/*
* 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 <byteswap.h>
#include <gpxe/blockdev.h>
#include <gpxe/scsi.h>
/** @file
*
* SCSI block device
*
*/
static inline __attribute__ (( always_inline )) struct scsi_device *
block_to_scsi ( struct block_device *blockdev ) {
return container_of ( blockdev, struct scsi_device, blockdev );
}
/**
* Issue SCSI command
*
* @v scsi SCSI device
* @v command SCSI command
* @ret rc Return status code
*/
static int scsi_command ( struct scsi_device *scsi,
struct scsi_command *command ) {
return scsi->command ( scsi, command );
}
/**
* Read block from SCSI device
*
* @v blockdev Block device
* @v block LBA block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int scsi_read ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct scsi_device *scsi = block_to_scsi ( blockdev );
struct scsi_command command;
struct scsi_cdb_read_16 *cdb = &command.cdb.read16;
/* Issue READ (16) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_READ_16;
cdb->lba = cpu_to_be64 ( block );
cdb->len = cpu_to_be32 ( count );
command.data_in = buffer;
command.data_in_len = ( count * blockdev->blksize );
return scsi_command ( scsi, &command );
}
/**
* Write block to SCSI device
*
* @v blockdev Block device
* @v block LBA block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int scsi_write ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct scsi_device *scsi = block_to_scsi ( blockdev );
struct scsi_command command;
struct scsi_cdb_write_16 *cdb = &command.cdb.write16;
/* Issue WRITE (16) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_WRITE_16;
cdb->lba = cpu_to_be64 ( block );
cdb->len = cpu_to_be32 ( count );
command.data_out = buffer;
command.data_out_len = ( count * blockdev->blksize );
return scsi_command ( scsi, &command );
}
/**
* Read capacity of SCSI device via READ CAPACITY (10)
*
* @v blockdev Block device
* @ret rc Return status code
*/
static int scsi_read_capacity_10 ( struct block_device *blockdev ) {
struct scsi_device *scsi = block_to_scsi ( blockdev );
struct scsi_command command;
struct scsi_cdb_read_capacity_10 *cdb = &command.cdb.readcap10;
struct scsi_capacity_10 capacity;
int rc;
/* Issue READ CAPACITY (10) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_READ_CAPACITY_10;
command.data_in = virt_to_user ( &capacity );
command.data_in_len = sizeof ( capacity );
if ( ( rc = scsi_command ( scsi, &command ) ) != 0 )
return rc;
/* Fill in block device fields */
blockdev->blksize = be32_to_cpu ( capacity.blksize );
blockdev->blocks = ( be32_to_cpu ( capacity.lba ) + 1 );
return 0;
}
/**
* Read capacity of SCSI device via READ CAPACITY (16)
*
* @v blockdev Block device
* @ret rc Return status code
*/
static int scsi_read_capacity_16 ( struct block_device *blockdev ) {
struct scsi_device *scsi = block_to_scsi ( blockdev );
struct scsi_command command;
struct scsi_cdb_read_capacity_16 *cdb = &command.cdb.readcap16;
struct scsi_capacity_16 capacity;
int rc;
/* Issue READ CAPACITY (16) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_SERVICE_ACTION_IN;
cdb->service_action = SCSI_SERVICE_ACTION_READ_CAPACITY_16;
cdb->len = cpu_to_be32 ( sizeof ( capacity ) );
command.data_in = virt_to_user ( &capacity );
command.data_in_len = sizeof ( capacity );
if ( ( rc = scsi_command ( scsi, &command ) ) != 0 )
return rc;
/* Fill in block device fields */
blockdev->blksize = be32_to_cpu ( capacity.blksize );
blockdev->blocks = ( be64_to_cpu ( capacity.lba ) + 1 );
return 0;
}
/**
* Read capacity of SCSI device
*
* @v blockdev Block device
* @ret rc Return status code
*/
static int scsi_read_capacity ( struct block_device *blockdev ) {
int rc;
/* Try READ CAPACITY (10), which is a mandatory command, first. */
if ( ( rc = scsi_read_capacity_10 ( blockdev ) ) != 0 )
return rc;
/* If capacity range was exceeded (i.e. capacity.lba was
* 0xffffffff, meaning that blockdev->blocks is now zero), use
* READ CAPACITY (16) instead. READ CAPACITY (16) is not
* mandatory, so we can't just use it straight off.
*/
if ( blockdev->blocks == 0 ) {
if ( ( rc = scsi_read_capacity_16 ( blockdev ) ) != 0 )
return rc;
}
return 0;
}
/**
* Initialise SCSI device
*
* @v scsi SCSI device
* @ret rc Return status code
*
* Initialises a SCSI device. The scsi_device::command and
* scsi_device::lun fields must already be filled in. This function
* will configure scsi_device::blockdev, including issuing a READ
* CAPACITY call to determine the block size and total device size.
*/
int init_scsidev ( struct scsi_device *scsi ) {
/** Fill in read and write methods, and get device capacity */
scsi->blockdev.read = scsi_read;
scsi->blockdev.write = scsi_write;
return scsi_read_capacity ( &scsi->blockdev );
}
