/*
* 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.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <gpxe/blockdev.h>
#include <gpxe/process.h>
#include <gpxe/scsi.h>
/** @file
*
* SCSI block device
*
*/
/** Maximum number of dummy "read capacity (10)" operations
*
* These are issued at connection setup to draw out various useless
* power-on messages.
*/
#define SCSI_MAX_DUMMY_READ_CAP 10
static inline __attribute__ (( always_inline )) struct scsi_device *
block_to_scsi ( struct block_device *blockdev ) {
return container_of ( blockdev, struct scsi_device, blockdev );
}
/**
* Handle SCSI command with no backing device
*
* @v scsi SCSI device
* @v command SCSI command
* @ret rc Return status code
*/
int scsi_detached_command ( struct scsi_device *scsi __unused,
struct scsi_command *command __unused ) {
return -ENODEV;
}
/**
* 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 ) {
int rc;
DBGC2 ( scsi, "SCSI %p " SCSI_CDB_FORMAT "\n",
scsi, SCSI_CDB_DATA ( command->cdb ) );
/* Clear sense response code before issuing command */
command->sense_response = 0;
/* Flag command as in-progress */
command->rc = -EINPROGRESS;
/* Issue SCSI command */
if ( ( rc = scsi->command ( scsi, command ) ) != 0 ) {
/* Something went wrong with the issuing mechanism */
DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " err %s\n",
scsi, SCSI_CDB_DATA ( command->cdb ), strerror ( rc ) );
return rc;
}
/* Wait for command to complete */
while ( command->rc == -EINPROGRESS )
step();
if ( ( rc = command->rc ) != 0 ) {
/* Something went wrong with the command execution */
DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " err %s\n",
scsi, SCSI_CDB_DATA ( command->cdb ), strerror ( rc ) );
return rc;
}
/* Check for SCSI errors */
if ( command->status != 0 ) {
DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " status %02x sense "
"%02x\n", scsi, SCSI_CDB_DATA ( command->cdb ),
command->status, command->sense_response );
return -EIO;
}
return 0;
}
/**
* Read block from SCSI device using READ (10)
*
* @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_10 ( 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_10 *cdb = &command.cdb.read10;
/* Issue READ (10) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_READ_10;
cdb->lba = cpu_to_be32 ( block );
cdb->len = cpu_to_be16 ( count );
command.data_in = buffer;
command.data_in_len = ( count * blockdev->blksize );
return scsi_command ( scsi, &command );
}
/**
* Read block from SCSI device using READ (16)
*
* @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_16 ( 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 using WRITE (10)
*
* @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_10 ( 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_10 *cdb = &command.cdb.write10;
/* Issue WRITE (10) */
memset ( &command, 0, sizeof ( command ) );
cdb->opcode = SCSI_OPCODE_WRITE_10;
cdb->lba = cpu_to_be32 ( block );
cdb->len = cpu_to_be16 ( count );
command.data_out = buffer;
command.data_out_len = ( count * blockdev->blksize );
return scsi_command ( scsi, &command );
}
/**
* Write block to SCSI device using WRITE (16)
*
* @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_16 ( 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;
}
static struct block_device_operations scsi_operations_16 = {
.read = scsi_read_16,
.write = scsi_write_16,
};
static struct block_device_operations scsi_operations_10 = {
.read = scsi_read_10,
.write = scsi_write_10,
};
/**
* 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 ) {
unsigned int i;
int rc;
/* Issue some theoretically extraneous READ CAPACITY (10)
* commands, solely in order to draw out the "CHECK CONDITION
* (power-on occurred)", "CHECK CONDITION (reported LUNs data
* has changed)" etc. that some dumb targets insist on sending
* as an error at start of day. The precise command that we
* use is unimportant; we just need to provide the target with
* an opportunity to send its responses.
*/
for ( i = 0 ; i < SCSI_MAX_DUMMY_READ_CAP ; i++ ) {
if ( ( rc = scsi_read_capacity_10 ( &scsi->blockdev ) ) == 0 )
break;
DBGC ( scsi, "SCSI %p ignoring start-of-day error (#%d)\n",
scsi, ( i + 1 ) );
}
/* Try READ CAPACITY (10), which is a mandatory command, first. */
scsi->blockdev.op = &scsi_operations_10;
if ( ( rc = scsi_read_capacity_10 ( &scsi->blockdev ) ) != 0 ) {
DBGC ( scsi, "SCSI %p could not READ CAPACITY (10): %s\n",
scsi, strerror ( rc ) );
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 ( scsi->blockdev.blocks == 0 ) {
scsi->blockdev.op = &scsi_operations_16;
if ( ( rc = scsi_read_capacity_16 ( &scsi->blockdev ) ) != 0 ){
DBGC ( scsi, "SCSI %p could not READ CAPACITY (16): "
"%s\n", scsi, strerror ( rc ) );
return rc;
}
}
DBGC ( scsi, "SCSI %p using READ/WRITE (%d) commands\n", scsi,
( ( scsi->blockdev.op == &scsi_operations_10 ) ? 10 : 16 ) );
DBGC ( scsi, "SCSI %p capacity is %ld MB (%#llx blocks)\n", scsi,
( ( unsigned long ) ( scsi->blockdev.blocks >> 11 ) ),
scsi->blockdev.blocks );
return 0;
}
/**
* Parse SCSI LUN
*
* @v lun_string LUN string representation
* @v lun LUN to fill in
* @ret rc Return status code
*/
int scsi_parse_lun ( const char *lun_string, struct scsi_lun *lun ) {
char *p;
int i;
memset ( lun, 0, sizeof ( *lun ) );
if ( lun_string ) {
p = ( char * ) lun_string;
for ( i = 0 ; i < 4 ; i++ ) {
lun->u16[i] = htons ( strtoul ( p, &p, 16 ) );
if ( *p == '\0' )
break;
if ( *p != '-' )
return -EINVAL;
p++;
}
if ( *p )
return -EINVAL;
}
return 0;
}
