facilitated a for-loop syntax that iterates over a memory region entire groups of set bits at a time. For example, suppose you would like to iterate over a 32-bit integer 8 bits at a time, skipping over 8-bit groups with no set bit, where XXXXXXXX represents the current 8-bit group: Example: 10111110 00000000 11111111 00110011 First loop: 10111110 00000000 11111111 XXXXXXXX Second loop: 10111110 00000000 XXXXXXXX 00110011 Third loop: XXXXXXXX 00000000 11111111 00110011 Each iteration of the loop returns the next 8-bit group that has at least one set bit. But with the new for_each_set_clump the clump size can be different from 8 bits. Moreover, the clump can be split at word boundary in situations where word size is not multiple of clump size. Following are examples showing the working of new macro for clump sizes of 24 bits and 6 bits. Example 1: clump size: 24 bits, Number of clumps (or ports): 10 bitmap stores the bit information from where successive clumps are retrieved. /* bitmap memory region */ 0x00aa0000ff000000; /* Most significant bits */ 0xaaaaaa0000ff0000; 0x000000aa000000aa; 0xbbbbabcdeffedcba; /* Least significant bits */ Different iterations of for_each_set_clump:- 'offset' is the bit position and 'clump' is the 24 bit clump from the above bitmap. Iteration first: offset: 0 clump: 0xfedcba Iteration second: offset: 24 clump: 0xabcdef Iteration third: offset: 48 clump: 0xaabbbb Iteration fourth: offset: 96 clump: 0xaa Iteration fifth: offset: 144 clump: 0xff Iteration sixth: offset: 168 clump: 0xaaaaaa Iteration seventh: offset: 216 clump: 0xff Loop breaks because in the end the remaining bits (0x00aa) size was less than clump size of 24 bits. In above example it can be seen that in iteration third, the 24 bit clump that was retrieved was split between bitmap[0] and bitmap[1]. This example also shows that 24 bit zeroes if present in between, were skipped (preserving the previous for_each_set_macro8 behaviour). Example 2: clump size = 6 bits, Number of clumps (or ports) = 3. /* bitmap memory region */ 0x00aa0000ff000000; /* Most significant bits */ 0xaaaaaa0000ff0000; 0x0f00000000000000; 0x0000000000000ac0; /* Least significant bits */ Different iterations of for_each_set_clump: 'offset' is the bit position and 'clump' is the 6 bit clump from the above bitmap. Iteration first: offset: 6 clump: 0x2b Loop breaks because 6 * 3 = 18 bits traversed in bitmap. Here 6 * 3 is clump size * no. of clumps. Syed Nayyar Waris (6): bitops: Introduce the the for_each_set_clump macro lib/test_bitmap.c: Add for_each_set_clump test cases gpio: thermal: Utilize for_each_set_clump macro bitops: Remove code related to for_each_set_clump8 gpio: thunderx: Utilize for_each_set_clump macro gpio: xilinx: Utilize for_each_set_clump macro drivers/gpio/gpio-104-dio-48e.c | 8 +- drivers/gpio/gpio-104-idi-48.c | 4 +- drivers/gpio/gpio-74x164.c | 4 +- drivers/gpio/gpio-gpio-mm.c | 8 +- drivers/gpio/gpio-max3191x.c | 4 +- drivers/gpio/gpio-pca953x.c | 4 +- drivers/gpio/gpio-pci-idio-16.c | 8 +- drivers/gpio/gpio-pcie-idio-24.c | 8 +- drivers/gpio/gpio-pisosr.c | 4 +- drivers/gpio/gpio-thunderx.c | 12 ++- drivers/gpio/gpio-uniphier.c | 4 +- drivers/gpio/gpio-ws16c48.c | 8 +- drivers/gpio/gpio-xilinx.c | 64 +++++++------- drivers/thermal/intel/intel_soc_dts_iosf.c | 6 +- include/asm-generic/bitops/find.h | 12 +-- include/linux/bitmap.h | 60 +++++++++---- include/linux/bitops.h | 9 +- lib/find_bit.c | 12 +-- lib/test_bitmap.c | 136 ++++++++++++++++++++++++----- 19 files changed, 253 insertions(+), 122 deletions(-)