Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 1 | /* $Id: process.c,v 1.21 2005/03/04 08:16:17 starvik Exp $ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 $ |
Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 11 | * Revision 1.21 2005/03/04 08:16:17 starvik |
| 12 | * Merge of Linux 2.6.11. |
| 13 | * |
| 14 | * Revision 1.20 2005/01/18 05:57:22 starvik |
| 15 | * Renamed hlt_counter to cris_hlt_counter and made it global. |
| 16 | * |
| 17 | * Revision 1.19 2004/10/19 13:07:43 starvik |
| 18 | * Merge of Linux 2.6.9 |
| 19 | * |
| 20 | * Revision 1.18 2004/08/16 12:37:23 starvik |
| 21 | * Merge of Linux 2.6.8 |
| 22 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | * Revision 1.17 2004/04/05 13:53:48 starvik |
| 24 | * Merge of Linux 2.6.5 |
| 25 | * |
| 26 | * Revision 1.16 2003/10/27 08:04:33 starvik |
| 27 | * Merge of Linux 2.6.0-test9 |
| 28 | * |
| 29 | * Revision 1.15 2003/09/11 07:29:52 starvik |
| 30 | * Merge of Linux 2.6.0-test5 |
| 31 | * |
| 32 | * Revision 1.14 2003/06/10 10:21:12 johana |
| 33 | * Moved thread_saved_pc() from arch/cris/kernel/process.c to |
| 34 | * subarch specific process.c. arch-v32 has an erp, no irp. |
| 35 | * |
| 36 | * Revision 1.13 2003/04/09 05:20:47 starvik |
| 37 | * Merge of Linux 2.5.67 |
| 38 | * |
| 39 | * Revision 1.12 2002/12/11 15:41:11 starvik |
| 40 | * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel |
| 41 | * |
| 42 | * Revision 1.11 2002/12/10 09:00:10 starvik |
| 43 | * Merge of Linux 2.5.51 |
| 44 | * |
| 45 | * Revision 1.10 2002/11/27 08:42:34 starvik |
| 46 | * Argument to user_regs() is thread_info* |
| 47 | * |
| 48 | * Revision 1.9 2002/11/26 09:44:21 starvik |
| 49 | * New threads exits through ret_from_fork (necessary for preemptive scheduling) |
| 50 | * |
| 51 | * Revision 1.8 2002/11/19 14:35:24 starvik |
| 52 | * Changes from linux 2.4 |
| 53 | * Changed struct initializer syntax to the currently prefered notation |
| 54 | * |
| 55 | * Revision 1.7 2002/11/18 07:39:42 starvik |
| 56 | * thread_saved_pc moved here from processor.h |
| 57 | * |
| 58 | * Revision 1.6 2002/11/14 06:51:27 starvik |
| 59 | * Made cpu_idle more similar with other archs |
| 60 | * init_task_union -> init_thread_union |
| 61 | * Updated for new interrupt macros |
| 62 | * sys_clone and do_fork have a new argument, user_tid |
| 63 | * |
| 64 | * Revision 1.5 2002/11/05 06:45:11 starvik |
| 65 | * Merge of Linux 2.5.45 |
| 66 | * |
| 67 | * Revision 1.4 2002/02/05 15:37:44 bjornw |
| 68 | * Need init_task.h |
| 69 | * |
| 70 | * Revision 1.3 2002/01/21 15:22:49 bjornw |
| 71 | * current->counter is gone |
| 72 | * |
| 73 | * Revision 1.22 2001/11/13 09:40:43 orjanf |
| 74 | * Added dump_fpu (needed for core dumps). |
| 75 | * |
| 76 | * Revision 1.21 2001/11/12 18:26:21 pkj |
| 77 | * Fixed compiler warnings. |
| 78 | * |
| 79 | * Revision 1.20 2001/10/03 08:21:39 jonashg |
| 80 | * cause_of_death does not exist if CONFIG_SVINTO_SIM is defined. |
| 81 | * |
| 82 | * Revision 1.19 2001/09/26 11:52:54 bjornw |
| 83 | * INIT_MMAP is gone in 2.4.10 |
| 84 | * |
| 85 | * Revision 1.18 2001/08/21 21:43:51 hp |
| 86 | * Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG |
| 87 | * |
| 88 | * Revision 1.17 2001/08/21 13:48:01 jonashg |
| 89 | * Added fix by HP to avoid oops when doing a hard_reset_now. |
| 90 | * |
| 91 | * Revision 1.16 2001/06/21 02:00:40 hp |
| 92 | * * entry.S: Include asm/unistd.h. |
| 93 | * (_sys_call_table): Use section .rodata, not .data. |
| 94 | * (_kernel_thread): Move from... |
| 95 | * * process.c: ... here. |
| 96 | * * entryoffsets.c (VAL): Break out from... |
| 97 | * (OF): Use VAL. |
| 98 | * (LCLONE_VM): New asmified value from CLONE_VM. |
| 99 | * |
| 100 | * Revision 1.15 2001/06/20 16:31:57 hp |
| 101 | * Add comments to describe empty functions according to review. |
| 102 | * |
| 103 | * Revision 1.14 2001/05/29 11:27:59 markusl |
| 104 | * Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled |
| 105 | * |
| 106 | * Revision 1.13 2001/03/20 19:44:06 bjornw |
| 107 | * Use the 7th syscall argument for regs instead of current_regs |
| 108 | * |
| 109 | */ |
| 110 | |
| 111 | /* |
| 112 | * This file handles the architecture-dependent parts of process handling.. |
| 113 | */ |
| 114 | |
| 115 | #include <asm/atomic.h> |
| 116 | #include <asm/pgtable.h> |
| 117 | #include <asm/uaccess.h> |
| 118 | #include <asm/irq.h> |
Adrian Bunk | cdb0452 | 2006-03-24 03:15:57 -0800 | [diff] [blame] | 119 | #include <asm/system.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | #include <linux/module.h> |
| 121 | #include <linux/spinlock.h> |
| 122 | #include <linux/fs_struct.h> |
| 123 | #include <linux/init_task.h> |
| 124 | #include <linux/sched.h> |
| 125 | #include <linux/fs.h> |
| 126 | #include <linux/user.h> |
| 127 | #include <linux/elfcore.h> |
| 128 | #include <linux/mqueue.h> |
Eric W. Biederman | 16dcb4b | 2005-07-26 11:32:34 -0600 | [diff] [blame] | 129 | #include <linux/reboot.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | //#define DEBUG |
| 132 | |
| 133 | /* |
