ibmvscsi.c

h内核

	/* Copy the IU into the transfer area */
	*evt_struct->xfer_iu = evt_struct->iu;
	evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;

	/* Add this to the sent list.  We need to do this 
	 * before we actually send 
	 * in case it comes back REALLY fast
	 */
	list_add_tail(&evt_struct->list, &hostdata->sent);

	if ((rc =
	     ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
		list_del(&evt_struct->list);

		printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
		       rc);
		goto send_error;
	}

	return 0;

 send_error:
	unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);

	if ((cmnd = evt_struct->cmnd) != NULL) {
		cmnd->result = DID_ERROR << 16;
		evt_struct->cmnd_done(cmnd);
	} else if (evt_struct->done)
		evt_struct->done(evt_struct);
	
	free_event_struct(&hostdata->pool, evt_struct);
	return 0;
}

/**
 * handle_cmd_rsp: -  Handle responses from commands
 * @evt_struct:	srp_event_struct to be handled
 *
 * Used as a callback by when sending scsi cmds.
 * Gets called by ibmvscsi_handle_crq()
*/
static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
{
	struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
	struct scsi_cmnd *cmnd = evt_struct->cmnd;

	if (unlikely(rsp->type != SRP_RSP_TYPE)) {
		if (printk_ratelimit())
			printk(KERN_WARNING 
			       "ibmvscsi: bad SRP RSP type %d\n",
			       rsp->type);
	}
	
	if (cmnd) {
		cmnd->result = rsp->status;
		if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
			memcpy(cmnd->sense_buffer,
			       rsp->sense_and_response_data,
			       rsp->sense_data_list_length);
		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
			       evt_struct->hostdata->dev);

		if (rsp->doover)
			cmnd->resid = rsp->data_out_residual_count;
		else if (rsp->diover)
			cmnd->resid = rsp->data_in_residual_count;
	}

	if (evt_struct->cmnd_done)
		evt_struct->cmnd_done(cmnd);
}

/**
 * lun_from_dev: - Returns the lun of the scsi device
 * @dev:	struct scsi_device
 *
*/
static inline u16 lun_from_dev(struct scsi_device *dev)
{
	return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
}

/**
 * ibmvscsi_queue: - The queuecommand function of the scsi template 
 * @cmd:	struct scsi_cmnd to be executed
 * @done:	Callback function to be called when cmd is completed
*/
static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
				 void (*done) (struct scsi_cmnd *))
{
	struct srp_cmd *srp_cmd;
	struct srp_event_struct *evt_struct;
	struct ibmvscsi_host_data *hostdata =
		(struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
	u16 lun = lun_from_dev(cmnd->device);

	evt_struct = get_event_struct(&hostdata->pool);
	if (!evt_struct)
		return SCSI_MLQUEUE_HOST_BUSY;

	init_event_struct(evt_struct,
			  handle_cmd_rsp,
			  VIOSRP_SRP_FORMAT,
			  cmnd->timeout);

	evt_struct->cmnd = cmnd;
	evt_struct->cmnd_done = done;

	/* Set up the actual SRP IU */
	srp_cmd = &evt_struct->iu.srp.cmd;
	memset(srp_cmd, 0x00, sizeof(*srp_cmd));
	srp_cmd->type = SRP_CMD_TYPE;
	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
	srp_cmd->lun = ((u64) lun) << 48;

	if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
		printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
		free_event_struct(&hostdata->pool, evt_struct);
		return SCSI_MLQUEUE_HOST_BUSY;
	}

	/* Fix up dma address of the buffer itself */
	if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
		struct indirect_descriptor *indirect =
		    (struct indirect_descriptor *)srp_cmd->additional_data;
		indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
		    offsetof(struct srp_cmd, additional_data) +
		    offsetof(struct indirect_descriptor, list);
	}

	return ibmvscsi_send_srp_event(evt_struct, hostdata);
}

/* ------------------------------------------------------------
 * Routines for driver initialization
 */
/**
 * adapter_info_rsp: - Handle response to MAD adapter info request
 * @evt_struct:	srp_event_struct with the response
 *
 * Used as a "done" callback by when sending adapter_info. Gets called
 * by ibmvscsi_handle_crq()
*/
static void adapter_info_rsp(struct srp_event_struct *evt_struct)
{
	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
	dma_unmap_single(hostdata->dev,
			 evt_struct->iu.mad.adapter_info.buffer,
			 evt_struct->iu.mad.adapter_info.common.length,
			 DMA_BIDIRECTIONAL);

	if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
		printk("ibmvscsi: error %d getting adapter info\n",
		       evt_struct->xfer_iu->mad.adapter_info.common.status);
	} else {
		printk("ibmvscsi: host srp version: %s, "
		       "host partition %s (%d), OS %d, max io %u\n",
		       hostdata->madapter_info.srp_version,
		       hostdata->madapter_info.partition_name,
		       hostdata->madapter_info.partition_number,
		       hostdata->madapter_info.os_type,
		       hostdata->madapter_info.port_max_txu[0]);
		
		if (hostdata->madapter_info.port_max_txu[0]) 
			hostdata->host->max_sectors = 
				hostdata->madapter_info.port_max_txu[0] >> 9;
	}
}

