From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 376616B0525 for ; Wed, 12 Jul 2017 08:47:38 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id s4so23700423pgr.3 for ; Wed, 12 Jul 2017 05:47:38 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id j10si1876028pfc.13.2017.07.12.05.47.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Jul 2017 05:47:36 -0700 (PDT) From: Wei Wang Subject: [PATCH v12 4/8] xbitmap: add xb_find_next_bit() and xb_zero() Date: Wed, 12 Jul 2017 20:40:17 +0800 Message-Id: <1499863221-16206-5-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1499863221-16206-1-git-send-email-wei.w.wang@intel.com> References: <1499863221-16206-1-git-send-email-wei.w.wang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, david@redhat.com, cornelia.huck@de.ibm.com, akpm@linux-foundation.org, mgorman@techsingularity.net, aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, wei.w.wang@intel.com, liliang.opensource@gmail.com Cc: virtio-dev@lists.oasis-open.org, yang.zhang.wz@gmail.com, quan.xu@aliyun.com xb_find_next_bit() is added to support find the next "1" or "0" bit in the given range. xb_zero() is added to support zero the given range of bits. Signed-off-by: Wei Wang --- include/linux/xbitmap.h | 4 ++++ lib/radix-tree.c | 26 ++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/xbitmap.h b/include/linux/xbitmap.h index 0b93a46..88c2045 100644 --- a/include/linux/xbitmap.h +++ b/include/linux/xbitmap.h @@ -36,6 +36,10 @@ int xb_set_bit(struct xb *xb, unsigned long bit); bool xb_test_bit(const struct xb *xb, unsigned long bit); int xb_clear_bit(struct xb *xb, unsigned long bit); +void xb_zero(struct xb *xb, unsigned long start, unsigned long end); +unsigned long xb_find_next_bit(struct xb *xb, unsigned long start, + unsigned long end, bool set); + static inline bool xb_empty(const struct xb *xb) { return radix_tree_empty(&xb->xbrt); diff --git a/lib/radix-tree.c b/lib/radix-tree.c index d624914..c45b910 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -2271,6 +2271,32 @@ bool xb_test_bit(const struct xb *xb, unsigned long bit) return test_bit(bit, bitmap->bitmap); } +void xb_zero(struct xb *xb, unsigned long start, unsigned long end) +{ + unsigned long i; + + for (i = start; i <= end; i++) + xb_clear_bit(xb, i); +} + +/* + * Find the next one (@set = 1) or zero (@set = 0) bit within the bit range + * from @start to @end in @xb. If no such bit is found in the given range, + * bit end + 1 will be returned. + */ +unsigned long xb_find_next_bit(struct xb *xb, unsigned long start, + unsigned long end, bool set) +{ + unsigned long i; + + for (i = start; i <= end; i++) { + if (xb_test_bit(xb, i) == set) + break; + } + + return i; +} + void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, int end) { -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org