| 134 | * Initial task structure. Make this a per-architecture thing, |
| 135 | * because different architectures tend to have different |
| 136 | * alignment requirements and potentially different initial |
| 137 | * setup. |
| 138 | */ |
| 139 | |
| 140 | static struct fs_struct init_fs = INIT_FS; |
| 141 | static struct files_struct init_files = INIT_FILES; |
| 142 | static struct signal_struct init_signals = INIT_SIGNALS(init_signals); |
| 143 | static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); |
| 144 | struct mm_struct init_mm = INIT_MM(init_mm); |
| 145 | |
| 146 | EXPORT_SYMBOL(init_mm); |
| 147 | |
| 148 | /* |
| 149 | * Initial thread structure. |
| 150 | * |
| 151 | * We need to make sure that this is 8192-byte aligned due to the |
| 152 | * way process stacks are handled. This is done by having a special |
| 153 | * "init_task" linker map entry.. |
| 154 | */ |
| 155 | union thread_union init_thread_union |
| 156 | __attribute__((__section__(".data.init_task"))) = |
| 157 | { INIT_THREAD_INFO(init_task) }; |
| 158 | |
| 159 | /* |
| 160 | * Initial task structure. |
| 161 | * |
| 162 | * All other task structs will be allocated on slabs in fork.c |
| 163 | */ |
| 164 | struct task_struct init_task = INIT_TASK(init_task); |
| 165 | |
| 166 | EXPORT_SYMBOL(init_task); |
| 167 | |
| 168 | /* |
| 169 | * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if |
| 170 | * there would ever be a halt sequence (for power save when idle) with |
| 171 | * some largish delay when halting or resuming *and* a driver that can't |
| 172 | * afford that delay. The hlt_counter would then be checked before |
| 173 | * executing the halt sequence, and the driver marks the unhaltable |
| 174 | * region by enable_hlt/disable_hlt. |
| 175 | */ |
| 176 | |
Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 177 | int cris_hlt_counter=0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
| 179 | void disable_hlt(void) |
| 180 | { |
Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 181 | cris_hlt_counter++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | } |
| 183 | |
| 184 | EXPORT_SYMBOL(disable_hlt); |
| 185 | |
| 186 | void enable_hlt(void) |
| 187 | { |
Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 188 | cris_hlt_counter--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | EXPORT_SYMBOL(enable_hlt); |
| 192 | |
| 193 | /* |
| 194 | * The following aren't currently used. |
| 195 | */ |
| 196 | void (*pm_idle)(void); |
| 197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | /* |
| 199 | * The idle thread. There's no useful work to be |
| 200 | * done, so just try to conserve power and have a |
| 201 | * low exit latency (ie sit in a loop waiting for |
| 202 | * somebody to say that they'd like to reschedule) |
| 203 | */ |
| 204 | void cpu_idle (void) |
| 205 | { |
| 206 | /* endless idle loop with no priority at all */ |
| 207 | while (1) { |
| 208 | while (!need_resched()) { |
Mikael Starvik | 5d01e6c | 2005-07-27 11:44:43 -0700 | [diff] [blame] | 209 | void (*idle)(void); |
| 210 | /* |
| 211 | * Mark this as an RCU critical section so that |
| 212 | * synchronize_kernel() in the unload path waits |
| 213 | * for our completion. |
| 214 | */ |
| 215 | idle = pm_idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | if (!idle) |
| 217 | idle = default_idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | idle(); |
| 219 | } |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 220 | preempt_enable_no_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | schedule(); |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 222 | preempt_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | } |
| 225 | |
| 226 | void hard_reset_now (void); |
| 227 | |
Eric W. Biederman | 16dcb4b | 2005-07-26 11:32:34 -0600 | [diff] [blame] | 228 | void machine_restart(char *cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | { |
| 230 | hard_reset_now(); |
| 231 | } |
| 232 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | /* |
| 234 | * Similar to machine_power_off, but don't shut off power. Add code |
| 235 | * here to freeze the system for e.g. post-mortem debug purpose when |
| 236 | * possible. This halt has nothing to do with the idle halt. |
| 237 | */ |
| 238 | |
| 239 | void machine_halt(void) |
| 240 | { |
| 241 | } |
| 242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | /* If or when software power-off is implemented, add code here. */ |
| 244 | |
| 245 | void machine_power_off(void) |
| 246 | { |
| 247 | } |
| 248 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | /* |
| 250 | * When a process does an "exec", machine state like FPU and debug |
| 251 | * registers need to be reset. This is a hook function for that. |
| 252 | * Currently we don't have any such state to reset, so this is empty. |
| 253 | */ |
| 254 | |
| 255 | void flush_thread(void) |
| 256 | { |
| 257 | } |
| 258 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | /* Fill in the fpu structure for a core dump. */ |
| 260 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) |
| 261 | { |
| 262 | return 0; |
| 263 | } |