2 * Copyright (C) STMicroelectronics 2009
3 * Copyright (C) ST-Ericsson SA 2010
5 * License Terms: GNU General Public License v2
6 * Based on ARM realview platform
8 * Author: Sundar Iyer <sundar.iyer@stericsson.com>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/smp.h>
14 #include <linux/completion.h>
16 #include <asm/cacheflush.h>
18 extern volatile int pen_release;
20 static DECLARE_COMPLETION(cpu_killed);
22 static inline void platform_do_lowpower(unsigned int cpu)
26 /* we put the platform to just WFI */
28 __asm__ __volatile__("dsb\n\t" "wfi\n\t"
30 if (pen_release == cpu) {
32 * OK, proper wakeup, we're done
39 int platform_cpu_kill(unsigned int cpu)
41 return wait_for_completion_timeout(&cpu_killed, 5000);
45 * platform-specific code to shutdown a CPU
47 * Called with IRQs disabled
49 void platform_cpu_die(unsigned int cpu)
52 unsigned int this_cpu = hard_smp_processor_id();
54 if (cpu != this_cpu) {
55 printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
61 printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
62 complete(&cpu_killed);
64 /* directly enter low power state, skipping secure registers */
65 platform_do_lowpower(cpu);
68 int platform_cpu_disable(unsigned int cpu)
71 * we don't allow CPU 0 to be shutdown (it is still too special
72 * e.g. clock tick interrupts)
74 return cpu == 0 ? -EPERM : 0;