ib_srp.c

linux-2.6.15.6

				n * sizeof (struct srp_direct_buf);
		}
	} else {
		struct srp_direct_buf *buf = (void *) cmd->add_data;
		dma_addr_t dma;

		dma = dma_map_single(target->srp_host->dev->dma_device,
				     scmnd->request_buffer, scmnd->request_bufflen,
				     scmnd->sc_data_direction);
		if (dma_mapping_error(dma)) {
			printk(KERN_WARNING PFX "unable to map %p/%d (dir %d)\n",
			       scmnd->request_buffer, (int) scmnd->request_bufflen,
			       scmnd->sc_data_direction);
			return -EINVAL;
		}

		pci_unmap_addr_set(req, direct_mapping, dma);

		buf->va  = cpu_to_be64(dma);
		buf->key = cpu_to_be32(target->srp_host->mr->rkey);
		buf->len = cpu_to_be32(scmnd->request_bufflen);

		fmt = SRP_DATA_DESC_DIRECT;

		len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
	}

	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
		cmd->buf_fmt = fmt << 4;
	else
		cmd->buf_fmt = fmt;


	return len;
}

static void srp_unmap_data(struct scsi_cmnd *scmnd,
			   struct srp_target_port *target,
			   struct srp_request *req)
{
	if (!scmnd->request_buffer ||
	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
	    return;

	if (scmnd->use_sg)
		dma_unmap_sg(target->srp_host->dev->dma_device,
			     (struct scatterlist *) scmnd->request_buffer,
			     scmnd->use_sg, scmnd->sc_data_direction);
	else
		dma_unmap_single(target->srp_host->dev->dma_device,
				 pci_unmap_addr(req, direct_mapping),
				 scmnd->request_bufflen,
				 scmnd->sc_data_direction);
}

static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
{
	struct srp_request *req;
	struct scsi_cmnd *scmnd;
	unsigned long flags;
	s32 delta;

	delta = (s32) be32_to_cpu(rsp->req_lim_delta);

	spin_lock_irqsave(target->scsi_host->host_lock, flags);

	target->req_lim += delta;

	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];

	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
		if (be32_to_cpu(rsp->resp_data_len) < 4)
			req->tsk_status = -1;
		else
			req->tsk_status = rsp->data[3];
		complete(&req->done);
	} else {
		scmnd 	      = req->scmnd;
		if (!scmnd)
			printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
			       (unsigned long long) rsp->tag);
		scmnd->result = rsp->status;

		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
			memcpy(scmnd->sense_buffer, rsp->data +
			       be32_to_cpu(rsp->resp_data_len),
			       min_t(int, be32_to_cpu(rsp->sense_data_len),
				     SCSI_SENSE_BUFFERSIZE));
		}

		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
			scmnd->resid = be32_to_cpu(rsp->data_out_res_cnt);
		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
			scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);

		srp_unmap_data(scmnd, target, req);

		if (!req->tsk_mgmt) {
			req->scmnd = NULL;
			scmnd->host_scribble = (void *) -1L;
			scmnd->scsi_done(scmnd);

			list_del(&req->list);
			req->next = target->req_head;
			target->req_head = rsp->tag & ~SRP_TAG_TSK_MGMT;
		} else
			req->cmd_done = 1;
	}

	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
}

static void srp_reconnect_work(void *target_ptr)
{
	struct srp_target_port *target = target_ptr;

	srp_reconnect_target(target);
}

static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
{
	struct srp_iu *iu;
	u8 opcode;

	iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];

	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
				target->max_ti_iu_len, DMA_FROM_DEVICE);

	opcode = *(u8 *) iu->buf;

	if (0) {
		int i;

		printk(KERN_ERR PFX "recv completion, opcode 0x%02x\n", opcode);

		for (i = 0; i < wc->byte_len; ++i) {
			if (i % 8 == 0)
				printk(KERN_ERR "  [%02x] ", i);
			printk(" %02x", ((u8 *) iu->buf)[i]);
			if ((i + 1) % 8 == 0)
				printk("\n");
		}

		if (wc->byte_len % 8)
			printk("\n");
	}

	switch (opcode) {
	case SRP_RSP:
		srp_process_rsp(target, iu->buf);
		break;

	case SRP_T_LOGOUT:
		/* XXX Handle target logout */
		printk(KERN_WARNING PFX "Got target logout request\n");
		break;

	default:
		printk(KERN_WARNING PFX "Unhandled SRP opcode 0x%02x\n", opcode);
		break;
	}

	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
				   target->max_ti_iu_len, DMA_FROM_DEVICE);
}

static void srp_completion(struct ib_cq *cq, void *target_ptr)
{
	struct srp_target_port *target = target_ptr;
	struct ib_wc wc;
	unsigned long flags;

