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

This reverts commit 9594ca6b87d9f11e9f14ac31581e0e5d79a8e839.

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
index a966d7b..4266a4d 100644 (file)
--- 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;