270 lines
7.0 KiB
C
270 lines
7.0 KiB
C
/*
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* Copyright (C) 2000-2003 Axis Communications AB
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*
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* Authors: Bjorn Wesen (bjornw@axis.com)
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* Mikael Starvik (starvik@axis.com)
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* Tobias Anderberg (tobiasa@axis.com), CRISv32 port.
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*
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* This file handles the architecture-dependent parts of process handling..
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*/
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#include <linux/sched.h>
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#include <linux/err.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <asm/arch/hwregs/reg_rdwr.h>
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#include <asm/arch/hwregs/reg_map.h>
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#include <asm/arch/hwregs/timer_defs.h>
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#include <asm/arch/hwregs/intr_vect_defs.h>
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extern void stop_watchdog(void);
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#ifdef CONFIG_ETRAX_GPIO
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extern void etrax_gpio_wake_up_check(void); /* Defined in drivers/gpio.c. */
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#endif
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extern int cris_hlt_counter;
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/* We use this if we don't have any better idle routine. */
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void default_idle(void)
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{
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local_irq_disable();
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if (!need_resched() && !cris_hlt_counter) {
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/* Halt until exception. */
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__asm__ volatile("ei \n\t"
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"halt ");
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}
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local_irq_enable();
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}
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/*
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* Free current thread data structures etc..
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*/
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extern void deconfigure_bp(long pid);
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void exit_thread(void)
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{
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deconfigure_bp(current->pid);
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}
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/*
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* If the watchdog is enabled, disable interrupts and enter an infinite loop.
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* The watchdog will reset the CPU after 0.1s. If the watchdog isn't enabled
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* then enable it and wait.
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*/
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extern void arch_enable_nmi(void);
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void
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hard_reset_now(void)
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{
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/*
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* Don't declare this variable elsewhere. We don't want any other
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* code to know about it than the watchdog handler in entry.S and
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* this code, implementing hard reset through the watchdog.
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*/
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#if defined(CONFIG_ETRAX_WATCHDOG)
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extern int cause_of_death;
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#endif
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printk("*** HARD RESET ***\n");
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local_irq_disable();
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#if defined(CONFIG_ETRAX_WATCHDOG)
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cause_of_death = 0xbedead;
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#else
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{
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reg_timer_rw_wd_ctrl wd_ctrl = {0};
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stop_watchdog();
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wd_ctrl.key = 16; /* Arbitrary key. */
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wd_ctrl.cnt = 1; /* Minimum time. */
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wd_ctrl.cmd = regk_timer_start;
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arch_enable_nmi();
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REG_WR(timer, regi_timer, rw_wd_ctrl, wd_ctrl);
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}
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#endif
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while (1)
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; /* Wait for reset. */
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}
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/*
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* Return saved PC of a blocked thread.
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*/
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unsigned long thread_saved_pc(struct task_struct *t)
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{
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return task_pt_regs(t)->erp;
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}
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static void
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kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
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{
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fn(arg);
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do_exit(-1); /* Should never be called, return bad exit value. */
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}
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/* Create a kernel thread. */
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int
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kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
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{
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struct pt_regs regs;
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memset(®s, 0, sizeof(regs));
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/* Don't use r10 since that is set to 0 in copy_thread. */
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regs.r11 = (unsigned long) fn;
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regs.r12 = (unsigned long) arg;
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regs.erp = (unsigned long) kernel_thread_helper;
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regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
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/* Create the new process. */
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return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
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}
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/*
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* Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
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* It will be unnested during _resume and _ret_from_sys_call when the new thread
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* is scheduled.
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*
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* Also setup the thread switching structure which is used to keep
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* thread-specific data during _resumes.
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*/
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extern asmlinkage void ret_from_fork(void);
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int
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copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
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unsigned long unused,
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struct task_struct *p, struct pt_regs *regs)
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{
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struct pt_regs *childregs;
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struct switch_stack *swstack;
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/*
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* Put the pt_regs structure at the end of the new kernel stack page and
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* fix it up. Note: the task_struct doubles as the kernel stack for the
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* task.
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*/
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childregs = task_pt_regs(p);
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*childregs = *regs; /* Struct copy of pt_regs. */
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p->set_child_tid = p->clear_child_tid = NULL;
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childregs->r10 = 0; /* Child returns 0 after a fork/clone. */
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/* Set a new TLS ?
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* The TLS is in $mof beacuse it is the 5th argument to sys_clone.
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*/
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if (p->mm && (clone_flags & CLONE_SETTLS)) {
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task_thread_info(p)->tls = regs->mof;
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}
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/* Put the switch stack right below the pt_regs. */
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swstack = ((struct switch_stack *) childregs) - 1;
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/* Paramater to ret_from_sys_call. 0 is don't restart the syscall. */
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swstack->r9 = 0;
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/*
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* We want to return into ret_from_sys_call after the _resume.
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* ret_from_fork will call ret_from_sys_call.
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*/
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swstack->return_ip = (unsigned long) ret_from_fork;
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/* Fix the user-mode and kernel-mode stackpointer. */
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p->thread.usp = usp;
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p->thread.ksp = (unsigned long) swstack;
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return 0;
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}
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/*
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* Be aware of the "magic" 7th argument in the four system-calls below.
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* They need the latest stackframe, which is put as the 7th argument by
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* entry.S. The previous arguments are dummies or actually used, but need
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* to be defined to reach the 7th argument.
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*
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* N.B.: Another method to get the stackframe is to use current_regs(). But
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* it returns the latest stack-frame stacked when going from _user mode_ and
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* some of these (at least sys_clone) are called from kernel-mode sometimes
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* (for example during kernel_thread, above) and thus cannot use it. Thus,
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* to be sure not to get any surprises, we use the method for the other calls
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* as well.
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*/
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asmlinkage int
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sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
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struct pt_regs *regs)
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{
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return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
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}
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/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
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asmlinkage int
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sys_clone(unsigned long newusp, unsigned long flags, int *parent_tid, int *child_tid,
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unsigned long tls, long srp, struct pt_regs *regs)
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{
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if (!newusp)
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newusp = rdusp();
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return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
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}
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/*
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* vfork is a system call in i386 because of register-pressure - maybe
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* we can remove it and handle it in libc but we put it here until then.
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*/
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asmlinkage int
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sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
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struct pt_regs *regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
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}
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/* sys_execve() executes a new program. */
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asmlinkage int
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sys_execve(const char *fname, char **argv, char **envp, long r13, long mof, long srp,
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struct pt_regs *regs)
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{
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int error;
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char *filename;
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filename = getname(fname);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename, argv, envp, regs);
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putname(filename);
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out:
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return error;
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}
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unsigned long
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get_wchan(struct task_struct *p)
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{
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/* TODO */
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return 0;
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}
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#undef last_sched
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#undef first_sched
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void show_regs(struct pt_regs * regs)
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{
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unsigned long usp = rdusp();
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printk("ERP: %08lx SRP: %08lx CCS: %08lx USP: %08lx MOF: %08lx\n",
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regs->erp, regs->srp, regs->ccs, usp, regs->mof);
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printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
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regs->r0, regs->r1, regs->r2, regs->r3);
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printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
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regs->r4, regs->r5, regs->r6, regs->r7);
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printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
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regs->r8, regs->r9, regs->r10, regs->r11);
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printk("r12: %08lx r13: %08lx oR10: %08lx\n",
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regs->r12, regs->r13, regs->orig_r10);
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}
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