diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-30 08:26:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-30 08:26:25 -0700 |
commit | 706d4b12f8d7edd28d7e879a77235472da393edb (patch) | |
tree | c9bc1ce06b1154a49da1d0d907cac544a818eb0e /arch/arm/mach-s5pv310/hotplug.c | |
parent | 3af54c9bd9e6f14f896aac1bb0e8405ae0bc7a44 (diff) | |
parent | 9bafc74163d8bccca9810159aab39be926fb877c (diff) |
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (215 commits)
ARM: memblock: setup lowmem mappings using memblock
ARM: memblock: move meminfo into find_limits directly
ARM: memblock: convert free_highpages() to use memblock
ARM: move freeing of highmem pages out of mem_init()
ARM: memblock: convert memory detail printing to use memblock
ARM: memblock: use memblock to free memory into arm_bootmem_init()
ARM: memblock: use memblock when initializing memory allocators
ARM: ensure membank array is always sorted
ARM: 6466/1: implement flush_icache_all for the rest of the CPUs
ARM: 6464/2: fix spinlock recursion in adjust_pte()
ARM: fix memblock breakage
ARM: 6465/1: Fix data abort accessing proc_info from __lookup_processor_type
ARM: 6460/1: ixp2000: fix type of ixp2000_timer_interrupt
ARM: 6449/1: Fix for compiler warning of uninitialized variable.
ARM: 6445/1: fixup TCM memory types
ARM: imx: Add wake functionality to GPIO
ARM: mx5: Add gpio-keys to mx51 babbage board
ARM: imx: Add gpio-keys to plat-mxc
mx31_3ds: Fix spi registration
mx31_3ds: Fix the logic for detecting the debug board
...
Diffstat (limited to 'arch/arm/mach-s5pv310/hotplug.c')
-rw-r--r-- | arch/arm/mach-s5pv310/hotplug.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/arch/arm/mach-s5pv310/hotplug.c b/arch/arm/mach-s5pv310/hotplug.c new file mode 100644 index 00000000000..03652c3605f --- /dev/null +++ b/arch/arm/mach-s5pv310/hotplug.c @@ -0,0 +1,144 @@ +/* linux arch/arm/mach-s5pv310/hotplug.c + * + * Cloned from linux/arch/arm/mach-realview/hotplug.c + * + * Copyright (C) 2002 ARM Ltd. + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/smp.h> +#include <linux/completion.h> + +#include <asm/cacheflush.h> + +extern volatile int pen_release; + +static DECLARE_COMPLETION(cpu_killed); + +static inline void cpu_enter_lowpower(void) +{ + unsigned int v; + + flush_cache_all(); + asm volatile( + " mcr p15, 0, %1, c7, c5, 0\n" + " mcr p15, 0, %1, c7, c10, 4\n" + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, #0x20\n" + " mcr p15, 0, %0, c1, c0, 1\n" + " mrc p15, 0, %0, c1, c0, 0\n" + " bic %0, %0, #0x04\n" + " mcr p15, 0, %0, c1, c0, 0\n" + : "=&r" (v) + : "r" (0) + : "cc"); +} + +static inline void cpu_leave_lowpower(void) +{ + unsigned int v; + + asm volatile( + "mrc p15, 0, %0, c1, c0, 0\n" + " orr %0, %0, #0x04\n" + " mcr p15, 0, %0, c1, c0, 0\n" + " mrc p15, 0, %0, c1, c0, 1\n" + " orr %0, %0, #0x20\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : + : "cc"); +} + +static inline void platform_do_lowpower(unsigned int cpu) +{ + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) { + /* + * here's the WFI + */ + asm(".word 0xe320f003\n" + : + : + : "memory", "cc"); + + if (pen_release == cpu) { + /* + * OK, proper wakeup, we're done + */ + break; + } + + /* + * getting here, means that we have come out of WFI without + * having been woken up - this shouldn't happen + * + * The trouble is, letting people know about this is not really + * possible, since we are currently running incoherently, and + * therefore cannot safely call printk() or anything else + */ +#ifdef DEBUG + printk(KERN_WARN "CPU%u: spurious wakeup call\n", cpu); +#endif + } +} + +int platform_cpu_kill(unsigned int cpu) +{ + return wait_for_completion_timeout(&cpu_killed, 5000); +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ +#ifdef DEBUG + unsigned int this_cpu = hard_smp_processor_id(); + + if (cpu != this_cpu) { + printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n", + this_cpu, cpu); + BUG(); + } +#endif + + printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); + complete(&cpu_killed); + + /* + * we're ready for shutdown now, so do it + */ + cpu_enter_lowpower(); + platform_do_lowpower(cpu); + + /* + * bring this CPU back into the world of cache + * coherency, and then restore interrupts + */ + cpu_leave_lowpower(); +} + +int platform_cpu_disable(unsigned int cpu) +{ + /* + * we don't allow CPU 0 to be shutdown (it is still too special + * e.g. clock tick interrupts) + */ + return cpu == 0 ? -EPERM : 0; +} |