[mirror_ubuntu-zesty-kernel.git] / arch / sh / kernel / process.c

/* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $
 *
 *  linux/arch/sh/kernel/process.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
 *		     Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#include <linux/module.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/elfcore.h>
#include <linux/a.out.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/ptrace.h>
#include <linux/kallsyms.h>
#include <linux/kexec.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/elf.h>
#include <asm/ubc.h>

static int hlt_counter=0;

int ubc_usercnt = 0;

#define HARD_IDLE_TIMEOUT (HZ / 3)

void (*pm_idle)(void);

void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

void disable_hlt(void)
{
	hlt_counter++;
}

EXPORT_SYMBOL(disable_hlt);

void enable_hlt(void)
{
	hlt_counter--;
}

EXPORT_SYMBOL(enable_hlt);

void default_idle(void)
{
	if (!hlt_counter)
		cpu_sleep();
	else
		cpu_relax();
}

void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		void (*idle)(void) = pm_idle;

		if (!idle)
			idle = default_idle;

		while (!need_resched())
			idle();

		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

void machine_restart(char * __unused)
{
	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	asm volatile("ldc %0, sr\n\t"
		     "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
}

void machine_halt(void)
{
	local_irq_disable();

	while (1)
		cpu_sleep();
}

void machine_power_off(void)
{
	if (pm_power_off)
		pm_power_off();
}

void show_regs(struct pt_regs * regs)
{
	printk("\n");
	printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
	print_symbol("PC is at %s\n", regs->pc);
	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
	       regs->pc, regs->regs[15], regs->sr);
#ifdef CONFIG_MMU
	printk("TEA : %08x    ", ctrl_inl(MMU_TEA));
#else
	printk("                  ");
#endif
	printk("%s\n", print_tainted());

	printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",
	       regs->regs[0],regs->regs[1],
	       regs->regs[2],regs->regs[3]);
	printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",
	       regs->regs[4],regs->regs[5],
	       regs->regs[6],regs->regs[7]);
	printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",
	       regs->regs[8],regs->regs[9],
	       regs->regs[10],regs->regs[11]);
	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	       regs->regs[12],regs->regs[13],
	       regs->regs[14]);
	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",
	       regs->mach, regs->macl, regs->gbr, regs->pr);

	/*
	 * If we're in kernel mode, dump the stack too..
	 */
	if (!user_mode(regs)) {
		extern void show_task(unsigned long *sp);
		unsigned long sp = regs->regs[15];

		show_task((unsigned long *)sp);
	}
}

/*
 * Create a kernel thread
 */

/*
 * This is the mechanism for creating a new kernel thread.
 *
 */
extern void kernel_thread_helper(void);
__asm__(".align 5\n"
	"kernel_thread_helper:\n\t"
	"jsr	@r5\n\t"
	" nop\n\t"
	"mov.l	1f, r1\n\t"
	"jsr	@r1\n\t"
	" mov	r0, r4\n\t"
	".align 2\n\t"
	"1:.long do_exit");

int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{	/* Don't use this in BL=1(cli).  Or else, CPU resets! */
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));
	regs.regs[4] = (unsigned long) arg;
	regs.regs[5] = (unsigned long) fn;

	regs.pc = (unsigned long) kernel_thread_helper;
	regs.sr = (1 << 30);

	/* Ok, create the new process.. */
	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}

/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
	if (current->thread.ubc_pc) {
		current->thread.ubc_pc = 0;
		ubc_usercnt -= 1;
	}
}

void flush_thread(void)
{
#if defined(CONFIG_SH_FPU)
	struct task_struct *tsk = current;
	/* Forget lazy FPU state */
	clear_fpu(tsk, task_pt_regs(tsk));
	clear_used_math();
#endif
}

void release_thread(struct task_struct *dead_task)
{
	/* do nothing */
}

/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
	int fpvalid = 0;

