original development tree for Linux kernel GTP module; now long in mainline.
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/*
* Copyright (C) 2000-2003 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
* Mikael Starvik (starvik@axis.com)
* Tobias Anderberg (tobiasa@axis.com), CRISv32 port.
*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/reg_map.h>
#include <hwregs/timer_defs.h>
#include <hwregs/intr_vect_defs.h>
extern void stop_watchdog(void);
extern int cris_hlt_counter;
/* We use this if we don't have any better idle routine. */
void default_idle(void)
{
local_irq_disable();
if (!need_resched() && !cris_hlt_counter) {
/* Halt until exception. */
__asm__ volatile("ei \n\t"
"halt ");
}
local_irq_enable();
}
/*
* Free current thread data structures etc..
*/
extern void deconfigure_bp(long pid);
void exit_thread(void)
{
deconfigure_bp(current->pid);
}
/*
* If the watchdog is enabled, disable interrupts and enter an infinite loop.
* The watchdog will reset the CPU after 0.1s. If the watchdog isn't enabled
* then enable it and wait.
*/
extern void arch_enable_nmi(void);
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)
extern int cause_of_death;
#endif
printk("*** HARD RESET ***\n");
local_irq_disable();
#if defined(CONFIG_ETRAX_WATCHDOG)
cause_of_death = 0xbedead;
#else
{
reg_timer_rw_wd_ctrl wd_ctrl = {0};
stop_watchdog();
wd_ctrl.key = 16; /* Arbitrary key. */
wd_ctrl.cnt = 1; /* Minimum time. */
wd_ctrl.cmd = regk_timer_start;
arch_enable_nmi();
REG_WR(timer, regi_timer0, rw_wd_ctrl, wd_ctrl);
}
#endif
while (1)
; /* Wait for reset. */
}
/*
* Return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *t)
{
return task_pt_regs(t)->erp;
}
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(&regs, 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.erp = (unsigned long) kernel_thread_helper;
regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
/* Create the new process. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
/*
* Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
* It will be unnested 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.
*/
extern asmlinkage void ret_from_fork(void);
int
copy_thread(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. Note: the task_struct doubles as the kernel stack for the
* task.
*/
childregs = task_pt_regs(p);
*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. */
/* Set a new TLS ?
* The TLS is in $mof because it is the 5th argument to sys_clone.
*/
if (p->mm && (clone_flags & CLONE_SETTLS)) {
task_thread_info(p)->tls = regs->mof;
}
/* Put the switch stack right below the pt_regs. */
swstack = ((struct switch_stack *) childregs) - 1;
/* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
swstack->r9 = 0;
/*
* We want to return into ret_from_sys_call after the _resume.
* ret_from_fork will call ret_from_sys_call.
*/
swstack->return_ip = (unsigned long) ret_from_fork;
/* Fix the user-mode and kernel-mode stackpointer. */
p->thread.usp = usp;
p->thread.ksp = (unsigned long) swstack;
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);
}
/* 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,
unsigned long tls, 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,
const char *const *argv,
const char *const *envp, long r13, long mof, long srp,
struct pt_regs *regs)
{
int error;
struct filename *filename;
filename = getname(fname);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename->name, argv, envp, regs);
putname(filename);
out:
return error;
}
unsigned long
get_wchan(struct task_struct *p)
{
/* TODO */
return 0;
}
#undef last_sched
#undef first_sched
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
printk("ERP: %08lx SRP: %08lx CCS: %08lx USP: %08lx MOF: %08lx\n",
regs->erp, regs->srp, regs->ccs, 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);
}