[deliverable/linux.git] / arch / sh / kernel / process_32.c

/*
 * arch/sh/kernel/process.c
 *
 * This file handles the architecture-dependent parts of process handling..
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
 *		     Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
 *		     Copyright (C) 2002 - 2007  Paul Mundt
 */
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/kallsyms.h>
#include <linux/kexec.h>
#include <linux/kdebug.h>
#include <linux/tick.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/preempt.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/ubc.h>

static int hlt_counter;
int ubc_usercnt = 0;

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);

static int __init nohlt_setup(char *__unused)
{
	hlt_counter = 1;
	return 1;
}
__setup("nohlt", nohlt_setup);

static int __init hlt_setup(char *__unused)
{
	hlt_counter = 0;
	return 1;
}
__setup("hlt", hlt_setup);

void default_idle(void)
{
	if (!hlt_counter) {
		clear_thread_flag(TIF_POLLING_NRFLAG);
		smp_mb__after_clear_bit();
		set_bl_bit();
		while (!need_resched())
			cpu_sleep();
		clear_bl_bit();
		set_thread_flag(TIF_POLLING_NRFLAG);
	} else
		while (!need_resched())
			cpu_relax();
}

void cpu_idle(void)
{
	set_thread_flag(TIF_POLLING_NRFLAG);

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

		if (!idle)
			idle = default_idle;

		tick_nohz_stop_sched_tick();
		while (!need_resched())
			idle();
		tick_nohz_restart_sched_tick();

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

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", task_pid_nr(current), current->comm);
	print_symbol("PC is at %s\n", instruction_pointer(regs));
	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);

	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
}

/*
 * 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");

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

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)childregs;
		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 wrote last, for checking update */
	val = ctrl_inl(UBC_CRR0);

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

#ifdef CONFIG_MMU
	ctrl_outb(asid, UBC_BASRA);
#endif

	ctrl_outl(0, UBC_BAMRA);

	if (current_cpu_data.type == CPU_SH7729 ||
	    current_cpu_data.type == CPU_SH7710 ||
	    current_cpu_data.type == CPU_SH7712) {
		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

#if defined(CONFIG_GUSA) && defined(CONFIG_PREEMPT)
	{
		struct pt_regs *regs;

		preempt_disable();
		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;
		}
		preempt_enable_no_resched();
	}
#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 |= cpu_asid(smp_processor_id(), next->mm);
#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
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	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)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	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)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	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 __user *ufilename, char __user * __user *uargv,
			  char __user * __user *uenvp, unsigned long r7,
			  struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	int error;
	char *filename;

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

	error = do_execve(filename, uargv, 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 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);

#ifdef CONFIG_FRAME_POINTER
	if (in_sched_functions(pc)) {
		unsigned long schedule_frame = (unsigned long)p->thread.sp;
		return ((unsigned long *)schedule_frame)[21];
	}
#endif

