/*
* Copyright (C) 2006 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.
*/
#include <stddef.h>
#include <string.h>
#include <vsprintf.h>
#include <errno.h>
#include <assert.h>
#include <byteswap.h>
#include <gpxe/list.h>
#include <gpxe/if_ether.h>
#include <gpxe/ethernet.h>
#include <gpxe/pkbuff.h>
#include <gpxe/uaccess.h>
#include <gpxe/ata.h>
#include <gpxe/netdevice.h>
#include <gpxe/async.h>
#include <gpxe/aoe.h>
/** @file
*
* AoE protocol
*
*/
struct net_protocol aoe_protocol;
/** List of all AoE sessions */
static LIST_HEAD ( aoe_sessions );
/**
* Mark current AoE command complete
*
* @v aoe AoE session
* @v rc Return status code
*/
static void aoe_done ( struct aoe_session *aoe, int rc ) {
/* Record overall command status */
aoe->command->cb.cmd_stat = aoe->status;
aoe->command = NULL;
/* Mark async operation as complete */
async_done ( &aoe->async, rc );
}
/**
* Send AoE command
*
* @v aoe AoE session
* @ret rc Return status code
*
* This transmits an AoE command packet. It does not wait for a
* response.
*/
static int aoe_send_command ( struct aoe_session *aoe ) {
struct ata_command *command = aoe->command;
struct pk_buff *pkb;
struct aoehdr *aoehdr;
struct aoecmd *aoecmd;
unsigned int count;
unsigned int data_out_len;
/* Fail immediately if we have no netdev to send on */
if ( ! aoe->netdev ) {
aoe_done ( aoe, -ENETUNREACH );
return -ENETUNREACH;
}
/* Calculate count and data_out_len for this subcommand */
count = command->cb.count.native;
if ( count > AOE_MAX_COUNT )
count = AOE_MAX_COUNT;
data_out_len = ( command->data_out ? ( count * ATA_SECTOR_SIZE ) : 0 );
/* Create outgoing packet buffer */
pkb = alloc_pkb ( ETH_HLEN + sizeof ( *aoehdr ) + sizeof ( *aoecmd ) +
data_out_len );
if ( ! pkb )
return -ENOMEM;
pkb_reserve ( pkb, ETH_HLEN );
aoehdr = pkb_put ( pkb, sizeof ( *aoehdr ) );
aoecmd = pkb_put ( pkb, sizeof ( *aoecmd ) );
memset ( aoehdr, 0, ( sizeof ( *aoehdr ) + sizeof ( *aoecmd ) ) );
/* Fill AoE header */
aoehdr->ver_flags = AOE_VERSION;
aoehdr->major = htons ( aoe->major );
aoehdr->minor = aoe->minor;
aoehdr->tag = htonl ( ++aoe->tag );
/* Fill AoE command */
linker_assert ( AOE_FL_DEV_HEAD == ATA_DEV_SLAVE, __fix_ata_h__ );
aoecmd->aflags = ( ( command->cb.lba48 ? AOE_FL_EXTENDED : 0 ) |
( command->cb.device & ATA_DEV_SLAVE ) |
( data_out_len ? AOE_FL_WRITE : 0 ) );
aoecmd->err_feat = command->cb.err_feat.bytes.cur;
aoecmd->count = count;
aoecmd->cmd_stat = command->cb.cmd_stat;
aoecmd->lba.u64 = cpu_to_le64 ( command->cb.lba.native );
if ( ! command->cb.lba48 )
aoecmd->lba.bytes[3] |= ( command->cb.device & ATA_DEV_MASK );
/* Fill data payload */
copy_from_user ( pkb_put ( pkb, data_out_len ), command->data_out,
aoe->command_offset, data_out_len );
/* Send packet */
start_timer ( &aoe->timer );
return net_tx ( pkb, aoe->netdev, &aoe_protocol, aoe->target );
}
/**
* Handle AoE retry timer expiry
*
* @v timer AoE retry timer
* @v fail Failure indicator
*/
static void aoe_timer_expired ( struct retry_timer *timer, int fail ) {
struct aoe_session *aoe =
container_of ( timer, struct aoe_session, timer );
if ( fail ) {
aoe_done ( aoe, -ETIMEDOUT );
} else {
aoe_send_command ( aoe );
}
}
/**
* Handle AoE response
*
* @v aoe AoE session
* @v aoehdr AoE header
* @ret rc Return status code
*/
static int aoe_rx_response ( struct aoe_session *aoe, struct aoehdr *aoehdr,
unsigned int len ) {
struct aoecmd *aoecmd = aoehdr->arg.command;
struct ata_command *command = aoe->command;
unsigned int rx_data_len;
unsigned int count;
unsigned int data_len;
/* Sanity check */
if ( len < ( sizeof ( *aoehdr ) + sizeof ( *aoecmd ) ) ) {
/* Ignore packet; allow timer to trigger retransmit */
return -EINVAL;
}
rx_data_len = ( len - sizeof ( *aoehdr ) - sizeof ( *aoecmd ) );
/* Stop retry timer. After this point, every code path must
* either terminate the AoE operation via aoe_done(), or
* transmit a new packet.
