/*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <ipxe/list.h>
#include <ipxe/process.h>
#include <ipxe/xfer.h>
#include <ipxe/blockdev.h>
#include <ipxe/scsi.h>
/** @file
*
* SCSI block device
*
*/
/** Maximum number of TEST UNIT READY retries */
#define SCSI_READY_MAX_RETRIES 10
/* Error numbers generated by SCSI sense data */
#define EIO_NO_SENSE __einfo_error ( EINFO_EIO_NO_SENSE )
#define EINFO_EIO_NO_SENSE \
__einfo_uniqify ( EINFO_EIO, 0x00, "No sense" )
#define EIO_RECOVERED_ERROR __einfo_error ( EINFO_EIO_RECOVERED_ERROR )
#define EINFO_EIO_RECOVERED_ERROR \
__einfo_uniqify ( EINFO_EIO, 0x01, "Recovered error" )
#define EIO_NOT_READY __einfo_error ( EINFO_EIO_NOT_READY )
#define EINFO_EIO_NOT_READY \
__einfo_uniqify ( EINFO_EIO, 0x02, "Not ready" )
#define EIO_MEDIUM_ERROR __einfo_error ( EINFO_EIO_MEDIUM_ERROR )
#define EINFO_EIO_MEDIUM_ERROR \
__einfo_uniqify ( EINFO_EIO, 0x03, "Medium error" )
#define EIO_HARDWARE_ERROR __einfo_error ( EINFO_EIO_HARDWARE_ERROR )
#define EINFO_EIO_HARDWARE_ERROR \
__einfo_uniqify ( EINFO_EIO, 0x04, "Hardware error" )
#define EIO_ILLEGAL_REQUEST __einfo_error ( EINFO_EIO_ILLEGAL_REQUEST )
#define EINFO_EIO_ILLEGAL_REQUEST \
__einfo_uniqify ( EINFO_EIO, 0x05, "Illegal request" )
#define EIO_UNIT_ATTENTION __einfo_error ( EINFO_EIO_UNIT_ATTENTION )
#define EINFO_EIO_UNIT_ATTENTION \
__einfo_uniqify ( EINFO_EIO, 0x06, "Unit attention" )
#define EIO_DATA_PROTECT __einfo_error ( EINFO_EIO_DATA_PROTECT )
#define EINFO_EIO_DATA_PROTECT \
__einfo_uniqify ( EINFO_EIO, 0x07, "Data protect" )
#define EIO_BLANK_CHECK __einfo_error ( EINFO_EIO_BLANK_CHECK )
#define EINFO_EIO_BLANK_CHECK \
__einfo_uniqify ( EINFO_EIO, 0x08, "Blank check" )
#define EIO_VENDOR_SPECIFIC __einfo_error ( EINFO_EIO_VENDOR_SPECIFIC )
#define EINFO_EIO_VENDOR_SPECIFIC \
__einfo_uniqify ( EINFO_EIO, 0x09, "Vendor specific" )
#define EIO_COPY_ABORTED __einfo_error ( EINFO_EIO_COPY_ABORTED )
#define EINFO_EIO_COPY_ABORTED \
__einfo_uniqify ( EINFO_EIO, 0x0a, "Copy aborted" )
#define EIO_ABORTED_COMMAND __einfo_error ( EINFO_EIO_ABORTED_COMMAND )
#define EINFO_EIO_ABORTED_COMMAND \
__einfo_uniqify ( EINFO_EIO, 0x0b, "Aborted command" )
#define EIO_RESERVED __einfo_error ( EINFO_EIO_RESERVED )
#define EINFO_EIO_RESERVED \
__einfo_uniqify ( EINFO_EIO, 0x0c, "Reserved" )
#define EIO_VOLUME_OVERFLOW __einfo_error ( EINFO_EIO_VOLUME_OVERFLOW )
#define EINFO_EIO_VOLUME_OVERFLOW \
__einfo_uniqify ( EINFO_EIO, 0x0d, "Volume overflow" )
#define EIO_MISCOMPARE __einfo_error ( EINFO_EIO_MISCOMPARE )
#define EINFO_EIO_MISCOMPARE \
__einfo_uniqify ( EINFO_EIO, 0x0e, "Miscompare" )
#define EIO_COMPLETED __einfo_error ( EINFO_EIO_COMPLETED )
#define EINFO_EIO_COMPLETED \
__einfo_uniqify ( EINFO_EIO, 0x0f, "Completed" )
#define EIO_SENSE( key ) \
EUNIQ ( EINFO_EIO, (key), EIO_NO_SENSE, EIO_RECOVERED_ERROR, \
EIO_NOT_READY, EIO_MEDIUM_ERROR, EIO_HARDWARE_ERROR, \
EIO_ILLEGAL_REQUEST, EIO_UNIT_ATTENTION, \
EIO_DATA_PROTECT, EIO_BLANK_CHECK, EIO_VENDOR_SPECIFIC, \
EIO_COPY_ABORTED, EIO_ABORTED_COMMAND, EIO_RESERVED, \
EIO_VOLUME_OVERFLOW, EIO_MISCOMPARE, EIO_COMPLETED )
/******************************************************************************
*
