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Commit 00bfef2c authored by Brian King's avatar Brian King Committed by James Bottomley
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[SCSI] ipr: Reduce queuecommand lock time 



Reduce the amount of time the host lock is held in queuecommand
for improved performance.

[jejb: fix up checkpatch noise]
Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 3013d918

drivers/scsi/ipr.c

+63 −27
Original line number Diff line number Diff line
@@ -620,24 +620,38 @@ static void ipr_init_ipr_cmnd(struct ipr_cmnd *ipr_cmd) 
}



/**

 * ipr_get_free_ipr_cmnd - Get a free IPR Cmnd block

 * __ipr_get_free_ipr_cmnd - Get a free IPR Cmnd block

 * @ioa_cfg:	ioa config struct

 *

 * Return value:

 * 	pointer to ipr command struct

 **/

static

struct ipr_cmnd *ipr_get_free_ipr_cmnd(struct ipr_ioa_cfg *ioa_cfg)

struct ipr_cmnd *__ipr_get_free_ipr_cmnd(struct ipr_ioa_cfg *ioa_cfg)

{

	struct ipr_cmnd *ipr_cmd;



	ipr_cmd = list_entry(ioa_cfg->free_q.next, struct ipr_cmnd, queue);

	list_del(&ipr_cmd->queue);

	ipr_init_ipr_cmnd(ipr_cmd);



	return ipr_cmd;

}



/**

 * ipr_get_free_ipr_cmnd - Get a free IPR Cmnd block and initialize it

 * @ioa_cfg:	ioa config struct

 *

 * Return value:

 *	pointer to ipr command struct

 **/

static

struct ipr_cmnd *ipr_get_free_ipr_cmnd(struct ipr_ioa_cfg *ioa_cfg)

{

	struct ipr_cmnd *ipr_cmd = __ipr_get_free_ipr_cmnd(ioa_cfg);

	ipr_init_ipr_cmnd(ipr_cmd);

	return ipr_cmd;

}



/**

 * ipr_mask_and_clear_interrupts - Mask all and clear specified interrupts

 * @ioa_cfg:	ioa config struct
@@ -5783,8 +5797,8 @@ static void ipr_scsi_done(struct ipr_cmnd *ipr_cmd) 


/**

 * ipr_queuecommand - Queue a mid-layer request

 * @shost:		scsi host struct

 * @scsi_cmd:	scsi command struct

 * @done:		done function

 *

 * This function queues a request generated by the mid-layer.

 *
@@ -5793,61 +5807,58 @@ static void ipr_scsi_done(struct ipr_cmnd *ipr_cmd) 
 *	SCSI_MLQUEUE_DEVICE_BUSY if device is busy

 *	SCSI_MLQUEUE_HOST_BUSY if host is busy

 **/

static int ipr_queuecommand_lck(struct scsi_cmnd *scsi_cmd,

			    void (*done) (struct scsi_cmnd *))

static int ipr_queuecommand(struct Scsi_Host *shost,

			    struct scsi_cmnd *scsi_cmd)

{

	struct ipr_ioa_cfg *ioa_cfg;

	struct ipr_resource_entry *res;

	struct ipr_ioarcb *ioarcb;

	struct ipr_cmnd *ipr_cmd;

	unsigned long lock_flags;

	int rc = 0;



	scsi_cmd->scsi_done = done;

	ioa_cfg = (struct ipr_ioa_cfg *)scsi_cmd->device->host->hostdata;

	res = scsi_cmd->device->hostdata;

	ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;



	spin_lock_irqsave(shost->host_lock, lock_flags);

	scsi_cmd->result = (DID_OK << 16);

	res = scsi_cmd->device->hostdata;



	/*

	 * We are currently blocking all devices due to a host reset

	 * We have told the host to stop giving us new requests, but

	 * ERP ops don't count. FIXME

	 */

	if (unlikely(!ioa_cfg->allow_cmds && !ioa_cfg->ioa_is_dead))

	if (unlikely(!ioa_cfg->allow_cmds && !ioa_cfg->ioa_is_dead)) {

		spin_unlock_irqrestore(shost->host_lock, lock_flags);

		return SCSI_MLQUEUE_HOST_BUSY;

