From patchwork Sat Mar 6 14:01:02 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: 12120017 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=ham 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 6E1A6C433E0 for ; Sat, 6 Mar 2021 14:02:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 380F16501D for ; Sat, 6 Mar 2021 14:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230514AbhCFOBy (ORCPT ); Sat, 6 Mar 2021 09:01:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230249AbhCFOBV (ORCPT ); Sat, 6 Mar 2021 09:01:21 -0500 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94A33C06174A; Sat, 6 Mar 2021 06:01:21 -0800 (PST) Received: by mail-pg1-x52f.google.com with SMTP id n10so3316527pgl.10; Sat, 06 Mar 2021 06:01:21 -0800 (PST) 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=chheps0e/vkn5whvXUYRVcoclWLVpyXMSnpK+Mnd1r0=; b=cfp63Hxx46c6zic3FfyNgIQly3oNLnJ96rxa+H0pnMq0HhNcYM18qlNnTswLjczPnm 6+RR6ci2RHA1ETpa33jKIPAsCh5xhbafWtzZDZV2h5j6oD5Zh8qXzhn7gBp/TMC2BzSy wfqLenyz1VL6WMF6VeD/8G7tHUCdlFmv9GsBdzmQ/3X9m5R6ZAhIbvaWEGzfhsDbZBRQ xymI7D9b/OXORqP3UfHCDwdiBc2hTIYuSLupVjgcZWnZDcpf9HuNDghwmZKYu2Egmi6J aYlCGttVAawoS28KYkdSHa9z94jiwrsTKqIoJlaqWJ1iD7A7jHnx8qiGhex4uF8r5RTl xEGA== 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=chheps0e/vkn5whvXUYRVcoclWLVpyXMSnpK+Mnd1r0=; b=D92/nVwLm+/yU8ZiwVz4U6QJnwO9lw6oRTuU1niK+BgXDf5A1YxYOWR4DgVaLkP8Qx b5n+w+Q3rDuCZY+/XjI0muVynewzxGq3ZI1Hm+XOHUPedR2TgUs+k9DE2q5oA7oRIizr Ri0rRxM3yZ9AEj3Sq/dbGTPoapB9tpHU/kFw90b10UqeeqVIqXyhGLpX0M7X8u+EKcn0 hZmvtcZyG7qOeEDy8El2CLxBp5Efp5EEmGEqnl81X2ovfrMPPqup33PXn7MYBzMNMRQb yJTUZPBb5+h6HjEertd2J1R35lTR4bkRoCZ6djvod4/bF9yvr5hpR7Z5NQr6i97OXNYL myXA== X-Gm-Message-State: AOAM533v9a2o7CMjHBGQ6YnXBZeadGrUDkV5Nhe/EXUTYUapoD5HpOMF td1CaIMqCyNLHS2EjGH8Jeo2AD1WV4MvZQ== X-Google-Smtp-Source: ABdhPJxdgYi758gUMmpnWluXLNY1UAjjimJmTvzZihGzR1v6wMywJxu6+6BuBMHexeHInOaL6B/EWg== X-Received: by 2002:a05:6a00:884:b029:1b4:440f:bce7 with SMTP id q4-20020a056a000884b02901b4440fbce7mr14127569pfj.20.1615039281113; Sat, 06 Mar 2021 06:01:21 -0800 (PST) Received: from syed.domain.name ([103.201.127.38]) by smtp.gmail.com with ESMTPSA id x11sm5343990pja.46.2021.03.06.06.01.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 06 Mar 2021 06:01:20 -0800 (PST) Date: Sat, 6 Mar 2021 19:31:02 +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: [PATCH v3 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-pm@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 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 | 63 ++++++++++++------------- drivers/gpio/gpiolib.c | 90 ++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib.h | 28 +++++++++++ 4 files changed, 158 insertions(+), 36 deletions(-) base-commit: e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62