The method to detect the number of CPU cores on Cortex-A9 MPCore and
Cortex-A15 MPCore is different. On Cortex-A9 MPCore we can get this
information from the Snoop Control Unit(SCU). On Cortex-A15 MPCore we
have to read it from the system coprocessor(CP15), because the SCU on
Cortex-A15 MPCore does not have software readable registers. This
patch selects the correct method at runtime based on the CPU ID.

Signed-off-by: Hiroshi Doyu <redacted>
---
 arch/arm/mach-tegra/platsmp.c |   31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
index 1b926df..68e76ef 100644
--- a/arch/arm/mach-tegra/platsmp.c
+++ b/arch/arm/mach-tegra/platsmp.c

@@ -23,6 +23,7 @@
 #include <asm/hardware/gic.h>
 #include <asm/mach-types.h>
 #include <asm/smp_scu.h>
+#include <asm/cputype.h>
 
 #include <mach/powergate.h>
 

@@ -34,9 +35,13 @@
 #include "common.h"
 #include "iomap.h"
 
+#define CPU_MASK		0xff0ffff0
+#define CPU_CORTEX_A9		0x410fc090
+#define CPU_CORTEX_A15		0x410fc0f0
+
 extern void tegra_secondary_startup(void);
 
-static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
+static void __iomem *scu_base;
 
 #define EVP_CPU_RESET_VECTOR \
 	(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)

@@ -149,7 +154,26 @@ done:
  */
 static void __init tegra_smp_init_cpus(void)
 {
-	unsigned int i, ncores = scu_get_core_count(scu_base);
+	unsigned int i, cpu_id, ncores;
+	u32 l2ctlr;
+	phys_addr_t pa;
+
+	cpu_id = read_cpuid(CPUID_ID) & CPU_MASK;
+	switch (cpu_id) {
+	case CPU_CORTEX_A15:
+		asm("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
+		ncores = ((l2ctlr >> 24) & 3) + 1;