* Utility functions
*
******************************************************************************
*/
/**
* 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;
}
/**
* Parse SCSI sense data
*
* @v data Raw sense data
* @v len Length of raw sense data
* @v sense Descriptor-format sense data to fill in
*/
void scsi_parse_sense ( const void *data, size_t len,
struct scsi_sns_descriptor *sense ) {
const union scsi_sns *sns = data;
/* Avoid returning uninitialised data */
memset ( sense, 0, sizeof ( *sense ) );
/* Copy, assuming descriptor-format data */
if ( len < sizeof ( sns->desc ) )
return;
memcpy ( sense, &sns->desc, sizeof ( *sense ) );
/* Convert fixed-format to descriptor-format, if applicable */
if ( len < sizeof ( sns->fixed ) )
return;
if ( ! SCSI_SENSE_FIXED ( sns->code ) )
return;
sense->additional = sns->fixed.additional;
}
/******************************************************************************
*
* Interface methods
*
******************************************************************************
*/
/**
* Issue SCSI command
*
* @v control SCSI control interface
* @v data SCSI data interface
* @v command SCSI command
* @ret tag Command tag, or negative error
*/
int scsi_command ( struct interface *control, struct interface *data,
struct scsi_cmd *command ) {
struct interface *dest;
scsi_command_TYPE ( void * ) *op =
intf_get_dest_op ( control, scsi_command, &dest );
void *object = intf_object ( dest );
int tap;
if ( op ) {
tap = op ( object, data, command );
} else {
/* Default is to fail to issue the command */
tap = -EOPNOTSUPP;
}
intf_put ( dest );
return tap;
}
/**
* Report SCSI response
*
* @v interface SCSI command interface
* @v response SCSI response
*/
void scsi_response ( struct interface *intf, struct scsi_rsp *response ) {
struct interface *dest;
scsi_response_TYPE ( void * ) *op =
intf_get_dest_op ( intf, scsi_response, &dest );
void *object = intf_object ( dest );
if ( op ) {
op ( object, response );
} else {
/* Default is to ignore the response */
}
intf_put ( dest );
}
/******************************************************************************
*
* SCSI devices and commands
*
******************************************************************************
*/
/** A SCSI device */
struct scsi_device {
/** Reference count */
struct refcnt refcnt;
/** Block control interface */
struct interface block;
/** SCSI control interface */
struct interface scsi;
/** SCSI LUN */
struct scsi_lun lun;
/** Flags */
unsigned int flags;
/** TEST UNIT READY interface */
struct interface ready;
/** TEST UNIT READY process */
struct process process;
/** TEST UNIT READY retry count */
unsigned int retries;
/** List of commands */
struct list_head cmds;
};
/** SCSI device flags */
enum scsi_device_flags {
/** TEST UNIT READY has been issued */
SCSIDEV_UNIT_TESTED = 0x0001,
/** TEST UNIT READY has completed successfully */
SCSIDEV_UNIT_READY = 0x0002,
};
/** A SCSI command */
struct scsi_command {
/** Reference count */
struct refcnt refcnt;
/** SCSI device */
struct scsi_device *scsidev;
/** List of SCSI commands */
struct list_head list;
/** Block data interface */
struct interface block;
/** SCSI data interface */
struct interface scsi;