/**
 * send_mad_adapter_info: - Sends the mad adapter info request
 *      and stores the result so it can be retrieved with
 *      sysfs.  We COULD consider causing a failure if the
 *      returned SRP version doesn't match ours.
 * @hostdata:	ibmvscsi_host_data of host
 * 
 * Returns zero if successful.
*/
static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
{
	struct viosrp_adapter_info *req;
	struct srp_event_struct *evt_struct;
	
	memset(&hostdata->madapter_info, 0x00, sizeof(hostdata->madapter_info));
	
	evt_struct = get_event_struct(&hostdata->pool);
	if (!evt_struct) {
		printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
		       "for ADAPTER_INFO_REQ!\n");
		return;
	}

	init_event_struct(evt_struct,
			  adapter_info_rsp,
			  VIOSRP_MAD_FORMAT,
			  init_timeout * HZ);
	
	req = &evt_struct->iu.mad.adapter_info;
	memset(req, 0x00, sizeof(*req));
	
	req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
	req->common.length = sizeof(hostdata->madapter_info);
	req->buffer = dma_map_single(hostdata->dev,
				     &hostdata->madapter_info,
				     sizeof(hostdata->madapter_info),
				     DMA_BIDIRECTIONAL);

	if (dma_mapping_error(req->buffer)) {
		printk(KERN_ERR
		       "ibmvscsi: Unable to map request_buffer "
		       "for adapter_info!\n");
		free_event_struct(&hostdata->pool, evt_struct);
		return;
	}
	
	if (ibmvscsi_send_srp_event(evt_struct, hostdata))
		printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
};

/**
 * login_rsp: - Handle response to SRP login request
 * @evt_struct:	srp_event_struct with the response
 *
 * Used as a "done" callback by when sending srp_login. Gets called
 * by ibmvscsi_handle_crq()
*/
static void login_rsp(struct srp_event_struct *evt_struct)
{
	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
	switch (evt_struct->xfer_iu->srp.generic.type) {
	case SRP_LOGIN_RSP_TYPE:	/* it worked! */
		break;
	case SRP_LOGIN_REJ_TYPE:	/* refused! */
		printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
		/* Login failed.  */
		atomic_set(&hostdata->request_limit, -1);
		return;
	default:
		printk(KERN_ERR
		       "ibmvscsi: Invalid login response typecode 0x%02x!\n",
		       evt_struct->xfer_iu->srp.generic.type);
		/* Login failed.  */
		atomic_set(&hostdata->request_limit, -1);
		return;
	}

	printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");

	if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
	    (max_requests - 2))
		evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
		    max_requests - 2;

	/* Now we know what the real request-limit is */
	atomic_set(&hostdata->request_limit,
		   evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);

	hostdata->host->can_queue =
	    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;

	if (hostdata->host->can_queue < 1) {
		printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
		return;
	}

	send_mad_adapter_info(hostdata);
	return;
}

/**
 * send_srp_login: - Sends the srp login
 * @hostdata:	ibmvscsi_host_data of host
 * 
 * Returns zero if successful.
*/
static int send_srp_login(struct ibmvscsi_host_data *hostdata)
{
	int rc;
	unsigned long flags;
	struct srp_login_req *login;
	struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
	if (!evt_struct) {
		printk(KERN_ERR
		       "ibmvscsi: couldn't allocate an event for login req!\n");
		return FAILED;
	}

	init_event_struct(evt_struct,
			  login_rsp,
			  VIOSRP_SRP_FORMAT,
			  init_timeout * HZ);

	login = &evt_struct->iu.srp.login_req;
	login->type = SRP_LOGIN_REQ_TYPE;
	login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
	login->required_buffer_formats = 0x0006;
	
	/* Start out with a request limit of 1, since this is negotiated in
	 * the login request we are just sending
	 */
	atomic_set(&hostdata->request_limit, 1);

	spin_lock_irqsave(hostdata->host->host_lock, flags);
	rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
	return rc;
};

/**
 * sync_completion: Signal that a synchronous command has completed
 * Note that after returning from this call, the evt_struct is freed.
 * the caller waiting on this completion shouldn't touch the evt_struct
 * again.
 */
static void sync_completion(struct srp_event_struct *evt_struct)
{
	/* copy the response back */
	if (evt_struct->sync_srp)
		*evt_struct->sync_srp = *evt_struct->xfer_iu;
	
	complete(&evt_struct->comp);
}

/**
 * ibmvscsi_abort: Abort a command...from scsi host template
 * send this over to the server and wait synchronously for the response
 */
static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
{
	struct ibmvscsi_host_data *hostdata =
	    (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
	struct srp_tsk_mgmt *tsk_mgmt;
	struct srp_event_struct *evt;
	struct srp_event_struct *tmp_evt, *found_evt;
	union viosrp_iu srp_rsp;
	int rsp_rc;
	u16 lun = lun_from_dev(cmd->device);

