From 41c1e2f54e6fc76dbc7047f1a95693f4d37b4623 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 2 Mar 2012 11:56:38 +0000 Subject: [PATCH] arm: make sure that number of irqs can be represented in GICD_TYPER. We currently assume that the number of interrupts (ITLinesNumber in the architecture reference manual) is divisible by 32, since we present it to the guest when it reads GICD_TYPER (in gic_dist_readb()) as (N / 32) - 1. Signed-off-by: Rusty Russell Signed-off-by: Peter Maydell --- hw/arm_gic.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/hw/arm_gic.c b/hw/arm_gic.c index 59eabcc60b..d8a7a190e8 100644 --- a/hw/arm_gic.c +++ b/hw/arm_gic.c @@ -819,6 +819,15 @@ static void gic_init(gic_state *s, int num_irq) hw_error("requested %u interrupt lines exceeds GIC maximum %d\n", num_irq, GIC_MAXIRQ); } + /* ITLinesNumber is represented as (N / 32) - 1 (see + * gic_dist_readb) so this is an implementation imposed + * restriction, not an architectural one: + */ + if (s->num_irq < 32 || (s->num_irq % 32)) { + hw_error("%d interrupt lines unsupported: not divisible by 32\n", + num_irq); + } + qdev_init_gpio_in(&s->busdev.qdev, gic_set_irq, s->num_irq - GIC_INTERNAL); for (i = 0; i < NUM_CPU(s); i++) { sysbus_init_irq(&s->busdev, &s->parent_irq[i]);