> On Jan 20, 2015, at 4:09 AM, Ananyev, Konstantin <konstantin.ananyev at > intel.com> wrote: > > Hi Thomas, > >> -----Original Message----- >> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] >> Sent: Monday, January 19, 2015 5:18 PM >> To: Ananyev, Konstantin >> Cc: dev at dpdk.org >> Subject: Re: [dpdk-dev] [PATCH v2 17/17] libte_acl: remove unused macros. >> >> 2015-01-12 19:16, Konstantin Ananyev: >>> /* >>> + * 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 transtion 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]. >>> + */ >> >> It's maybe an error. You were only supposed to remove some macros in this >> patch. > > Ah yes, I added some comments about ACL internal layout. > Thought it might be useful. > Forgot to add it into patch description. > Are you saying I need to split it into 2 patches, or it is ok like that?
it?s great info, but it should probably go in doc/guides/prog_guide/packet_classif_access_ctrl.rst. Jim
