path: root/drivers/target/target_core_sbc.c

/*
 * SCSI Block Commands (SBC) parsing and emulation.
 *
 * (c) Copyright 2002-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * 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
 * (at your option) 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ratelimit.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_tcq.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>

#include "target_core_internal.h"
#include "target_core_ua.h"


static sense_reason_t
sbc_emulate_readcapacity(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned char *cdb = cmd->t_task_cdb;
	unsigned long long blocks_long = dev->transport->get_blocks(dev);
	unsigned char *rbuf;
	unsigned char buf[8];
	u32 blocks;

	/*
	 * SBC-2 says:
	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
	 *   ADDRESS field is not set to zero, the device server shall
	 *   terminate the command with CHECK CONDITION status with
	 *   the sense key set to ILLEGAL REQUEST and the additional
	 *   sense code set to INVALID FIELD IN CDB.
	 *
	 * In SBC-3, these fields are obsolete, but some SCSI
	 * compliance tests actually check this, so we might as well
	 * follow SBC-2.
	 */
	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
		return TCM_INVALID_CDB_FIELD;

	if (blocks_long >= 0x00000000ffffffff)
		blocks = 0xffffffff;
	else
		blocks = (u32)blocks_long;

	buf[0] = (blocks >> 24) & 0xff;
	buf[1] = (blocks >> 16) & 0xff;
	buf[2] = (blocks >> 8) & 0xff;
	buf[3] = blocks & 0xff;
	buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
	buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
	buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
	buf[7] = dev->dev_attrib.block_size & 0xff;

	rbuf = transport_kmap_data_sg(cmd);
	if (rbuf) {
		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
		transport_kunmap_data_sg(cmd);
	}

	target_complete_cmd(cmd, GOOD);
	return 0;
}

static sense_reason_t
sbc_emulate_readcapacity_16(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned char *rbuf;
	unsigned char buf[32];
	unsigned long long blocks = dev->transport->get_blocks(dev);

	memset(buf, 0, sizeof(buf));
	buf[0] = (blocks >> 56) & 0xff;
	buf[1] = (blocks >> 48) & 0xff;
	buf[2] = (blocks >> 40) & 0xff;
	buf[3] = (blocks >> 32) & 0xff;
	buf[4] = (blocks >> 24) & 0xff;
	buf[5] = (blocks >> 16) & 0xff;
	buf[6] = (blocks >> 8) & 0xff;
	buf[7] = blocks & 0xff;
	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
	buf[11] = dev->dev_attrib.block_size & 0xff;
	/*
	 * Set Thin Provisioning Enable bit following sbc3r22 in section
	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
	 */
	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
		buf[14] = 0x80;

	rbuf = transport_kmap_data_sg(cmd);
	if (rbuf) {
		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
		transport_kunmap_data_sg(cmd);
	}

	target_complete_cmd(cmd, GOOD);
	return 0;
}

sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
{
	u32 num_blocks;

	if (cmd-><