Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752078AbdHaPpB (ORCPT ); Thu, 31 Aug 2017 11:45:01 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36564 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752024AbdHaPo6 (ORCPT ); Thu, 31 Aug 2017 11:44:58 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Nazarewicz , Kyungmin Park , Marek Szyprowski , Gregory Fong , Joonsoo Kim , Kukjin Kim , Laurent Pinchart , Laura Abbott , Andrew Morton , Linus Torvalds Subject: [PATCH 3.18 08/24] lib: bitmap: add alignment offset for bitmap_find_next_zero_area() Date: Thu, 31 Aug 2017 17:43:44 +0200 Message-Id: <20170831154105.591810909@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170831154105.116844281@linuxfoundation.org> References: <20170831154105.116844281@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5253 Lines: 138 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Nazarewicz commit 5e19b013f55a884c59a14391b22138899d1cc4cc upstream. Add a bitmap_find_next_zero_area_off() function which works like bitmap_find_next_zero_area() function except it allows an offset to be specified when alignment is checked. This lets caller request a bit such that its number plus the offset is aligned according to the mask. [gregory.0xf0@gmail.com: Retrieved from https://patchwork.linuxtv.org/patch/6254/ and updated documentation] Signed-off-by: Michal Nazarewicz Signed-off-by: Kyungmin Park Signed-off-by: Marek Szyprowski Signed-off-by: Gregory Fong Cc: Joonsoo Kim Cc: Kukjin Kim Cc: Laurent Pinchart Cc: Laura Abbott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/bitmap.h | 36 +++++++++++++++++++++++++++++++----- lib/bitmap.c | 24 +++++++++++++----------- 2 files changed, 44 insertions(+), 16 deletions(-) --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -45,6 +45,7 @@ * bitmap_set(dst, pos, nbits) Set specified bit area * bitmap_clear(dst, pos, nbits) Clear specified bit area * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area + * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) @@ -114,11 +115,36 @@ extern int __bitmap_weight(const unsigne extern void bitmap_set(unsigned long *map, unsigned int start, int len); extern void bitmap_clear(unsigned long *map, unsigned int start, int len); -extern unsigned long bitmap_find_next_zero_area(unsigned long *map, - unsigned long size, - unsigned long start, - unsigned int nr, - unsigned long align_mask); + +extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask, + unsigned long align_offset); + +/** + * bitmap_find_next_zero_area - find a contiguous aligned zero area + * @map: The address to base the search on + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at + * @nr: The number of zeroed bits we're looking for + * @align_mask: Alignment mask for zero area + * + * The @align_mask should be one less than a power of 2; the effect is that + * the bit offset of all zero areas this function finds is multiples of that + * power of 2. A @align_mask of 0 means no alignment is required. + */ +static inline unsigned long +bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask) +{ + return bitmap_find_next_zero_area_off(map, size, start, nr, + align_mask, 0); +} extern int bitmap_scnprintf(char *buf, unsigned int len, const unsigned long *src, int nbits); --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -326,30 +326,32 @@ void bitmap_clear(unsigned long *map, un } EXPORT_SYMBOL(bitmap_clear); -/* - * bitmap_find_next_zero_area - find a contiguous aligned zero area +/** + * bitmap_find_next_zero_area_off - find a contiguous aligned zero area * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @align_mask: Alignment mask for zero area + * @align_offset: Alignment offset for zero area. * * The @align_mask should be one less than a power of 2; the effect is that - * the bit offset of all zero areas this function finds is multiples of that - * power of 2. A @align_mask of 0 means no alignment is required. + * the bit offset of all zero areas this function finds plus @align_offset + * is multiple of that power of 2. */ -unsigned long bitmap_find_next_zero_area(unsigned long *map, - unsigned long size, - unsigned long start, - unsigned int nr, - unsigned long align_mask) +unsigned long bitmap_find_next_zero_area_off(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask, + unsigned long align_offset) { unsigned long index, end, i; again: index = find_next_zero_bit(map, size, start); /* Align allocation */ - index = __ALIGN_MASK(index, align_mask); + index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; end = index + nr; if (end > size) @@ -361,7 +363,7 @@ again: } return index; } -EXPORT_SYMBOL(bitmap_find_next_zero_area); +EXPORT_SYMBOL(bitmap_find_next_zero_area_off); /* * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,