fw-sbp2.c

linux 内核源代码

				     SBP2_RECONNECT_REQUEST,
				     lu->login_id, NULL) < 0) {
		if (lu->retries++ >= 5) {
			fw_error("failed to reconnect to %s\n",
				 unit->device.bus_id);
			/* Fall back and try to log in again. */
			lu->retries = 0;
			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
		}
		if (queue_delayed_work(sbp2_wq, &lu->work, DIV_ROUND_UP(HZ, 5)))
			kref_get(&lu->tgt->kref);
		kref_put(&lu->tgt->kref, sbp2_release_target);
		return;
	}

	lu->generation        = generation;
	lu->tgt->node_id      = node_id;
	lu->tgt->address_high = local_node_id << 16;

	fw_notify("reconnected to %s LUN %04x (%d retries)\n",
		  unit->device.bus_id, lu->lun, lu->retries);

	sbp2_agent_reset(lu);
	sbp2_cancel_orbs(lu);

	kref_put(&lu->tgt->kref, sbp2_release_target);
}

static void sbp2_update(struct fw_unit *unit)
{
	struct sbp2_target *tgt = unit->device.driver_data;
	struct sbp2_logical_unit *lu;

	fw_device_enable_phys_dma(fw_device(unit->device.parent));

	/*
	 * Fw-core serializes sbp2_update() against sbp2_remove().
	 * Iteration over tgt->lu_list is therefore safe here.
	 */
	list_for_each_entry(lu, &tgt->lu_list, link) {
		lu->retries = 0;
		if (queue_delayed_work(sbp2_wq, &lu->work, 0))
			kref_get(&tgt->kref);
	}
}

#define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
#define SBP2_SW_VERSION_ENTRY	0x00010483

static const struct fw_device_id sbp2_id_table[] = {
	{
		.match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
		.version      = SBP2_SW_VERSION_ENTRY,
	},
	{ }
};

static struct fw_driver sbp2_driver = {
	.driver   = {
		.owner  = THIS_MODULE,
		.name   = sbp2_driver_name,
		.bus    = &fw_bus_type,
		.probe  = sbp2_probe,
		.remove = sbp2_remove,
	},
	.update   = sbp2_update,
	.id_table = sbp2_id_table,
};

static unsigned int
sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
{
	int sam_status;

	sense_data[0] = 0x70;
	sense_data[1] = 0x0;
	sense_data[2] = sbp2_status[1];
	sense_data[3] = sbp2_status[4];
	sense_data[4] = sbp2_status[5];
	sense_data[5] = sbp2_status[6];
	sense_data[6] = sbp2_status[7];
	sense_data[7] = 10;
	sense_data[8] = sbp2_status[8];
	sense_data[9] = sbp2_status[9];
	sense_data[10] = sbp2_status[10];
	sense_data[11] = sbp2_status[11];
	sense_data[12] = sbp2_status[2];
	sense_data[13] = sbp2_status[3];
	sense_data[14] = sbp2_status[12];
	sense_data[15] = sbp2_status[13];

	sam_status = sbp2_status[0] & 0x3f;

	switch (sam_status) {
	case SAM_STAT_GOOD:
	case SAM_STAT_CHECK_CONDITION:
	case SAM_STAT_CONDITION_MET:
	case SAM_STAT_BUSY:
	case SAM_STAT_RESERVATION_CONFLICT:
	case SAM_STAT_COMMAND_TERMINATED:
		return DID_OK << 16 | sam_status;

	default:
		return DID_ERROR << 16;
	}
}

static void
complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
{
	struct sbp2_command_orb *orb =
		container_of(base_orb, struct sbp2_command_orb, base);
	struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
	int result;

	if (status != NULL) {
		if (STATUS_GET_DEAD(*status))
			sbp2_agent_reset(orb->lu);

		switch (STATUS_GET_RESPONSE(*status)) {
		case SBP2_STATUS_REQUEST_COMPLETE:
			result = DID_OK << 16;
			break;
		case SBP2_STATUS_TRANSPORT_FAILURE:
			result = DID_BUS_BUSY << 16;
			break;
		case SBP2_STATUS_ILLEGAL_REQUEST:
		case SBP2_STATUS_VENDOR_DEPENDENT:
		default:
			result = DID_ERROR << 16;
			break;
		}

