/*
* Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <gpxe/infiniband.h>
#include <gpxe/ib_mi.h>
#include <gpxe/ib_pathrec.h>
/** @file
*
* Infiniband path lookups
*
*/
/**
* Handle path transaction completion
*
* @v ibdev Infiniband device
* @v mi Management interface
* @v madx Management transaction
* @v rc Status code
* @v mad Received MAD (or NULL on error)
* @v av Source address vector (or NULL on error)
*/
static void ib_path_complete ( struct ib_device *ibdev,
struct ib_mad_interface *mi,
struct ib_mad_transaction *madx,
int rc, union ib_mad *mad,
struct ib_address_vector *av __unused ) {
struct ib_path *path = ib_madx_get_ownerdata ( madx );
struct ib_gid *dgid = &path->av.gid;
struct ib_path_record *pathrec = &mad->sa.sa_data.path_record;
/* Report failures */
if ( ( rc == 0 ) && ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ))
rc = -ENETUNREACH;
if ( rc != 0 ) {
DBGC ( ibdev, "IBDEV %p path lookup for %08x:%08x:%08x:%08x "
"failed: %s\n", ibdev, htonl ( dgid->u.dwords[0] ),
htonl ( dgid->u.dwords[1] ),
htonl ( dgid->u.dwords[2] ),
htonl ( dgid->u.dwords[3] ), strerror ( rc ) );
goto out;
}
/* Extract values from MAD */
path->av.lid = ntohs ( pathrec->dlid );
path->av.sl = ( pathrec->reserved__sl & 0x0f );
path->av.rate = ( pathrec->rate_selector__rate & 0x3f );
DBGC ( ibdev, "IBDEV %p path to %08x:%08x:%08x:%08x is %04x sl %d "
"rate %d\n", ibdev, htonl ( dgid->u.dwords[0] ),
htonl ( dgid->u.dwords[1] ), htonl ( dgid->u.dwords[2] ),
htonl ( dgid->u.dwords[3] ), path->av.lid, path->av.sl,
path->av.rate );
out:
/* Destroy the completed transaction */
ib_destroy_madx ( ibdev, mi, madx );
path->madx = NULL;
/* Hand off to upper completion handler */
path->op->complete ( ibdev, path, rc, &path->av );
}
/** Path transaction completion operations */
static struct ib_mad_transaction_operations ib_path_op = {
.complete = ib_path_complete,
};
/**
* Create path
*
* @v ibdev Infiniband device
* @v av Address vector to complete
* @v op Path operations
* @ret path Path
*/
struct ib_path *
ib_create_path ( struct ib_device *ibdev, struct ib_address_vector *av,
struct ib_path_operations *op ) {
struct ib_path *path;
union ib_mad mad;
struct ib_mad_sa *sa = &mad.sa;
/* Allocate and initialise structure */
path = zalloc ( sizeof ( *path ) );
if ( ! path )
goto err_alloc_path;
path->ibdev = ibdev;
memcpy ( &path->av, av, sizeof ( path->av ) );
path->op = op;
/* Construct path request */
memset ( sa, 0, sizeof ( *sa ) );
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, &path->av.gid,
sizeof ( sa->sa_data.path_record.dgid ) );
memcpy ( &sa->sa_data.path_record.sgid, &ibdev->gid,
sizeof ( sa->sa_data.path_record.sgid ) );
/* Create management transaction */
path->madx = ib_create_madx ( ibdev, ibdev->gsi, &mad, NULL,
&ib_path_op );
if ( ! path->madx )
goto err_create_madx;
ib_madx_set_ownerdata ( path->madx, path );
return path;
ib_destroy_madx ( ibdev, ibdev->gsi, path->madx );
err_create_madx:
free ( path );
err_alloc_path:
return NULL;
}
/**
* Destroy path
*
* @v ibdev Infiniband device
* @v path Path
*/
void ib_destroy_path ( struct ib_device *ibdev, struct ib_path *path ) {
if ( path->madx )
ib_destroy_madx ( ibdev, ibdev->gsi, path->madx );
free ( path );
}
/** Number of path cache entries
*
* Must be a power of two.
