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Diffstat (limited to 'arch/cris/arch-v10/kernel/process.c')
| -rw-r--r-- | arch/cris/arch-v10/kernel/process.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c new file mode 100644 index 00000000000..87ff3779082 --- /dev/null +++ b/arch/cris/arch-v10/kernel/process.c @@ -0,0 +1,270 @@ +/* $Id: process.c,v 1.9 2004/10/19 13:07:37 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) + * Mikael Starvik (starvik@axis.com) + * + * This file handles the architecture-dependent parts of process handling.. + */ + +#include <linux/config.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <asm/arch/svinto.h> +#include <linux/init.h> + +#ifdef CONFIG_ETRAX_GPIO +void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */ +#endif + +/* + * We use this if we don't have any better + * idle routine.. + */ +void default_idle(void) +{ +#ifdef CONFIG_ETRAX_GPIO + etrax_gpio_wake_up_check(); +#endif +} + +/* + * Free current thread data structures etc.. + */ + +void exit_thread(void) +{ + /* Nothing needs to be done. */ +} + +/* 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"); + local_irq_disable(); + +#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! */ ; +} + +/* + * Return saved PC of a blocked thread. + */ +unsigned long thread_saved_pc(struct task_struct *t) +{ + return (unsigned long)user_regs(t->thread_info)->irp; +} + +static void kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg) +{ + fn(arg); + do_exit(-1); /* Should never be called, return bad exit value */ +} + +/* + * Create a kernel thread + */ +int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + /* Don't use r10 since that is set to 0 in copy_thread */ + regs.r11 = (unsigned long)fn; + regs.r12 = (unsigned long)arg; + regs.irp = (unsigned long)kernel_thread_helper; + + /* Ok, create the new process.. */ + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); +} + +/* 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. + * + */ +asmlinkage void ret_from_fork(void); + +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->thread_info); + + *childregs = *regs; /* struct copy of pt_regs */ + + p->set_child_tid = p->clear_child_tid = NULL; + + 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_fork; /* Will call 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; +} + +/* + * 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) +{ + return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); +} + +/* if newusp is 0, we just grab the old usp */ +/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */ +asmlinkage int sys_clone(unsigned long newusp, unsigned long flags, + int* parent_tid, int* child_tid, long mof, long srp, + struct pt_regs *regs) +{ + if (!newusp) + newusp = rdusp(); + return do_fork(flags, newusp, regs, 0, parent_tid, child_tid); +} + +/* 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) +{ + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL); +} + +/* + * 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; +} + +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 (!in_sched_functions(eip)) + return eip; + ebp = *(unsigned long *) ebp; + } while (count++ < 16); +#endif + return 0; +} +#undef last_sched +#undef first_sched + +void show_regs(struct pt_regs * regs) +{ + unsigned long usp = rdusp(); + printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n", + regs->irp, regs->srp, regs->dccr, usp, regs->mof ); + printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n", + regs->r0, regs->r1, regs->r2, regs->r3); + printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n", + regs->r4, regs->r5, regs->r6, regs->r7); + printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n", + regs->r8, regs->r9, regs->r10, regs->r11); + printk("r12: %08lx r13: %08lx oR10: %08lx\n", + regs->r12, regs->r13, regs->orig_r10); +} + |