/* * OMAP4 SMP cpu-hotplug support * * Copyright (C) 2010 Texas Instruments, Inc. * Author: * Santosh Shilimkar <santosh.shilimkar@ti.com> * * Platform file needed for the OMAP4 SMP. This file is based on arm * realview smp platform. * Copyright (c) 2002 ARM Limited. * * 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> #include "common.h" #include "powerdomain.h" int platform_cpu_kill(unsigned int cpu) { return 1; } /* * platform-specific code to shutdown a CPU * Called with IRQs disabled */ void __ref platform_cpu_die(unsigned int cpu) { unsigned int this_cpu; flush_cache_all(); dsb(); /* * we're ready for shutdown now, so do it */ if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0) pr_err("Secure clear status failed\n"); for (;;) { /* * Enter into low power state */ omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF); this_cpu = smp_processor_id(); if (omap_read_auxcoreboot0() == this_cpu) { /* * OK, proper wakeup, we're done */ break; } pr_debug("CPU%u: spurious wakeup call\n", cpu); } } 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; }