/** Command type */
struct scsi_command_type *type;
/** Starting logical block address */
uint64_t lba;
/** Number of blocks */
unsigned int count;
/** Data buffer */
userptr_t buffer;
/** Length of data buffer */
size_t len;
/** Command tag */
uint32_t tag;
/** Private data */
uint8_t priv[0];
};
/** A SCSI command type */
struct scsi_command_type {
/** Name */
const char *name;
/** Additional working space */
size_t priv_len;
/**
* Construct SCSI command IU
*
* @v scsicmd SCSI command
* @v command SCSI command IU
*/
void ( * cmd ) ( struct scsi_command *scsicmd,
struct scsi_cmd *command );
/**
* Handle SCSI command completion
*
* @v scsicmd SCSI command
* @v rc Reason for completion
*/
void ( * done ) ( struct scsi_command *scsicmd, int rc );
};
/**
* Get reference to SCSI device
*
* @v scsidev SCSI device
* @ret scsidev SCSI device
*/
static inline __attribute__ (( always_inline )) struct scsi_device *
scsidev_get ( struct scsi_device *scsidev ) {
ref_get ( &scsidev->refcnt );
return scsidev;
}
/**
* Drop reference to SCSI device
*
* @v scsidev SCSI device
*/
static inline __attribute__ (( always_inline )) void
scsidev_put ( struct scsi_device *scsidev ) {
ref_put ( &scsidev->refcnt );
}
/**
* Get reference to SCSI command
*
* @v scsicmd SCSI command
* @ret scsicmd SCSI command
*/
static inline __attribute__ (( always_inline )) struct scsi_command *
scsicmd_get ( struct scsi_command *scsicmd ) {
ref_get ( &scsicmd->refcnt );
return scsicmd;
}
/**
* Drop reference to SCSI command
*
* @v scsicmd SCSI command
*/
static inline __attribute__ (( always_inline )) void
scsicmd_put ( struct scsi_command *scsicmd ) {
ref_put ( &scsicmd->refcnt );
}
/**
* Get SCSI command private data
*
* @v scsicmd SCSI command
* @ret priv Private data
*/
static inline __attribute__ (( always_inline )) void *
scsicmd_priv ( struct scsi_command *scsicmd ) {
return scsicmd->priv;
}
/**
* Free SCSI command
*
* @v refcnt Reference count
*/
static void scsicmd_free ( struct refcnt *refcnt ) {
struct scsi_command *scsicmd =
container_of ( refcnt, struct scsi_command, refcnt );
/* Drop reference to SCSI device */
scsidev_put ( scsicmd->scsidev );
/* Free command */
free ( scsicmd );
}
/**
* Close SCSI command
*
* @v scsicmd SCSI command
* @v rc Reason for close
*/
static void scsicmd_close ( struct scsi_command *scsicmd, int rc ) {
struct scsi_device *scsidev = scsicmd->scsidev;
if ( rc != 0 ) {
DBGC ( scsidev, "SCSI %p tag %08x closed: %s\n",
scsidev, scsicmd->tag, strerror ( rc ) );
}
/* Remove from list of commands */
list_del ( &scsicmd->list );
/* Shut down interfaces */
intfs_shutdown ( rc, &scsicmd->scsi, &scsicmd->block, NULL );
/* Drop list's reference */
scsicmd_put ( scsicmd );
}
/**
* Construct and issue SCSI command
*
* @ret rc Return status code
*/
static int scsicmd_command ( struct scsi_command *scsicmd ) {
struct scsi_device *scsidev = scsicmd->scsidev;
struct scsi_cmd command;
int tag;
int rc;
/* Construct command */
memset ( &command, 0, sizeof ( command ) );
memcpy ( &command.lun, &scsidev->lun, sizeof ( command.lun ) );
scsicmd->type->cmd ( scsicmd, &command );
/* Issue command */
if ( ( tag = scsi_command ( &scsidev->scsi, &scsicmd->scsi,
