path: root/drivers/target/target_core_xcopy.c

/*******************************************************************************
 * Filename: target_core_xcopy.c
 *
 * This file contains support for SPC-4 Extended-Copy offload with generic
 * TCM backends.
 *
 * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
 *
 * Author:
 * Nicholas A. Bellinger <nab@daterainc.com>
 *
 * 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.
 *
 ******************************************************************************/

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/configfs.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <asm/unaligned.h>

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

#include "target_core_pr.h"
#include "target_core_ua.h"
#include "target_core_xcopy.h"

static struct workqueue_struct *xcopy_wq = NULL;
/*
 * From target_core_spc.c
 */
extern void spc_parse_naa_6h_vendor_specific(struct se_device *, unsigned char *);
/*
 * From target_core_device.c
 */
extern struct mutex g_device_mutex;
extern struct list_head g_device_list;
/*
 * From target_core_configfs.c
 */
extern struct configfs_subsystem *target_core_subsystem[];

static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
{
	int off = 0;

	buf[off++] = (0x6 << 4);
	buf[off++] = 0x01;
	buf[off++] = 0x40;
	buf[off] = (0x5 << 4);

	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
	return 0;
}

static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
					bool src)
{
	struct se_device *se_dev;
	struct configfs_subsystem *subsys = target_core_subsystem[0];
	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
	int rc;

	if (src == true)
		dev_wwn = &xop->dst_tid_wwn[0];
	else
		dev_wwn = &xop->src_tid_wwn[0];

	mutex_lock(&g_device_mutex);
	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {

		if (!se_dev->dev_attrib.emulate_3pc)
			continue;

		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);

		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
		if (rc != 0)
			continue;

		if (src == true) {
			xop->dst_dev = se_dev;
			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
				" se_dev\n", xop->dst_dev);
		} else {
			xop->src_dev = se_dev;
			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
				" se_dev\n", xop->src_dev);
		}

		rc = configfs_depend_item(subsys,
				&se_dev->dev_group.cg_item);
		if (rc != 0) {
			pr_err("configfs_depend_item attempt failed:"
				" %d for se_dev: %p\n", rc, se_dev);
			mutex_unlock(&g_device_mutex);
			return rc;
		}

		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
			" se_dev->se_dev_group: %p\n", subsys, se_dev,
			&se_dev->dev_group);

		mutex_unlock(&g_device_mutex);
		return 0;
	}
	mutex_unlock(&g_device_mutex);

	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
	return -EINVAL;
}

static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
				unsigned char *p, bool src)
{
	unsigned char *desc = p;
	unsigned short ript;
	u8 desig_len;
	/*
	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
	 */
	ript = get_unaligned_be16(&desc[2]);
	pr_debug(<