sbp2.c

Ieee1394驱动实现

		return -EIO;
	}

	if (STATUS_TEST_RDS(lu->status_block.ORB_offset_hi_misc)) {
		SBP2_ERR("Error reconnecting to SBP-2 device - failed");
		return -EIO;
	}

	SBP2_INFO("Reconnected to SBP-2 device");
	return 0;
}

/*
 * Set the target node's Single Phase Retry limit. Affects the target's retry
 * behaviour if our node is too busy to accept requests.
 */
static int sbp2_set_busy_timeout(struct sbp2_lu *lu)
{
	quadlet_t data;

	data = cpu_to_be32(SBP2_BUSY_TIMEOUT_VALUE);
	if (hpsb_node_write(lu->ne, SBP2_BUSY_TIMEOUT_ADDRESS, &data, 4))
		SBP2_ERR("%s error", __FUNCTION__);
	return 0;
}

static void sbp2_parse_unit_directory(struct sbp2_lu *lu,
				      struct unit_directory *ud)
{
	struct csr1212_keyval *kv;
	struct csr1212_dentry *dentry;
	u64 management_agent_addr;
	u32 unit_characteristics, firmware_revision;
	unsigned workarounds;
	int i;

	management_agent_addr = 0;
	unit_characteristics = 0;
	firmware_revision = 0;

	csr1212_for_each_dir_entry(ud->ne->csr, kv, ud->ud_kv, dentry) {
		switch (kv->key.id) {
		case CSR1212_KV_ID_DEPENDENT_INFO:
			if (kv->key.type == CSR1212_KV_TYPE_CSR_OFFSET)
				management_agent_addr =
				    CSR1212_REGISTER_SPACE_BASE +
				    (kv->value.csr_offset << 2);

			else if (kv->key.type == CSR1212_KV_TYPE_IMMEDIATE)
				lu->lun = ORB_SET_LUN(kv->value.immediate);
			break;

		case SBP2_UNIT_CHARACTERISTICS_KEY:
			/* FIXME: This is ignored so far.
			 * See SBP-2 clause 7.4.8. */
			unit_characteristics = kv->value.immediate;
			break;

		case SBP2_FIRMWARE_REVISION_KEY:
			firmware_revision = kv->value.immediate;
			break;

		default:
			/* FIXME: Check for SBP2_DEVICE_TYPE_AND_LUN_KEY.
			 * Its "ordered" bit has consequences for command ORB
			 * list handling. See SBP-2 clauses 4.6, 7.4.11, 10.2 */
			break;
		}
	}

	workarounds = sbp2_default_workarounds;

	if (!(workarounds & SBP2_WORKAROUND_OVERRIDE))
		for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
			if (sbp2_workarounds_table[i].firmware_revision !=
			    SBP2_ROM_VALUE_WILDCARD &&
			    sbp2_workarounds_table[i].firmware_revision !=
			    (firmware_revision & 0xffff00))
				continue;
			if (sbp2_workarounds_table[i].model_id !=
			    SBP2_ROM_VALUE_WILDCARD &&
			    sbp2_workarounds_table[i].model_id != ud->model_id)
				continue;
			workarounds |= sbp2_workarounds_table[i].workarounds;
			break;
		}

	if (workarounds)
		SBP2_INFO("Workarounds for node " NODE_BUS_FMT ": 0x%x "
			  "(firmware_revision 0x%06x, vendor_id 0x%06x,"
			  " model_id 0x%06x)",
			  NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
			  workarounds, firmware_revision,
			  ud->vendor_id ? ud->vendor_id : ud->ne->vendor_id,
			  ud->model_id);

	/* We would need one SCSI host template for each target to adjust
	 * max_sectors on the fly, therefore warn only. */
	if (workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
	    (sbp2_max_sectors * 512) > (128 * 1024))
		SBP2_INFO("Node " NODE_BUS_FMT ": Bridge only supports 128KB "
			  "max transfer size. WARNING: Current max_sectors "
			  "setting is larger than 128KB (%d sectors)",
			  NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
			  sbp2_max_sectors);