&command ) ) < 0 ) {
rc = tag;
DBGC ( scsidev, "SCSI %p could not issue command: %s\n",
scsidev, strerror ( rc ) );
return rc;
}
/* Record tag */
if ( scsicmd->tag ) {
DBGC ( scsidev, "SCSI %p tag %08x is now tag %08x\n",
scsidev, scsicmd->tag, tag );
}
scsicmd->tag = tag;
DBGC2 ( scsidev, "SCSI %p tag %08x %s " SCSI_CDB_FORMAT "\n",
scsidev, scsicmd->tag, scsicmd->type->name,
SCSI_CDB_DATA ( command.cdb ) );
return 0;
}
/**
* Handle SCSI command completion
*
* @v scsicmd SCSI command
* @v rc Reason for close
*/
static void scsicmd_done ( struct scsi_command *scsicmd, int rc ) {
/* Restart SCSI interface */
intf_restart ( &scsicmd->scsi, rc );
/* Hand over to the command completion handler */
scsicmd->type->done ( scsicmd, rc );
}
/**
* Handle SCSI response
*
* @v scsicmd SCSI command
* @v response SCSI response
*/
static void scsicmd_response ( struct scsi_command *scsicmd,
struct scsi_rsp *response ) {
struct scsi_device *scsidev = scsicmd->scsidev;
size_t overrun;
size_t underrun;
int rc;
if ( response->status == 0 ) {
scsicmd_done ( scsicmd, 0 );
} else {
DBGC ( scsidev, "SCSI %p tag %08x status %02x",
scsidev, scsicmd->tag, response->status );
if ( response->overrun > 0 ) {
overrun = response->overrun;
DBGC ( scsidev, " overrun +%zd", overrun );
} else if ( response->overrun < 0 ) {
underrun = -(response->overrun);
DBGC ( scsidev, " underrun -%zd", underrun );
}
DBGC ( scsidev, " sense %02x key %02x additional %04x\n",
( response->sense.code & SCSI_SENSE_CODE_MASK ),
( response->sense.key & SCSI_SENSE_KEY_MASK ),
ntohs ( response->sense.additional ) );
/* Construct error number from sense data */
rc = -EIO_SENSE ( response->sense.key & SCSI_SENSE_KEY_MASK );
scsicmd_done ( scsicmd, rc );
}
}
/**
* Construct SCSI READ command
*
* @v scsicmd SCSI command
* @v command SCSI command IU
*/
static void scsicmd_read_cmd ( struct scsi_command *scsicmd,
struct scsi_cmd *command ) {
if ( ( scsicmd->lba + scsicmd->count ) > SCSI_MAX_BLOCK_10 ) {
/* Use READ (16) */
command->cdb.read16.opcode = SCSI_OPCODE_READ_16;
command->cdb.read16.lba = cpu_to_be64 ( scsicmd->lba );
command->cdb.read16.len = cpu_to_be32 ( scsicmd->count );
} else {
/* Use READ (10) */
command->cdb.read10.opcode = SCSI_OPCODE_READ_10;
command->cdb.read10.lba = cpu_to_be32 ( scsicmd->lba );
command->cdb.read10.len = cpu_to_be16 ( scsicmd->count );
}
command->data_in = scsicmd->buffer;
command->data_in_len = scsicmd->len;
}
/** SCSI READ command type */
static struct scsi_command_type scsicmd_read = {
.name = "READ",
.cmd = scsicmd_read_cmd,
.done = scsicmd_close,
};
/**
* Construct SCSI WRITE command
*
* @v scsicmd SCSI command
* @v command SCSI command IU
*/
static void scsicmd_write_cmd ( struct scsi_command *scsicmd,
struct scsi_cmd *command ) {
if ( ( scsicmd->lba + scsicmd->count ) > SCSI_MAX_BLOCK_10 ) {
/* Use WRITE (16) */
command->cdb.write16.opcode = SCSI_OPCODE_WRITE_16;
command->cdb.write16.lba = cpu_to_be64 ( scsicmd->lba );
command->cdb.write16.len = cpu_to_be32 ( scsicmd->count );
} else {
/* Use WRITE (10) */
command->cdb.write10.opcode = SCSI_OPCODE_WRITE_10;
command->cdb.write10.lba = cpu_to_be32 ( scsicmd->lba );
command->cdb.write10.len = cpu_to_be16 ( scsicmd->count );