#if defined(CONFIG_SH_FPU)
	struct task_struct *tsk = current;

	fpvalid = !!tsk_used_math(tsk);
	if (fpvalid) {
		unlazy_fpu(tsk, regs);
		memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	}
#endif

	return fpvalid;
}

/* 
 * Capture the user space registers if the task is not running (in user space)
 */
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
{
	struct pt_regs ptregs;
	
	ptregs = *task_pt_regs(tsk);
	elf_core_copy_regs(regs, &ptregs);

	return 1;
}

int
dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
{
	int fpvalid = 0;

#if defined(CONFIG_SH_FPU)
	fpvalid = !!tsk_used_math(tsk);
	if (fpvalid) {
		unlazy_fpu(tsk, task_pt_regs(tsk));
		memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	}
#endif

	return fpvalid;
}

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 thread_info *ti = task_thread_info(p);
	struct pt_regs *childregs;
#if defined(CONFIG_SH_FPU)
	struct task_struct *tsk = current;

	unlazy_fpu(tsk, regs);
	p->thread.fpu = tsk->thread.fpu;
	copy_to_stopped_child_used_math(p);
#endif

	childregs = task_pt_regs(p);
	*childregs = *regs;

	if (user_mode(regs)) {
		childregs->regs[15] = usp;
		ti->addr_limit = USER_DS;
	} else {
		childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
		ti->addr_limit = KERNEL_DS;
	}
        if (clone_flags & CLONE_SETTLS) {
		childregs->gbr = childregs->regs[0];
	}
	childregs->regs[0] = 0; /* Set return value for child */

	p->thread.sp = (unsigned long) childregs;
	p->thread.pc = (unsigned long) ret_from_fork;

	p->thread.ubc_pc = 0;

	return 0;
}

/* Tracing by user break controller.  */
static void
ubc_set_tracing(int asid, unsigned long pc)
{
#if defined(CONFIG_CPU_SH4A)
	unsigned long val;

	val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
	val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));

	ctrl_outl(val, UBC_CBR0);
	ctrl_outl(pc,  UBC_CAR0);
	ctrl_outl(0x0, UBC_CAMR0);
	ctrl_outl(0x0, UBC_CBCR);

	val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
	ctrl_outl(val, UBC_CRR0);

	/* Read UBC register that we writed last. For chekking UBC Register changed */
	val = ctrl_inl(UBC_CRR0);

#else	/* CONFIG_CPU_SH4A */
	ctrl_outl(pc, UBC_BARA);

#ifdef CONFIG_MMU
	/* We don't have any ASID settings for the SH-2! */
	if (cpu_data->type != CPU_SH7604)
		ctrl_outb(asid, UBC_BASRA);
#endif

	ctrl_outl(0, UBC_BAMRA);

	if (cpu_data->type == CPU_SH7729 || cpu_data->type == CPU_SH7710) {
		ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
		ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
	} else {
		ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
		ctrl_outw(BRCR_PCBA, UBC_BRCR);
	}
#endif	/* CONFIG_CPU_SH4A */
}

/*
 *	switch_to(x,y) should switch tasks from x to y.
 *
 */
struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
{
#if defined(CONFIG_SH_FPU)
	unlazy_fpu(prev, task_pt_regs(prev));
#endif

#ifdef CONFIG_PREEMPT
	{
		unsigned long flags;
		struct pt_regs *regs;

		local_irq_save(flags);
		regs = task_pt_regs(prev);
		if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
			int offset = (int)regs->regs[15];

			/* Reset stack pointer: clear critical region mark */
			regs->regs[15] = regs->regs[1];
			if (regs->pc < regs->regs[0])
				/* Go to rewind point */
				regs->pc = regs->regs[0] + offset;
		}
		local_irq_restore(flags);
	}
#endif

#ifdef CONFIG_MMU
	/*
	 * Restore the kernel mode register
	 *   	k7 (r7_bank1)
	 */
	asm volatile("ldc	%0, r7_bank"
		     : /* no output */
		     : "r" (task_thread_info(next)));
#endif

