/* * Copyright (C) 2009 Michael Brown . * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ FILE_LICENCE ( GPL2_OR_LATER ); #include #include #include #include #include #include #include /** @file * * Infiniband path lookups * */ /** Number of path record cache entries * * Must be a power of two. */ #define IB_NUM_CACHED_PATHS 4 /** A path record cache entry */ struct ib_cached_path_record { /** Infiniband device's port GID * * Used to disambiguate cache entries when we have multiple * Infiniband devices, without having to maintain a pointer to * the Infiniband device. */ struct ib_gid sgid; /** Destination GID */ struct ib_gid dgid; /** Destination LID */ unsigned int dlid; /** Rate */ unsigned int rate; /** Service level */ unsigned int sl; }; /** Path record cache */ static struct ib_cached_path_record ib_path_cache[IB_NUM_CACHED_PATHS]; /** Oldest path record cache entry index */ static unsigned int ib_path_cache_idx; /** * Find path record cache entry * * @v ibdev Infiniband device * @v dgid Destination GID * @ret cached Path record cache entry, or NULL */ static struct ib_cached_path_record * ib_find_path_cache_entry ( struct ib_device *ibdev, struct ib_gid *dgid ) { struct ib_cached_path_record *cached; unsigned int i; for ( i = 0 ; i < IB_NUM_CACHED_PATHS ; i++ ) { cached = &ib_path_cache[i]; if ( memcmp ( &cached->sgid, &ibdev->gid, sizeof ( cached->sgid ) ) != 0 ) continue; if ( memcmp ( &cached->dgid, dgid, sizeof ( cached->dgid ) ) != 0 ) continue; return cached; } return NULL; } /** * Resolve path record * * @v ibdev Infiniband device * @v av Address vector to complete * @ret rc Return status code */ int ib_resolve_path ( struct ib_device *ibdev, struct ib_address_vector *av ) { struct ib_gma *gma = ibdev->gma; struct ib_gid *gid = &av->gid; struct ib_cached_path_record *cached; union ib_mad mad; struct ib_mad_sa *sa = &mad.sa; unsigned int cache_idx; int rc; /* Sanity check */ if ( ! av->gid_present ) { DBGC ( gma, "GMA %p attempt to look up path record " "without GID\n", gma ); return -EINVAL; } /* Look in cache for a matching entry */ cached = ib_find_path_cache_entry ( ibdev, gid ); if ( cached && cached->dlid ) { /* Populated entry found */ av->lid = cached->dlid; av->rate = cached->rate; av->sl = cached->sl; DBGC2 ( gma, "GMA %p cache hit for %08x:%08x:%08x:%08x\n", gma, htonl ( gid->u.dwords[0] ), htonl ( gid->u.dwords[1] ), htonl ( gid->u.dwords[2] ), htonl ( gid->u.dwords[3] ) ); return 0; } DBGC ( gma, "GMA %p cache miss for %08x:%08x:%08x:%08x%s\n", gma, htonl ( gid->u.dwords[0] ), htonl ( gid->u.dwords[1] ), htonl ( gid->u.dwords[2] ), htonl ( gid->u.dwords[3] ), ( cached ? " (in progress)" : "" ) ); /* If no unresolved entry was found, then create a new one */ if ( ! cached ) { cache_idx = ( (ib_path_cache_idx++) % IB_NUM_CACHED_PATHS ); cached = &ib_path_cache[cache_idx]; memset ( cached, 0, sizeof ( *cached ) ); memcpy ( &cached->sgid, &ibdev->gid, sizeof ( cached->sgid ) ); memcpy ( &cached->dgid, gid, sizeof ( cached->dgid ) ); } /* Construct path record request */ memset ( sa, 0, sizeof ( *sa ) ); sa->mad_hdr.base_version = IB_MGMT_BASE_VERSION; sa->mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM; sa->mad_hdr.class_version = IB_SA_CLASS_VERSION; sa->mad_hdr.method = IB_MGMT_METHOD_GET; sa->mad_hdr.attr_id = htons ( IB_SA_ATTR_PATH_REC ); sa->sa_hdr.comp_mask[1] = htonl ( IB_SA_PATH_REC_DGID | IB_SA_PATH_REC_SGID ); memcpy ( &sa->sa_data.path_record.dgid, &cached->dgid, sizeof ( sa->sa_data.path_record.dgid ) ); memcpy ( &sa->sa_data.path_record.sgid, &cached->sgid, sizeof ( sa->sa_data.path_record.sgid ) ); /* Issue path record request */ if ( ( rc = ib_gma_request ( gma, &mad, NULL, 1 ) ) != 0 ) { DBGC ( gma, "GMA %p could not get path record: %s\n", gma, strerror ( rc ) ); return rc; } /* Not found yet */ return -ENOENT; } /** * Handle path record response * * @v gma General management agent * @v mad MAD */ static void ib_handle_path_record ( struct ib_gma *gma, union ib_mad *mad ) { struct ib_device *ibdev = gma->ibdev; struct ib_path_record *path_record = &mad->sa.sa_data.path_record; struct ib_gid *dgid = &path_record->dgid; struct ib_cached_path_record *cached; unsigned int dlid; unsigned int sl; unsigned int rate; /* Ignore if not a success */ if ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ) { DBGC ( gma, "GMA %p path record lookup failed with status " "%04x\n", gma, ntohs ( mad->hdr.status ) ); return; } /* Extract values from MAD */ dlid = ntohs ( path_record->dlid ); sl = ( path_record->reserved__sl & 0x0f ); rate = ( path_record->rate_selector__rate & 0x3f ); DBGC ( gma, "GMA %p path to %08x:%08x:%08x:%08x is %04x sl %d " "rate %d\n", gma, htonl ( dgid->u.dwords[0] ), htonl ( dgid->u.dwords[1] ), htonl ( dgid->u.dwords[2] ), htonl ( dgid->u.dwords[3] ), dlid, sl, rate ); /* Look for a matching cache entry to fill in */ if ( ( cached = ib_find_path_cache_entry ( ibdev, dgid ) ) != NULL ) { DBGC ( gma, "GMA %p cache add for %08x:%08x:%08x:%08x\n", gma, htonl ( dgid->u.dwords[0] ), htonl ( dgid->u.dwords[1] ), htonl ( dgid->u.dwords[2] ), htonl ( dgid->u.dwords[3] ) ); cached->dlid = dlid; cached->rate = rate; cached->sl = sl; } } /** Path record response handler */ struct ib_gma_handler ib_path_record_handler __ib_gma_handler = { .mgmt_class = IB_MGMT_CLASS_SUBN_ADM, .class_version = IB_SA_CLASS_VERSION, .method = IB_MGMT_METHOD_GET_RESP, .attr_id = htons ( IB_SA_ATTR_PATH_REC ), .handle = ib_handle_path_record, };