*/
#define IB_NUM_CACHED_PATHS 4
/** A cached path */
struct ib_cached_path {
/** Path */
struct ib_path *path;
};
/** Path cache */
static struct ib_cached_path ib_path_cache[IB_NUM_CACHED_PATHS];
/** Oldest path cache entry index */
static unsigned int ib_path_cache_idx;
/**
* Find path cache entry
*
* @v ibdev Infiniband device
* @v dgid Destination GID
* @ret path Path cache entry, or NULL
*/
static struct ib_cached_path *
ib_find_path_cache_entry ( struct ib_device *ibdev, struct ib_gid *dgid ) {
struct ib_cached_path *cached;
unsigned int i;
for ( i = 0 ; i < IB_NUM_CACHED_PATHS ; i++ ) {
cached = &ib_path_cache[i];
if ( ! cached->path )
continue;
if ( cached->path->ibdev != ibdev )
continue;
if ( memcmp ( &cached->path->av.gid, dgid,
sizeof ( cached->path->av.gid ) ) != 0 )
continue;
return cached;
}
return NULL;
}
/**
* Handle cached path transaction completion
*
* @v ibdev Infiniband device
* @v path Path
* @v rc Status code
* @v av Address vector, or NULL on error
*/
static void ib_cached_path_complete ( struct ib_device *ibdev,
struct ib_path *path, int rc,
struct ib_address_vector *av __unused ) {
struct ib_cached_path *cached = ib_path_get_ownerdata ( path );
/* If the transaction failed, erase the cache entry */
if ( rc != 0 ) {
/* Destroy the old cache entry */
ib_destroy_path ( ibdev, path );
memset ( cached, 0, sizeof ( *cached ) );
return;
}
/* Do not destroy the completed transaction; we still need to
* refer to the resolved path.
*/
}
/** Cached path transaction completion operations */
static struct ib_path_operations ib_cached_path_op = {
.complete = ib_cached_path_complete,
};
/**
* Resolve path
*
* @v ibdev Infiniband device
* @v av Address vector to complete
* @ret rc Return status code
*
* This provides a non-transactional way to resolve a path, via a
* cache similar to ARP.
*/
int ib_resolve_path ( struct ib_device *ibdev, struct ib_address_vector *av ) {
struct ib_gid *gid = &av->gid;
struct ib_cached_path *cached;
unsigned int cache_idx;
/* Sanity check */
if ( ! av->gid_present ) {
DBGC ( ibdev, "IBDEV %p attempt to look up path "
"without GID\n", ibdev );
return -EINVAL;
}
/* Look in cache for a matching entry */
cached = ib_find_path_cache_entry ( ibdev, gid );
if ( cached && cached->path->av.lid ) {
/* Populated entry found */
av->lid = cached->path->av.lid;
av->rate = cached->path->av.rate;
av->sl = cached->path->av.sl;
DBGC2 ( ibdev, "IBDEV %p cache hit for %08x:%08x:%08x:%08x\n",
ibdev, htonl ( gid->u.dwords[0] ),
htonl ( gid->u.dwords[1] ), htonl ( gid->u.dwords[2] ),
htonl ( gid->u.dwords[3] ) );
return 0;
}
DBGC ( ibdev, "IBDEV %p cache miss for %08x:%08x:%08x:%08x%s\n",
ibdev, htonl ( gid->u.dwords[0] ), htonl ( gid->u.dwords[1] ),
htonl ( gid->u.dwords[2] ), htonl ( gid->u.dwords[3] ),
( cached ? " (in progress)" : "" ) );
/* If lookup is already in progress, do nothing */
if ( cached )
return -ENOENT;
/* Locate a new cache entry to use */
cache_idx = ( (ib_path_cache_idx++) % IB_NUM_CACHED_PATHS );
cached = &ib_path_cache[cache_idx];
/* Destroy the old cache entry */
if ( cached->path )
ib_destroy_path ( ibdev, cached->path );
memset ( cached, 0, sizeof ( *cached ) );
/* Create new path */
cached->path = ib_create_path ( ibdev, av, &ib_cached_path_op );
if ( ! cached->path ) {
DBGC ( ibdev, "IBDEV %p could not create path\n",
ibdev );
return -ENOMEM;
}
ib_path_set_ownerdata ( cached->path, cached );
/* Not found yet */
return -ENOENT;
}