path: root/drivers/target/target_core_pscsi.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * Filename:  target_core_pscsi.c
 *
 * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
 *
 * (c) Copyright 2003-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 ******************************************************************************/

#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
#include <linux/blk_types.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/cdrom.h>
#include <linux/ratelimit.h>
#include <linux/module.h>
#include <asm/unaligned.h>

#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

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

#include "target_core_alua.h"
#include "target_core_internal.h"
#include "target_core_pscsi.h"

static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
{
	return container_of(dev, struct pscsi_dev_virt, dev);
}

static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
static enum rq_end_io_ret pscsi_req_done(struct request *, blk_status_t);

/*	pscsi_attach_hba():
 *
 * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
 *	from the passed SCSI Host ID.
 */
static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct pscsi_hba_virt *phv;

	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
	if (!phv) {
		pr_err("Unable to allocate struct pscsi_hba_virt\n");
		return -ENOMEM;
	}
	phv->phv_host_id = host_id;
	phv->phv_mode = PHV_VIRTUAL_HOST_ID;

	hba->hba_ptr = phv;

	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
		" Generic Target Core Stack %s\n", hba->hba_id,
		PSCSI_VERSION, TARGET_CORE_VERSION);
	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
	       hba->hba_id);

	return 0;
}

static void pscsi_detach_hba(struct se_hba *hba)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	struct Scsi_Host *scsi_host = phv->phv_lld_host;

	if (scsi_host) {
		scsi_host_put(scsi_host);

		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
			" Generic Target Core\n", hba->hba_id,
			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
			"Unknown");
	} else
		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
			" from Generic Target Core\n", hba->hba_id);

	kfree(phv);
	hba->hba_ptr = NULL;
}

static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	struct Scsi_Host *sh = phv->phv_lld_host;
	/*
	 * Release the struct Scsi_Host
	 */
	if (!mode_flag) {
		if (!sh)
			return 0;

		phv->phv_lld_host = NULL;
		phv->phv_mode = PHV_VIRTUAL_HOST_ID;

		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
			" %s\n", hba->hba_id, (sh->hostt->name) ?
			(sh->hostt->name) : "Unknown");

		scsi_host_put(sh);
		return 0;
	}
	/*
	 * Otherwise, locate struct Scsi_Host from the original passed
	 * pSCSI Host ID and enable for phba mode
	 */
	sh = scsi_host_lookup(phv->phv_host_id);
	if (!sh) {
		pr_err("pSCSI: Unable to locate SCSI Host for"
			" phv_host_id: %d\n", phv->phv_host_id);
		return -EINVAL;
	}

	phv->phv_lld_host = sh;
	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;

	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");

	return 1;
}

static void pscsi_tape_read_blocksize(struct se_device *dev,
		struct scsi_device *sdev)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
	int ret;

	buf = kzalloc(12, GFP_KERNEL);
	if (!buf)
		goto out_free;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = MODE_SENSE;
	cdb[4] = 0x0c; /* 12 bytes */

	ret = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, buf, 12, HZ, 1, NULL);
	if (ret)
		goto out_free;

	/*
	 * If MODE_SENSE still returns zero, set the default value to 1024.
	 */
	sdev->sector_size = get_unaligned_be24(&buf[9]);
out_free:
	if (!sdev->sector_size)
		sdev->sector_size = 1024;

	kfree(buf);
}

static void
pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
{
	if (sdev->inquiry_len < INQUIRY_LEN)
		return;
	/*
	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
	 */
	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
	snprintf(wwn->vendor, sizeof(wwn-><