From patchwork Thu May 14 23:16:03 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: 206905 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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 EA6A4C433E0 for ; Thu, 14 May 2020 23:16:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B22FB204EF for ; Thu, 14 May 2020 23:16:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DcMY/BwG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726174AbgENXQ0 (ORCPT ); Thu, 14 May 2020 19:16:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726088AbgENXQZ (ORCPT ); Thu, 14 May 2020 19:16:25 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B23F1C061A0C; Thu, 14 May 2020 16:16:25 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id x2so57366pfx.7; Thu, 14 May 2020 16:16:25 -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=/+eJp01tcGIi1FS6nFoffCHP/3vMG+E9qZfC/akFkdg=; b=DcMY/BwGW9Ui9hS5lf+6zAGj+OmK2cB2fnuNjh62obBQ8tM0MRuSOYJ+fncTgpIzjl Fr+G43Ze3vE389xISo74EvA5+F+pwxdq08UOHL93AoQVJdRseYr71wLDSffjOCejHxOw sDUEWQJaYfVGt1pPvT5UhdNq5b5EWWJT/dYV39X3soljP5oukSwuraLSZhNMgD8gT36O 0WY12k7mzMgqL4i7LU2CROOvdP9Z4u4fVAPH0G8g5zT2l+dEtVq0T1+UQQwHYSHwXwmY PddE82IB1dy4WSCzikNexASjizHGyyXjKkSKQBK6Yi7BCXESMSIB5m833S0uF/PqqNEl vzog== 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=/+eJp01tcGIi1FS6nFoffCHP/3vMG+E9qZfC/akFkdg=; b=fN2mwNfRXOLbBbXHyJKasdooL0v4wzNDdfoLida50w3Oi72d8+Ahgt9znwcaVKmvJ+ TtKqFtLoSsgNzSomzEkVBatSNrVrKQi4u3gnKLHzwIh9tTk1GVe4b0/mlCPJx1WiI2s6 ND3EejEyu0Y1quDRMpyUe66RwtAmb4IgDGwPvlUlP05PKD5HlKfzkCjHyogWNGWNcV/S I9Mm6BMg3VYD7SZM5lcI9SurNWYWz4EoBR6vVqYPg+WrQs6kjfYHz2GEfDrFX8X1Qjq4 +ghZsMukrAB1kytCSxn1de6hjW1E88M9MmHZZWjSYcgWbUBkuNagjpQo1odedv9E+Gx1 Zs9Q== X-Gm-Message-State: AOAM533tKT2BFNTGbRF/v83nM64+SoEQFY3O+9J/KOlZ+BAq6x4SOcbH 2pTcXBCUzckHn+6d6ULPCV0= X-Google-Smtp-Source: ABdhPJwRRq+bL5xaxHN1P6mCwtKSPR/WiDUgW/JFP+3vWldtyl1raVdBJTKBlG9MkAPg1TEaxdcXGg== X-Received: by 2002:a63:5026:: with SMTP id e38mr430641pgb.149.1589498185092; Thu, 14 May 2020 16:16:25 -0700 (PDT) Received: from syed ([106.223.1.212]) by smtp.gmail.com with ESMTPSA id t14sm231437pgr.61.2020.05.14.16.16.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 May 2020 16:16:24 -0700 (PDT) Date: Fri, 15 May 2020 04:46:03 +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 v6 0/4] 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) Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@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. Changes in v6: - [Patch 2/4]: Make 'for loop' inside test_for_each_set_clump more succinct. Changes in v5: - [Patch 4/4]: Minor change: Hardcode value for better code readability. Changes in v4: - [Patch 2/4]: Use 'for' loop in test function of for_each_set_clump. - [Patch 3/4]: Minor change: Inline value for better code readability. - [Patch 4/4]: Minor change: Inline value for better code readability. Changes in v3: - [Patch 3/4]: Change datatype of some variables from u64 to unsigned long in function thunderx_gpio_set_multiple. CHanges in v2: - [Patch 2/4]: Unify different tests for 'for_each_set_clump'. Pass test data as function parameters. - [Patch 2/4]: Remove unnecessary bitmap_zero calls. Syed Nayyar Waris (4): bitops: Introduce the the for_each_set_clump macro lib/test_bitmap.c: Add for_each_set_clump test cases gpio: thunderx: Utilize for_each_set_clump macro gpio: xilinx: Utilize for_each_set_clump macro drivers/gpio/gpio-thunderx.c | 11 ++- drivers/gpio/gpio-xilinx.c | 62 ++++++------- include/asm-generic/bitops/find.h | 19 ++++ include/linux/bitmap.h | 61 +++++++++++++ include/linux/bitops.h | 13 +++ lib/find_bit.c | 14 +++ lib/test_bitmap.c | 142 ++++++++++++++++++++++++++++++ 7 files changed, 288 insertions(+), 34 deletions(-) base-commit: 5f458e572071a54841b93f41e25fbe8ded82df79