	/* If this is a logical unit directory entry, process the parent
	 * to get the values. */
	if (ud->flags & UNIT_DIRECTORY_LUN_DIRECTORY) {
		struct unit_directory *parent_ud = container_of(
			ud->device.parent, struct unit_directory, device);
		sbp2_parse_unit_directory(lu, parent_ud);
	} else {
		lu->management_agent_addr = management_agent_addr;
		lu->workarounds = workarounds;
		if (ud->flags & UNIT_DIRECTORY_HAS_LUN)
			lu->lun = ORB_SET_LUN(ud->lun);
	}
}

#define SBP2_PAYLOAD_TO_BYTES(p) (1 << ((p) + 2))

/*
 * This function is called in order to determine the max speed and packet
 * size we can use in our ORBs. Note, that we (the driver and host) only
 * initiate the transaction. The SBP-2 device actually transfers the data
 * (by reading from the DMA area we tell it). This means that the SBP-2
 * device decides the actual maximum data it can transfer. We just tell it
 * the speed that it needs to use, and the max_rec the host supports, and
 * it takes care of the rest.
 */
static int sbp2_max_speed_and_size(struct sbp2_lu *lu)
{
	struct sbp2_fwhost_info *hi = lu->hi;
	u8 payload;

	lu->speed_code = hi->host->speed[NODEID_TO_NODE(lu->ne->nodeid)];

	if (lu->speed_code > sbp2_max_speed) {
		lu->speed_code = sbp2_max_speed;
		SBP2_INFO("Reducing speed to %s",
			  hpsb_speedto_str[sbp2_max_speed]);
	}

	/* Payload size is the lesser of what our speed supports and what
	 * our host supports.  */
	payload = min(sbp2_speedto_max_payload[lu->speed_code],
		      (u8) (hi->host->csr.max_rec - 1));

	/* If physical DMA is off, work around limitation in ohci1394:
	 * packet size must not exceed PAGE_SIZE */
	if (lu->ne->host->low_addr_space < (1ULL << 32))
		while (SBP2_PAYLOAD_TO_BYTES(payload) + 24 > PAGE_SIZE &&
		       payload)
			payload--;

	SBP2_INFO("Node " NODE_BUS_FMT ": Max speed [%s] - Max payload [%u]",
		  NODE_BUS_ARGS(hi->host, lu->ne->nodeid),
		  hpsb_speedto_str[lu->speed_code],
		  SBP2_PAYLOAD_TO_BYTES(payload));

	lu->max_payload_size = payload;
	return 0;
}

static int sbp2_agent_reset(struct sbp2_lu *lu, int wait)
{
	quadlet_t data;
	u64 addr;
	int retval;
	unsigned long flags;

	/* flush lu->protocol_work */
	if (wait)
		flush_scheduled_work();

	data = ntohl(SBP2_AGENT_RESET_DATA);
	addr = lu->command_block_agent_addr + SBP2_AGENT_RESET_OFFSET;

	if (wait)
		retval = hpsb_node_write(lu->ne, addr, &data, 4);
	else
		retval = sbp2util_node_write_no_wait(lu->ne, addr, &data, 4);

	if (retval < 0) {
		SBP2_ERR("hpsb_node_write failed.\n");
		return -EIO;
	}

	/* make sure that the ORB_POINTER is written on next command */
	spin_lock_irqsave(&lu->cmd_orb_lock, flags);
	lu->last_orb = NULL;
	spin_unlock_irqrestore(&lu->cmd_orb_lock, flags);

	return 0;
}

static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
				     struct sbp2_fwhost_info *hi,
				     struct sbp2_command_info *cmd,
				     unsigned int scsi_use_sg,
				     struct scatterlist *sgpnt,
				     u32 orb_direction,
				     enum dma_data_direction dma_dir)
{
	cmd->dma_dir = dma_dir;
	orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
	orb->misc |= ORB_SET_DIRECTION(orb_direction);

