diff options
Diffstat (limited to 'arch/arm/mach-s5pv310/platsmp.c')
| -rw-r--r-- | arch/arm/mach-s5pv310/platsmp.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/arm/mach-s5pv310/platsmp.c b/arch/arm/mach-s5pv310/platsmp.c index 18aaf5f54033..98c04748ed84 100644 --- a/arch/arm/mach-s5pv310/platsmp.c +++ b/arch/arm/mach-s5pv310/platsmp.c @@ -37,6 +37,19 @@ extern void s5pv310_secondary_startup(void); volatile int __cpuinitdata pen_release = -1; +/* + * Write pen_release in a way that is guaranteed to be visible to all + * observers, irrespective of whether they're taking part in coherency + * or not. This is necessary for the hotplug code to work reliably. + */ +static void write_pen_release(int val) +{ + pen_release = val; + smp_wmb(); + __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); +} + static void __iomem *scu_base_addr(void) { return (void __iomem *)(S5P_VA_SCU); @@ -57,8 +70,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu) * let the primary processor know we're out of the * pen, then head off into the C entry point */ - pen_release = -1; - smp_wmb(); + write_pen_release(-1); /* * Synchronise with the boot thread. @@ -85,9 +97,7 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) * Note that "pen_release" is the hardware CPU ID, whereas * "cpu" is Linux's internal ID. */ - pen_release = cpu; - __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); - outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); + write_pen_release(cpu); /* * Send the secondary CPU a soft interrupt, thereby causing |