		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
							   orb->cmd->sense_buffer);
	} else {
		/*
		 * If the orb completes with status == NULL, something
		 * went wrong, typically a bus reset happened mid-orb
		 * or when sending the write (less likely).
		 */
		result = DID_BUS_BUSY << 16;
	}

	dma_unmap_single(device->card->device, orb->base.request_bus,
			 sizeof(orb->request), DMA_TO_DEVICE);

	if (scsi_sg_count(orb->cmd) > 0)
		dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
			     scsi_sg_count(orb->cmd),
			     orb->cmd->sc_data_direction);

	if (orb->page_table_bus != 0)
		dma_unmap_single(device->card->device, orb->page_table_bus,
				 sizeof(orb->page_table), DMA_TO_DEVICE);

	orb->cmd->result = result;
	orb->done(orb->cmd);
}

static int
sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
		     struct sbp2_logical_unit *lu)
{
	struct scatterlist *sg;
	int sg_len, l, i, j, count;
	dma_addr_t sg_addr;

	sg = scsi_sglist(orb->cmd);
	count = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
			   orb->cmd->sc_data_direction);
	if (count == 0)
		goto fail;

	/*
	 * Handle the special case where there is only one element in
	 * the scatter list by converting it to an immediate block
	 * request. This is also a workaround for broken devices such
	 * as the second generation iPod which doesn't support page
	 * tables.
	 */
	if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
		orb->request.data_descriptor.high = lu->tgt->address_high;
		orb->request.data_descriptor.low  = sg_dma_address(sg);
		orb->request.misc |= COMMAND_ORB_DATA_SIZE(sg_dma_len(sg));
		return 0;
	}

	/*
	 * Convert the scatterlist to an sbp2 page table.  If any
	 * scatterlist entries are too big for sbp2, we split them as we
	 * go.  Even if we ask the block I/O layer to not give us sg
	 * elements larger than 65535 bytes, some IOMMUs may merge sg elements
	 * during DMA mapping, and Linux currently doesn't prevent this.
	 */
	for (i = 0, j = 0; i < count; i++) {
		sg_len = sg_dma_len(sg + i);
		sg_addr = sg_dma_address(sg + i);
		while (sg_len) {
			/* FIXME: This won't get us out of the pinch. */
			if (unlikely(j >= ARRAY_SIZE(orb->page_table))) {
				fw_error("page table overflow\n");
				goto fail_page_table;
			}
			l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
			orb->page_table[j].low = sg_addr;
			orb->page_table[j].high = (l << 16);
			sg_addr += l;
			sg_len -= l;
			j++;
		}
	}

	fw_memcpy_to_be32(orb->page_table, orb->page_table,
			  sizeof(orb->page_table[0]) * j);
	orb->page_table_bus =
		dma_map_single(device->card->device, orb->page_table,
			       sizeof(orb->page_table), DMA_TO_DEVICE);
	if (dma_mapping_error(orb->page_table_bus))
		goto fail_page_table;

	/*
	 * The data_descriptor pointer is the one case where we need
	 * to fill in the node ID part of the address.  All other
	 * pointers assume that the data referenced reside on the
	 * initiator (i.e. us), but data_descriptor can refer to data
	 * on other nodes so we need to put our ID in descriptor.high.
	 */
	orb->request.data_descriptor.high = lu->tgt->address_high;
	orb->request.data_descriptor.low  = orb->page_table_bus;
	orb->request.misc |=
		COMMAND_ORB_PAGE_TABLE_PRESENT |
		COMMAND_ORB_DATA_SIZE(j);

	return 0;

 fail_page_table:
	dma_unmap_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
		     orb->cmd->sc_data_direction);
 fail:
	return -ENOMEM;
}

/* SCSI stack integration */

static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
{
	struct sbp2_logical_unit *lu = cmd->device->hostdata;
	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
	struct sbp2_command_orb *orb;
	unsigned max_payload;
	int retval = SCSI_MLQUEUE_HOST_BUSY;

	/*
	 * Bidirectional commands are not yet implemented, and unknown
	 * transfer direction not handled.
	 */
	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
		fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
		cmd->result = DID_ERROR << 16;
		done(cmd);
		return 0;
	}

	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
	if (orb == NULL) {
		fw_notify("failed to alloc orb\n");
		return SCSI_MLQUEUE_HOST_BUSY;
	}

	/* Initialize rcode to something not RCODE_COMPLETE. */
	orb->base.rcode = -1;
	kref_init(&orb->base.kref);

	orb->lu   = lu;
	orb->done = done;
	orb->cmd  = cmd;

	orb->request.next.high   = SBP2_ORB_NULL;
	orb->request.next.low    = 0x0;
	/*
	 * At speed 100 we can do 512 bytes per packet, at speed 200,
	 * 1024 bytes per packet etc.  The SBP-2 max_payload field
	 * specifies the max payload size as 2 ^ (max_payload + 2), so
	 * if we set this to max_speed + 7, we get the right value.
	 */
	max_payload = min(device->max_speed + 7,
			  device->card->max_receive - 1);
	orb->request.misc =
		COMMAND_ORB_MAX_PAYLOAD(max_payload) |
		COMMAND_ORB_SPEED(device->max_speed) |
		COMMAND_ORB_NOTIFY;

