path: root/drivers/scsi/ibmvscsi/ibmvstgt.c

/*
 * IBM eServer i/pSeries Virtual SCSI Target Driver
 * Copyright (C) 2003-2005 Dave Boutcher (boutcher@us.ibm.com) IBM Corp.
 *			   Santiago Leon (santil@us.ibm.com) IBM Corp.
 *			   Linda Xie (lxie@us.ibm.com) IBM Corp.
 *
 * Copyright (C) 2005-2006 FUJITA Tomonori <tomof@acm.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/interrupt.h>
#include <linux/module.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tgt.h>
#include <scsi/libsrp.h>
#include <asm/hvcall.h>
#include <asm/iommu.h>
#include <asm/prom.h>
#include <asm/vio.h>

#include "ibmvscsi.h"

#define	INITIAL_SRP_LIMIT	16
#define	DEFAULT_MAX_SECTORS	512

#define	TGT_NAME	"ibmvstgt"

/*
 * Hypervisor calls.
 */
#define h_copy_rdma(l, sa, sb, da, db) \
			plpar_hcall_norets(H_COPY_RDMA, l, sa, sb, da, db)
#define h_send_crq(ua, l, h) \
			plpar_hcall_norets(H_SEND_CRQ, ua, l, h)
#define h_reg_crq(ua, tok, sz)\
			plpar_hcall_norets(H_REG_CRQ, ua, tok, sz);
#define h_free_crq(ua) \
			plpar_hcall_norets(H_FREE_CRQ, ua);

/* tmp - will replace with SCSI logging stuff */
#define eprintk(fmt, args...)					\
do {								\
	printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args);	\
} while (0)
/* #define dprintk eprintk */
#define dprintk(fmt, args...)

struct vio_port {
	struct vio_dev *dma_dev;

	struct crq_queue crq_queue;
	struct work_struct crq_work;

	unsigned long liobn;
	unsigned long riobn;
	struct srp_target *target;
};

static struct workqueue_struct *vtgtd;

/*
 * These are fixed for the system and come from the Open Firmware device tree.
 * We just store them here to save getting them every time.
 */
static char system_id[64] = "";
static char partition_name[97] = "UNKNOWN";
static unsigned int partition_number = -1;

static struct vio_port *target_to_port(struct srp_target *target)
{
	return (struct vio_port *) target->ldata;
}

static inline union viosrp_iu *vio_iu(struct iu_entry *iue)
{
	return (union viosrp_iu *) (iue->sbuf->buf);
}

static int send_iu(struct iu_entry *iue, uint64_t length, uint8_t format)
{
	struct srp_target *target = iue->target;
	struct vio_port *vport = target_to_port(target);
	long rc, rc1;
	union {
		struct viosrp_crq cooked;
		uint64_t raw[2];
	} crq;

	/* First copy the SRP */
	rc = h_copy_rdma(length, vport->liobn, iue->sbuf->dma,
			 vport->riobn, iue->remote_token);

	if (rc)
		eprintk("Error %ld transferring data\n", rc);

	crq.cooked.valid = 0x80;
	crq.cooked.format = format;
	crq.cooked.reserved = 0x00;
	crq.cooked.timeout = 0x00;
	crq.cooked.IU_length = length;
	crq.cooked.IU_data_ptr = vio_iu(iue)->srp.rsp.tag;

	if (rc == 0)
		crq.cooked.status = 0x99;	/* Just needs to be non-zero */
	else
		crq.cooked.status = 0x00;

	rc1 = h_send_crq(vport->dma_dev->unit_address, crq.raw[0], crq.raw[1]);

	if (rc1) {
		eprintk("%ld sending response\n", rc1);
		return rc1;
	}

	return rc;
}

#define SRP_RSP_SENSE_DATA_LEN	18

static int send_rsp(struct iu_entry *iue, struct scsi_cmnd *sc,
		    unsigned char status, unsigned char asc)
{
	union viosrp_iu *iu = vio_iu(iue);
	uint64_t tag = iu->srp.rsp.tag;

	/* If the linked bit is on and status is good */
	if (test_bit(V_LINKED, &iue->flags) && (status == NO_SENSE))
		status = 0x10;

	memset(iu, 0, sizeof(struct srp_rsp));
	iu->srp.rsp.opcode = SRP_RSP;
	iu->srp.rsp.req_lim_delta = 1;
	iu->srp.rsp.tag = tag;

	if (test_bit(V_DIOVER, &iue->flags))
		iu->srp.rsp.flags |= SRP_RSP_FLAG_DIOVER;

	iu->srp.rsp.data_in_res_cnt = 0;
	iu->srp.rsp.data_out_res_cnt = 0;

	iu->srp.rsp.flags &= ~SRP_RSP_FLAG_RSPVALID;

	iu->srp.rsp.resp_data_len = 0;
	iu->srp.rsp.status = status;
	if (status) {
		uint8_t *sense = iu->srp.rsp.data;

		if (sc) {
			iu->srp.rsp.flags |= SRP_RSP_FLAG_SNSVALID;
			iu->srp.rsp.sense_data_len