From 41ff445cdb8b3d618425f8a16e2b873046bbe536 Mon Sep 17 00:00:00 2001 From: Jeff Ohlstein Date: Thu, 7 Apr 2011 17:41:09 -0700 Subject: [PATCH] ARM: msm: platsmp: determine number of CPU cores at boot time Previously we just assumed there were CONFIG_NR_CPUS cpus present in the system. Instead, figure out the number of cpus from the MIDR register. Signed-off-by: Jeff Ohlstein Signed-off-by: David Brown [arnd: clarified patch title] Signed-off-by: Arnd Bergmann --- arch/arm/mach-msm/platsmp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c index 2034098..5ba77d0 100644 --- a/arch/arm/mach-msm/platsmp.c +++ b/arch/arm/mach-msm/platsmp.c @@ -18,6 +18,7 @@ #include #include +#include #include #include @@ -40,6 +41,12 @@ volatile int pen_release = -1; static DEFINE_SPINLOCK(boot_lock); +static inline int get_core_count(void) +{ + /* 1 + the PART[1:0] field of MIDR */ + return ((read_cpuid_id() >> 4) & 3) + 1; +} + void __cpuinit platform_secondary_init(unsigned int cpu) { /* Configure edge-triggered PPIs */ @@ -147,9 +154,9 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) */ void __init smp_init_cpus(void) { - unsigned int i; + unsigned int i, ncores = get_core_count(); - for (i = 0; i < NR_CPUS; i++) + for (i = 0; i < ncores; i++) set_cpu_possible(i, true); set_smp_cross_call(gic_raise_softirq); -- 2.7.4