powerpc: Make IRQ_NOREQUEST last to clear, first to set
When creating an irq, don't allow a concurent driver request until
we have caled map, which will likley call set_chip_and_handler to
change the irq_chip and its operations.
Similarly, when tearing down an IRQ, make sure no new uses come
along while we change the irq back to the nop chip and then reset
the descriptor to freed status.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 4368b5e..a24d37d 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -586,14 +586,14 @@
irq_map[i].host = host;
smp_wmb();
- /* Clear norequest flags */
- irq_clear_status_flags(i, IRQ_NOREQUEST);
-
/* Legacy flags are left to default at this point,
* one can then use irq_create_mapping() to
* explicitly change them
*/
ops->map(host, i, i);
+
+ /* Clear norequest flags */
+ irq_clear_status_flags(i, IRQ_NOREQUEST);
}
break;
case IRQ_HOST_MAP_LINEAR:
@@ -664,8 +664,6 @@
goto error;
}
- irq_clear_status_flags(virq, IRQ_NOREQUEST);
-
/* map it */
smp_wmb();
irq_map[virq].hwirq = hwirq;
@@ -676,6 +674,8 @@
goto errdesc;
}
+ irq_clear_status_flags(virq, IRQ_NOREQUEST);
+
return 0;
errdesc:
@@ -819,6 +819,8 @@
if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
return;
+ irq_set_status_flags(virq, IRQ_NOREQUEST);
+
/* remove chip and handler */
irq_set_chip_and_handler(virq, NULL, NULL);
@@ -848,8 +850,6 @@
smp_mb();
irq_map[virq].hwirq = host->inval_irq;
- irq_set_status_flags(virq, IRQ_NOREQUEST);
-
irq_free_descs(virq, 1);
/* Free it */
irq_free_virt(virq, 1);