}
command->data_out = scsicmd->buffer;
command->data_out_len = scsicmd->len;
}
/** SCSI WRITE command type */
static struct scsi_command_type scsicmd_write = {
.name = "WRITE",
.cmd = scsicmd_write_cmd,
.done = scsicmd_close,
};
/** SCSI READ CAPACITY private data */
struct scsi_read_capacity_private {
/** Use READ CAPACITY (16) */
int use16;
/** Data buffer for READ CAPACITY commands */
union {
/** Data buffer for READ CAPACITY (10) */
struct scsi_capacity_10 capacity10;
/** Data buffer for READ CAPACITY (16) */
struct scsi_capacity_16 capacity16;
} capacity;
};
/**
* Construct SCSI READ CAPACITY command
*
* @v scsicmd SCSI command
* @v command SCSI command IU
*/
static void scsicmd_read_capacity_cmd ( struct scsi_command *scsicmd,
struct scsi_cmd *command ) {
struct scsi_read_capacity_private *priv = scsicmd_priv ( scsicmd );
struct scsi_cdb_read_capacity_16 *readcap16 = &command->cdb.readcap16;
struct scsi_cdb_read_capacity_10 *readcap10 = &command->cdb.readcap10;
struct scsi_capacity_16 *capacity16 = &priv->capacity.capacity16;
struct scsi_capacity_10 *capacity10 = &priv->capacity.capacity10;
if ( priv->use16 ) {
/* Use READ CAPACITY (16) */
readcap16->opcode = SCSI_OPCODE_SERVICE_ACTION_IN;
readcap16->service_action =
SCSI_SERVICE_ACTION_READ_CAPACITY_16;
readcap16->len = cpu_to_be32 ( sizeof ( *capacity16 ) );
command->data_in = virt_to_user ( capacity16 );
command->data_in_len = sizeof ( *capacity16 );
} else {
/* Use READ CAPACITY (10) */
readcap10->opcode = SCSI_OPCODE_READ_CAPACITY_10;
command->data_in = virt_to_user ( capacity10 );
command->data_in_len = sizeof ( *capacity10 );
}
}
/**
* Handle SCSI READ CAPACITY command completion
*
* @v scsicmd SCSI command
* @v rc Reason for completion
*/
static void scsicmd_read_capacity_done ( struct scsi_command *scsicmd,
int rc ) {
struct scsi_read_capacity_private *priv = scsicmd_priv ( scsicmd );
struct scsi_capacity_16 *capacity16 = &priv->capacity.capacity16;
struct scsi_capacity_10 *capacity10 = &priv->capacity.capacity10;
struct block_device_capacity capacity;
/* Close if command failed */
if ( rc != 0 ) {
scsicmd_close ( scsicmd, rc );
return;
}
/* Extract capacity */
if ( priv->use16 ) {
capacity.blocks = ( be64_to_cpu ( capacity16->lba ) + 1 );
capacity.blksize = be32_to_cpu ( capacity16->blksize );
} else {
capacity.blocks = ( be32_to_cpu ( capacity10->lba ) + 1 );
capacity.blksize = be32_to_cpu ( capacity10->blksize );
/* 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 ( capacity.blocks == 0 ) {
priv->use16 = 1;
if ( ( rc = scsicmd_command ( scsicmd ) ) != 0 ) {
scsicmd_close ( scsicmd, rc );
return;
}
return;
}
}
capacity.max_count = -1U;
/* Return capacity to caller */
block_capacity ( &scsicmd->block, &capacity );
/* Close command */
scsicmd_close ( scsicmd, 0 );
}
/** SCSI READ CAPACITY command type */
static struct scsi_command_type scsicmd_read_capacity = {
.name = "READ CAPACITY",
.priv_len = sizeof ( struct scsi_read_capacity_private ),
.cmd = scsicmd_read_capacity_cmd,
.done = scsicmd_read_capacity_done,
};
/**
* Construct SCSI TEST UNIT READY command
*
* @v scsicmd SCSI command
* @v command SCSI command IU
*/
static void scsicmd_test_unit_ready_cmd ( struct scsi_command *scsicmd __unused,
