ARM: GIC: function to retrieve the physical address of the SGIR
In order to have early assembly code signal other CPUs in the system,
we need to get the physical address for the SGIR register used to
send IPIs. Because the register will be used with a precomputed CPU
interface ID number, there is no need for any locking in the assembly
code where this register is written to.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 6365b59..09fdf3d5 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -769,6 +769,33 @@
}
}
}
+
+/*
+ * gic_get_sgir_physaddr - get the physical address for the SGI register
+ *
+ * REturn the physical address of the SGI register to be used
+ * by some early assembly code when the kernel is not yet available.
+ */
+static unsigned long gic_dist_physaddr;
+
+unsigned long gic_get_sgir_physaddr(void)
+{
+ if (!gic_dist_physaddr)
+ return 0;
+ return gic_dist_physaddr + GIC_DIST_SOFTINT;
+}
+
+void __init gic_init_physaddr(struct device_node *node)
+{
+ struct resource res;
+ if (of_address_to_resource(node, 0, &res) == 0) {
+ gic_dist_physaddr = res.start;
+ pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
+ }
+}
+
+#else
+#define gic_init_physaddr(node) do { } while (0)
#endif
static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
@@ -952,6 +979,8 @@
percpu_offset = 0;
gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
+ if (!gic_cnt)
+ gic_init_physaddr(node);
if (parent) {
irq = irq_of_parse_and_map(node, 0);