From: Will Deacon <will.deacon@arm.com>
Date: Fri, 25 Nov 2011 18:23:36 +0000 (+0100)
Subject: ARM: 7177/1: GIC: avoid skipping non-existent PPIs in irq_start calculation
X-Git-Tag: MMI-PSA29.97-13-9~17942^2~3
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fe41db7b3aca512e19b8ef4fbd5ad55545005d25;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

ARM: 7177/1: GIC: avoid skipping non-existent PPIs in irq_start calculation

Commit 4294f8baa ("ARM: gic: add irq_domain support") defines irq_start
as irq_start = (irq_start & ~31) + 16; On a platform with a GIC and a
CPU without PPIs, this results in irq_start being off by 16.

This patch fixes gic_init so that we only carve out a PPI space when
PPIs exist for the GIC being initialised.

Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 43240f315dea..410a546060a2 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -582,13 +582,16 @@ void __init gic_init(unsigned int gic_nr, int irq_start,
 	 * For primary GICs, skip over SGIs.
 	 * For secondary GICs, skip over PPIs, too.
 	 */
+	domain->hwirq_base = 32;
 	if (gic_nr == 0) {
 		gic_cpu_base_addr = cpu_base;
-		domain->hwirq_base = 16;
-		if (irq_start > 0)
-			irq_start = (irq_start & ~31) + 16;
-	} else
-		domain->hwirq_base = 32;
+
+		if ((irq_start & 31) > 0) {
+			domain->hwirq_base = 16;
+			if (irq_start != -1)
+				irq_start = (irq_start & ~31) + 16;
+		}
+	}
 
 	/*
 	 * Find out how many interrupts are supported.