1 /* 2 * OMAP4 SMP cpu-hotplug support 3 * 4 * Copyright (C) 2010 Texas Instruments, Inc. 5 * Author: 6 * Santosh Shilimkar <santosh.shilimkar@ti.com> 7 * 8 * Platform file needed for the OMAP4 SMP. This file is based on arm 9 * realview smp platform. 10 * Copyright (c) 2002 ARM Limited. 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License version 2 as 14 * published by the Free Software Foundation. 15 */ 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/smp.h> 20 21 #include <asm/cacheflush.h> 22 #include <mach/omap4-common.h> 23 24 int platform_cpu_kill(unsigned int cpu) 25 { 26 return 1; 27 } 28 29 /* 30 * platform-specific code to shutdown a CPU 31 * Called with IRQs disabled 32 */ 33 void platform_cpu_die(unsigned int cpu) 34 { 35 flush_cache_all(); 36 dsb(); 37 38 /* 39 * we're ready for shutdown now, so do it 40 */ 41 if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0) 42 printk(KERN_CRIT "Secure clear status failed\n"); 43 44 for (;;) { 45 /* 46 * Execute WFI 47 */ 48 do_wfi(); 49 50 if (omap_read_auxcoreboot0() == cpu) { 51 /* 52 * OK, proper wakeup, we're done 53 */ 54 break; 55 } 56 pr_debug("CPU%u: spurious wakeup call\n", cpu); 57 } 58 } 59 60 int platform_cpu_disable(unsigned int cpu) 61 { 62 /* 63 * we don't allow CPU 0 to be shutdown (it is still too special 64 * e.g. clock tick interrupts) 65 */ 66 return cpu == 0 ? -EPERM : 0; 67 } 68