	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
	while (ib_poll_cq(cq, 1, &wc) > 0) {
		if (wc.status) {
			printk(KERN_ERR PFX "failed %s status %d\n",
			       wc.wr_id & SRP_OP_RECV ? "receive" : "send",
			       wc.status);
			spin_lock_irqsave(target->scsi_host->host_lock, flags);
			if (target->state == SRP_TARGET_LIVE)
				schedule_work(&target->work);
			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
			break;
		}

		if (wc.wr_id & SRP_OP_RECV)
			srp_handle_recv(target, &wc);
		else
			++target->tx_tail;
	}
}

static int __srp_post_recv(struct srp_target_port *target)
{
	struct srp_iu *iu;
	struct ib_sge list;
	struct ib_recv_wr wr, *bad_wr;
	unsigned int next;
	int ret;

	next 	 = target->rx_head & (SRP_RQ_SIZE - 1);
	wr.wr_id = next | SRP_OP_RECV;
	iu 	 = target->rx_ring[next];

	list.addr   = iu->dma;
	list.length = iu->size;
	list.lkey   = target->srp_host->mr->lkey;

	wr.next     = NULL;
	wr.sg_list  = &list;
	wr.num_sge  = 1;

	ret = ib_post_recv(target->qp, &wr, &bad_wr);
	if (!ret)
		++target->rx_head;

	return ret;
}

static int srp_post_recv(struct srp_target_port *target)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(target->scsi_host->host_lock, flags);
	ret = __srp_post_recv(target);
	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);

	return ret;
}

/*
 * Must be called with target->scsi_host->host_lock held to protect
 * req_lim and tx_head.  Lock cannot be dropped between call here and
 * call to __srp_post_send().
 */
static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target)
{
	if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
		return NULL;

	if (unlikely(target->req_lim < 1)) {
		if (printk_ratelimit())
			printk(KERN_DEBUG PFX "Target has req_lim %d\n",
			       target->req_lim);
		return NULL;
	}

	return target->tx_ring[target->tx_head & SRP_SQ_SIZE];
}

/*
 * Must be called with target->scsi_host->host_lock held to protect
 * req_lim and tx_head.
 */
static int __srp_post_send(struct srp_target_port *target,
			   struct srp_iu *iu, int len)
{
	struct ib_sge list;
	struct ib_send_wr wr, *bad_wr;
	int ret = 0;

	list.addr   = iu->dma;
	list.length = len;
	list.lkey   = target->srp_host->mr->lkey;

	wr.next       = NULL;
	wr.wr_id      = target->tx_head & SRP_SQ_SIZE;
	wr.sg_list    = &list;
	wr.num_sge    = 1;
	wr.opcode     = IB_WR_SEND;
	wr.send_flags = IB_SEND_SIGNALED;

	ret = ib_post_send(target->qp, &wr, &bad_wr);

	if (!ret) {
		++target->tx_head;
		--target->req_lim;
	}

	return ret;
}

static int srp_queuecommand(struct scsi_cmnd *scmnd,
			    void (*done)(struct scsi_cmnd *))
{
	struct srp_target_port *target = host_to_target(scmnd->device->host);
	struct srp_request *req;
	struct srp_iu *iu;
	struct srp_cmd *cmd;
	long req_index;
	int len;

	if (target->state == SRP_TARGET_CONNECTING)
		goto err;

	if (target->state == SRP_TARGET_DEAD ||
	    target->state == SRP_TARGET_REMOVED) {
		scmnd->result = DID_BAD_TARGET << 16;
		done(scmnd);
		return 0;
	}

	iu = __srp_get_tx_iu(target);
	if (!iu)
		goto err;

	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
				SRP_MAX_IU_LEN, DMA_TO_DEVICE);

	req_index = target->req_head;

	scmnd->scsi_done     = done;
	scmnd->result        = 0;
	scmnd->host_scribble = (void *) req_index;

	cmd = iu->buf;
	memset(cmd, 0, sizeof *cmd);

	cmd->opcode = SRP_CMD;
	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
	cmd->tag    = req_index;
	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);

	req = &target->req_ring[req_index];

	req->scmnd    = scmnd;
	req->cmd      = iu;
	req->cmd_done = 0;
	req->tsk_mgmt = NULL;

	len = srp_map_data(scmnd, target, req);
	if (len < 0) {
		printk(KERN_ERR PFX "Failed to map data\n");
		goto err;
	}

	if (__srp_post_recv(target)) {
		printk(KERN_ERR PFX "Recv failed\n");
		goto err_unmap;
	}

	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
				   SRP_MAX_IU_LEN, DMA_TO_DEVICE);

	if (__srp_post_send(target, iu, len)) {
		printk(KERN_ERR PFX "Send failed\n");
		goto err_unmap;
	}

	target->req_head = req->next;
	list_add_tail(&req->list, &target->req_queue);

	return 0;

err_unmap:
	srp_unmap_data(scmnd, target, req);

err:
	return SCSI_MLQUEUE_HOST_BUSY;
}

static int srp_alloc_iu_bufs(struct srp_target_port *target)
{
	int i;

	for (i = 0; i < SRP_RQ_SIZE; ++i) {
		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
						  target->max_ti_iu_len,
						  GFP_KERNEL, DMA_FROM_DEVICE);
		if (!target->rx_ring[i])
			goto err;
	}