	/* If no tasks are using the UBC, we're done */
	if (ubc_usercnt == 0)
		/* If no tasks are using the UBC, we're done */;
	else if (next->thread.ubc_pc && next->mm) {
		int asid = 0;
#ifdef CONFIG_MMU
		asid |= next->mm->context.id & MMU_CONTEXT_ASID_MASK;
#endif
		ubc_set_tracing(asid, next->thread.ubc_pc);
	} else {
#if defined(CONFIG_CPU_SH4A)
		ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
		ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
#else
		ctrl_outw(0, UBC_BBRA);
		ctrl_outw(0, UBC_BBRB);
#endif
	}

	return prev;
}

asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
			unsigned long r6, unsigned long r7,
			struct pt_regs regs)
{
#ifdef CONFIG_MMU
	return do_fork(SIGCHLD, regs.regs[15], &regs, 0, NULL, NULL);
#else
	/* fork almost works, enough to trick you into looking elsewhere :-( */
	return -EINVAL;
#endif
}

asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
			 unsigned long parent_tidptr,
			 unsigned long child_tidptr,
			 struct pt_regs regs)
{
	if (!newsp)
		newsp = regs.regs[15];
	return do_fork(clone_flags, newsp, &regs, 0,
			(int __user *)parent_tidptr, (int __user *)child_tidptr);
}

/*
 * This is trivial, and on the face of it looks like it
 * could equally well be done in user mode.
 *
 * Not so, for quite unobvious reasons - register pressure.
 * In user mode vfork() cannot have a stack frame, and if
 * done by calling the "clone()" system call directly, you
 * do not have enough call-clobbered registers to hold all
 * the information you need.
 */
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
			 unsigned long r6, unsigned long r7,
			 struct pt_regs regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], &regs,
		       0, NULL, NULL);
}

/*
 * sys_execve() executes a new program.
 */
asmlinkage int sys_execve(char *ufilename, char **uargv,
			  char **uenvp, unsigned long r7,
			  struct pt_regs regs)
{
	int error;
	char *filename;

	filename = getname((char __user *)ufilename);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;

	error = do_execve(filename,
			  (char __user * __user *)uargv,
			  (char __user * __user *)uenvp,
			  &regs);
	if (error == 0) {
		task_lock(current);
		current->ptrace &= ~PT_DTRACE;
		task_unlock(current);
	}
	putname(filename);
out:
	return error;
}

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long schedule_frame;
	unsigned long pc;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	/*
	 * The same comment as on the Alpha applies here, too ...
	 */
	pc = thread_saved_pc(p);
	if (in_sched_functions(pc)) {
		schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
		return (unsigned long)((unsigned long *)schedule_frame)[1];
	}
	return pc;
}

asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
				 unsigned long r6, unsigned long r7,
				 struct pt_regs regs)
{
	/* Clear tracing.  */
#if defined(CONFIG_CPU_SH4A)
	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
#else
	ctrl_outw(0, UBC_BBRA);
	ctrl_outw(0, UBC_BBRB);
#endif
	current->thread.ubc_pc = 0;
	ubc_usercnt -= 1;

