powerpc/mpic: Remove MPIC_BROKEN_FRR_NIRQS and duplicate irq_count

The mpic->irq_count variable is only used as a software error-checking
limit to determine whether or not an IRQ number is valid.  In board code
which does not manually specify an IRQ count to mpic_alloc(), i.e. 0, it
is automatically detected from the number of ISUs and the ISU size.

In practice, all hardware ends up with irq_count == num_sources, so all
of the runtime checks on mpic->irq_count should just check the value of
mpic->num_sources instead.

When platform hardware does not correctly report the number of IRQs,
which only happens on the MPC85xx/MPC86xx, the MPIC_BROKEN_FRR_NIRQS
flag is used to override the detected value of num_sources with the
manual irq_count parameter.  Since there's no need to manually specify
the number of IRQs except in this case, the extra flag can be eliminated
and the test changed to "irq_count != 0".

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 8 insertions, 13 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index c297a524f761..cbffeb742d66 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -873,7 +873,7 @@ int mpic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 	DBG("mpic: set_irq_type(mpic:@%p,virq:%d,src:0x%x,type:0x%x)\n",
 	    mpic, d->irq, src, flow_type);
 
-	if (src >= mpic->irq_count)
+	if (src >= mpic->num_sources)
 		return -EINVAL;
 
 	if (flow_type == IRQ_TYPE_NONE)
@@ -909,7 +909,7 @@ void mpic_set_vector(unsigned int virq, unsigned int vector)
 	DBG("mpic: set_vector(mpic:@%p,virq:%d,src:%d,vector:0x%x)\n",
 	    mpic, virq, src, vector);
 
-	if (src >= mpic->irq_count)
+	if (src >= mpic->num_sources)
 		return;
 
 	vecpri = mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI));
@@ -926,7 +926,7 @@ void mpic_set_destination(unsigned int virq, unsigned int cpuid)
 	DBG("mpic: set_destination(mpic:@%p,virq:%d,src:%d,cpuid:0x%x)\n",
 	    mpic, virq, src, cpuid);
 
-	if (src >= mpic->irq_count)
+	if (src >= mpic->num_sources)
 		return;
 
 	mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION), 1 << cpuid);
@@ -1006,7 +1006,7 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq,
 		return 0;
 	}
 
-	if (hw >= mpic->irq_count)
+	if (hw >= mpic->num_sources)
 		return -EINVAL;
 
 	mpic_msi_reserve_hwirq(mpic, hw);
@@ -1221,7 +1221,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	mpic->hc_tm.name = name;
 
 	mpic->isu_size = isu_size;
-	mpic->irq_count = irq_count;
 	mpic->num_sources = 0; /* so far */
 
 	if (mpic->flags & MPIC_LARGE_VECTORS)
@@ -1314,8 +1313,8 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	 */
 	greg_feature = mpic_read(mpic->gregs, MPIC_INFO(GREG_FEATURE_0));
 	if (isu_size == 0) {
-		if (mpic->flags & MPIC_BROKEN_FRR_NIRQS)
-			mpic->num_sources = mpic->irq_count;
+		if (irq_count)
+			mpic->num_sources = irq_count;
 		else
 			mpic->num_sources =
 				((greg_feature & MPIC_GREG_FEATURE_LAST_SRC_MASK)
@@ -1450,10 +1449,6 @@ void __init mpic_init(struct mpic *mpic)
 			       (mpic->ipi_vecs[0] + i));
 	}
 
-	/* Initialize interrupt sources */
-	if (mpic->irq_count == 0)
-		mpic->irq_count = mpic->num_sources;
-
 	/* Do the HT PIC fixups on U3 broken mpic */
 	DBG("MPIC flags: %x\n", mpic->flags);
 	if ((mpic->flags & MPIC_U3_HT_IRQS) && !(mpic->flags & MPIC_SECONDARY)) {
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
index 0f67cd79d481..cfe394716f68 100644
--- a/arch/powerpc/sysdev/mpic_msi.c
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -54,7 +54,7 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 	for (i = 100; i < 105; i++)
 		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
-	for (i = 124; i < mpic->irq_count; i++)
+	for (i = 124; i < mpic->num_sources; i++)
 		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
 
@@ -83,7 +83,7 @@ int mpic_msi_init_allocator(struct mpic *mpic)
 {
 	int rc;
 
-	rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->irq_count,
+	rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
 			      mpic->irqhost->of_node);
 	if (rc)
 		return rc;