*/
stop_timer ( &aoe->timer );
/* Check for fatal errors */
if ( aoehdr->ver_flags & AOE_FL_ERROR ) {
aoe_done ( aoe, -EIO );
return 0;
}
/* Calculate count and data_len for this subcommand */
count = command->cb.count.native;
if ( count > AOE_MAX_COUNT )
count = AOE_MAX_COUNT;
data_len = count * ATA_SECTOR_SIZE;
/* Merge into overall ATA status */
aoe->status |= aoecmd->cmd_stat;
/* Copy data payload */
if ( command->data_in ) {
if ( rx_data_len > data_len )
rx_data_len = data_len;
copy_to_user ( command->data_in, aoe->command_offset,
aoecmd->data, rx_data_len );
}
/* Update ATA command and offset */
aoe->command_offset += data_len;
command->cb.lba.native += count;
command->cb.count.native -= count;
/* Check for operation complete */
if ( ! command->cb.count.native ) {
aoe_done ( aoe, 0 );
return 0;
}
/* Transmit next portion of request */
aoe_send_command ( aoe );
return 0;
}
/**
* Process incoming AoE packets
*
* @v pkb Packet buffer
* @v netdev Network device
* @v ll_source Link-layer source address
* @ret rc Return status code
*
*/
static int aoe_rx ( struct pk_buff *pkb, struct net_device *netdev __unused,
const void *ll_source ) {
struct aoehdr *aoehdr = pkb->data;
unsigned int len = pkb_len ( pkb );
struct aoe_session *aoe;
int rc = 0;
/* Sanity checks */
if ( len < sizeof ( *aoehdr ) ) {
rc = -EINVAL;
goto done;
}
if ( ( aoehdr->ver_flags & AOE_VERSION_MASK ) != AOE_VERSION ) {
rc = -EPROTONOSUPPORT;
goto done;
}
if ( ! ( aoehdr->ver_flags & AOE_FL_RESPONSE ) ) {
/* Ignore AoE requests that we happen to see */
goto done;
}
/* Demultiplex amongst active AoE sessions */
list_for_each_entry ( aoe, &aoe_sessions, list ) {
if ( ntohs ( aoehdr->major ) != aoe->major )
continue;
if ( aoehdr->minor != aoe->minor )
continue;
if ( ntohl ( aoehdr->tag ) != aoe->tag )
continue;
memcpy ( aoe->target, ll_source, sizeof ( aoe->target ) );
rc = aoe_rx_response ( aoe, aoehdr, len );
break;
}
done:
free_pkb ( pkb );
return rc;
}
/** AoE protocol */
struct net_protocol aoe_protocol __net_protocol = {
.name = "AoE",
.net_proto = htons ( ETH_P_AOE ),
.rx = aoe_rx,
};
/**
* Forget reference to net_device
*
* @v ref Persistent reference
*/
static void aoe_forget_netdev ( struct reference *ref ) {
struct aoe_session *aoe
= container_of ( ref, struct aoe_session, netdev_ref );
aoe->netdev = NULL;
ref_del ( &aoe->netdev_ref );
}
/**
* Open AoE session
*
* @v aoe AoE session
*/
void aoe_open ( struct aoe_session *aoe ) {
memcpy ( aoe->target, ethernet_protocol.ll_broadcast,
sizeof ( aoe->target ) );
aoe->tag = AOE_TAG_MAGIC;
aoe->timer.expired = aoe_timer_expired;
aoe->netdev_ref.forget = aoe_forget_netdev;
ref_add ( &aoe->netdev_ref, &aoe->netdev->references );
list_add ( &aoe->list, &aoe_sessions );
}
/**
* Close AoE session
*
* @v aoe AoE session
*/
void aoe_close ( struct aoe_session *aoe ) {
if ( aoe->netdev )
ref_del ( &aoe->netdev_ref );
list_del ( &aoe->list );
}
/**
* Issue ATA command via an open AoE session
*
* @v aoe AoE session
* @v command ATA command
* @v parent Parent asynchronous operation
* @ret rc Return status code
*
* Only one command may be issued concurrently per session. This call
* is non-blocking; use async_wait() to wait for the command to
* complete.
*/
int aoe_issue ( struct aoe_session *aoe, struct ata_command *command,
struct async *parent ) {
aoe->command = command;
aoe->status = 0;
aoe->command_offset = 0;
aoe_send_command ( aoe );
async_init ( &aoe->async, &default_async_operations, parent );
return 0;
}
