1/* $Id: process.c,v 1.1.1.1 2007/08/03 18:51:42 Exp $ 2 * 3 * linux/arch/cris/kernel/process.c 4 * 5 * Copyright (C) 1995 Linus Torvalds 6 * Copyright (C) 2000-2002 Axis Communications AB 7 * 8 * Authors: Bjorn Wesen (bjornw@axis.com) 9 * 10 * $Log: process.c,v $ 11 * Revision 1.1.1.1 2007/08/03 18:51:42 rnuti 12 * Importing Linux MIPS Kernel 2.6.22 13 * 14 * Revision 1.21 2005/03/04 08:16:17 starvik 15 * Merge of Linux 2.6.11. 16 * 17 * Revision 1.20 2005/01/18 05:57:22 starvik 18 * Renamed hlt_counter to cris_hlt_counter and made it global. 19 * 20 * Revision 1.19 2004/10/19 13:07:43 starvik 21 * Merge of Linux 2.6.9 22 * 23 * Revision 1.18 2004/08/16 12:37:23 starvik 24 * Merge of Linux 2.6.8 25 * 26 * Revision 1.17 2004/04/05 13:53:48 starvik 27 * Merge of Linux 2.6.5 28 * 29 * Revision 1.16 2003/10/27 08:04:33 starvik 30 * Merge of Linux 2.6.0-test9 31 * 32 * Revision 1.15 2003/09/11 07:29:52 starvik 33 * Merge of Linux 2.6.0-test5 34 * 35 * Revision 1.14 2003/06/10 10:21:12 johana 36 * Moved thread_saved_pc() from arch/cris/kernel/process.c to 37 * subarch specific process.c. arch-v32 has an erp, no irp. 38 * 39 * Revision 1.13 2003/04/09 05:20:47 starvik 40 * Merge of Linux 2.5.67 41 * 42 * Revision 1.12 2002/12/11 15:41:11 starvik 43 * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel 44 * 45 * Revision 1.11 2002/12/10 09:00:10 starvik 46 * Merge of Linux 2.5.51 47 * 48 * Revision 1.10 2002/11/27 08:42:34 starvik 49 * Argument to user_regs() is thread_info* 50 * 51 * Revision 1.9 2002/11/26 09:44:21 starvik 52 * New threads exits through ret_from_fork (necessary for preemptive scheduling) 53 * 54 * Revision 1.8 2002/11/19 14:35:24 starvik 55 * Changes from linux 2.4 56 * Changed struct initializer syntax to the currently prefered notation 57 * 58 * Revision 1.7 2002/11/18 07:39:42 starvik 59 * thread_saved_pc moved here from processor.h 60 * 61 * Revision 1.6 2002/11/14 06:51:27 starvik 62 * Made cpu_idle more similar with other archs 63 * init_task_union -> init_thread_union 64 * Updated for new interrupt macros 65 * sys_clone and do_fork have a new argument, user_tid 66 * 67 * Revision 1.5 2002/11/05 06:45:11 starvik 68 * Merge of Linux 2.5.45 69 * 70 * Revision 1.4 2002/02/05 15:37:44 bjornw 71 * Need init_task.h 72 * 73 * Revision 1.3 2002/01/21 15:22:49 bjornw 74 * current->counter is gone 75 * 76 * Revision 1.22 2001/11/13 09:40:43 orjanf 77 * Added dump_fpu (needed for core dumps). 78 * 79 * Revision 1.21 2001/11/12 18:26:21 pkj 80 * Fixed compiler warnings. 81 * 82 * Revision 1.20 2001/10/03 08:21:39 jonashg 83 * cause_of_death does not exist if CONFIG_SVINTO_SIM is defined. 84 * 85 * Revision 1.19 2001/09/26 11:52:54 bjornw 86 * INIT_MMAP is gone in 2.4.10 87 * 88 * Revision 1.18 2001/08/21 21:43:51 hp 89 * Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG 90 * 91 * Revision 1.17 2001/08/21 13:48:01 jonashg 92 * Added fix by HP to avoid oops when doing a hard_reset_now. 93 * 94 * Revision 1.16 2001/06/21 02:00:40 hp 95 * * entry.S: Include asm/unistd.h. 96 * (_sys_call_table): Use section .rodata, not .data. 97 * (_kernel_thread): Move from... 98 * * process.c: ... here. 99 * * entryoffsets.c (VAL): Break out from... 100 * (OF): Use VAL. 101 * (LCLONE_VM): New asmified value from CLONE_VM. 102 * 103 * Revision 1.15 2001/06/20 16:31:57 hp 104 * Add comments to describe empty functions according to review. 105 * 106 * Revision 1.14 2001/05/29 11:27:59 markusl 107 * Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled 108 * 109 * Revision 1.13 2001/03/20 19:44:06 bjornw 110 * Use the 7th syscall argument for regs instead of current_regs 111 * 112 */ 113 114/* 115 * This file handles the architecture-dependent parts of process handling.. 