Last irq calculation logic uses below priority order:
1) irq_count from platform
2) "last-interrupt-source" from device tree
3) isu_size from platform
4) MPIC h/w GREG_FEATURE_0 register
This patch reworks the last irq calculation logic but
functionality and priority order are same as before.
Signed-off-by: Bharat Bhushan <bharat.bhus...@nxp.com>
---
arch/powerpc/sysdev/mpic.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index b6803bc..d503887 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1217,25 +1217,32 @@ static int mpic_get_last_irq_source(struct mpic *mpic,
u32 last_irq;
u32 greg_feature;
+ /* Current priority order for getting last irq:
+ * 1) irq_count from platform
+ * 2) "last-interrupt-source" from device tree
+ * 3) isu_size from platform
+ * 4) MPIC h/w GREG_FEATURE_0 register
+ */
+
+ if (irq_count)
+ return (irq_count - 1);
+
+ if (!of_property_read_u32(mpic->node, "last-interrupt-source",
+ &last_irq)) {
+ return last_irq;
+ }
+
+ if (isu_size)
+ return (isu_size * MPIC_MAX_ISU - 1);
+
/*
- * Read feature register. For non-ISU MPICs, num sources as well. On
+ * Read feature register. For non-ISU MPICs, num sources as well. On
* ISU MPICs, sources are counted as ISUs are added
*/
greg_feature = mpic_read(mpic->gregs, MPIC_INFO(GREG_FEATURE_0));
- /*
- * By default, the last source number comes from the MPIC, but the
- * device-tree and board support code can override it on buggy hw.
- * If we get passed an isu_size (multi-isu MPIC) then we use that
- * as a default instead of the value read from the HW.
- */
last_irq = (greg_feature & MPIC_GREG_FEATURE_LAST_SRC_MASK)
>> MPIC_GREG_FEATURE_LAST_SRC_SHIFT;
- if (isu_size)
- last_irq = isu_size * MPIC_MAX_ISU - 1;
- of_property_read_u32(mpic->node, "last-interrupt-source", &last_irq);
- if (irq_count)
- last_irq = irq_count - 1;
return last_irq;
}
--
1.9.3
