powerpc/mpic: Fix allocation of reverse-map for multi-ISU mpics

When using a multi-ISU MPIC, we can interrupts up to
isu_size * MPIC_MAX_ISU, not just isu_size, so allocate
the right size reverse map.

Without this, the code will constantly fallback to
a linear search.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index b9b989d305ddf25ca6df773582b11a33c66f386e..16eb743b38a7ea0f91a1ee3b99eb9d25558708e9 100644 (file)
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1331,9 +1331,13 @@ struct mpic * __init mpic_alloc(struct device_node *node,
        /*
         * 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;
+                               >> 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;
@@ -1352,7 +1356,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
        mpic->isu_mask = (1 << mpic->isu_shift) - 1;
 
        mpic->irqhost = irq_alloc_host(mpic->node, IRQ_HOST_MAP_LINEAR,
-                                      mpic->isu_size, &mpic_host_ops,
+                                      last_irq + 1, &mpic_host_ops,
                                       intvec_top + 1);
 
        /*