Revert "s390/pci: remove bit_lock usage in interrupt handler"

sebott · Martin Schwidefsky · commit 614db26954ff · 2019-02-07T11:56:29.000+01:00
This reverts commit 9594ca6. With the handle_simple_irq irq_flow_handler it must be ensured to not call generic_handle_irq with the same IRQ number on 2 CPUs at the same time (interrupts are floating on s390). Contrary to my initial investigation the irq_desc's lock usage in handle_simple_irq does not ensure this. Thus re-introduce the bit- lock usage in s390's pci handler. Reported-by: Ursula Braun <ubraun@linux.ibm.com> Reported-by: Alexander Schmidt <alexs@linux.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
@@ -382,7 +382,9 @@ 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);
 		}
 	}
 }
@@ -408,7 +410,7 @@ 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);
+	zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
 	if (!zdev->aibv)
 		return -ENOMEM;
 

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