	force_sig(SIGTRAP, current);
}

asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
					  unsigned long r6, unsigned long r7,
					  struct pt_regs regs)
{
	regs.pc -= 2;
	force_sig(SIGTRAP, current);
}
Commit	Line	Data
1da177e4 LT	1	/* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $
	2	*
	3	* linux/arch/sh/kernel/process.c
	4	*
	5	* Copyright (C) 1995 Linus Torvalds
	6	*
	7	* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
8ae91b9a	8	* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
1da177e4 LT	9	*/
	10
	11	/*
	12	* This file handles the architecture-dependent parts of process handling..
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/unistd.h>
	17	#include <linux/mm.h>
	18	#include <linux/elfcore.h>
1da177e4	19	#include <linux/a.out.h>
a3310bbd PM	20	#include <linux/slab.h>
a3310bbd PM	21	#include <linux/pm.h>
1da177e4	22	#include <linux/ptrace.h>
1da177e4	23	#include <linux/kallsyms.h>
a3310bbd	24	#include <linux/kexec.h>
1da177e4 LT	25
	26	#include <asm/io.h>
	27	#include <asm/uaccess.h>
	28	#include <asm/mmu_context.h>
	29	#include <asm/elf.h>
b5233d07	30	#include <asm/ubc.h>
1da177e4 LT	31
	32	static int hlt_counter=0;
	33
	34	int ubc_usercnt = 0;
	35
	36	#define HARD_IDLE_TIMEOUT (HZ / 3)
	37
a3310bbd PM	38	void (*pm_idle)(void);
	39
	40	void (*pm_power_off)(void);
	41	EXPORT_SYMBOL(pm_power_off);
	42
1da177e4 LT	43	void disable_hlt(void)
	44	{
	45	hlt_counter++;
	46	}
	47
	48	EXPORT_SYMBOL(disable_hlt);
	49
	50	void enable_hlt(void)
	51	{
	52	hlt_counter--;
	53	}
	54
	55	EXPORT_SYMBOL(enable_hlt);
	56
a3310bbd PM	57	void default_idle(void)
	58	{
	59	if (!hlt_counter)
	60	cpu_sleep();
	61	else
	62	cpu_relax();
	63	}
	64
64c7c8f8	65	void cpu_idle(void)
1da177e4 LT	66	{
	67	/* endless idle loop with no priority at all */
	68	while (1) {
a3310bbd PM	69	void (*idle)(void) = pm_idle;
	70
	71	if (!idle)
	72	idle = default_idle;
	73
	74	while (!need_resched())
	75	idle();
1da177e4	76
5bfb5d69	77	preempt_enable_no_resched();
1da177e4	78	schedule();
5bfb5d69	79	preempt_disable();
1da177e4 LT	80	}
	81	}
	82
1da177e4 LT	83	void machine_restart(char * __unused)
	84	{
	85	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	86	asm volatile("ldc %0, sr\n\t"
	87	"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
	88	}
	89
1da177e4 LT	90	void machine_halt(void)
1da177e4 LT	91	{
a3310bbd	92	local_irq_disable();
1da177e4	93
1da177e4 LT	94	while (1)
	95	cpu_sleep();
	96	}
	97
1da177e4 LT	98	void machine_power_off(void)
1da177e4 LT	99	{
a3310bbd PM	100	if (pm_power_off)
a3310bbd PM	101	pm_power_off();
1da177e4 LT	102	}
1da177e4 LT	103
1da177e4 LT	104	void show_regs(struct pt_regs * regs)
	105	{
	106	printk("\n");
	107	printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
	108	print_symbol("PC is at %s\n", regs->pc);
	109	printk("PC : %08lx SP : %08lx SR : %08lx ",
	110	regs->pc, regs->regs[15], regs->sr);
	111	#ifdef CONFIG_MMU
	112	printk("TEA : %08x ", ctrl_inl(MMU_TEA));
	113	#else
	114	printk(" ");
	115	#endif
	116	printk("%s\n", print_tainted());
	117
	118	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
	119	regs->regs[0],regs->regs[1],
	120	regs->regs[2],regs->regs[3]);
	121	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
	122	regs->regs[4],regs->regs[5],
	123	regs->regs[6],regs->regs[7]);
	124	printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
	125	regs->regs[8],regs->regs[9],
	126	regs->regs[10],regs->regs[11]);
	127	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	128	regs->regs[12],regs->regs[13],
