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[SCSI] ipr: Reduce queuecommand lock time
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Reduce the amount of time the host lock is held in queuecommand
for improved performance.

[jejb: fix up checkpatch noise]
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Brian King authored and James Bottomley committed Aug 24, 2012
1 parent 3013d91 commit 00bfef2
Showing 1 changed file with 63 additions and 27 deletions.
90 changes: 63 additions & 27 deletions drivers/scsi/ipr.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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.
*
Expand All @@ -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;
Expand All @@ -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
Expand Down

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