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[23.128.96.18]) by mx.google.com with ESMTP id m8si1637951eji.741.2020.10.06.02.22.04; Tue, 06 Oct 2020 02:22:28 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=KNOO1op0; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726000AbgJFJU6 (ORCPT + 99 others); Tue, 6 Oct 2020 05:20:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbgJFJU5 (ORCPT ); Tue, 6 Oct 2020 05:20:57 -0400 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB41EC061755; Tue, 6 Oct 2020 02:20:57 -0700 (PDT) Received: by mail-pj1-x1042.google.com with SMTP id ds1so1256344pjb.5; Tue, 06 Oct 2020 02:20:57 -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=d3jdb/5lz1KiMUpxKMIKdfOKuYYaMLuxcEbpzM+Zj2E=; b=KNOO1op0I6GTujszc0nTBZFzEzbdmck/hDFL68Pmp8Qkil+KhY+6O5QmcDcoBO6IQd 4MAjgfuWwpdN1Y4/9CyBU7Nw0YcSRl3vPiSkeUKQwGbV7mEqOrL6pcqX2guKRTboyvWk doun9WRQcOAn9u3hHMsaqXAWW5399deLJQX8PBe9G/JIjVlqH3NMaaJEqmEmeA6ZUSBC WpVMTtZfH6Vq8DvbA4AELIG7k9D7ZoQiIFlXoEFCJ+9fSnnuZC13mqfIeYLnTZHcuiA+ I2FgylEe+PJABVf+9XSrn4tEOR/LO3Y+gXKEHLkSd3zmUlSV1ZTb4JL9pE5SbyPu0Dzy TNYA== 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=d3jdb/5lz1KiMUpxKMIKdfOKuYYaMLuxcEbpzM+Zj2E=; b=qpwk6k2ru1YozhfLbT+R40inbEUR8vzEl/27z03iIfTibYRwI6PhK9ksX7yp0IuvKG 5WWgKLcad5Kvt8ZsBCC1dzy8xTWIVelwszuDtgDOq2kIMzA/LOz4GRBQ3e/6XiINvLKT C5dM0eWlRpJGcNgeuz4vivKsWlj6OeuGEr2nsCGCBgUPJ9lNsKbw8X6PPRR6J8Sxku5I r21um4qH5QtrxhnTefo2IqGq6hdHxtnDLuy9tJguMtXQaQ70V/LN7jfZJUQRE8SlE6qc GikU8SBEu1T0t7YdKFgYGbrh6fQicwFoC0I0WT5a75pprCiCEaOdgdL+a0jRAK/+6Axh TbJQ== X-Gm-Message-State: AOAM532d+vWMSPT6sabBooHNk+RycfZ1n4Bmap6tcrNsqpxdG7VLfN2O MDToyteNIQcjlHIKi4PRKww= X-Received: by 2002:a17:902:b113:b029:d2:abce:b689 with SMTP id q19-20020a170902b113b02900d2abceb689mr2324927plr.51.1601976057364; Tue, 06 Oct 2020 02:20:57 -0700 (PDT) Received: from syed ([117.97.226.113]) by smtp.gmail.com with ESMTPSA id s20sm2743067pfu.112.2020.10.06.02.20.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Oct 2020 02:20:56 -0700 (PDT) Date: Tue, 6 Oct 2020 14:50:38 +0530 From: Syed Nayyar Waris To: linus.walleij@linaro.org, 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 v11 0/4] Introduce the for_each_set_clump macro Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Linus, 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 v11: - [Patch 1/4]: Document range of values 'nbits' can take. - [Patch 4/4]: Change variable name 'flag' to 'flags'. Changes in v10: - Patchset based on v5.9-rc1. Changes in v9: - [Patch 4/4]: Remove looping of 'for_each_set_clump' and instead process two halves of a 64-bit bitmap separately or individually. Use normal spin_lock call for second inner lock. And take the spin_lock_init call outside the 'if' condition in the probe function of driver. Changes in v8: - [Patch 2/4]: Minor change: Use '__initdata' for correct section mismatch in 'clump_test_data' array. Changes in v7: - [Patch 2/4]: Minor changes: Use macro 'DECLARE_BITMAP()' and split 'struct' definition and test data. 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 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 generic bitmap_get_value and _set_value drivers/gpio/gpio-thunderx.c | 11 ++- drivers/gpio/gpio-xilinx.c | 64 ++++++------- include/asm-generic/bitops/find.h | 19 ++++ include/linux/bitmap.h | 63 +++++++++++++ include/linux/bitops.h | 13 +++ lib/find_bit.c | 14 +++ lib/test_bitmap.c | 144 ++++++++++++++++++++++++++++++ 7 files changed, 292 insertions(+), 36 deletions(-) base-commit: 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5 -- 2.26.2