ibmvscsi.c

linux-2.6.15.6

	struct indirect_descriptor *indirect =
	    (struct indirect_descriptor *)data;

	sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);

	if (sg_mapped == 0)
		return 0;

	set_srp_direction(cmd, srp_cmd, sg_mapped);

	/* special case; we can use a single direct descriptor */
	if (sg_mapped == 1) {
		data->virtual_address = sg_dma_address(&sg[0]);
		data->length = sg_dma_len(&sg[0]);
		data->memory_handle = 0;
		return 1;
	}

	if (sg_mapped > SG_ALL) {
		printk(KERN_ERR
		       "ibmvscsi: More than %d mapped sg entries, got %d\n",
		       SG_ALL, sg_mapped);
		return 0;
	}

	indirect->head.virtual_address = 0;
	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
	indirect->head.memory_handle = 0;

	if (sg_mapped <= MAX_INDIRECT_BUFS) {
		total_length = map_sg_list(sg_mapped, sg, &indirect->list[0]);
		indirect->total_length = total_length;
		return 1;
	}

	/* get indirect table */
	if (!evt_struct->ext_list) {
		evt_struct->ext_list =(struct memory_descriptor*)
			dma_alloc_coherent(dev, 
				SG_ALL * sizeof(struct memory_descriptor),
				&evt_struct->ext_list_token, 0);
		if (!evt_struct->ext_list) {
		    printk(KERN_ERR
		   	"ibmvscsi: Can't allocate memory for indirect table\n");
			return 0;
			
		}
	}

	total_length = map_sg_list(sg_mapped, sg, evt_struct->ext_list);	

	indirect->total_length = total_length;
	indirect->head.virtual_address = evt_struct->ext_list_token;
	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
	memcpy(indirect->list, evt_struct->ext_list,
		MAX_INDIRECT_BUFS * sizeof(struct memory_descriptor));
	
 	return 1;
}

/**
 * map_single_data: - Maps memory and initializes memory decriptor fields
 * @cmd:	struct scsi_cmnd with the memory to be mapped
 * @srp_cmd:	srp_cmd that contains the memory descriptor
 * @dev:	device for which to map dma memory
 *
 * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 * Returns 1 on success.
*/
static int map_single_data(struct scsi_cmnd *cmd,
			   struct srp_cmd *srp_cmd, struct device *dev)
{
	struct memory_descriptor *data =
	    (struct memory_descriptor *)srp_cmd->additional_data;

	data->virtual_address =
		dma_map_single(dev, cmd->request_buffer,
			       cmd->request_bufflen,
			       DMA_BIDIRECTIONAL);
	if (dma_mapping_error(data->virtual_address)) {
		printk(KERN_ERR
		       "ibmvscsi: Unable to map request_buffer for command!\n");
		return 0;
	}
	data->length = cmd->request_bufflen;
	data->memory_handle = 0;

	set_srp_direction(cmd, srp_cmd, 1);

	return 1;
}

/**
 * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
 * @cmd:	struct scsi_cmnd with the memory to be mapped
 * @srp_cmd:	srp_cmd that contains the memory descriptor
 * @dev:	dma device for which to map dma memory
 *
 * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
 * Returns 1 on success.
*/
static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
				struct srp_event_struct *evt_struct,
				struct srp_cmd *srp_cmd, struct device *dev)
{
	switch (cmd->sc_data_direction) {
	case DMA_FROM_DEVICE:
	case DMA_TO_DEVICE:
		break;
	case DMA_NONE:
		return 1;
	case DMA_BIDIRECTIONAL:
		printk(KERN_ERR
		       "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
		return 0;
	default:
		printk(KERN_ERR
		       "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
		       cmd->sc_data_direction);
		return 0;
	}

	if (!cmd->request_buffer)
		return 1;
	if (cmd->use_sg)
		return map_sg_data(cmd, evt_struct, srp_cmd, dev);
	return map_single_data(cmd, srp_cmd, dev);
}

/* ------------------------------------------------------------
 * Routines for sending and receiving SRPs
 */
/**
 * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
 * @evt_struct:	evt_struct to be sent
 * @hostdata:	ibmvscsi_host_data of host
 *
 * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
 * Note that this routine assumes that host_lock is held for synchronization
*/
static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
				   struct ibmvscsi_host_data *hostdata)
{
	struct scsi_cmnd *cmnd;
	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
	int rc;

	/* If we have exhausted our request limit, just fail this request.
	 * Note that there are rare cases involving driver generated requests 
	 * (such as task management requests) that the mid layer may think we
	 * can handle more requests (can_queue) when we actually can't
	 */
	if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
	    (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
		/* See if the adapter is disabled */
		if (atomic_read(&hostdata->request_limit) < 0)
			goto send_error;
	
		printk(KERN_WARNING 
		       "ibmvscsi: Warning, request_limit exceeded\n");
		unmap_cmd_data(&evt_struct->iu.srp.cmd,
			       evt_struct,
			       hostdata->dev);
		free_event_struct(&hostdata->pool, evt_struct);
		return SCSI_MLQUEUE_HOST_BUSY;
	}

	/* 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, evt_struct, 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, 
			       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 indirect_descriptor *indirect;
	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;

	/* 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, evt_struct, 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;
	}

	init_event_struct(evt_struct,
			  handle_cmd_rsp,
			  VIOSRP_SRP_FORMAT,
			  cmnd->timeout_per_command/HZ);

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

	/* Fix up dma address of the buffer itself */
	indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
	if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
	    (indirect->head.virtual_address == 0)) {
		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;
		
		if (hostdata->madapter_info.os_type == 3 &&
		    strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
			printk("ibmvscsi: host (Ver. %s) doesn't support large"
			       "transfers\n",
			       hostdata->madapter_info.srp_version);
			printk("ibmvscsi: limiting scatterlists to %d\n",
			       MAX_INDIRECT_BUFS);
			hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
		}
	}
}

/**
 * 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;
	
	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;
	}