From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id BA2DC5AA6 for ; Tue, 20 Jan 2015 19:41:25 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 20 Jan 2015 10:35:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="442827091" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by FMSMGA003.fm.intel.com with ESMTP; 20 Jan 2015 10:28:05 -0800 Received: from sivswdev02.ir.intel.com (sivswdev02.ir.intel.com [10.237.217.46]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id t0KIfLxB029528; Tue, 20 Jan 2015 18:41:21 GMT Received: from sivswdev02.ir.intel.com (localhost [127.0.0.1]) by sivswdev02.ir.intel.com with ESMTP id t0KIfLbV018912; Tue, 20 Jan 2015 18:41:21 GMT Received: (from kananye1@localhost) by sivswdev02.ir.intel.com with id t0KIfLJw018908; Tue, 20 Jan 2015 18:41:21 GMT From: Konstantin Ananyev To: dev@dpdk.org Date: Tue, 20 Jan 2015 18:41:07 +0000 Message-Id: <1421779267-18492-19-git-send-email-konstantin.ananyev@intel.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1421779267-18492-1-git-send-email-konstantin.ananyev@intel.com> References: <1421779267-18492-1-git-send-email-konstantin.ananyev@intel.com> Subject: [dpdk-dev] [PATCH v3 18/18] libte_acl: add some comments about ACL internal layout. X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Jan 2015 18:41:28 -0000 Signed-off-by: Konstantin Ananyev --- lib/librte_acl/acl.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/lib/librte_acl/acl.h b/lib/librte_acl/acl.h index 217bab3..4dadab5 100644 --- a/lib/librte_acl/acl.h +++ b/lib/librte_acl/acl.h @@ -68,6 +68,44 @@ struct rte_acl_bitset { #define RTE_ACL_NODE_UNDEFINED UINT32_MAX /* + * ACL RT structure is a set of multibit tries (with stride == 8) + * represented by an array of transitions. The next position is calculated + * based on the current position and the input byte. + * Each transition is 64 bit value with the following format: + * | node_type_specific : 32 | node_type : 3 | node_addr : 29 | + * For all node types except RTE_ACL_NODE_MATCH, node_addr is an index + * to the start of the node in the transtions array. + * Few different node types are used: + * RTE_ACL_NODE_MATCH: + * node_addr value is and index into an array that contains the return value + * and its priority for each category. + * Upper 32 bits of the transition value are not used for that node type. + * RTE_ACL_NODE_QRANGE: + * that node consist of up to 5 transitions. + * Upper 32 bits are interpreted as 4 signed character values which + * are ordered from smallest(INT8_MIN) to largest (INT8_MAX). + * These values define 5 ranges: + * INT8_MIN <= range[0] <= ((int8_t *)&transition)[4] + * ((int8_t *)&transition)[4] < range[1] <= ((int8_t *)&transition)[5] + * ((int8_t *)&transition)[5] < range[2] <= ((int8_t *)&transition)[6] + * ((int8_t *)&transition)[6] < range[3] <= ((int8_t *)&transition)[7] + * ((int8_t *)&transition)[7] < range[4] <= INT8_MAX + * So for input byte value within range[i] i-th transition within that node + * will be used. + * RTE_ACL_NODE_SINGLE: + * always transitions to the same node regardless of the input value. + * RTE_ACL_NODE_DFA: + * that node consits of up to 256 transitions. + * In attempt to conserve space all transitions are divided into 4 consecutive + * groups, by 64 transitions per group: + * group64[i] contains transitions[i * 64, .. i * 64 + 63]. + * Upper 32 bits are interpreted as 4 unsigned character values one per group, + * which contain index to the start of the given group within the node. + * So to calculate transition index within the node for given input byte value: + * input_byte - ((uint8_t *)&transition)[4 + input_byte / 64]. + */ + +/* * Structure of a node is a set of ptrs and each ptr has a bit map * of values associated with this transition. */ -- 1.8.5.3