	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
		orb->request.misc |=
			COMMAND_ORB_DIRECTION(SBP2_DIRECTION_FROM_MEDIA);
	else if (cmd->sc_data_direction == DMA_TO_DEVICE)
		orb->request.misc |=
			COMMAND_ORB_DIRECTION(SBP2_DIRECTION_TO_MEDIA);

	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
		goto out;

	fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));

	memset(orb->request.command_block,
	       0, sizeof(orb->request.command_block));
	memcpy(orb->request.command_block, cmd->cmnd, COMMAND_SIZE(*cmd->cmnd));

	orb->base.callback = complete_command_orb;
	orb->base.request_bus =
		dma_map_single(device->card->device, &orb->request,
			       sizeof(orb->request), DMA_TO_DEVICE);
	if (dma_mapping_error(orb->base.request_bus))
		goto out;

	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, lu->generation,
		      lu->command_block_agent_address + SBP2_ORB_POINTER);
	retval = 0;
 out:
	kref_put(&orb->base.kref, free_orb);
	return retval;
}

static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
{
	struct sbp2_logical_unit *lu = sdev->hostdata;

	sdev->allow_restart = 1;

	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
		sdev->inquiry_len = 36;

	return 0;
}

static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
{
	struct sbp2_logical_unit *lu = sdev->hostdata;

	sdev->use_10_for_rw = 1;

	if (sdev->type == TYPE_ROM)
		sdev->use_10_for_ms = 1;

	if (sdev->type == TYPE_DISK &&
	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
		sdev->skip_ms_page_8 = 1;

	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
		sdev->fix_capacity = 1;

	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
		blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);

	return 0;
}

/*
 * Called by scsi stack when something has really gone wrong.  Usually
 * called when a command has timed-out for some reason.
 */
static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
{
	struct sbp2_logical_unit *lu = cmd->device->hostdata;

	fw_notify("sbp2_scsi_abort\n");
	sbp2_agent_reset(lu);
	sbp2_cancel_orbs(lu);

	return SUCCESS;
}

/*
 * Format of /sys/bus/scsi/devices/.../ieee1394_id:
 * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
 *
 * This is the concatenation of target port identifier and logical unit
 * identifier as per SAM-2...SAM-4 annex A.
 */
static ssize_t
sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct sbp2_logical_unit *lu;
	struct fw_device *device;

	if (!sdev)
		return 0;

	lu = sdev->hostdata;
	device = fw_device(lu->tgt->unit->device.parent);

	return sprintf(buf, "%08x%08x:%06x:%04x\n",
			device->config_rom[3], device->config_rom[4],
			lu->tgt->directory_id, lu->lun);
}

static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);

static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
	&dev_attr_ieee1394_id,
	NULL
};

static struct scsi_host_template scsi_driver_template = {
	.module			= THIS_MODULE,
	.name			= "SBP-2 IEEE-1394",
	.proc_name		= sbp2_driver_name,
	.queuecommand		= sbp2_scsi_queuecommand,
	.slave_alloc		= sbp2_scsi_slave_alloc,
	.slave_configure	= sbp2_scsi_slave_configure,
	.eh_abort_handler	= sbp2_scsi_abort,
	.this_id		= -1,
	.sg_tablesize		= SG_ALL,
	.use_clustering		= ENABLE_CLUSTERING,
	.cmd_per_lun		= 1,
	.can_queue		= 1,
	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
};

MODULE_AUTHOR("Kristian Hoegsberg <[e-mail]>");
MODULE_DESCRIPTION("SCSI over IEEE1394");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);

/* Provide a module alias so root-on-sbp2 initrds don't break. */
#ifndef CONFIG_IEEE1394_SBP2_MODULE
MODULE_ALIAS("sbp2");
#endif

static int __init sbp2_init(void)
{
	sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
	if (!sbp2_wq)
		return -ENOMEM;

	return driver_register(&sbp2_driver.driver);
}

static void __exit sbp2_cleanup(void)
{
	driver_unregister(&sbp2_driver.driver);
	destroy_workqueue(sbp2_wq);
}

module_init(sbp2_init);
module_exit(sbp2_cleanup);