1 /*
2  * Copyright (C) STMicroelectronics 2009
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * License Terms: GNU General Public License v2
6  *	Based on ARM realview platform
7  *
8  * Author: Sundar Iyer <sundar.iyer@stericsson.com>
9  *
10  */
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/smp.h>
14 
15 #include <asm/cacheflush.h>
16 #include <asm/smp_plat.h>
17 
18 extern volatile int pen_release;
19 
platform_do_lowpower(unsigned int cpu)20 static inline void platform_do_lowpower(unsigned int cpu)
21 {
22 	flush_cache_all();
23 
24 	/* we put the platform to just WFI */
25 	for (;;) {
26 		__asm__ __volatile__("dsb\n\t" "wfi\n\t"
27 				: : : "memory");
28 		if (pen_release == cpu_logical_map(cpu)) {
29 			/*
30 			 * OK, proper wakeup, we're done
31 			 */
32 			break;
33 		}
34 	}
35 }
36 
platform_cpu_kill(unsigned int cpu)37 int platform_cpu_kill(unsigned int cpu)
38 {
39 	return 1;
40 }
41 
42 /*
43  * platform-specific code to shutdown a CPU
44  *
45  * Called with IRQs disabled
46  */
platform_cpu_die(unsigned int cpu)47 void platform_cpu_die(unsigned int cpu)
48 {
49 	/* directly enter low power state, skipping secure registers */
50 	platform_do_lowpower(cpu);
51 }
52 
platform_cpu_disable(unsigned int cpu)53 int platform_cpu_disable(unsigned int cpu)
54 {
55 	/*
56 	 * we don't allow CPU 0 to be shutdown (it is still too special
57 	 * e.g. clock tick interrupts)
58 	 */
59 	return cpu == 0 ? -EPERM : 0;
60 }
61