From df321c43e3c3ed44d2434fd12d378736a82152d5 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 28 Nov 2012 18:17:25 -0500 Subject: [PATCH] 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 --- drivers/irqchip/irq-gic.c | 29 +++++++++++++++++++++++++++++ include/linux/irqchip/arm-gic.h | 1 + 2 files changed, 30 insertions(+) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 29b876b98d44..8389e381f7cb 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -757,6 +757,33 @@ 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, @@ -940,6 +967,8 @@ 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 2d7d47e8dfaf..8de992f6eae2 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -77,6 +77,7 @@ 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 */ -- 2.34.1