/* $Id: process.c,v 1.17 2004/04/05 13:53:48 starvik Exp $ * * linux/arch/cris/kernel/process.c * * Copyright (C) 1995 Linus Torvalds * Copyright (C) 2000-2002 Axis Communications AB * * Authors: Bjorn Wesen (bjornw@axis.com) * * $Log: process.c,v $ * Revision 1.17 2004/04/05 13:53:48 starvik * Merge of Linux 2.6.5 * * Revision 1.16 2003/10/27 08:04:33 starvik * Merge of Linux 2.6.0-test9 * * Revision 1.15 2003/09/11 07:29:52 starvik * Merge of Linux 2.6.0-test5 * * Revision 1.14 2003/06/10 10:21:12 johana * Moved thread_saved_pc() from arch/cris/kernel/process.c to * subarch specific process.c. arch-v32 has an erp, no irp. * * Revision 1.13 2003/04/09 05:20:47 starvik * Merge of Linux 2.5.67 * * Revision 1.12 2002/12/11 15:41:11 starvik * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel * * Revision 1.11 2002/12/10 09:00:10 starvik * Merge of Linux 2.5.51 * * Revision 1.10 2002/11/27 08:42:34 starvik * Argument to user_regs() is thread_info* * * Revision 1.9 2002/11/26 09:44:21 starvik * New threads exits through ret_from_fork (necessary for preemptive scheduling) * * Revision 1.8 2002/11/19 14:35:24 starvik * Changes from linux 2.4 * Changed struct initializer syntax to the currently prefered notation * * Revision 1.7 2002/11/18 07:39:42 starvik * thread_saved_pc moved here from processor.h * * Revision 1.6 2002/11/14 06:51:27 starvik * Made cpu_idle more similar with other archs * init_task_union -> init_thread_union * Updated for new interrupt macros * sys_clone and do_fork have a new argument, user_tid * * Revision 1.5 2002/11/05 06:45:11 starvik * Merge of Linux 2.5.45 * * Revision 1.4 2002/02/05 15:37:44 bjornw * Need init_task.h * * Revision 1.3 2002/01/21 15:22:49 bjornw * current->counter is gone * * Revision 1.22 2001/11/13 09:40:43 orjanf * Added dump_fpu (needed for core dumps). * * Revision 1.21 2001/11/12 18:26:21 pkj * Fixed compiler warnings. * * Revision 1.20 2001/10/03 08:21:39 jonashg * cause_of_death does not exist if CONFIG_SVINTO_SIM is defined. * * Revision 1.19 2001/09/26 11:52:54 bjornw * INIT_MMAP is gone in 2.4.10 * * Revision 1.18 2001/08/21 21:43:51 hp * Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG * * Revision 1.17 2001/08/21 13:48:01 jonashg * Added fix by HP to avoid oops when doing a hard_reset_now. * * Revision 1.16 2001/06/21 02:00:40 hp * * entry.S: Include asm/unistd.h. * (_sys_call_table): Use section .rodata, not .data. * (_kernel_thread): Move from... * * process.c: ... here. * * entryoffsets.c (VAL): Break out from... * (OF): Use VAL. * (LCLONE_VM): New asmified value from CLONE_VM. * * Revision 1.15 2001/06/20 16:31:57 hp * Add comments to describe empty functions according to review. * * Revision 1.14 2001/05/29 11:27:59 markusl * Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled * * Revision 1.13 2001/03/20 19:44:06 bjornw * Use the 7th syscall argument for regs instead of current_regs * */ /* * This file handles the architecture-dependent parts of process handling.. */ #include #include #include #include #include #include #include #include #include #include #include #include #include //#define DEBUG /* * Initial task structure. Make this a per-architecture thing, * because different architectures tend to have different * alignment requirements and potentially different initial * setup. */ static struct fs_struct init_fs = INIT_FS; static struct files_struct init_files = INIT_FILES; static struct signal_struct init_signals = INIT_SIGNALS(init_signals); static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); struct mm_struct init_mm = INIT_MM(init_mm); EXPORT_SYMBOL(init_mm); /* * Initial thread structure. * * We need to make sure that this is 8192-byte aligned due to the * way process stacks are handled. This is done by having a special * "init_task" linker map entry.. */ union thread_union init_thread_union __attribute__((__section__(".data.init_task"))) = { INIT_THREAD_INFO(init_task) }; /* * Initial task structure. * * All other task structs will be allocated on slabs in fork.c */ struct task_struct init_task = INIT_TASK(init_task); EXPORT_SYMBOL(init_task); /* * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if * there would ever be a halt sequence (for power save when idle) with * some largish delay when halting or resuming *and* a driver that can't * afford that delay. The hlt_counter would then be checked before * executing the halt sequence, and the driver marks the unhaltable * region by enable_hlt/disable_hlt. */ static int hlt_counter=0; void disable_hlt(void) { hlt_counter++; } EXPORT_SYMBOL(disable_hlt); void enable_hlt(void) { hlt_counter--; } EXPORT_SYMBOL(enable_hlt); /* * The following aren't currently used. */ void (*pm_idle)(void); extern void default_idle(void); /* * The idle thread. There's no useful work to be * done, so just try to conserve power and have a * low exit latency (ie sit in a loop waiting for * somebody to say that they'd like to reschedule) */ void cpu_idle (void) { /* endless idle loop with no priority at all */ while (1) { while (!need_resched()) { void (*idle)(void) = pm_idle; if (!idle) idle = default_idle; idle(); } schedule(); } } void hard_reset_now (void); void machine_restart(void) { hard_reset_now(); } EXPORT_SYMBOL(machine_restart); /* * Similar to machine_power_off, but don't shut off power. Add code * here to freeze the system for e.g. post-mortem debug purpose when * possible. This halt has nothing to do with the idle halt. */ void machine_halt(void) { } EXPORT_SYMBOL(machine_halt); /* If or when software power-off is implemented, add code here. */ void machine_power_off(void) { } EXPORT_SYMBOL(machine_power_off); /* * When a process does an "exec", machine state like FPU and debug * registers need to be reset. This is a hook function for that. * Currently we don't have any such state to reset, so this is empty. */ void flush_thread(void) { } /* * fill in the user structure for a core dump.. */ void dump_thread(struct pt_regs * regs, struct user * dump) { #if 0 int i; /* changed the size calculations - should hopefully work better. lbt */ dump->magic = CMAGIC; dump->start_code = 0; dump->start_stack = regs->esp & ~(PAGE_SIZE - 1); dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT; dump->u_dsize -= dump->u_tsize; dump->u_ssize = 0; for (i = 0; i < 8; i++) dump->u_debugreg[i] = current->debugreg[i]; if (dump->start_stack < TASK_SIZE) dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; dump->regs = *regs; dump->u_fpvalid = dump_fpu (regs, &dump->i387); #endif } /* Fill in the fpu structure for a core dump. */ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) { return 0; }