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authorNicolas Pitre <nicolas.pitre@linaro.org>2012-11-28 18:17:25 -0500
committerNicolas Pitre <nicolas.pitre@linaro.org>2013-05-13 19:03:35 -0400
commit3410b145bc6f1fb7a2dd6ee520f0234232bee152 (patch)
tree16cd0042eb9866710c35495ca307eb16495fd662
parentc3d132aedfc0ad6e4cfb679084cf3fba68bd7e87 (diff)
downloadvexpress-lsk-3410b145bc6f1fb7a2dd6ee520f0234232bee152.tar.gz
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>
-rw-r--r--drivers/irqchip/irq-gic.c29
-rw-r--r--include/linux/irqchip/arm-gic.h1
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 870d87e57d3..a760f6b1b44 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -755,6 +755,33 @@ void gic_migrate_target(unsigned int new_cpu_id)
}
}
}
+
+/*
+ * 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,
@@ -925,6 +952,8 @@ int __init gic_of_init(struct device_node *node, struct device_node *parent)
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);
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index d160bb7a371..00795de5dc6 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -78,6 +78,7 @@ static inline void gic_init(unsigned int nr, int start,
int gic_get_cpu_id(unsigned int cpu);
void gic_migrate_target(unsigned int new_cpu_id);
+unsigned long gic_get_sgir_physaddr(void);
#endif /* __ASSEMBLY */