	/* First, find this command in our sent list so we can figure
	 * out the correct tag
	 */
	found_evt = NULL;
	list_for_each_entry(tmp_evt, &hostdata->sent, list) {
		if (tmp_evt->cmnd == cmd) {
			found_evt = tmp_evt;
			break;
		}
	}

	if (!found_evt) 
		return FAILED;

	evt = get_event_struct(&hostdata->pool);
	if (evt == NULL) {
		printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
		return FAILED;
	}
	
	init_event_struct(evt,
			  sync_completion,
			  VIOSRP_SRP_FORMAT,
			  init_timeout * HZ);

	tsk_mgmt = &evt->iu.srp.tsk_mgmt;
	
	/* Set up an abort SRP command */
	memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
	tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
	tsk_mgmt->lun = ((u64) lun) << 48;
	tsk_mgmt->task_mgmt_flags = 0x01;	/* ABORT TASK */
	tsk_mgmt->managed_task_tag = (u64) found_evt;

	printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
	       tsk_mgmt->lun, tsk_mgmt->managed_task_tag);

	evt->sync_srp = &srp_rsp;
	init_completion(&evt->comp);
	if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
		printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
		return FAILED;
	}

	spin_unlock_irq(hostdata->host->host_lock);
	wait_for_completion(&evt->comp);
	spin_lock_irq(hostdata->host->host_lock);

	/* make sure we got a good response */
	if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
		if (printk_ratelimit())
			printk(KERN_WARNING 
			       "ibmvscsi: abort bad SRP RSP type %d\n",
			       srp_rsp.srp.generic.type);
		return FAILED;
	}

	if (srp_rsp.srp.rsp.rspvalid)
		rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
	else
		rsp_rc = srp_rsp.srp.rsp.status;

	if (rsp_rc) {
		if (printk_ratelimit())
			printk(KERN_WARNING 
		       "ibmvscsi: abort code %d for task tag 0x%lx\n",
			       rsp_rc,
			       tsk_mgmt->managed_task_tag);
		return FAILED;
	}

	/* Because we dropped the spinlock above, it's possible
	 * The event is no longer in our list.  Make sure it didn't
	 * complete while we were aborting
	 */
	found_evt = NULL;
	list_for_each_entry(tmp_evt, &hostdata->sent, list) {
		if (tmp_evt->cmnd == cmd) {
			found_evt = tmp_evt;
			break;
		}
	}

	if (found_evt == NULL) {
		printk(KERN_INFO
		       "ibmvscsi: aborted task tag 0x%lx completed\n",
		       tsk_mgmt->managed_task_tag);
		return SUCCESS;
	}

	printk(KERN_INFO
	       "ibmvscsi: successfully aborted task tag 0x%lx\n",
	       tsk_mgmt->managed_task_tag);

	cmd->result = (DID_ABORT << 16);
	list_del(&found_evt->list);
	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
	free_event_struct(&found_evt->hostdata->pool, found_evt);
	atomic_inc(&hostdata->request_limit);
	return SUCCESS;
}

/**
 * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
 * template send this over to the server and wait synchronously for the 
 * response
 */
static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
	struct ibmvscsi_host_data *hostdata =
	    (struct ibmvscsi_host_data *)cmd->device->host->hostdata;

	struct srp_tsk_mgmt *tsk_mgmt;
	struct srp_event_struct *evt;
	struct srp_event_struct *tmp_evt, *pos;
	union viosrp_iu srp_rsp;
	int rsp_rc;
	u16 lun = lun_from_dev(cmd->device);

	evt = get_event_struct(&hostdata->pool);
	if (evt == NULL) {
		printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
		return FAILED;
	}
	
	init_event_struct(evt,
			  sync_completion,
			  VIOSRP_SRP_FORMAT,
			  init_timeout * HZ);

	tsk_mgmt = &evt->iu.srp.tsk_mgmt;

	/* Set up a lun reset SRP command */
	memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
	tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
	tsk_mgmt->lun = ((u64) lun) << 48;
	tsk_mgmt->task_mgmt_flags = 0x08;	/* LUN RESET */

	printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
	       tsk_mgmt->lun);

	evt->sync_srp = &srp_rsp;
	init_completion(&evt->comp);
	if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
		printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
		return FAILED;
	}

	spin_unlock_irq(hostdata->host->host_lock);
	wait_for_completion(&evt->comp);
	spin_lock_irq(hostdata->host->host_lock);