From patchwork Fri Feb 12 13:19:28 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: 1439836 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=o5ZQbFt3; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DcYz14Hsvz9s1l for ; Sat, 13 Feb 2021 00:20:45 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230484AbhBLNU1 (ORCPT ); Fri, 12 Feb 2021 08:20:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230482AbhBLNUZ (ORCPT ); Fri, 12 Feb 2021 08:20:25 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E96F7C061756; Fri, 12 Feb 2021 05:19:44 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id cl8so418684pjb.0; Fri, 12 Feb 2021 05:19:44 -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=4cqievP1oLWYJ4Ny++CVFsTeEL6uztXwZyN4nT6gCro=; b=o5ZQbFt3B3FNXTmRxyQrf5MaQvp1zVQr+8Ct25pANYhFgjoWEVXVvSB/sP3eFz8bRR +GRpVSWZZTTeAR8kL+vzT2VfOBPiEz3tEJWEZ2MbI7Z/xO7M1iEkJPw7z7SANxTNL1Lu p/l7Gxu5fEPPZ7VVmOIHNcWcuj0GCUyQGUn0BMUnX0LwFJNA5PdroaKS2NtNBEzInIVM TQImvrYekeJhPHUmYAOdxSiB6uuoqLZMyYQJacafSLCTQchn6BD5h5sQ681Uv1/kDu/k gtE2j8nGri1FW298EGy6ug3ATnrT2d0SwB1Lk2uZfAGcAZzxKWPj+yxYYNkQjg5bVfTQ Tsfg== 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=4cqievP1oLWYJ4Ny++CVFsTeEL6uztXwZyN4nT6gCro=; b=GbvQlrmPj2KXBbhvB0oefD+M3QJk/0gDri3AWsdlVKq2+pePK0wtaWUwpgGsxjChe3 8w5xm5yTMcs20WlmJD1p8XFPNbaOgzYVFktQwGzH07SH1SYis4yZ0jxRsLotcw04AkDg CUTM6F6CxcQwJ1jKI/J+s1fiM0uHYlYRc1L1Zv+fVcj2iJOBXvjfp2tfQ7km5zDv5/rF D2iKpJeyJERoJNhcVX9exi94xRyxnQeazpzWCerZ4tK1zVOi3UEBUxAEcPT90ZsJNGLg p6833ww8p6kfr9PUlr1NjOZkqkywYrJcGPMgemTD6VoKmzlGvRd+yMnsNQ65NjsJs5+4 qE6Q== X-Gm-Message-State: AOAM533aP4IMhWrkdtkMAOCatc6H1i/Uj5BfwpHzIrnK/USCIVctwLzK 5mrvm7yJNz0H1elepyI2At4= X-Google-Smtp-Source: ABdhPJw0W9r8mdFX58Wo4VzZMJed+tKGDHGxxiRlac9ze/7Q95PPuP7D90PvhGJ1KFgc0+sISreARg== X-Received: by 2002:a17:90a:c84:: with SMTP id v4mr2763919pja.228.1613135984448; Fri, 12 Feb 2021 05:19:44 -0800 (PST) Received: from syed.domain.name ([103.201.127.1]) by smtp.gmail.com with ESMTPSA id g6sm8729106pfi.15.2021.02.12.05.19.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Feb 2021 05:19:43 -0800 (PST) Date: Fri, 12 Feb 2021 18:49:28 +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 v2 0/3] Introduce the for_each_set_clump 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_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. 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_clump macro gpio: thunderx: Utilize for_each_set_clump 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