	129	regs->regs[14]);
	130	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
	131	regs->mach, regs->macl, regs->gbr, regs->pr);
	132
	133	/*
	134	* If we're in kernel mode, dump the stack too..
	135	*/
	136	if (!user_mode(regs)) {
	137	extern void show_task(unsigned long *sp);
	138	unsigned long sp = regs->regs[15];
	139
	140	show_task((unsigned long *)sp);
	141	}
	142	}
	143
	144	/*
	145	* Create a kernel thread
	146	*/
	147
	148	/*
	149	* This is the mechanism for creating a new kernel thread.
	150	*
	151	*/
	152	extern void kernel_thread_helper(void);
	153	__asm__(".align 5\n"
	154	"kernel_thread_helper:\n\t"
	155	"jsr @r5\n\t"
	156	" nop\n\t"
	157	"mov.l 1f, r1\n\t"
	158	"jsr @r1\n\t"
	159	" mov r0, r4\n\t"
	160	".align 2\n\t"
	161	"1:.long do_exit");
	162
	163	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
	164	{ /* Don't use this in BL=1(cli). Or else, CPU resets! */
	165	struct pt_regs regs;
	166
	167	memset(&regs, 0, sizeof(regs));
168	regs.regs[4] = (unsigned long) arg;
169	regs.regs[5] = (unsigned long) fn;
170
171	regs.pc = (unsigned long) kernel_thread_helper;
172	regs.sr = (1 << 30);
173
174	/* Ok, create the new process.. */
175	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
176	}
177
178	/*
179	* Free current thread data structures etc..
180	*/
181	void exit_thread(void)
182	{
183	if (current->thread.ubc_pc) {
184	current->thread.ubc_pc = 0;
185	ubc_usercnt -= 1;
186	}
187	}
188
189	void flush_thread(void)
190	{
191	#if defined(CONFIG_SH_FPU)
192	struct task_struct *tsk = current;
1da177e4	193	/* Forget lazy FPU state */
3cf0f4ec	194	clear_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	195	clear_used_math();
	196	#endif
	197	}
	198
	199	void release_thread(struct task_struct *dead_task)
	200	{
	201	/* do nothing */
	202	}
	203
	204	/* Fill in the fpu structure for a core dump.. */
	205	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	206	{
	207	int fpvalid = 0;
	208
	209	#if defined(CONFIG_SH_FPU)
	210	struct task_struct *tsk = current;
	211
	212	fpvalid = !!tsk_used_math(tsk);
	213	if (fpvalid) {
	214	unlazy_fpu(tsk, regs);
	215	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	216	}
	217	#endif
	218
	219	return fpvalid;
	220	}
	221
	222	/*
	223	* Capture the user space registers if the task is not running (in user space)
	224	*/
	225	int dump_task_regs(struct task_struct tsk, elf_gregset_t regs)
	226	{
	227	struct pt_regs ptregs;
	228
3cf0f4ec	229	ptregs = *task_pt_regs(tsk);
1da177e4 LT	230	elf_core_copy_regs(regs, &ptregs);
	231
	232	return 1;
	233	}
	234
	235	int
	236	dump_task_fpu (struct task_struct tsk, elf_fpregset_t fpu)
	237	{
	238	int fpvalid = 0;
	239
	240	#if defined(CONFIG_SH_FPU)
	241	fpvalid = !!tsk_used_math(tsk);
	242	if (fpvalid) {
3cf0f4ec	243	unlazy_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	244	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	245	}
	246	#endif
	247
	248	return fpvalid;
	249	}
	250
	251	asmlinkage void ret_from_fork(void);
	252
	253	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	254	unsigned long unused,
	255	struct task_struct p, struct pt_regs regs)
	256	{
2991be72	257	struct thread_info *ti = task_thread_info(p);
1da177e4 LT	258	struct pt_regs *childregs;
	259	#if defined(CONFIG_SH_FPU)
	260	struct task_struct *tsk = current;
	261
	262	unlazy_fpu(tsk, regs);
	263	p->thread.fpu = tsk->thread.fpu;
	264	copy_to_stopped_child_used_math(p);
	265	#endif
	266
3cf0f4ec	267	childregs = task_pt_regs(p);
1da177e4 LT	268	childregs = regs;
	269
