From patchwork Tue Oct 18 14:00:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 13010586 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 196AEC4332F for ; Tue, 18 Oct 2022 14:02:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229909AbiJROCi (ORCPT ); Tue, 18 Oct 2022 10:02:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230359AbiJROCg (ORCPT ); Tue, 18 Oct 2022 10:02:36 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64886CF874; Tue, 18 Oct 2022 07:02:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666101755; x=1697637755; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=k+eTdXtPkqMwaDNTEUKdoz77rxk+Xe2f7Xhhd5O90Uw=; b=RYfsiW3w1rA+mF7KLK98laPAmBWCFQJL3Kc/Dzgc/aoZh62PTo3uVxdy eoDT/EQ33Mt+dSNKvDyV/GwhOZioh7U11PJaJpdWPNYHBZkhgaiZjLEB1 b2mdLCoELEJbYiJdwKQjXP60QlZADuQ4AdyUSPpCyo6eIr8YwgtYqTmSg f/WlbGz5jUZH9/pbE7aYQUqmv7KvEIBMvwkjEi4mcanV8O4G3Ri3cYgiK H/Q6S+M8d9jfofo0qJKQW8N2w3Lv9MtAZm517010WQn9YUGDSZiQpbyB3 oALt3cWrDTGffjo+JEtOkFOMFy5QV7kxbAsO7fEBa/AjjK6hcxPwYxAwy Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10504"; a="286502856" X-IronPort-AV: E=Sophos;i="5.95,193,1661842800"; d="scan'208";a="286502856" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2022 07:02:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10504"; a="697510392" X-IronPort-AV: E=Sophos;i="5.95,193,1661842800"; d="scan'208";a="697510392" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by fmsmga004.fm.intel.com with ESMTP; 18 Oct 2022 07:02:32 -0700 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 29IE2TUM011675; Tue, 18 Oct 2022 15:02:31 +0100 From: Alexander Lobakin To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Yury Norov , Andy Shevchenko , Rasmus Villemoes , Michal Swiatkowski , Maciej Fijalkowski , Alexander Lobakin , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 net-next 2/6] bitmap: add a couple more helpers to work with arrays of u32s Date: Tue, 18 Oct 2022 16:00:23 +0200 Message-Id: <20221018140027.48086-3-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221018140027.48086-1-alexandr.lobakin@intel.com> References: <20221018140027.48086-1-alexandr.lobakin@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Add two new functions to work on arr32s: * bitmap_arr32_size() - takes number of bits to be stored in arr32 and returns number of bytes required to store such arr32, can be useful when allocating memory for arr32 containers; * bitmap_validate_arr32() - takes pointer to an arr32 and its size in bytes, plus expected number of bits. Ensures that the size is valid (must be a multiply of `sizeof(u32)`) and no bits past the number is set. Also add BITMAP_TO_U64() macro to help return a u64 from a DECLARE_BITMAP(1-64) (it may pick one or two longs depending on the platform). Signed-off-by: Alexander Lobakin --- include/linux/bitmap.h | 20 +++++++++++++++++++- lib/bitmap.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+), 1 deletion(-) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 79d12e0f748b..c737b0fe2f41 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -7,7 +7,7 @@ #include #include #include -#include +#include #include #include @@ -75,6 +75,8 @@ struct device; * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst + * bitmap_validate_arr32(buf, len, nbits) Validate u32[] buf of len bytes + * bitmap_arr32_size(nbits) Get size of u32[] arr for nbits * bitmap_get_value8(map, start) Get 8bit value from map at start * bitmap_set_value8(map, value, start) Set 8bit value to map at start * @@ -324,6 +326,20 @@ static inline void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, __bitmap_to_arr32(buf, bitmap, nbits); } +bool bitmap_validate_arr32(const u32 *arr, size_t len, size_t nbits); + +/** + * bitmap_arr32_size - determine the size of array of u32s for a number of bits + * @nbits: number of bits to store in the array + * + * Returns the size in bytes of a u32s-array needed to carry the specified + * number of bits. + */ +static inline size_t bitmap_arr32_size(size_t nbits) +{ + return array_size(BITS_TO_U32(nbits), sizeof(u32)); +} + /* * On 64-bit systems bitmaps are represented as u64 arrays internally. On LE32 * machines the order of hi and lo parts of numbers match the bitmap structure. @@ -571,9 +587,11 @@ static inline void bitmap_next_set_region(unsigned long *bitmap, */ #if __BITS_PER_LONG == 64 #define BITMAP_FROM_U64(n) (n) +#define BITMAP_TO_U64(map) ((u64)(map)[0]) #else #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ ((unsigned long) ((u64)(n) >> 32)) +#define BITMAP_TO_U64(map) (((u64)(map)[1] << 32) | (u64)(map)[0]) #endif /** diff --git a/lib/bitmap.c b/lib/bitmap.c index e3eb12ff1637..e0045ecf34d6 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -1495,6 +1495,46 @@ void __bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits EXPORT_SYMBOL(__bitmap_to_arr32); #endif +/** + * bitmap_validate_arr32 - perform validation of a u32-array bitmap + * @arr: array of u32s, the dest bitmap + * @len: length of the array, in bytes + * @nbits: expected/supported number of bits in the bitmap + * + * Returns true if the array passes the checks (see below), false otherwise. + */ +bool bitmap_validate_arr32(const u32 *arr, size_t len, size_t nbits) +{ + size_t word = (nbits - 1) / BITS_PER_TYPE(u32); + u32 pos = (nbits - 1) % BITS_PER_TYPE(u32); + + /* Must consist of 1...n full u32s */ + if (!len || len % sizeof(u32)) + return false; + + /* + * If the array is shorter than expected, assume we support + * all of the bits set there. + */ + if (word >= len / sizeof(u32)) + return true; + + /* Last word must not contain any bits past the expected number */ + if (arr[word] & (u32)~GENMASK(pos, 0)) + return false; + + /* + * If the array is longer than expected, make sure all the bytes + * past the expected length are zeroed. + */ + len -= bitmap_arr32_size(nbits); + if (memchr_inv(&arr[word + 1], 0, len)) + return false; + + return true; +} +EXPORT_SYMBOL(bitmap_validate_arr32); + #if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN) /** * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap