arch/cris/arch-v32/kernel/process.c - maze/linux - Git at Google

 /*
  *  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;
 	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)
 {
 	/* 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);
 }
	/*
	* 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;
	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)
	{
	/* 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);
	}