diff options
Diffstat (limited to 'arch/arm/mach-ux500/hotplug.c')
-rw-r--r-- | arch/arm/mach-ux500/hotplug.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/hotplug.c b/arch/arm/mach-ux500/hotplug.c new file mode 100644 index 000000000000..b782a03024be --- /dev/null +++ b/arch/arm/mach-ux500/hotplug.c @@ -0,0 +1,75 @@ +/* + * Copyright (C) STMicroelectronics 2009 + * Copyright (C) ST-Ericsson SA 2010 + * + * License Terms: GNU General Public License v2 + * Based on ARM realview platform + * + * Author: Sundar Iyer <sundar.iyer@stericsson.com> + * + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/smp.h> +#include <linux/completion.h> + +#include <asm/cacheflush.h> + +extern volatile int pen_release; + +static DECLARE_COMPLETION(cpu_killed); + +static inline void platform_do_lowpower(unsigned int cpu) +{ + flush_cache_all(); + + /* we put the platform to just WFI */ + for (;;) { + __asm__ __volatile__("dsb\n\t" "wfi\n\t" + : : : "memory"); + if (pen_release == cpu) { + /* + * OK, proper wakeup, we're done + */ + break; + } + } +} + +int platform_cpu_kill(unsigned int cpu) +{ + return wait_for_completion_timeout(&cpu_killed, 5000); +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ +#ifdef DEBUG + unsigned int this_cpu = hard_smp_processor_id(); + + if (cpu != this_cpu) { + printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n", + this_cpu, cpu); + BUG(); + } +#endif + + printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); + complete(&cpu_killed); + + /* directly enter low power state, skipping secure registers */ + platform_do_lowpower(cpu); +} + +int platform_cpu_disable(unsigned int cpu) +{ + /* + * we don't allow CPU 0 to be shutdown (it is still too special + * e.g. clock tick interrupts) + */ + return cpu == 0 ? -EPERM : 0; +} |