Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751826AbdHCGsy (ORCPT ); Thu, 3 Aug 2017 02:48:54 -0400 Received: from mga09.intel.com ([134.134.136.24]:33123 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751094AbdHCGsk (ORCPT ); Thu, 3 Aug 2017 02:48:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,314,1498546800"; d="scan'208";a="1158532619" From: Wei Wang To: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, mawilcox@microsoft.com, akpm@linux-foundation.org Cc: virtio-dev@lists.oasis-open.org, david@redhat.com, cornelia.huck@de.ibm.com, mgorman@techsingularity.net, aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu@aliyun.com Subject: [PATCH v13 2/5] xbitmap: add xb_find_next_bit() and xb_zero() Date: Thu, 3 Aug 2017 14:38:16 +0800 Message-Id: <1501742299-4369-3-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1501742299-4369-1-git-send-email-wei.w.wang@intel.com> References: <1501742299-4369-1-git-send-email-wei.w.wang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1941 Lines: 65 xb_find_next_bit() supports to find the next "1" or "0" bit in the given range. xb_zero() supports to zero the given range of bits. Signed-off-by: Wei Wang --- include/linux/xbitmap.h | 4 ++++ lib/radix-tree.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 32 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 d8c3c18..84842a3 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -2272,6 +2272,34 @@ 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); +} +EXPORT_SYMBOL(xb_zero); + +/* + * 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; +} +EXPORT_SYMBOL(xb_find_next_bit); + void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, int end) { -- 2.7.4