From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36331) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAvwu-0002zZ-SY for qemu-devel@nongnu.org; Fri, 12 Oct 2018 07:49:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAvwr-0000fv-Ds for qemu-devel@nongnu.org; Fri, 12 Oct 2018 07:49:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45596) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gAvwp-0000Io-3Q for qemu-devel@nongnu.org; Fri, 12 Oct 2018 07:49:39 -0400 From: David Hildenbrand Date: Fri, 12 Oct 2018 13:49:13 +0200 Message-Id: <20181012114916.23532-5-david@redhat.com> In-Reply-To: <20181012114916.23532-1-david@redhat.com> References: <20181012114916.23532-1-david@redhat.com> Subject: [Qemu-devel] [PATCH v2 4/7] range: add some more functions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Michael S . Tsirkin" , Igor Mammedov , Markus Armbruster , Michael Roth , David Gibson , Eduardo Habkost , "Dr . David Alan Gilbert" , David Hildenbrand Add some more functions that will be used in memory-device context. range_init(): Init using lower bound and size, check for validity range_init_nofail(): Init using lower bound and size, validity asserted range_size(): Extract the size of a range range_overlaps_range(): Check for overlaps of two ranges range_contains_range(): Check if one range is contained in the other Signed-off-by: David Hildenbrand --- include/qemu/range.h | 62 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/include/qemu/range.h b/include/qemu/range.h index 7e75f4e655..ba606c6bc0 100644 --- a/include/qemu/range.h +++ b/include/qemu/range.h @@ -112,6 +112,68 @@ static inline uint64_t range_upb(Range *range) return range->upb; } +/* + * Initialize @range to span the interval [@lob,@lob + @size - 1]. + * @size may be 0. If the range would overflow, returns -ERANGE, otherwise + * 0. + */ +static inline int QEMU_WARN_UNUSED_RESULT range_init(Range *range, uint64_t lob, + uint64_t size) +{ + if (lob + size < lob) { + return -ERANGE; + } + range->lob = lob; + range->upb = lob + size - 1; + range_invariant(range); + return 0; +} + +/* + * Initialize @range to span the interval [@lob,@lob + @size - 1]. + * @size may be 0. Range must not overflow. + */ +static inline void range_init_nofail(Range *range, uint64_t lob, uint64_t size) +{ + range->lob = lob; + range->upb = lob + size - 1; + range_invariant(range); +} + +/* + * Get the size of @range. + */ +static inline uint64_t range_size(const Range *range) +{ + return range->upb - range->lob + 1; +} + +/* + * Check if @range1 overlaps with @range2. If one of the ranges is empty, + * the result is always "false". + */ +static inline bool range_overlaps_range(const Range *range1, + const Range *range2) +{ + if (range_is_empty(range1) || range_is_empty(range2)) { + return false; + } + return !(range2->upb < range1->lob || range1->upb < range2->lob); +} + +/* + * Check if @range1 contains @range2. If one of the ranges is empty, + * the result is always "false". + */ +static inline bool range_contains_range(const Range *range1, + const Range *range2) +{ + if (range_is_empty(range1) || range_is_empty(range2)) { + return false; + } + return range1->lob <= range2->lob && range1->upb >= range2->upb; +} + /* * Extend @range to the smallest interval that includes @extend_by, too. */ -- 2.17.1