	270	if (user_mode(regs)) {
	271	childregs->regs[15] = usp;
2991be72	272	ti->addr_limit = USER_DS;
1da177e4	273	} else {
308a792f	274	childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
2991be72	275	ti->addr_limit = KERNEL_DS;
1da177e4 LT	276	}
	277	if (clone_flags & CLONE_SETTLS) {
	278	childregs->gbr = childregs->regs[0];
	279	}
	280	childregs->regs[0] = 0; /* Set return value for child */
	281
	282	p->thread.sp = (unsigned long) childregs;
	283	p->thread.pc = (unsigned long) ret_from_fork;
	284
	285	p->thread.ubc_pc = 0;
	286
	287	return 0;
	288	}
	289
1da177e4 LT	290	/* Tracing by user break controller. */
	291	static void
	292	ubc_set_tracing(int asid, unsigned long pc)
	293	{
8ae91b9a RS	294	#if defined(CONFIG_CPU_SH4A)
	295	unsigned long val;
	296
	297	val = (UBC_CBR_ID_INST \| UBC_CBR_RW_READ \| UBC_CBR_CE);
	298	val \|= (UBC_CBR_AIE \| UBC_CBR_AIV_SET(asid));
	299
	300	ctrl_outl(val, UBC_CBR0);
	301	ctrl_outl(pc, UBC_CAR0);
	302	ctrl_outl(0x0, UBC_CAMR0);
	303	ctrl_outl(0x0, UBC_CBCR);
	304
	305	val = (UBC_CRR_RES \| UBC_CRR_PCB \| UBC_CRR_BIE);
	306	ctrl_outl(val, UBC_CRR0);
	307
	308	/* Read UBC register that we writed last. For chekking UBC Register changed */
	309	val = ctrl_inl(UBC_CRR0);
	310
	311	#else /* CONFIG_CPU_SH4A */
1da177e4 LT	312	ctrl_outl(pc, UBC_BARA);
1da177e4 LT	313
a2d1a5fa	314	#ifdef CONFIG_MMU
1da177e4 LT	315	/* We don't have any ASID settings for the SH-2! */
	316	if (cpu_data->type != CPU_SH7604)
	317	ctrl_outb(asid, UBC_BASRA);
a2d1a5fa	318	#endif
1da177e4 LT	319
	320	ctrl_outl(0, UBC_BAMRA);
	321
e5723e0e	322	if (cpu_data->type == CPU_SH7729 \|\| cpu_data->type == CPU_SH7710) {
1da177e4 LT	323	ctrl_outw(BBR_INST \| BBR_READ \| BBR_CPU, UBC_BBRA);
	324	ctrl_outl(BRCR_PCBA \| BRCR_PCTE, UBC_BRCR);
	325	} else {
	326	ctrl_outw(BBR_INST \| BBR_READ, UBC_BBRA);
	327	ctrl_outw(BRCR_PCBA, UBC_BRCR);
	328	}
8ae91b9a	329	#endif /* CONFIG_CPU_SH4A */
1da177e4 LT	330	}
	331
	332	/*
	333	* switch_to(x,y) should switch tasks from x to y.
	334	*
	335	*/
	336	struct task_struct __switch_to(struct task_struct prev, struct task_struct *next)
	337	{
	338	#if defined(CONFIG_SH_FPU)
3cf0f4ec	339	unlazy_fpu(prev, task_pt_regs(prev));
1da177e4 LT	340	#endif
	341
	342	#ifdef CONFIG_PREEMPT
	343	{
	344	unsigned long flags;
	345	struct pt_regs *regs;
	346
	347	local_irq_save(flags);
3cf0f4ec	348	regs = task_pt_regs(prev);
1da177e4 LT	349	if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
	350	int offset = (int)regs->regs[15];
	351
	352	/* Reset stack pointer: clear critical region mark */
	353	regs->regs[15] = regs->regs[1];
	354	if (regs->pc < regs->regs[0])
	355	/* Go to rewind point */
	356	regs->pc = regs->regs[0] + offset;
	357	}
	358	local_irq_restore(flags);
	359	}
	360	#endif
	361
a2d1a5fa	362	#ifdef CONFIG_MMU
1da177e4 LT	363	/*
	364	* Restore the kernel mode register
	365	* k7 (r7_bank1)
	366	*/
	367	asm volatile("ldc %0, r7_bank"
	368	: /* no output */
cafcfcaa	369	: "r" (task_thread_info(next)));
a2d1a5fa	370	#endif
1da177e4	371
1da177e4 LT	372	/* If no tasks are using the UBC, we're done */
	373	if (ubc_usercnt == 0)
	374	/* If no tasks are using the UBC, we're done */;
	375	else if (next->thread.ubc_pc && next->mm) {
a2d1a5fa YS	376	int asid = 0;
a2d1a5fa YS	377	#ifdef CONFIG_MMU
19f9a34f	378	asid \|= next->mm->context.id & MMU_CONTEXT_ASID_MASK;
a2d1a5fa YS	379	#endif
a2d1a5fa YS	380	ubc_set_tracing(asid, next->thread.ubc_pc);
1da177e4	381	} else {
8ae91b9a RS	382	#if defined(CONFIG_CPU_SH4A)
