ARM: vexpress: Select multi-cluster SMP operation if required

Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>

3 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h
index f134cd4a85f1..bde4374ab6d5 100644
--- a/arch/arm/mach-vexpress/core.h
+++ b/arch/arm/mach-vexpress/core.h
@@ -6,6 +6,8 @@
 
 void vexpress_dt_smp_map_io(void);
 
+bool vexpress_smp_init_ops(void);
+
 extern struct smp_operations    vexpress_smp_ops;
 
 extern void vexpress_cpu_die(unsigned int cpu);
diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index dc1ace55d557..993c9ae5dc5e 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -12,9 +12,11 @@
 #include <linux/errno.h>
 #include <linux/smp.h>
 #include <linux/io.h>
+#include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/vexpress.h>
 
+#include <asm/mcpm.h>
 #include <asm/smp_scu.h>
 #include <asm/mach/map.h>
 
@@ -203,3 +205,21 @@ struct smp_operations __initdata vexpress_smp_ops = {
         .cpu_die                = vexpress_cpu_die,
 #endif
 };
+
+bool __init vexpress_smp_init_ops(void)
+{
+#ifdef CONFIG_MCPM
+        /*
+         * The best way to detect a multi-cluster configuration at the moment
+         * is to look for the presence of a CCI in the system.
+         * Override the default vexpress_smp_ops if so.
+         */
+        struct device_node *node;
+        node = of_find_compatible_node(NULL, NULL, "arm,cci-400");
+        if (node && of_device_is_available(node)) {
+                mcpm_smp_set_ops();
+                return true;
+        }
+#endif
+        return false;
+}
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index 8802030df98d..b0eccf7e06ec 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -456,6 +456,7 @@ static const char * const v2m_dt_match[] __initconst = {
 DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
         .dt_compat      = v2m_dt_match,
         .smp            = smp_ops(vexpress_smp_ops),
+        .smp_init       = smp_init_ops(vexpress_smp_init_ops),
         .map_io         = v2m_dt_map_io,
         .init_early     = v2m_dt_init_early,
         .init_irq       = irqchip_init,