116 */ 117 118#include <asm/atomic.h> 119#include <asm/pgtable.h> 120#include <asm/uaccess.h> 121#include <asm/irq.h> 122#include <asm/system.h> 123#include <linux/module.h> 124#include <linux/spinlock.h> 125#include <linux/fs_struct.h> 126#include <linux/init_task.h> 127#include <linux/sched.h> 128#include <linux/fs.h> 129#include <linux/user.h> 130#include <linux/elfcore.h> 131#include <linux/mqueue.h> 132#include <linux/reboot.h> 133 134//#define DEBUG 135 136/* 137 * Initial task structure. Make this a per-architecture thing, 138 * because different architectures tend to have different 139 * alignment requirements and potentially different initial 140 * setup. 141 */ 142 143static struct fs_struct init_fs = INIT_FS; 144static struct files_struct init_files = INIT_FILES; 145static struct signal_struct init_signals = INIT_SIGNALS(init_signals); 146static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); 147struct mm_struct init_mm = INIT_MM(init_mm); 148 149EXPORT_SYMBOL(init_mm); 150 151/* 152 * Initial thread structure. 153 * 154 * We need to make sure that this is 8192-byte aligned due to the 155 * way process stacks are handled. This is done by having a special 156 * "init_task" linker map entry.. 157 */ 158union thread_union init_thread_union 159 __attribute__((__section__(".data.init_task"))) = 160 { INIT_THREAD_INFO(init_task) }; 161 162/* 163 * Initial task structure. 164 * 165 * All other task structs will be allocated on slabs in fork.c 166 */ 167struct task_struct init_task = INIT_TASK(init_task); 168 169EXPORT_SYMBOL(init_task); 170 171/* 172 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if 173 * there would ever be a halt sequence (for power save when idle) with 174 * some largish delay when halting or resuming *and* a driver that can't 175 * afford that delay. The hlt_counter would then be checked before 176 * executing the halt sequence, and the driver marks the unhaltable 177 * region by enable_hlt/disable_hlt. 178 */ 179 180int cris_hlt_counter=0; 181 182void disable_hlt(void) 183{ 184 cris_hlt_counter++; 185} 186 187EXPORT_SYMBOL(disable_hlt); 188 189void enable_hlt(void) 190{ 191 cris_hlt_counter--; 192} 193 194EXPORT_SYMBOL(enable_hlt); 195 196/* 197 * The following aren't currently used. 198 */ 199void (*pm_idle)(void); 200 201/* 202 * The idle thread. There's no useful work to be 203 * done, so just try to conserve power and have a 204 * low exit latency (ie sit in a loop waiting for 205 * somebody to say that they'd like to reschedule) 206 */ 207void cpu_idle (void) 208{ 209 /* endless idle loop with no priority at all */ 210 while (1) { 211 while (!need_resched()) { 212 void (*idle)(void); 213 /* 214 * Mark this as an RCU critical section so that 215 * synchronize_kernel() in the unload path waits 216 * for our completion. 217 */ 218 idle = pm_idle; 219 if (!idle) 220 idle = default_idle; 221 idle(); 222 } 223 preempt_enable_no_resched(); 224 schedule(); 225 preempt_disable(); 226 } 227} 228 229void hard_reset_now (void); 230 231void machine_restart(char *cmd) 232{ 233 hard_reset_now(); 234} 235 236/* 237 * Similar to machine_power_off, but don't shut off power. Add code 238 * here to freeze the system for e.g. post-mortem debug purpose when 239 * possible. This halt has nothing to do with the idle halt. 240 */ 241 242void machine_halt(void) 243{ 244} 245 246/* If or when software power-off is implemented, add code here. */ 247 248void machine_power_off(void) 249{ 250} 251 252/* 253 * When a process does an "exec", machine state like FPU and debug 254 * registers need to be reset. This is a hook function for that. 255 * Currently we don't have any such state to reset, so this is empty. 256 */ 257 258void flush_thread(void) 259{ 260} 261 262/* Fill in the fpu structure for a core dump. */ 263int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 264{ 265 return 0; 266} 267