s390/pci: remove bit_lock usage in interrupt handler

sebott · Martin Schwidefsky · commit 9594ca6b87d9 · 2018-12-13T10:42:25.000+01:00
The interrupt handler uses bit_spin_lock around a call to retrieve
per irq data (the irq number). However this per irq data is only
set during irq setup time and never changed until the irq is freed.

Thus it's safe to remove the lock usage.

Signed-off-by: Sebastian Ott &lt;sebott@linux.ibm.com&gt;
Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
@@ -382,9 +382,7 @@ static void zpci_irq_handler(struct airq_struct *airq)
 			if (ai == -1UL)
 				break;
 			inc_irq_stat(IRQIO_MSI);
-			airq_iv_lock(aibv, ai);
 			generic_handle_irq(airq_iv_get_data(aibv, ai));
-			airq_iv_unlock(aibv, ai);
 		}
 	}
 }
@@ -410,7 +408,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 	zdev->aisb = aisb;
 
 	/* Create adapter interrupt vector */
-	zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
+	zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA);
 	if (!zdev->aibv)
 		return -ENOMEM;
 

Original file line number	Diff line number	Diff line change
`@@ -382,9 +382,7 @@ static void zpci_irq_handler(struct airq_struct *airq)`
`382`	`382`	`if (ai == -1UL)`
`383`	`383`	`break;`
`384`	`384`	`inc_irq_stat(IRQIO_MSI);`
`385`		`- airq_iv_lock(aibv, ai);`
`386`	`385`	`generic_handle_irq(airq_iv_get_data(aibv, ai));`
`387`		`- airq_iv_unlock(aibv, ai);`
`388`	`386`	`}`
`389`	`387`	`}`
`390`	`388`	`}`
`@@ -410,7 +408,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)`
`410`	`408`	`zdev->aisb = aisb;`
`411`	`409`
`412`	`410`	`/* Create adapter interrupt vector */`
`413`		`- zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA \| AIRQ_IV_BITLOCK);`
	`411`	`+ zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA);`
`414`	`412`	`if (!zdev->aibv)`
`415`	`413`	`return -ENOMEM;`
`416`	`414`