diff options
| -rw-r--r-- | arch/arm/mach-msm/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/mach-msm/hotplug.c | 91 |
2 files changed, 93 insertions, 0 deletions
diff --git a/arch/arm/mach-msm/Makefile b/arch/arm/mach-msm/Makefile index 5765ef1e60f..c673e5fdabf 100644 --- a/arch/arm/mach-msm/Makefile +++ b/arch/arm/mach-msm/Makefile @@ -20,6 +20,8 @@ obj-$(CONFIG_MSM_SMD) += smd.o smd_debug.o obj-$(CONFIG_MSM_SMD) += last_radio_log.o obj-$(CONFIG_MSM_SCM) += scm.o scm-boot.o +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o + obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o devices-msm7x00.o obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o board-trout-panel.o devices-msm7x00.o obj-$(CONFIG_MACH_HALIBUT) += board-halibut.o devices-msm7x00.o diff --git a/arch/arm/mach-msm/hotplug.c b/arch/arm/mach-msm/hotplug.c new file mode 100644 index 00000000000..5a31f70dfb8 --- /dev/null +++ b/arch/arm/mach-msm/hotplug.c @@ -0,0 +1,91 @@ +/* + * 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 <asm/cacheflush.h> + +extern volatile int pen_release; + +static inline void cpu_enter_lowpower(void) +{ + /* Just flush the cache. Changing the coherency is not yet + * available on msm. */ + flush_cache_all(); +} + +static inline void cpu_leave_lowpower(void) +{ +} + +static inline void platform_do_lowpower(unsigned int cpu) +{ + /* Just enter wfi for now. TODO: Properly shut off the cpu. */ + for (;;) { + /* + * here's the WFI + */ + asm("wfi" + : + : + : "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 + */ + pr_debug("CPU%u: spurious wakeup call\n", cpu); + } +} + +int platform_cpu_kill(unsigned int cpu) +{ + return 1; +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ + /* + * 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; +} |