diff options
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/mach-realview/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/mach-realview/hotplug.c | 138 |
2 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile index a6a40dac26a9..36e76ba937fc 100644 --- a/arch/arm/mach-realview/Makefile +++ b/arch/arm/mach-realview/Makefile | |||
@@ -5,4 +5,5 @@ | |||
5 | obj-y := core.o clock.o | 5 | obj-y := core.o clock.o |
6 | obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o | 6 | obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o |
7 | obj-$(CONFIG_SMP) += platsmp.o headsmp.o | 7 | obj-$(CONFIG_SMP) += platsmp.o headsmp.o |
8 | obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o | ||
8 | obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o | 9 | obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o |
diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c new file mode 100644 index 000000000000..09748cbcd10e --- /dev/null +++ b/arch/arm/mach-realview/hotplug.c | |||
@@ -0,0 +1,138 @@ | |||
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 | #include <linux/completion.h> | ||
15 | |||
16 | extern volatile int pen_release; | ||
17 | |||
18 | static DECLARE_COMPLETION(cpu_killed); | ||
19 | |||
20 | static inline void cpu_enter_lowpower(void) | ||
21 | { | ||
22 | unsigned int v; | ||
23 | |||
24 | asm volatile( "mcr p15, 0, %1, c7, c14, 0\n" | ||
25 | " mcr p15, 0, %1, c7, c5, 0\n" | ||
26 | " mcr p15, 0, %1, c7, c10, 4\n" | ||
27 | /* | ||
28 | * Turn off coherency | ||
29 | */ | ||
30 | " mrc p15, 0, %0, c1, c0, 1\n" | ||
31 | " bic %0, %0, #0x20\n" | ||
32 | " mcr p15, 0, %0, c1, c0, 1\n" | ||
33 | " mrc p15, 0, %0, c1, c0, 0\n" | ||
34 | " bic %0, %0, #0x04\n" | ||
35 | " mcr p15, 0, %0, c1, c0, 0\n" | ||
36 | : "=&r" (v) | ||
37 | : "r" (0) | ||
38 | : "cc"); | ||
39 | } | ||
40 | |||
41 | static inline void cpu_leave_lowpower(void) | ||
42 | { | ||
43 | unsigned int v; | ||
44 | |||
45 | asm volatile( "mrc p15, 0, %0, c1, c0, 0\n" | ||
46 | " orr %0, %0, #0x04\n" | ||
47 | " mcr p15, 0, %0, c1, c0, 0\n" | ||
48 | " mrc p15, 0, %0, c1, c0, 1\n" | ||
49 | " orr %0, %0, #0x20\n" | ||
50 | " mcr p15, 0, %0, c1, c0, 1\n" | ||
51 | : "=&r" (v) | ||
52 | : | ||
53 | : "cc"); | ||
54 | } | ||
55 | |||
56 | static inline void platform_do_lowpower(unsigned int cpu) | ||
57 | { | ||
58 | /* | ||
59 | * there is no power-control hardware on this platform, so all | ||
60 | * we can do is put the core into WFI; this is safe as the calling | ||
61 | * code will have already disabled interrupts | ||
62 | */ | ||
63 | for (;;) { | ||
64 | /* | ||
65 | * here's the WFI | ||
66 | */ | ||
67 | asm(".word 0xe320f003\n" | ||
68 | : | ||
69 | : | ||
70 | : "memory", "cc"); | ||
71 | |||
72 | if (pen_release == cpu) { | ||
73 | /* | ||
74 | * OK, proper wakeup, we're done | ||
75 | */ | ||
76 | break; | ||
77 | } | ||
78 | |||
79 | /* | ||
80 | * getting here, means that we have come out of WFI without | ||
81 | * having been woken up - this shouldn't happen | ||
82 | * | ||
83 | * The trouble is, letting people know about this is not really | ||
84 | * possible, since we are currently running incoherently, and | ||
85 | * therefore cannot safely call printk() or anything else | ||
86 | */ | ||
87 | #ifdef DEBUG | ||
88 | printk("CPU%u: spurious wakeup call\n", cpu); | ||
89 | #endif | ||
90 | } | ||
91 | } | ||
92 | |||
93 | int platform_cpu_kill(unsigned int cpu) | ||
94 | { | ||
95 | return wait_for_completion_timeout(&cpu_killed, 5000); | ||
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 | { | ||
105 | #ifdef DEBUG | ||
106 | unsigned int this_cpu = hard_smp_processor_id(); | ||
107 | |||
108 | if (cpu != this_cpu) { | ||
109 | printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n", | ||
110 | this_cpu, cpu); | ||
111 | BUG(); | ||
112 | } | ||
113 | #endif | ||
114 | |||
115 | printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); | ||
116 | complete(&cpu_killed); | ||
117 | |||
118 | /* | ||
119 | * we're ready for shutdown now, so do it | ||
120 | */ | ||
121 | cpu_enter_lowpower(); | ||
122 | platform_do_lowpower(cpu); | ||
123 | |||
124 | /* | ||
125 | * bring this CPU back into the world of cache | ||
126 | * coherency, and then restore interrupts | ||
127 | */ | ||
128 | cpu_leave_lowpower(); | ||
129 | } | ||
130 | |||
131 | int mach_cpu_disable(unsigned int cpu) | ||
132 | { | ||
133 | /* | ||
134 | * we don't allow CPU 0 to be shutdown (it is still too special | ||
135 | * e.g. clock tick interrupts) | ||
136 | */ | ||
137 | return cpu == 0 ? -EPERM : 0; | ||
138 | } | ||