	}



	/*

	 * FIXME - Create scsi_set_host_offline interface

	 *  and the ioa_is_dead check can be removed

	 */

	if (unlikely(ioa_cfg->ioa_is_dead || !res)) {

		memset(scsi_cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);

		scsi_cmd->result = (DID_NO_CONNECT << 16);

		scsi_cmd->scsi_done(scsi_cmd);

		return 0;

		spin_unlock_irqrestore(shost->host_lock, lock_flags);

		goto err_nodev;

	}



	if (ipr_is_gata(res) && res->sata_port)

		return ata_sas_queuecmd(scsi_cmd, res->sata_port->ap);



	ipr_cmd = ipr_get_free_ipr_cmnd(ioa_cfg);

	ipr_cmd = __ipr_get_free_ipr_cmnd(ioa_cfg);

	spin_unlock_irqrestore(shost->host_lock, lock_flags);



	ipr_init_ipr_cmnd(ipr_cmd);

	ioarcb = &ipr_cmd->ioarcb;

	list_add_tail(&ipr_cmd->queue, &ioa_cfg->pending_q);



	memcpy(ioarcb->cmd_pkt.cdb, scsi_cmd->cmnd, scsi_cmd->cmd_len);

	ipr_cmd->scsi_cmd = scsi_cmd;

	ioarcb->res_handle = res->res_handle;

	ipr_cmd->done = ipr_scsi_done;

	ipr_trc_hook(ipr_cmd, IPR_TRACE_START, IPR_GET_RES_PHYS_LOC(res));



	if (ipr_is_gscsi(res) || ipr_is_vset_device(res)) {

		if (scsi_cmd->underflow == 0)

			ioarcb->cmd_pkt.flags_hi |= IPR_FLAGS_HI_NO_ULEN_CHK;



		if (res->needs_sync_complete) {

			ioarcb->cmd_pkt.flags_hi |= IPR_FLAGS_HI_SYNC_COMPLETE;

			res->needs_sync_complete = 0;

		}



		ioarcb->cmd_pkt.flags_hi |= IPR_FLAGS_HI_NO_LINK_DESC;

		if (ipr_is_gscsi(res))

			ioarcb->cmd_pkt.flags_lo |= IPR_FLAGS_LO_DELAY_AFTER_RST;
@@ -5866,16 +5877,41 @@ static int ipr_queuecommand_lck(struct scsi_cmnd *scsi_cmd, 
			rc = ipr_build_ioadl(ioa_cfg, ipr_cmd);

	}



	if (unlikely(rc != 0)) {

		list_move_tail(&ipr_cmd->queue, &ioa_cfg->free_q);

	spin_lock_irqsave(shost->host_lock, lock_flags);

	if (unlikely(rc || (!ioa_cfg->allow_cmds && !ioa_cfg->ioa_is_dead))) {

		list_add_tail(&ipr_cmd->queue, &ioa_cfg->free_q);

		spin_unlock_irqrestore(shost->host_lock, lock_flags);

		if (!rc)

			scsi_dma_unmap(scsi_cmd);

		return SCSI_MLQUEUE_HOST_BUSY;

	}



	if (unlikely(ioa_cfg->ioa_is_dead)) {

		list_add_tail(&ipr_cmd->queue, &ioa_cfg->free_q);

		spin_unlock_irqrestore(shost->host_lock, lock_flags);

		scsi_dma_unmap(scsi_cmd);

		goto err_nodev;

	}



	ioarcb->res_handle = res->res_handle;

	if (res->needs_sync_complete) {

		ioarcb->cmd_pkt.flags_hi |= IPR_FLAGS_HI_SYNC_COMPLETE;

		res->needs_sync_complete = 0;

	}

	list_add_tail(&ipr_cmd->queue, &ioa_cfg->pending_q);

	ipr_trc_hook(ipr_cmd, IPR_TRACE_START, IPR_GET_RES_PHYS_LOC(res));

	ipr_send_command(ipr_cmd);

	spin_unlock_irqrestore(shost->host_lock, lock_flags);

	return 0;

}



static DEF_SCSI_QCMD(ipr_queuecommand)

err_nodev:

	spin_lock_irqsave(shost->host_lock, lock_flags);

	memset(scsi_cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);

	scsi_cmd->result = (DID_NO_CONNECT << 16);

	scsi_cmd->scsi_done(scsi_cmd);

	spin_unlock_irqrestore(shost->host_lock, lock_flags);

	return 0;

}



/**

 * ipr_ioctl - IOCTL handler