| /* $Id: process.c,v 1.3 2002/01/21 15:22:49 bjornw Exp $ |
| * |
| * linux/arch/cris/kernel/process.c |
| * |
| * Copyright (C) 1995 Linus Torvalds |
| * Copyright (C) 2000, 2001 Axis Communications AB |
| * |
| * Authors: Bjorn Wesen (bjornw@axis.com) |
| * |
| * $Log: process.c,v $ |
| * 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.. |
| */ |
| |
| #define __KERNEL_SYSCALLS__ |
| #include <stdarg.h> |
| |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/stddef.h> |
| #include <linux/unistd.h> |
| #include <linux/ptrace.h> |
| #include <linux/slab.h> |
| #include <linux/user.h> |
| #include <linux/a.out.h> |
| #include <linux/elfcore.h> |
| #include <linux/interrupt.h> |
| #include <linux/delay.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/io.h> |
| #include <asm/processor.h> |
| |
| #include <linux/smp.h> |
| |
| //#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; |
| struct mm_struct init_mm = INIT_MM(init_mm); |
| |
| /* |
| * Initial task 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 task_union init_task_union |
| __attribute__((__section__(".data.init_task"))) = |
| { INIT_TASK(init_task_union.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++; |
| } |
| |
| void enable_hlt(void) |
| { |
| hlt_counter--; |
| } |
| |
| int cpu_idle(void *unused) |
| { |
| while(1) { |
| schedule(); |
| } |
| } |
| |
| /* if the watchdog is enabled, we can simply disable interrupts and go |
| * into an eternal loop, and the watchdog will reset the CPU after 0.1s |
| * if on the other hand the watchdog wasn't enabled, we just enable it and wait |
| */ |
| |
| void hard_reset_now (void) |
| { |
| /* |
| * Don't declare this variable elsewhere. We don't want any other |
| * code to know about it than the watchdog handler in entry.S and |
| * this code, implementing hard reset through the watchdog. |
| */ |
| #if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM) |
| extern int cause_of_death; |
| #endif |
| |
| printk("*** HARD RESET ***\n"); |
| cli(); |
| |
| #if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM) |
| cause_of_death = 0xbedead; |
| #else |
| /* Since we dont plan to keep on reseting the watchdog, |
| the key can be arbitrary hence three */ |
| *R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, 3) | |
| IO_STATE(R_WATCHDOG, enable, start); |
| #endif |
| |
| while(1) /* waiting for RETRIBUTION! */ ; |
| } |
| |
| void machine_restart(void) |
| { |
| hard_reset_now(); |
| } |
| |
| /* |
| * 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) |
| { |
| } |
| |
| /* If or when software power-off is implemented, add code here. */ |
| |
| void machine_power_off(void) |
| { |
| } |
| |
| /* |
| * 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) |
| { |
| } |
| |
| asmlinkage void ret_from_sys_call(void); |
| |
| /* setup the child's kernel stack with a pt_regs and switch_stack on it. |
| * it will be un-nested during _resume and _ret_from_sys_call when the |
| * new thread is scheduled. |
| * |
| * also setup the thread switching structure which is used to keep |
| * thread-specific data during _resumes. |
| * |
| */ |
| |
| int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, |
| unsigned long unused, |
| struct task_struct *p, struct pt_regs *regs) |
| { |
| struct pt_regs * childregs; |
| struct switch_stack *swstack; |
| |
| /* put the pt_regs structure at the end of the new kernel stack page and fix it up |
| * remember that the task_struct doubles as the kernel stack for the task |
| */ |
| |
| childregs = user_regs(p); |
| |
| *childregs = *regs; /* struct copy of pt_regs */ |
| |
| childregs->r10 = 0; /* child returns 0 after a fork/clone */ |
| |
| /* put the switch stack right below the pt_regs */ |
| |
| swstack = ((struct switch_stack *)childregs) - 1; |
| |
| swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */ |
| |
| /* we want to return into ret_from_sys_call after the _resume */ |
| |
| swstack->return_ip = (unsigned long) ret_from_sys_call; |
| |
| /* fix the user-mode stackpointer */ |
| |
| p->thread.usp = usp; |
| |
| /* and the kernel-mode one */ |
| |
| p->thread.ksp = (unsigned long) swstack; |
| |
| #ifdef DEBUG |
| printk("copy_thread: new regs at 0x%p, as shown below:\n", childregs); |
| show_registers(childregs); |
| #endif |
| |
| return 0; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * Be aware of the "magic" 7th argument in the four system-calls below. |
| * They need the latest stackframe, which is put as the 7th argument by |
| * entry.S. The previous arguments are dummies or actually used, but need |
| * to be defined to reach the 7th argument. |
| * |
| * N.B.: Another method to get the stackframe is to use current_regs(). But |
| * it returns the latest stack-frame stacked when going from _user mode_ and |
| * some of these (at least sys_clone) are called from kernel-mode sometimes |
| * (for example during kernel_thread, above) and thus cannot use it. Thus, |
| * to be sure not to get any surprises, we use the method for the other calls |
| * as well. |
| */ |
| |
| asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp, |
| struct pt_regs *regs) |
| { |
| struct task_struct *p; |
| p = do_fork(SIGCHLD, rdusp(), regs, 0); |
| return IS_ERR(p) ? PTR_ERR(p) : p->pid; |
| } |
| |
| /* if newusp is 0, we just grab the old usp */ |
| |
| asmlinkage int sys_clone(unsigned long newusp, unsigned long flags, |
| long r12, long r13, long mof, long srp, |
| struct pt_regs *regs) |
| { |
| struct task_struct *p; |
| if (!newusp) |
| newusp = rdusp(); |
| p = do_fork(flags & ~CLONE_IDLETASK, newusp, regs, 0); |
| return IS_ERR(p) ? PTR_ERR(p) : p->pid; |
| } |
| |
| /* vfork is a system call in i386 because of register-pressure - maybe |
| * we can remove it and handle it in libc but we put it here until then. |
| */ |
| |
| asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp, |
| struct pt_regs *regs) |
| { |
| struct task_struct *p; |
| p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0); |
| return IS_ERR(p) ? PTR_ERR(p) : p->pid; |
| } |
| |
| /* |
| * sys_execve() executes a new program. |
| */ |
| asmlinkage int sys_execve(const char *fname, char **argv, char **envp, |
| long r13, long mof, long srp, |
| struct pt_regs *regs) |
| { |
| int error; |
| char *filename; |
| |
| filename = getname(fname); |
| error = PTR_ERR(filename); |
| |
| if (IS_ERR(filename)) |
| goto out; |
| error = do_execve(filename, argv, envp, regs); |
| putname(filename); |
| out: |
| return error; |
| } |
| |
| /* |
| * These bracket the sleeping functions.. |
| */ |
| |
| extern void scheduling_functions_start_here(void); |
| extern void scheduling_functions_end_here(void); |
| #define first_sched ((unsigned long) scheduling_functions_start_here) |
| #define last_sched ((unsigned long) scheduling_functions_end_here) |
| |
| unsigned long get_wchan(struct task_struct *p) |
| { |
| #if 0 |
| /* YURGH. TODO. */ |
| |
| unsigned long ebp, esp, eip; |
| unsigned long stack_page; |
| int count = 0; |
| if (!p || p == current || p->state == TASK_RUNNING) |
| return 0; |
| stack_page = (unsigned long)p; |
| esp = p->thread.esp; |
| if (!stack_page || esp < stack_page || esp > 8188+stack_page) |
| return 0; |
| /* include/asm-i386/system.h:switch_to() pushes ebp last. */ |
| ebp = *(unsigned long *) esp; |
| do { |
| if (ebp < stack_page || ebp > 8184+stack_page) |
| return 0; |
| eip = *(unsigned long *) (ebp+4); |
| if (eip < first_sched || eip >= last_sched) |
| return eip; |
| ebp = *(unsigned long *) ebp; |
| } while (count++ < 16); |
| #endif |
| return 0; |
| } |
| #undef last_sched |
| #undef first_sched |