2 * linux/arch/arm/mach-realview/hotplug.c
4 * Copyright (C) 2002 ARM Ltd.
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.
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/smp.h>
16 #include <asm/smp_plat.h>
19 static inline void cpu_enter_lowpower(void)
24 " mcr p15, 0, %1, c7, c5, 0\n"
25 " mcr p15, 0, %1, c7, c10, 4\n"
29 " mrc p15, 0, %0, c1, c0, 1\n"
30 " bic %0, %0, #0x20\n"
31 " mcr p15, 0, %0, c1, c0, 1\n"
32 " mrc p15, 0, %0, c1, c0, 0\n"
34 " mcr p15, 0, %0, c1, c0, 0\n"
36 : "r" (0), "Ir" (CR_C)
40 static inline void cpu_leave_lowpower(void)
44 asm volatile("mrc p15, 0, %0, c1, c0, 0\n"
46 " mcr p15, 0, %0, c1, c0, 0\n"
47 " mrc p15, 0, %0, c1, c0, 1\n"
48 " orr %0, %0, #0x20\n"
49 " mcr p15, 0, %0, c1, c0, 1\n"
55 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
58 * there is no power-control hardware on this platform, so all
59 * we can do is put the core into WFI; this is safe as the calling
60 * code will have already disabled interrupts
66 asm(".word 0xe320f003\n"
71 if (read_pen_release() == cpu_logical_map(cpu)) {
73 * OK, proper wakeup, we're done
79 * Getting here, means that we have come out of WFI without
80 * having been woken up - this shouldn't happen
82 * Just note it happening - when we're woken, we can report
90 * platform-specific code to shutdown a CPU
92 * Called with IRQs disabled
94 void __ref ox820_cpu_die(unsigned int cpu)
99 * we're ready for shutdown now, so do it
101 cpu_enter_lowpower();
102 platform_do_lowpower(cpu, &spurious);
105 * bring this CPU back into the world of cache
106 * coherency, and then restore interrupts
108 cpu_leave_lowpower();
111 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);