| /* |
| * 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; |
| } |
