]>
Commit | Line | Data |
---|---|---|
7d30e8b3 | 1 | /* linux arch/arm/mach-exynos4/hotplug.c |
11adcc29 CY |
2 | * |
3 | * Cloned from linux/arch/arm/mach-realview/hotplug.c | |
4 | * | |
5 | * Copyright (C) 2002 ARM Ltd. | |
6 | * All Rights Reserved | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/smp.h> | |
11adcc29 CY |
16 | |
17 | #include <asm/cacheflush.h> | |
18 | ||
19 | extern volatile int pen_release; | |
20 | ||
11adcc29 CY |
21 | static inline void cpu_enter_lowpower(void) |
22 | { | |
23 | unsigned int v; | |
24 | ||
25 | flush_cache_all(); | |
26 | asm volatile( | |
27 | " mcr p15, 0, %1, c7, c5, 0\n" | |
28 | " mcr p15, 0, %1, c7, c10, 4\n" | |
29 | /* | |
30 | * Turn off coherency | |
31 | */ | |
32 | " mrc p15, 0, %0, c1, c0, 1\n" | |
ad849a22 | 33 | " bic %0, %0, %3\n" |
11adcc29 CY |
34 | " mcr p15, 0, %0, c1, c0, 1\n" |
35 | " mrc p15, 0, %0, c1, c0, 0\n" | |
30b99d07 | 36 | " bic %0, %0, %2\n" |
11adcc29 CY |
37 | " mcr p15, 0, %0, c1, c0, 0\n" |
38 | : "=&r" (v) | |
ad849a22 | 39 | : "r" (0), "Ir" (CR_C), "Ir" (0x40) |
11adcc29 CY |
40 | : "cc"); |
41 | } | |
42 | ||
43 | static inline void cpu_leave_lowpower(void) | |
44 | { | |
45 | unsigned int v; | |
46 | ||
47 | asm volatile( | |
48 | "mrc p15, 0, %0, c1, c0, 0\n" | |
e3d9c625 | 49 | " orr %0, %0, %1\n" |
11adcc29 CY |
50 | " mcr p15, 0, %0, c1, c0, 0\n" |
51 | " mrc p15, 0, %0, c1, c0, 1\n" | |
ad849a22 | 52 | " orr %0, %0, %2\n" |
11adcc29 CY |
53 | " mcr p15, 0, %0, c1, c0, 1\n" |
54 | : "=&r" (v) | |
ad849a22 | 55 | : "Ir" (CR_C), "Ir" (0x40) |
11adcc29 CY |
56 | : "cc"); |
57 | } | |
58 | ||
d4450261 | 59 | static inline void platform_do_lowpower(unsigned int cpu, int *spurious) |
11adcc29 CY |
60 | { |
61 | /* | |
62 | * there is no power-control hardware on this platform, so all | |
63 | * we can do is put the core into WFI; this is safe as the calling | |
64 | * code will have already disabled interrupts | |
65 | */ | |
66 | for (;;) { | |
67 | /* | |
68 | * here's the WFI | |
69 | */ | |
70 | asm(".word 0xe320f003\n" | |
71 | : | |
72 | : | |
73 | : "memory", "cc"); | |
74 | ||
75 | if (pen_release == cpu) { | |
76 | /* | |
77 | * OK, proper wakeup, we're done | |
78 | */ | |
79 | break; | |
80 | } | |
81 | ||
82 | /* | |
d4450261 | 83 | * Getting here, means that we have come out of WFI without |
11adcc29 CY |
84 | * having been woken up - this shouldn't happen |
85 | * | |
d4450261 RK |
86 | * Just note it happening - when we're woken, we can report |
87 | * its occurrence. | |
11adcc29 | 88 | */ |
d4450261 | 89 | (*spurious)++; |
11adcc29 CY |
90 | } |
91 | } | |
92 | ||
93 | int platform_cpu_kill(unsigned int cpu) | |
94 | { | |
3c030bea | 95 | return 1; |
11adcc29 CY |
96 | } |
97 | ||
98 | /* | |
99 | * platform-specific code to shutdown a CPU | |
100 | * | |
101 | * Called with IRQs disabled | |
102 | */ | |
103 | void platform_cpu_die(unsigned int cpu) | |
104 | { | |
d4450261 RK |
105 | int spurious = 0; |
106 | ||
11adcc29 CY |
107 | /* |
108 | * we're ready for shutdown now, so do it | |
109 | */ | |
110 | cpu_enter_lowpower(); | |
d4450261 | 111 | platform_do_lowpower(cpu, &spurious); |
11adcc29 CY |
112 | |
113 | /* | |
114 | * bring this CPU back into the world of cache | |
115 | * coherency, and then restore interrupts | |
116 | */ | |
117 | cpu_leave_lowpower(); | |
d4450261 RK |
118 | |
119 | if (spurious) | |
120 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); | |
11adcc29 CY |
121 | } |
122 | ||
123 | int platform_cpu_disable(unsigned int cpu) | |
124 | { | |
125 | /* | |
126 | * we don't allow CPU 0 to be shutdown (it is still too special | |
127 | * e.g. clock tick interrupts) | |
128 | */ | |
129 | return cpu == 0 ? -EPERM : 0; | |
130 | } |