	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
						  SRP_MAX_IU_LEN,
						  GFP_KERNEL, DMA_TO_DEVICE);
		if (!target->tx_ring[i])
			goto err;
	}

	return 0;

err:
	for (i = 0; i < SRP_RQ_SIZE; ++i) {
		srp_free_iu(target->srp_host, target->rx_ring[i]);
		target->rx_ring[i] = NULL;
	}

	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
		srp_free_iu(target->srp_host, target->tx_ring[i]);
		target->tx_ring[i] = NULL;
	}

	return -ENOMEM;
}

static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
			       struct ib_cm_event *event,
			       struct srp_target_port *target)
{
	struct ib_class_port_info *cpi;
	int opcode;

	switch (event->param.rej_rcvd.reason) {
	case IB_CM_REJ_PORT_CM_REDIRECT:
		cpi = event->param.rej_rcvd.ari;
		target->path.dlid = cpi->redirect_lid;
		target->path.pkey = cpi->redirect_pkey;
		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);

		target->status = target->path.dlid ?
			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
		break;

	case IB_CM_REJ_PORT_REDIRECT:
		if (topspin_workarounds &&
		    !memcmp(&target->ioc_guid, topspin_oui, 3)) {
			/*
			 * Topspin/Cisco SRP gateways incorrectly send
			 * reject reason code 25 when they mean 24
			 * (port redirect).
			 */
			memcpy(target->path.dgid.raw,
			       event->param.rej_rcvd.ari, 16);

			printk(KERN_DEBUG PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
			       (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
			       (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));

			target->status = SRP_PORT_REDIRECT;
		} else {
			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
			target->status = -ECONNRESET;
		}
		break;

	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
		printk(KERN_WARNING "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
		target->status = -ECONNRESET;
		break;

	case IB_CM_REJ_CONSUMER_DEFINED:
		opcode = *(u8 *) event->private_data;
		if (opcode == SRP_LOGIN_REJ) {
			struct srp_login_rej *rej = event->private_data;
			u32 reason = be32_to_cpu(rej->reason);

			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
				printk(KERN_WARNING PFX
				       "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
			else
				printk(KERN_WARNING PFX
				       "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
		} else
			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
			       " opcode 0x%02x\n", opcode);
		target->status = -ECONNRESET;
		break;

	default:
		printk(KERN_WARNING "  REJ reason 0x%x\n",
		       event->param.rej_rcvd.reason);
		target->status = -ECONNRESET;
	}
}

static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
{
	struct srp_target_port *target = cm_id->context;
	struct ib_qp_attr *qp_attr = NULL;
	int attr_mask = 0;
	int comp = 0;
	int opcode = 0;

	switch (event->event) {
	case IB_CM_REQ_ERROR:
		printk(KERN_DEBUG PFX "Sending CM REQ failed\n");
		comp = 1;
		target->status = -ECONNRESET;
		break;

	case IB_CM_REP_RECEIVED:
		comp = 1;
		opcode = *(u8 *) event->private_data;

		if (opcode == SRP_LOGIN_RSP) {
			struct srp_login_rsp *rsp = event->private_data;

			target->max_ti_iu_len = be32_to_cpu(rsp->max_ti_iu_len);
			target->req_lim       = be32_to_cpu(rsp->req_lim_delta);

			target->scsi_host->can_queue = min(target->req_lim,
							   target->scsi_host->can_queue);
		} else {
			printk(KERN_WARNING PFX "Unhandled RSP opcode %#x\n", opcode);
			target->status = -ECONNRESET;
			break;
		}

		target->status = srp_alloc_iu_bufs(target);
		if (target->status)
			break;

		qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
		if (!qp_attr) {
			target->status = -ENOMEM;
			break;
		}

		qp_attr->qp_state = IB_QPS_RTR;
		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
		if (target->status)
			break;

		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
		if (target->status)
			break;

		target->status = srp_post_recv(target);
		if (target->status)
			break;

		qp_attr->qp_state = IB_QPS_RTS;
		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
		if (target->status)
			break;

		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
		if (target->status)
			break;

		target->status = ib_send_cm_rtu(cm_id, NULL, 0);
		if (target->status)
			break;

		break;

	case IB_CM_REJ_RECEIVED:
		printk(KERN_DEBUG PFX "REJ received\n");
		comp = 1;

		srp_cm_rej_handler(cm_id, event, target);
		break;

	case IB_CM_MRA_RECEIVED:
		printk(KERN_ERR PFX "MRA received\n");
		break;

	case IB_CM_DREP_RECEIVED:
		break;

	case IB_CM_TIMEWAIT_EXIT:
		printk(KERN_ERR PFX "connection closed\n");

		comp = 1;
		target->status = 0;
		break;

	default:
		printk(KERN_WARNING PFX "Unhandled CM event %d\n", event->event);
		break;
	}

	if (comp)