From patchwork Fri Apr 2 16:35:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Syed Nayyar Waris X-Patchwork-Id: 414679 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC545C43461 for ; Fri, 2 Apr 2021 16:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97BF261168 for ; Fri, 2 Apr 2021 16:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235094AbhDBQgA (ORCPT ); Fri, 2 Apr 2021 12:36:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbhDBQf5 (ORCPT ); Fri, 2 Apr 2021 12:35:57 -0400 Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D7DCC0613E6; Fri, 2 Apr 2021 09:35:53 -0700 (PDT) Received: by mail-pf1-x430.google.com with SMTP id x126so3888328pfc.13; Fri, 02 Apr 2021 09:35:53 -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=uM4dm7jLQqekDUMig2wBthP5qLW3ECK8m3uDHks54tU=; b=FNQ96PXqShSkb3HyAtOtQJGWzw39+nOcttjEqWqIrzW3psRSPGr4frfDPf7OHvyAbq ZH5f4K8PVB5UyvTz94RU2f8OqTPqF/rfAvBAIew/6CrjMw/od+skNCprbDLj/21CgAn6 iBqthZ+MJdR2FVHarjLeqYu2BWqF9oMrI6yEv/4NjkJbn+eICignQvrfGFoLMdsxgf1l zoY9ylsHMnmSvuQX2CKHinXasZp5gibHqrYJ4Ns+JZC/eoCEg19F+B6xvUv2f3aiZw2h 0s7TQJw0CU5o1tGbXk0OkItZz3IwPkbE2ezt2Kz6MIKOw/DaONOCkGRKAs6Jzqi0ovgp 5YdA== 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=uM4dm7jLQqekDUMig2wBthP5qLW3ECK8m3uDHks54tU=; b=EK8HVpSc6Y5/Zv2pejtMoyJom11AwxzNji2YLILQvWV/V3aHmMnIs9enQ2COY9lFh+ /3acd29a1iPs20R97aB6SVZVSAfAajj0EKbZTDElbL2tZDKeX7CWZ1NDf2MKphVY/w8g 4R2dRt3Zyez8NiLbk4jWwID/uLtCOKoBT9wk8YcoQcYxl5Z7sNYtNH57Q4xb/A1jAif6 flzhUDNxApy8Tx2cmk61J+TCKTE/uI4WOibLp+7oKqkH7w7DcxTqNeU32bPwWXbjlaYU /A5yglZqE/ksv8ucMw7AFG40tAQ3+yPFrFk2/kzjBHOwPNw6ez/blC2jtINVEJ1g6SMO YjlA== X-Gm-Message-State: AOAM533jZz5M4OHoNsnXqTAXm21tdCuxfkoVAGUtHEE41mMqLCDL9IJd v+6GZPIs6S165HglJOVZKyo= X-Google-Smtp-Source: ABdhPJxlVTIcbe9PyT710PIwA5TAufhstS7k7UVKk8YGWegZt4sCcXmdZNfe1M9w9ZQCStgYZC2oJA== X-Received: by 2002:aa7:900d:0:b029:230:2d6a:2940 with SMTP id m13-20020aa7900d0000b02902302d6a2940mr10766216pfo.23.1617381352521; Fri, 02 Apr 2021 09:35:52 -0700 (PDT) Received: from syed ([223.225.109.149]) by smtp.gmail.com with ESMTPSA id m9sm8461571pgt.65.2021.04.02.09.35.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Apr 2021 09:35:52 -0700 (PDT) Date: Fri, 2 Apr 2021 22:05:36 +0530 From: Syed Nayyar Waris To: bgolaszewski@baylibre.com 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, akpm@linux-foundation.org, 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: [RESEND PATCH v4 0/3] Introduce the for_each_set_nbits macro Message-ID: MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hello Bartosz, Since this patchset primarily affects GPIO drivers, would you like to pick it up through your GPIO tree? This patchset introduces a new generic version of for_each_set_nbits. 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_nbits 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_nbits:- '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_nbits: '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. Changes in v4: - [Patch 3/3]: Remove extra line and add few comments. - [Patch 3/3]: Use single lock (and unlock) call instead of two lock (and two unlock) calls. - [Patch 3/3]: Use bitmap_from_arr32() where applicalble. - [Patch 3/3]: Remove unnecessary 'const'. Changes in v3: - [Patch 1/3]: Rename for_each_set_clump to for_each_set_nbits. - [Patch 1/3]: Shift function definitions outside 'ifdef CONFIG_DEBUG_FS' macro guard to resolve build (linking) error in xilinx Patch[3/3]. - [Patch 2/3]: Rename for_each_set_clump to for_each_set_nbits. Changes in v2: - [Patch 1/3]: Shift the macros and related functions to gpiolib inside gpio/. Reduce the visibilty of 'for_each_set_clump' to gpio. - [Patch 1/3]: Remove __builtin_unreachable and simply use return statement. - Remove tests from lib/test_bitmap.c as 'for_each_set_clump' is now localised inside gpio/ only. Syed Nayyar Waris (3): gpiolib: Introduce the for_each_set_nbits macro gpio: thunderx: Utilize for_each_set_nbits macro gpio: xilinx: Utilize generic bitmap_get_value and _set_value drivers/gpio/gpio-thunderx.c | 13 ++++-- drivers/gpio/gpio-xilinx.c | 52 ++++++++++----------- drivers/gpio/gpiolib.c | 90 ++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib.h | 28 +++++++++++ 4 files changed, 152 insertions(+), 31 deletions(-) base-commit: e1b7033ecdac56c1cc4dff72d67cac25d449efc6