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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> | |
911c29b0 | 16 | #include <linux/io.h> |
11adcc29 CY |
17 | |
18 | #include <asm/cacheflush.h> | |
19 | ||
911c29b0 JM |
20 | #include <mach/regs-pmu.h> |
21 | ||
11adcc29 CY |
22 | extern volatile int pen_release; |
23 | ||
11adcc29 CY |
24 | static inline void cpu_enter_lowpower(void) |
25 | { | |
26 | unsigned int v; | |
27 | ||
28 | flush_cache_all(); | |
29 | asm volatile( | |
30 | " mcr p15, 0, %1, c7, c5, 0\n" | |
31 | " mcr p15, 0, %1, c7, c10, 4\n" | |
32 | /* | |
33 | * Turn off coherency | |
34 | */ | |
35 | " mrc p15, 0, %0, c1, c0, 1\n" | |
ad849a22 | 36 | " bic %0, %0, %3\n" |
11adcc29 CY |
37 | " mcr p15, 0, %0, c1, c0, 1\n" |
38 | " mrc p15, 0, %0, c1, c0, 0\n" | |
30b99d07 | 39 | " bic %0, %0, %2\n" |
11adcc29 CY |
40 | " mcr p15, 0, %0, c1, c0, 0\n" |
41 | : "=&r" (v) | |
ad849a22 | 42 | : "r" (0), "Ir" (CR_C), "Ir" (0x40) |
11adcc29 CY |
43 | : "cc"); |
44 | } | |
45 | ||
46 | static inline void cpu_leave_lowpower(void) | |
47 | { | |
48 | unsigned int v; | |
49 | ||
50 | asm volatile( | |
51 | "mrc p15, 0, %0, c1, c0, 0\n" | |
e3d9c625 | 52 | " orr %0, %0, %1\n" |
11adcc29 CY |
53 | " mcr p15, 0, %0, c1, c0, 0\n" |
54 | " mrc p15, 0, %0, c1, c0, 1\n" | |
ad849a22 | 55 | " orr %0, %0, %2\n" |
11adcc29 CY |
56 | " mcr p15, 0, %0, c1, c0, 1\n" |
57 | : "=&r" (v) | |
ad849a22 | 58 | : "Ir" (CR_C), "Ir" (0x40) |
11adcc29 CY |
59 | : "cc"); |
60 | } | |
61 | ||
d4450261 | 62 | static inline void platform_do_lowpower(unsigned int cpu, int *spurious) |
11adcc29 | 63 | { |
11adcc29 | 64 | for (;;) { |
911c29b0 JM |
65 | |
66 | /* make cpu1 to be turned off at next WFI command */ | |
67 | if (cpu == 1) | |
68 | __raw_writel(0, S5P_ARM_CORE1_CONFIGURATION); | |
69 | ||
11adcc29 CY |
70 | /* |
71 | * here's the WFI | |
72 | */ | |
73 | asm(".word 0xe320f003\n" | |
74 | : | |
75 | : | |
76 | : "memory", "cc"); | |
77 | ||
78 | if (pen_release == cpu) { | |
79 | /* | |
80 | * OK, proper wakeup, we're done | |
81 | */ | |
82 | break; | |
83 | } | |
84 | ||
85 | /* | |
d4450261 | 86 | * Getting here, means that we have come out of WFI without |
11adcc29 CY |
87 | * having been woken up - this shouldn't happen |
88 | * | |
d4450261 RK |
89 | * Just note it happening - when we're woken, we can report |
90 | * its occurrence. | |
11adcc29 | 91 | */ |
d4450261 | 92 | (*spurious)++; |
11adcc29 CY |
93 | } |
94 | } | |
95 | ||
96 | int platform_cpu_kill(unsigned int cpu) | |
97 | { | |
3c030bea | 98 | return 1; |
11adcc29 CY |
99 | } |
100 | ||
101 | /* | |
102 | * platform-specific code to shutdown a CPU | |
103 | * | |
104 | * Called with IRQs disabled | |
105 | */ | |
106 | void platform_cpu_die(unsigned int cpu) | |
107 | { | |
d4450261 RK |
108 | int spurious = 0; |
109 | ||
11adcc29 CY |
110 | /* |
111 | * we're ready for shutdown now, so do it | |
112 | */ | |
113 | cpu_enter_lowpower(); | |
d4450261 | 114 | platform_do_lowpower(cpu, &spurious); |
11adcc29 CY |
115 | |
116 | /* | |
117 | * bring this CPU back into the world of cache | |
118 | * coherency, and then restore interrupts | |
119 | */ | |
120 | cpu_leave_lowpower(); | |
d4450261 RK |
121 | |
122 | if (spurious) | |
123 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); | |
11adcc29 CY |
124 | } |
125 | ||
126 | int platform_cpu_disable(unsigned int cpu) | |
127 | { | |
128 | /* | |
129 | * we don't allow CPU 0 to be shutdown (it is still too special | |
130 | * e.g. clock tick interrupts) | |
131 | */ | |
132 | return cpu == 0 ? -EPERM : 0; | |
133 | } |