OpenWrt – Blame information for rev 4
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Rev | Author | Line No. | Line |
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1 | office | 1 | /* linux arch/arm/mach-cns3xxx/hotplug.c |
2 | * |
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3 | * Cloned from linux/arch/arm/mach-realview/hotplug.c |
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4 | * |
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5 | * Copyright (C) 2002 ARM Ltd. |
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6 | * All Rights Reserved |
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7 | * |
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8 | * This program is free software; you can redistribute it and/or modify |
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9 | * it under the terms of the GNU General Public License version 2 as |
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10 | * published by the Free Software Foundation. |
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11 | */ |
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12 | |||
13 | #include <linux/kernel.h> |
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14 | #include <linux/errno.h> |
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15 | #include <linux/smp.h> |
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16 | |||
17 | #include <asm/cacheflush.h> |
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18 | |||
19 | extern volatile int pen_release; |
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20 | |||
21 | static inline void cpu_enter_lowpower(void) |
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22 | { |
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23 | unsigned int v; |
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24 | |||
25 | flush_cache_all(); |
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26 | asm volatile( |
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27 | " mcr p15, 0, %1, c7, c5, 0\n" |
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28 | " mcr p15, 0, %1, c7, c10, 4\n" |
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29 | /* |
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30 | * Turn off coherency |
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31 | */ |
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32 | " mrc p15, 0, %0, c1, c0, 1\n" |
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33 | " bic %0, %0, %3\n" |
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34 | " mcr p15, 0, %0, c1, c0, 1\n" |
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35 | " mrc p15, 0, %0, c1, c0, 0\n" |
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36 | " bic %0, %0, %2\n" |
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37 | " mcr p15, 0, %0, c1, c0, 0\n" |
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38 | : "=&r" (v) |
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39 | : "r" (0), "Ir" (CR_C), "Ir" (0x40) |
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40 | : "cc"); |
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41 | } |
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42 | |||
43 | static inline void cpu_leave_lowpower(void) |
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44 | { |
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45 | unsigned int v; |
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46 | |||
47 | asm volatile( |
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48 | "mrc p15, 0, %0, c1, c0, 0\n" |
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49 | " orr %0, %0, %1\n" |
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50 | " mcr p15, 0, %0, c1, c0, 0\n" |
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51 | " mrc p15, 0, %0, c1, c0, 1\n" |
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52 | " orr %0, %0, %2\n" |
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53 | " mcr p15, 0, %0, c1, c0, 1\n" |
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54 | : "=&r" (v) |
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55 | : "Ir" (CR_C), "Ir" (0x40) |
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56 | : "cc"); |
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57 | } |
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58 | |||
59 | static inline void platform_do_lowpower(unsigned int cpu, int *spurious) |
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60 | { |
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61 | /* |
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62 | * there is no power-control hardware on this platform, so all |
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63 | * we can do is put the core into WFI; this is safe as the calling |
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64 | * code will have already disabled interrupts |
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65 | */ |
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66 | for (;;) { |
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67 | /* |
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68 | * here's the WFI |
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69 | */ |
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70 | asm(".word 0xe320f003\n" |
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71 | : |
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72 | : |
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73 | : "memory", "cc"); |
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74 | |||
75 | if (pen_release == cpu) { |
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76 | /* |
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77 | * OK, proper wakeup, we're done |
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78 | */ |
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79 | break; |
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80 | } |
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81 | |||
82 | /* |
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83 | * Getting here, means that we have come out of WFI without |
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84 | * having been woken up - this shouldn't happen |
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85 | * |
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86 | * Just note it happening - when we're woken, we can report |
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87 | * its occurrence. |
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88 | */ |
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89 | (*spurious)++; |
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90 | } |
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91 | } |
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92 | |||
93 | int platform_cpu_kill(unsigned int cpu) |
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94 | { |
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95 | return 1; |
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96 | } |
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97 | |||
98 | /* |
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99 | * platform-specific code to shutdown a CPU |
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100 | * |
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101 | * Called with IRQs disabled |
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102 | */ |
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103 | void platform_cpu_die(unsigned int cpu) |
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104 | { |
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105 | int spurious = 0; |
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106 | |||
107 | /* |
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108 | * we're ready for shutdown now, so do it |
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109 | */ |
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110 | cpu_enter_lowpower(); |
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111 | platform_do_lowpower(cpu, &spurious); |
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112 | |||
113 | /* |
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114 | * bring this CPU back into the world of cache |
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115 | * coherency, and then restore interrupts |
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116 | */ |
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117 | cpu_leave_lowpower(); |
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118 | |||
119 | if (spurious) |
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120 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); |
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121 | } |
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122 | |||
123 | int platform_cpu_disable(unsigned int cpu) |
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124 | { |
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125 | /* |
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126 | * we don't allow CPU 0 to be shutdown (it is still too special |
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127 | * e.g. clock tick interrupts) |
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128 | */ |
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129 | return cpu == 0 ? -EPERM : 0; |
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130 | } |