[SCSI] ipr: Reduce interrupt lock time

Reduce the amount of time the host lock is held in the interrupt handler
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>

1 files changed, 46 insertions, 14 deletions

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index b2994e2cf017..07b14ba6906a 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -566,6 +566,23 @@ static void ipr_trc_hook(struct ipr_cmnd *ipr_cmd,
 #endif
 
 /**
+ * ipr_lock_and_done - Acquire lock and complete command
+ * @ipr_cmd:    ipr command struct
+ *
+ * Return value:
+ *      none
+ **/
+static void ipr_lock_and_done(struct ipr_cmnd *ipr_cmd)
+{
+        unsigned long lock_flags;
+        struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+
+        spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+        ipr_cmd->done(ipr_cmd);
+        spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+}
+
+/**
  * ipr_reinit_ipr_cmnd - Re-initialize an IPR Cmnd block for reuse
  * @ipr_cmd:    ipr command struct
  *
@@ -611,11 +628,13 @@ static void ipr_reinit_ipr_cmnd(struct ipr_cmnd *ipr_cmd)
  * Return value:
  *      none
  **/
-static void ipr_init_ipr_cmnd(struct ipr_cmnd *ipr_cmd)
+static void ipr_init_ipr_cmnd(struct ipr_cmnd *ipr_cmd,
+                              void (*fast_done) (struct ipr_cmnd *))
 {
         ipr_reinit_ipr_cmnd(ipr_cmd);
         ipr_cmd->u.scratch = 0;
         ipr_cmd->sibling = NULL;
+        ipr_cmd->fast_done = fast_done;
         init_timer(&ipr_cmd->timer);
 }
 
@@ -648,7 +667,7 @@ 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);
+        ipr_init_ipr_cmnd(ipr_cmd, ipr_lock_and_done);
         return ipr_cmd;
 }
 
@@ -5130,8 +5149,9 @@ static irqreturn_t ipr_isr(int irq, void *devp)
         u16 cmd_index;
         int num_hrrq = 0;
         int irq_none = 0;
-        struct ipr_cmnd *ipr_cmd;
+        struct ipr_cmnd *ipr_cmd, *temp;
         irqreturn_t rc = IRQ_NONE;
+        LIST_HEAD(doneq);
 
         spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
 
@@ -5152,8 +5172,8 @@ static irqreturn_t ipr_isr(int irq, void *devp)
 
                         if (unlikely(cmd_index >= IPR_NUM_CMD_BLKS)) {
                                 ipr_isr_eh(ioa_cfg, "Invalid response handle from IOA");
-                                spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
-                                return IRQ_HANDLED;
+                                rc = IRQ_HANDLED;
+                                goto unlock_out;
                         }
 
                         ipr_cmd = ioa_cfg->ipr_cmnd_list[cmd_index];
@@ -5162,9 +5182,7 @@ static irqreturn_t ipr_isr(int irq, void *devp)
 
                         ipr_trc_hook(ipr_cmd, IPR_TRACE_FINISH, ioasc);
 
-                        list_del(&ipr_cmd->queue);
-                        del_timer(&ipr_cmd->timer);
-                        ipr_cmd->done(ipr_cmd);
+                        list_move_tail(&ipr_cmd->queue, &doneq);
 
                         rc = IRQ_HANDLED;
 
@@ -5194,8 +5212,8 @@ static irqreturn_t ipr_isr(int irq, void *devp)
                 } else if (num_hrrq == IPR_MAX_HRRQ_RETRIES &&
                            int_reg & IPR_PCII_HRRQ_UPDATED) {
                         ipr_isr_eh(ioa_cfg, "Error clearing HRRQ");
-                        spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
-                        return IRQ_HANDLED;
+                        rc = IRQ_HANDLED;
+                        goto unlock_out;
                 } else
                         break;
         }
@@ -5203,7 +5221,14 @@ static irqreturn_t ipr_isr(int irq, void *devp)
         if (unlikely(rc == IRQ_NONE))
                 rc = ipr_handle_other_interrupt(ioa_cfg, int_reg);
 
+unlock_out:
         spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+        list_for_each_entry_safe(ipr_cmd, temp, &doneq, queue) {
+                list_del(&ipr_cmd->queue);
+                del_timer(&ipr_cmd->timer);
+                ipr_cmd->fast_done(ipr_cmd);
+        }
+
         return rc;
 }
 
@@ -5784,15 +5809,22 @@ static void ipr_scsi_done(struct ipr_cmnd *ipr_cmd)
         struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
         struct scsi_cmnd *scsi_cmd = ipr_cmd->scsi_cmd;
         u32 ioasc = be32_to_cpu(ipr_cmd->s.ioasa.hdr.ioasc);
+        unsigned long lock_flags;
 
         scsi_set_resid(scsi_cmd, be32_to_cpu(ipr_cmd->s.ioasa.hdr.residual_data_len));
 
         if (likely(IPR_IOASC_SENSE_KEY(ioasc) == 0)) {
-                scsi_dma_unmap(ipr_cmd->scsi_cmd);
+                scsi_dma_unmap(scsi_cmd);
+
+                spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
                 list_add_tail(&ipr_cmd->queue, &ioa_cfg->free_q);
                 scsi_cmd->scsi_done(scsi_cmd);
-        } else
+                spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+        } else {
+                spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
                 ipr_erp_start(ioa_cfg, ipr_cmd);
+                spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+        }
 }
 
 /**
@@ -5848,12 +5880,12 @@ static int ipr_queuecommand(struct Scsi_Host *shost,
         ipr_cmd = __ipr_get_free_ipr_cmnd(ioa_cfg);
         spin_unlock_irqrestore(shost->host_lock, lock_flags);
 
-        ipr_init_ipr_cmnd(ipr_cmd);
+        ipr_init_ipr_cmnd(ipr_cmd, ipr_scsi_done);
         ioarcb = &ipr_cmd->ioarcb;
 
         memcpy(ioarcb->cmd_pkt.cdb, scsi_cmd->cmnd, scsi_cmd->cmd_len);
         ipr_cmd->scsi_cmd = scsi_cmd;
-        ipr_cmd->done = ipr_scsi_done;
+        ipr_cmd->done = ipr_scsi_eh_done;
 
         if (ipr_is_gscsi(res) || ipr_is_vset_device(res)) {
                 if (scsi_cmd->underflow == 0)