struct scsi_cmd *command ) {
struct scsi_cdb_test_unit_ready *testready = &command->cdb.testready;
testready->opcode = SCSI_OPCODE_TEST_UNIT_READY;
}
/** SCSI TEST UNIT READY command type */
static struct scsi_command_type scsicmd_test_unit_ready = {
.name = "TEST UNIT READY",
.cmd = scsicmd_test_unit_ready_cmd,
.done = scsicmd_close,
};
/** SCSI command block interface operations */
static struct interface_operation scsicmd_block_op[] = {
INTF_OP ( intf_close, struct scsi_command *, scsicmd_close ),
};
/** SCSI command block interface descriptor */
static struct interface_descriptor scsicmd_block_desc =
INTF_DESC_PASSTHRU ( struct scsi_command, block,
scsicmd_block_op, scsi );
/** SCSI command SCSI interface operations */
static struct interface_operation scsicmd_scsi_op[] = {
INTF_OP ( intf_close, struct scsi_command *, scsicmd_done ),
INTF_OP ( scsi_response, struct scsi_command *, scsicmd_response ),
};
/** SCSI command SCSI interface descriptor */
static struct interface_descriptor scsicmd_scsi_desc =
INTF_DESC_PASSTHRU ( struct scsi_command, scsi,
scsicmd_scsi_op, block );
/**
* Create SCSI command
*
* @v scsidev SCSI device
* @v block Block data interface
* @v type SCSI command type
* @v lba Starting logical block address
* @v count Number of blocks to transfer
* @v buffer Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
static int scsidev_command ( struct scsi_device *scsidev,
struct interface *block,
struct scsi_command_type *type,
uint64_t lba, unsigned int count,
userptr_t buffer, size_t len ) {
struct scsi_command *scsicmd;
int rc;
/* Allocate and initialise structure */
scsicmd = zalloc ( sizeof ( *scsicmd ) + type->priv_len );
if ( ! scsicmd ) {
rc = -ENOMEM;
goto err_zalloc;
}
ref_init ( &scsicmd->refcnt, scsicmd_free );
intf_init ( &scsicmd->block, &scsicmd_block_desc, &scsicmd->refcnt );
intf_init ( &scsicmd->scsi, &scsicmd_scsi_desc,
&scsicmd->refcnt );
scsicmd->scsidev = scsidev_get ( scsidev );
list_add ( &scsicmd->list, &scsidev->cmds );
scsicmd->type = type;
scsicmd->lba = lba;
scsicmd->count = count;
scsicmd->buffer = buffer;
scsicmd->len = len;
/* Issue SCSI command */
if ( ( rc = scsicmd_command ( scsicmd ) ) != 0 )
goto err_command;
/* Attach to parent interface, transfer reference to list, and return */
intf_plug_plug ( &scsicmd->block, block );
return 0;
err_command:
scsicmd_close ( scsicmd, rc );
ref_put ( &scsicmd->refcnt );
err_zalloc:
return rc;
}
/**
* Issue SCSI block read
*
* @v scsidev SCSI device
* @v block Block data interface
* @v lba Starting logical block address
* @v count Number of blocks to transfer
* @v buffer Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
static int scsidev_read ( struct scsi_device *scsidev,
struct interface *block,
uint64_t lba, unsigned int count,
userptr_t buffer, size_t len ) {
return scsidev_command ( scsidev, block, &scsicmd_read,
lba, count, buffer, len );
}
/**
* Issue SCSI block write
*
* @v scsidev SCSI device
* @v block Block data interface
* @v lba Starting logical block address
* @v count Number of blocks to transfer
* @v buffer Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
static int scsidev_write ( struct scsi_device *scsidev,
