projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| e9882777 RK |
1 | /* |
| 2 | * linux/arch/arm/mach-realview/hotplug.c | |
| 3 | * | |
| 4 | * Copyright (C) 2002 ARM Ltd. | |
| 5 | * All Rights Reserved | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | #include <linux/kernel.h> | |
| 12 | #include <linux/errno.h> | |
| 13 | #include <linux/smp.h> | |
| 14 | ||
| 15 | #include <asm/cacheflush.h> | |
| b3377d18 | 16 | #include <asm/system.h> |
| e9882777 RK |
17 | |
| 18 | extern volatile int pen_release; | |
| 19 | ||
| 20 | static inline void cpu_enter_lowpower(void) | |
| 21 | { | |
| 22 | unsigned int v; | |
| 23 | ||
| 24 | flush_cache_all(); | |
| 25 | asm volatile( | |
| 26 | "mcr p15, 0, %1, c7, c5, 0\n" | |
| 27 | " mcr p15, 0, %1, c7, c10, 4\n" | |
| 28 | /* | |
| 29 | * Turn off coherency | |
| 30 | */ | |
| 31 | " mrc p15, 0, %0, c1, c0, 1\n" | |
| 32 | " bic %0, %0, %3\n" | |
| 33 | " mcr p15, 0, %0, c1, c0, 1\n" | |
| 34 | " mrc p15, 0, %0, c1, c0, 0\n" | |
| 35 | " bic %0, %0, %2\n" | |
| 36 | " mcr p15, 0, %0, c1, c0, 0\n" | |
| 37 | : "=&r" (v) | |
| 38 | : "r" (0), "Ir" (CR_C), "Ir" (0x40) | |
| 39 | : "cc"); | |
| 40 | } | |
| 41 | ||
| 42 | static inline void cpu_leave_lowpower(void) | |
| 43 | { | |
| 44 | unsigned int v; | |
| 45 | ||
| 46 | asm volatile( | |
| 47 | "mrc p15, 0, %0, c1, c0, 0\n" | |
| 48 | " orr %0, %0, %1\n" | |
| 49 | " mcr p15, 0, %0, c1, c0, 0\n" | |
| 50 | " mrc p15, 0, %0, c1, c0, 1\n" | |
| 51 | " orr %0, %0, %2\n" | |
| 52 | " mcr p15, 0, %0, c1, c0, 1\n" | |
| 53 | : "=&r" (v) | |
| 54 | : "Ir" (CR_C), "Ir" (0x40) | |
| 55 | : "cc"); | |
| 56 | } | |
| 57 | ||
| 58 | static inline void platform_do_lowpower(unsigned int cpu, int *spurious) | |
| 59 | { | |
| 60 | /* | |
| 61 | * there is no power-control hardware on this platform, so all | |
| 62 | * we can do is put the core into WFI; this is safe as the calling | |
| 63 | * code will have already disabled interrupts | |
| 64 | */ | |
| 65 | for (;;) { | |
| b3377d18 | 66 | wfi(); |
| e9882777 | 67 | |
| 4a139b64 | 68 | if (pen_release == cpu_logical_map(cpu)) { |
| e9882777 RK |
69 | /* |
| 70 | * OK, proper wakeup, we're done | |
| 71 | */ | |
| 72 | break; | |
| 73 | } | |
| 74 | ||
| 75 | /* | |
| 76 | * Getting here, means that we have come out of WFI without | |
| 77 | * having been woken up - this shouldn't happen | |
| 78 | * | |
| 79 | * Just note it happening - when we're woken, we can report | |
| 80 | * its occurrence. | |
| 81 | */ | |
| 82 | (*spurious)++; | |
| 83 | } | |
| 84 | } | |
| 85 | ||
| 86 | int platform_cpu_kill(unsigned int cpu) | |
| 87 | { | |
| 88 | return 1; | |
| 89 | } | |
| 90 | ||
| 91 | /* | |
| 92 | * platform-specific code to shutdown a CPU | |
| 93 | * | |
| 94 | * Called with IRQs disabled | |
| 95 | */ | |
| 96 | void platform_cpu_die(unsigned int cpu) | |
| 97 | { | |
| 98 | int spurious = 0; | |
| 99 | ||
| 100 | /* | |
| 101 | * we're ready for shutdown now, so do it | |
| 102 | */ | |
| 103 | cpu_enter_lowpower(); | |
| 104 | platform_do_lowpower(cpu, &spurious); | |
| 105 | ||
| 106 | /* | |
| 107 | * bring this CPU back into the world of cache | |
| 108 | * coherency, and then restore interrupts | |
| 109 | */ | |
| 110 | cpu_leave_lowpower(); | |
| 111 | ||
| 112 | if (spurious) | |
| 113 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); | |
| 114 | } | |
| 115 | ||
| 116 | int platform_cpu_disable(unsigned int cpu) | |
| 117 | { | |
| 118 | /* | |
| 119 | * we don't allow CPU 0 to be shutdown (it is still too special | |
| 120 | * e.g. clock tick interrupts) | |
| 121 | */ | |
| 122 | return cpu == 0 ? -EPERM : 0; | |
| 123 | } |