	/* special case if only one element (and less than 64KB in size) */
	if ((scsi_use_sg == 1) &&
	    (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {

		cmd->dma_size = sgpnt[0].length;
		cmd->dma_type = CMD_DMA_PAGE;
		cmd->cmd_dma = dma_map_page(hi->host->device.parent,
					    sgpnt[0].page, sgpnt[0].offset,
					    cmd->dma_size, cmd->dma_dir);

		orb->data_descriptor_lo = cmd->cmd_dma;
		orb->misc |= ORB_SET_DATA_SIZE(cmd->dma_size);

	} else {
		struct sbp2_unrestricted_page_table *sg_element =
						&cmd->scatter_gather_element[0];
		u32 sg_count, sg_len;
		dma_addr_t sg_addr;
		int i, count = dma_map_sg(hi->host->device.parent, sgpnt,
					  scsi_use_sg, dma_dir);

		cmd->dma_size = scsi_use_sg;
		cmd->sge_buffer = sgpnt;

		/* use page tables (s/g) */
		orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
		orb->data_descriptor_lo = cmd->sge_dma;

		/* loop through and fill out our SBP-2 page tables
		 * (and split up anything too large) */
		for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
			sg_len = sg_dma_len(sgpnt);
			sg_addr = sg_dma_address(sgpnt);
			while (sg_len) {
				sg_element[sg_count].segment_base_lo = sg_addr;
				if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
					sg_element[sg_count].length_segment_base_hi =
						PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
					sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
					sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
				} else {
					sg_element[sg_count].length_segment_base_hi =
						PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
					sg_len = 0;
				}
				sg_count++;
			}
		}

		orb->misc |= ORB_SET_DATA_SIZE(sg_count);

		sbp2util_cpu_to_be32_buffer(sg_element,
				(sizeof(struct sbp2_unrestricted_page_table)) *
				sg_count);
	}
}

static void sbp2_prep_command_orb_no_sg(struct sbp2_command_orb *orb,
					struct sbp2_fwhost_info *hi,
					struct sbp2_command_info *cmd,
					struct scatterlist *sgpnt,
					u32 orb_direction,
					unsigned int scsi_request_bufflen,
					void *scsi_request_buffer,
					enum dma_data_direction dma_dir)
{
	cmd->dma_dir = dma_dir;
	cmd->dma_size = scsi_request_bufflen;
	cmd->dma_type = CMD_DMA_SINGLE;
	cmd->cmd_dma = dma_map_single(hi->host->device.parent,
				      scsi_request_buffer,
				      cmd->dma_size, cmd->dma_dir);
	orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
	orb->misc |= ORB_SET_DIRECTION(orb_direction);

	/* handle case where we get a command w/o s/g enabled
	 * (but check for transfers larger than 64K) */
	if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) {

		orb->data_descriptor_lo = cmd->cmd_dma;
		orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen);

	} else {
		/* The buffer is too large. Turn this into page tables. */

		struct sbp2_unrestricted_page_table *sg_element =
						&cmd->scatter_gather_element[0];
		u32 sg_count, sg_len;
		dma_addr_t sg_addr;

		orb->data_descriptor_lo = cmd->sge_dma;
		orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);

		/* fill out our SBP-2 page tables; split up the large buffer */
		sg_count = 0;
		sg_len = scsi_request_bufflen;
		sg_addr = cmd->cmd_dma;
		while (sg_len) {
			sg_element[sg_count].segment_base_lo = sg_addr;
			if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
				sg_element[sg_count].length_segment_base_hi =
					PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
				sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
				sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
			} else {
				sg_element[sg_count].length_segment_base_hi =
					PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
				sg_len = 0;
			}
			sg_count++;
		}

		orb->misc |= ORB_SET_DATA_SIZE(sg_count);

