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authorWayne Boyer <wayneb@linux.vnet.ibm.com>2010-05-19 11:56:13 -0700
committerJames Bottomley <James.Bottomley@suse.de>2010-05-24 11:11:06 -0500
commit64ffdb762241c0a9c0c8fac7ea92aa0ba1529334 (patch)
tree725809ab8f69e6df498ae51b58193d9fa38f702b /drivers/scsi
parentb8803b1cef28af785c4e903b9b1449898d68c758 (diff)
downloadlinux-2.6.34-ux500-64ffdb762241c0a9c0c8fac7ea92aa0ba1529334.tar.gz
[SCSI] ipr: improve interrupt service routine performance
During performance testing on P7 machines it was observed that the interrupt service routine was doing unnecessary MMIO operations. This patch rearranges the logic of the routine and moves some of the code out of the main routine. The result is that there are now fewer MMIO operations in the performance path of the code. Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> Acked-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/ipr.c63
1 files changed, 30 insertions, 33 deletions
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 5244282cd97..82ea4a8226b 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -4818,15 +4818,39 @@ static int ipr_eh_abort(struct scsi_cmnd * scsi_cmd)
/**
* ipr_handle_other_interrupt - Handle "other" interrupts
* @ioa_cfg: ioa config struct
- * @int_reg: interrupt register
*
* Return value:
* IRQ_NONE / IRQ_HANDLED
**/
-static irqreturn_t ipr_handle_other_interrupt(struct ipr_ioa_cfg *ioa_cfg,
- volatile u32 int_reg)
+static irqreturn_t ipr_handle_other_interrupt(struct ipr_ioa_cfg *ioa_cfg)
{
irqreturn_t rc = IRQ_HANDLED;
+ volatile u32 int_reg, int_mask_reg;
+
+ int_mask_reg = readl(ioa_cfg->regs.sense_interrupt_mask_reg32);
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_reg32) & ~int_mask_reg;
+
+ /* If an interrupt on the adapter did not occur, ignore it.
+ * Or in the case of SIS 64, check for a stage change interrupt.
+ */
+ if ((int_reg & IPR_PCII_OPER_INTERRUPTS) == 0) {
+ if (ioa_cfg->sis64) {
+ int_mask_reg = readl(ioa_cfg->regs.sense_interrupt_mask_reg);
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_reg) & ~int_mask_reg;
+ if (int_reg & IPR_PCII_IPL_STAGE_CHANGE) {
+
+ /* clear stage change */
+ writel(IPR_PCII_IPL_STAGE_CHANGE, ioa_cfg->regs.clr_interrupt_reg);
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_reg) & ~int_mask_reg;
+ list_del(&ioa_cfg->reset_cmd->queue);
+ del_timer(&ioa_cfg->reset_cmd->timer);
+ ipr_reset_ioa_job(ioa_cfg->reset_cmd);
+ return IRQ_HANDLED;
+ }
+ }
+
+ return IRQ_NONE;
+ }
if (int_reg & IPR_PCII_IOA_TRANS_TO_OPER) {
/* Mask the interrupt */
@@ -4887,7 +4911,7 @@ static irqreturn_t ipr_isr(int irq, void *devp)
{
struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)devp;
unsigned long lock_flags = 0;
- volatile u32 int_reg, int_mask_reg;
+ volatile u32 int_reg;
u32 ioasc;
u16 cmd_index;
int num_hrrq = 0;
@@ -4902,33 +4926,6 @@ static irqreturn_t ipr_isr(int irq, void *devp)
return IRQ_NONE;
}
- int_mask_reg = readl(ioa_cfg->regs.sense_interrupt_mask_reg32);
- int_reg = readl(ioa_cfg->regs.sense_interrupt_reg32) & ~int_mask_reg;
-
- /* If an interrupt on the adapter did not occur, ignore it.
- * Or in the case of SIS 64, check for a stage change interrupt.
- */
- if (unlikely((int_reg & IPR_PCII_OPER_INTERRUPTS) == 0)) {
- if (ioa_cfg->sis64) {
- int_mask_reg = readl(ioa_cfg->regs.sense_interrupt_mask_reg);
- int_reg = readl(ioa_cfg->regs.sense_interrupt_reg) & ~int_mask_reg;
- if (int_reg & IPR_PCII_IPL_STAGE_CHANGE) {
-
- /* clear stage change */
- writel(IPR_PCII_IPL_STAGE_CHANGE, ioa_cfg->regs.clr_interrupt_reg);
- int_reg = readl(ioa_cfg->regs.sense_interrupt_reg) & ~int_mask_reg;
- list_del(&ioa_cfg->reset_cmd->queue);
- del_timer(&ioa_cfg->reset_cmd->timer);
- ipr_reset_ioa_job(ioa_cfg->reset_cmd);
- spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
- return IRQ_HANDLED;
- }
- }
-
- spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
- return IRQ_NONE;
- }
-
while (1) {
ipr_cmd = NULL;
@@ -4968,7 +4965,7 @@ static irqreturn_t ipr_isr(int irq, void *devp)
/* Clear the PCI interrupt */
do {
writel(IPR_PCII_HRRQ_UPDATED, ioa_cfg->regs.clr_interrupt_reg32);
- int_reg = readl(ioa_cfg->regs.sense_interrupt_reg32) & ~int_mask_reg;
+ int_reg = readl(ioa_cfg->regs.sense_interrupt_reg32);
} while (int_reg & IPR_PCII_HRRQ_UPDATED &&
num_hrrq++ < IPR_MAX_HRRQ_RETRIES);
@@ -4983,7 +4980,7 @@ static irqreturn_t ipr_isr(int irq, void *devp)
}
if (unlikely(rc == IRQ_NONE))
- rc = ipr_handle_other_interrupt(ioa_cfg, int_reg);
+ rc = ipr_handle_other_interrupt(ioa_cfg);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return rc;