struct interface *block,
uint64_t lba, unsigned int count,
userptr_t buffer, size_t len ) {
return scsidev_command ( scsidev, block, &scsicmd_write,
lba, count, buffer, len );
}
/**
* Read SCSI device capacity
*
* @v scsidev SCSI device
* @v block Block data interface
* @ret rc Return status code
*/
static int scsidev_read_capacity ( struct scsi_device *scsidev,
struct interface *block ) {
return scsidev_command ( scsidev, block, &scsicmd_read_capacity,
0, 0, UNULL, 0 );
}
/**
* Test to see if SCSI device is ready
*
* @v scsidev SCSI device
* @v block Block data interface
* @ret rc Return status code
*/
static int scsidev_test_unit_ready ( struct scsi_device *scsidev,
struct interface *block ) {
return scsidev_command ( scsidev, block, &scsicmd_test_unit_ready,
0, 0, UNULL, 0 );
}
/**
* Check SCSI device flow-control window
*
* @v scsidev SCSI device
* @ret len Length of window
*/
static size_t scsidev_window ( struct scsi_device *scsidev ) {
/* Refuse commands until unit is confirmed ready */
if ( ! ( scsidev->flags & SCSIDEV_UNIT_READY ) )
return 0;
return xfer_window ( &scsidev->scsi );
}
/**
* Close SCSI device
*
* @v scsidev SCSI device
* @v rc Reason for close
*/
static void scsidev_close ( struct scsi_device *scsidev, int rc ) {
struct scsi_command *scsicmd;
struct scsi_command *tmp;
/* Stop process */
process_del ( &scsidev->process );
/* Shut down interfaces */
intfs_shutdown ( rc, &scsidev->block, &scsidev->scsi, &scsidev->ready,
NULL );
/* Shut down any remaining commands */
list_for_each_entry_safe ( scsicmd, tmp, &scsidev->cmds, list )
scsicmd_close ( scsicmd, rc );
}
/** SCSI device block interface operations */
static struct interface_operation scsidev_block_op[] = {
INTF_OP ( xfer_window, struct scsi_device *, scsidev_window ),
INTF_OP ( block_read, struct scsi_device *, scsidev_read ),
INTF_OP ( block_write, struct scsi_device *, scsidev_write ),
INTF_OP ( block_read_capacity, struct scsi_device *,
scsidev_read_capacity ),
INTF_OP ( intf_close, struct scsi_device *, scsidev_close ),
};
/** SCSI device block interface descriptor */
static struct interface_descriptor scsidev_block_desc =
INTF_DESC_PASSTHRU ( struct scsi_device, block,
scsidev_block_op, scsi );
/**
* Handle SCSI TEST UNIT READY response
*
* @v scsidev SCSI device
* @v rc Reason for close
*/
static void scsidev_ready ( struct scsi_device *scsidev, int rc ) {
/* Shut down interface */
intf_restart ( &scsidev->ready, rc );
/* Mark device as ready, if applicable */
if ( rc == 0 ) {
DBGC ( scsidev, "SCSI %p unit is ready\n", scsidev );
scsidev->flags |= SCSIDEV_UNIT_READY;
xfer_window_changed ( &scsidev->block );
return;
}
DBGC ( scsidev, "SCSI %p not ready: %s\n", scsidev, strerror ( rc ) );
/* SCSI targets have an annoying habit of returning occasional
* pointless "error" messages such as "power-on occurred", so
* we have to be prepared to retry commands.
*
* For most commands, we rely on the caller (e.g. the generic
* SAN device layer) to retry commands as needed. However, a
* TEST UNIT READY failure is used as an indication that the
* whole SCSI device is unavailable and should be closed. We
* must therefore perform this retry loop within the SCSI
* layer.