		sbp2util_cpu_to_be32_buffer(sg_element,
				(sizeof(struct sbp2_unrestricted_page_table)) *
				sg_count);
	}
}

static void sbp2_create_command_orb(struct sbp2_lu *lu,
				    struct sbp2_command_info *cmd,
				    unchar *scsi_cmd,
				    unsigned int scsi_use_sg,
				    unsigned int scsi_request_bufflen,
				    void *scsi_request_buffer,
				    enum dma_data_direction dma_dir)
{
	struct sbp2_fwhost_info *hi = lu->hi;
	struct scatterlist *sgpnt = (struct scatterlist *)scsi_request_buffer;
	struct sbp2_command_orb *orb = &cmd->command_orb;
	u32 orb_direction;

	/*
	 * Set-up our command ORB.
	 *
	 * NOTE: We're doing unrestricted page tables (s/g), as this is
	 * best performance (at least with the devices I have). This means
	 * that data_size becomes the number of s/g elements, and
	 * page_size should be zero (for unrestricted).
	 */
	orb->next_ORB_hi = ORB_SET_NULL_PTR(1);
	orb->next_ORB_lo = 0x0;
	orb->misc = ORB_SET_MAX_PAYLOAD(lu->max_payload_size);
	orb->misc |= ORB_SET_SPEED(lu->speed_code);
	orb->misc |= ORB_SET_NOTIFY(1);

	if (dma_dir == DMA_NONE)
		orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
	else if (dma_dir == DMA_TO_DEVICE && scsi_request_bufflen)
		orb_direction = ORB_DIRECTION_WRITE_TO_MEDIA;
	else if (dma_dir == DMA_FROM_DEVICE && scsi_request_bufflen)
		orb_direction = ORB_DIRECTION_READ_FROM_MEDIA;
	else {
		SBP2_INFO("Falling back to DMA_NONE");
		orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
	}

	/* set up our page table stuff */
	if (orb_direction == ORB_DIRECTION_NO_DATA_TRANSFER) {
		orb->data_descriptor_hi = 0x0;
		orb->data_descriptor_lo = 0x0;
		orb->misc |= ORB_SET_DIRECTION(1);
	} else if (scsi_use_sg)
		sbp2_prep_command_orb_sg(orb, hi, cmd, scsi_use_sg, sgpnt,
					 orb_direction, dma_dir);
	else
		sbp2_prep_command_orb_no_sg(orb, hi, cmd, sgpnt, orb_direction,
					    scsi_request_bufflen,
					    scsi_request_buffer, dma_dir);

	sbp2util_cpu_to_be32_buffer(orb, sizeof(*orb));

	memset(orb->cdb, 0, 12);
	memcpy(orb->cdb, scsi_cmd, COMMAND_SIZE(*scsi_cmd));
}

static void sbp2_link_orb_command(struct sbp2_lu *lu,
				  struct sbp2_command_info *cmd)
{
	struct sbp2_fwhost_info *hi = lu->hi;
	struct sbp2_command_orb *last_orb;
	dma_addr_t last_orb_dma;
	u64 addr = lu->command_block_agent_addr;
	quadlet_t data[2];
	size_t length;
	unsigned long flags;

	dma_sync_single_for_device(hi->host->device.parent,
				   cmd->command_orb_dma,
				   sizeof(struct sbp2_command_orb),
				   DMA_TO_DEVICE);
	dma_sync_single_for_device(hi->host->device.parent, cmd->sge_dma,
				   sizeof(cmd->scatter_gather_element),
				   DMA_TO_DEVICE);

	/* check to see if there are any previous orbs to use */
	spin_lock_irqsave(&lu->cmd_orb_lock, flags);
	last_orb = lu->last_orb;
	last_orb_dma = lu->last_orb_dma;
	if (!last_orb) {
		/*
		 * last_orb == NULL means: We know that the target's fetch agent
		 * is not active right now.
		 */
		addr += SBP2_ORB_POINTER_OFFSET;