	383	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	384	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	385	#else
1da177e4 LT	386	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	387	ctrl_outw(0, UBC_BBRB);
8ae91b9a	388	#endif
1da177e4	389	}
1da177e4 LT	390
	391	return prev;
	392	}
	393
	394	asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
	395	unsigned long r6, unsigned long r7,
	396	struct pt_regs regs)
	397	{
	398	#ifdef CONFIG_MMU
	399	return do_fork(SIGCHLD, regs.regs[15], &regs, 0, NULL, NULL);
	400	#else
	401	/* fork almost works, enough to trick you into looking elsewhere :-( */
	402	return -EINVAL;
	403	#endif
	404	}
	405
	406	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
	407	unsigned long parent_tidptr,
	408	unsigned long child_tidptr,
	409	struct pt_regs regs)
	410	{
	411	if (!newsp)
	412	newsp = regs.regs[15];
	413	return do_fork(clone_flags, newsp, &regs, 0,
	414	(int __user )parent_tidptr, (int __user )child_tidptr);
	415	}
	416
	417	/*
	418	* This is trivial, and on the face of it looks like it
	419	* could equally well be done in user mode.
	420	*
	421	* Not so, for quite unobvious reasons - register pressure.
	422	* In user mode vfork() cannot have a stack frame, and if
	423	* done by calling the "clone()" system call directly, you
	424	* do not have enough call-clobbered registers to hold all
	425	* the information you need.
	426	*/
	427	asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
	428	unsigned long r6, unsigned long r7,
	429	struct pt_regs regs)
	430	{
	431	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs.regs[15], &regs,
	432	0, NULL, NULL);
	433	}
	434
	435	/*
	436	* sys_execve() executes a new program.
	437	*/
	438	asmlinkage int sys_execve(char ufilename, char *uargv,
	439	char **uenvp, unsigned long r7,
	440	struct pt_regs regs)
	441	{
	442	int error;
	443	char *filename;
	444
	445	filename = getname((char __user *)ufilename);
	446	error = PTR_ERR(filename);
	447	if (IS_ERR(filename))
	448	goto out;
	449
	450	error = do_execve(filename,
	451	(char __user * __user *)uargv,
	452	(char __user * __user *)uenvp,
	453	&regs);
454	if (error == 0) {
455	task_lock(current);
456	current->ptrace &= ~PT_DTRACE;
457	task_unlock(current);
458	}
459	putname(filename);
460	out:
461	return error;
462	}
463
464	unsigned long get_wchan(struct task_struct *p)
465	{
466	unsigned long schedule_frame;
467	unsigned long pc;
468
469	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
470	return 0;
471
472	/*
473	* The same comment as on the Alpha applies here, too ...
474	*/
475	pc = thread_saved_pc(p);
476	if (in_sched_functions(pc)) {
477	schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
478	return (unsigned long)((unsigned long *)schedule_frame)[1];
479	}
480	return pc;
481	}
482
483	asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
484	unsigned long r6, unsigned long r7,
485	struct pt_regs regs)
486	{
487	/* Clear tracing. */
8ae91b9a RS	488	#if defined(CONFIG_CPU_SH4A)
	489	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	490	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	491	#else
1da177e4 LT	492	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	493	ctrl_outw(0, UBC_BBRB);
8ae91b9a	494	#endif
1da177e4 LT	495	current->thread.ubc_pc = 0;
	496	ubc_usercnt -= 1;
	497
	498	force_sig(SIGTRAP, current);
	499	}
	500
	501	asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
	502	unsigned long r6, unsigned long r7,
	503	struct pt_regs regs)
	504	{
	505	regs.pc -= 2;
	506	force_sig(SIGTRAP, current);
	507	}