*/
if ( scsidev->retries++ < SCSI_READY_MAX_RETRIES ) {
DBGC ( scsidev, "SCSI %p retrying (retry %d)\n",
scsidev, scsidev->retries );
scsidev->flags &= ~SCSIDEV_UNIT_TESTED;
process_add ( &scsidev->process );
return;
}
/* Close device */
DBGC ( scsidev, "SCSI %p never became ready: %s\n",
scsidev, strerror ( rc ) );
scsidev_close ( scsidev, rc );
}
/** SCSI device TEST UNIT READY interface operations */
static struct interface_operation scsidev_ready_op[] = {
INTF_OP ( intf_close, struct scsi_device *, scsidev_ready ),
};
/** SCSI device TEST UNIT READY interface descriptor */
static struct interface_descriptor scsidev_ready_desc =
INTF_DESC ( struct scsi_device, ready, scsidev_ready_op );
/**
* SCSI TEST UNIT READY process
*
* @v scsidev SCSI device
*/
static void scsidev_step ( struct scsi_device *scsidev ) {
int rc;
/* Do nothing if we have already issued TEST UNIT READY */
if ( scsidev->flags & SCSIDEV_UNIT_TESTED )
return;
/* Wait until underlying SCSI device is ready */
if ( xfer_window ( &scsidev->scsi ) == 0 )
return;
DBGC ( scsidev, "SCSI %p waiting for unit to become ready\n",
scsidev );
/* Mark TEST UNIT READY as sent */
scsidev->flags |= SCSIDEV_UNIT_TESTED;
/* Issue TEST UNIT READY command */
if ( ( rc = scsidev_test_unit_ready ( scsidev, &scsidev->ready )) !=0){
scsidev_close ( scsidev, rc );
return;
}
}
/** SCSI device SCSI interface operations */
static struct interface_operation scsidev_scsi_op[] = {
INTF_OP ( xfer_window_changed, struct scsi_device *, scsidev_step ),
INTF_OP ( intf_close, struct scsi_device *, scsidev_close ),
};
/** SCSI device SCSI interface descriptor */
static struct interface_descriptor scsidev_scsi_desc =
INTF_DESC_PASSTHRU ( struct scsi_device, scsi,
scsidev_scsi_op, block );
/** SCSI device process descriptor */
static struct process_descriptor scsidev_process_desc =
PROC_DESC_ONCE ( struct scsi_device, process, scsidev_step );
/**
* Open SCSI device
*
* @v block Block control interface
* @v scsi SCSI control interface
* @v lun SCSI LUN
* @ret rc Return status code
*/
int scsi_open ( struct interface *block, struct interface *scsi,
struct scsi_lun *lun ) {
struct scsi_device *scsidev;
/* Allocate and initialise structure */
scsidev = zalloc ( sizeof ( *scsidev ) );
if ( ! scsidev )
return -ENOMEM;
ref_init ( &scsidev->refcnt, NULL );
intf_init ( &scsidev->block, &scsidev_block_desc, &scsidev->refcnt );
intf_init ( &scsidev->scsi, &scsidev_scsi_desc, &scsidev->refcnt );
intf_init ( &scsidev->ready, &scsidev_ready_desc, &scsidev->refcnt );
process_init ( &scsidev->process, &scsidev_process_desc,
&scsidev->refcnt );
INIT_LIST_HEAD ( &scsidev->cmds );
memcpy ( &scsidev->lun, lun, sizeof ( scsidev->lun ) );
DBGC ( scsidev, "SCSI %p created for LUN " SCSI_LUN_FORMAT "\n",
scsidev, SCSI_LUN_DATA ( scsidev->lun ) );
/* Attach to SCSI and parent interfaces, mortalise self, and return */
intf_plug_plug ( &scsidev->scsi, scsi );
intf_plug_plug ( &scsidev->block, block );
ref_put ( &scsidev->refcnt );
return 0;
}