	return pc;
}

asmlinkage void break_point_trap(void)
{
	/* 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);
}
Commit	Line	Data
aec5e0e1 PM	1	/*
aec5e0e1 PM	2	* arch/sh/kernel/process.c
1da177e4	3	*
aec5e0e1	4	* This file handles the architecture-dependent parts of process handling..
1da177e4 LT	5	*
	6	* Copyright (C) 1995 Linus Torvalds
	7	*
	8	* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
8ae91b9a	9	* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
3a2e117e	10	* Copyright (C) 2002 - 2007 Paul Mundt
1da177e4	11	*/
1da177e4	12	#include <linux/module.h>
1da177e4 LT	13	#include <linux/mm.h>
1da177e4 LT	14	#include <linux/elfcore.h>
a3310bbd	15	#include <linux/pm.h>
1da177e4	16	#include <linux/kallsyms.h>
a3310bbd	17	#include <linux/kexec.h>
b118ca57	18	#include <linux/kdebug.h>
57be2b48	19	#include <linux/tick.h>
e08f457c	20	#include <linux/reboot.h>
e06c4e57	21	#include <linux/fs.h>
995bb781	22	#include <linux/preempt.h>
1da177e4 LT	23	#include <asm/uaccess.h>
1da177e4 LT	24	#include <asm/mmu_context.h>
5f8c9908	25	#include <asm/pgalloc.h>
bd079997	26	#include <asm/system.h>
b5233d07	27	#include <asm/ubc.h>
1da177e4	28
aec5e0e1	29	static int hlt_counter;
1da177e4 LT	30	int ubc_usercnt = 0;
1da177e4 LT	31
a3310bbd	32	void (*pm_idle)(void);
a3310bbd PM	33	void (*pm_power_off)(void);
	34	EXPORT_SYMBOL(pm_power_off);
	35
1da177e4 LT	36	void disable_hlt(void)
	37	{
	38	hlt_counter++;
	39	}
1da177e4 LT	40	EXPORT_SYMBOL(disable_hlt);
	41
	42	void enable_hlt(void)
	43	{
	44	hlt_counter--;
	45	}
1da177e4 LT	46	EXPORT_SYMBOL(enable_hlt);
1da177e4 LT	47
f3a9022f PM	48	static int __init nohlt_setup(char *__unused)
	49	{
	50	hlt_counter = 1;
	51	return 1;
	52	}
	53	__setup("nohlt", nohlt_setup);
	54
	55	static int __init hlt_setup(char *__unused)
	56	{
	57	hlt_counter = 0;
	58	return 1;
	59	}
	60	__setup("hlt", hlt_setup);
	61
a3310bbd PM	62	void default_idle(void)
a3310bbd PM	63	{
f3a9022f PM	64	if (!hlt_counter) {
	65	clear_thread_flag(TIF_POLLING_NRFLAG);
	66	smp_mb__after_clear_bit();
	67	set_bl_bit();
	68	while (!need_resched())
	69	cpu_sleep();
	70	clear_bl_bit();
	71	set_thread_flag(TIF_POLLING_NRFLAG);
	72	} else
	73	while (!need_resched())
	74	cpu_relax();
a3310bbd PM	75	}
a3310bbd PM	76
64c7c8f8	77	void cpu_idle(void)
1da177e4	78	{
f3a9022f PM	79	set_thread_flag(TIF_POLLING_NRFLAG);
f3a9022f PM	80
1da177e4 LT	81	/* endless idle loop with no priority at all */
1da177e4 LT	82	while (1) {
a3310bbd PM	83	void (*idle)(void) = pm_idle;
	84
	85	if (!idle)
	86	idle = default_idle;
	87
57be2b48	88	tick_nohz_stop_sched_tick();
a3310bbd PM	89	while (!need_resched())
a3310bbd PM	90	idle();
57be2b48	91	tick_nohz_restart_sched_tick();
1da177e4	92
5bfb5d69	93	preempt_enable_no_resched();
1da177e4	94	schedule();
5bfb5d69	95	preempt_disable();
5f8c9908	96	check_pgt_cache();
1da177e4 LT	97	}
	98	}
	99
1da177e4 LT	100	void machine_restart(char * __unused)
	101	{
	102	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	103	asm volatile("ldc %0, sr\n\t"
	104	"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
	105	}
	106
1da177e4 LT	107	void machine_halt(void)
1da177e4 LT	108	{
a3310bbd	109	local_irq_disable();
1da177e4	110
1da177e4 LT	111	while (1)
	112	cpu_sleep();
	113	}
	114
1da177e4 LT	115	void machine_power_off(void)
1da177e4 LT	116	{
a3310bbd PM	117	if (pm_power_off)
a3310bbd PM	118	pm_power_off();
1da177e4 LT	119	}
1da177e4 LT	120
1da177e4 LT	121	void show_regs(struct pt_regs * regs)
	122	{
	123	printk("\n");
19c5870c	124	printk("Pid : %d, Comm: %20s\n", task_pid_nr(current), current->comm);
6b002230	125	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	126	printk("PC : %08lx SP : %08lx SR : %08lx ",
	127	regs->pc, regs->regs[15], regs->sr);
	128	#ifdef CONFIG_MMU
	129	printk("TEA : %08x ", ctrl_inl(MMU_TEA));
	130	#else
	131	printk(" ");
	132	#endif
	133	printk("%s\n", print_tainted());
	134
	135	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
	136	regs->regs[0],regs->regs[1],
	137	regs->regs[2],regs->regs[3]);
	138	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
	139	regs->regs[4],regs->regs[5],
	140	regs->regs[6],regs->regs[7]);
	141	printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
	142	regs->regs[8],regs->regs[9],
	143	regs->regs[10],regs->regs[11]);
	144	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	145	regs->regs[12],regs->regs[13],
	146	regs->regs[14]);
	147	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
	148	regs->mach, regs->macl, regs->gbr, regs->pr);
	149
6b002230	150	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
1da177e4 LT	151	}
	152
	153	/*
	154	* Create a kernel thread
	155	*/
	156
	157	/*
	158	* This is the mechanism for creating a new kernel thread.
	159	*
	160	*/
	161	extern void kernel_thread_helper(void);
	162	__asm__(".align 5\n"
	163	"kernel_thread_helper:\n\t"
	164	"jsr @r5\n\t"
	165	" nop\n\t"
	166	"mov.l 1f, r1\n\t"
	167	"jsr @r1\n\t"
	168	" mov r0, r4\n\t"
	169	".align 2\n\t"
	170	"1:.long do_exit");
	171
aec5e0e1	172	/* Don't use this in BL=1(cli). Or else, CPU resets! */
1da177e4	173	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
aec5e0e1	174	{
1da177e4 LT	175	struct pt_regs regs;
	176
	177	memset(&regs, 0, sizeof(regs));
aec5e0e1 PM	178	regs.regs[4] = (unsigned long)arg;
aec5e0e1 PM	179	regs.regs[5] = (unsigned long)fn;
1da177e4	180
aec5e0e1	181	regs.pc = (unsigned long)kernel_thread_helper;
1da177e4 LT	182	regs.sr = (1 << 30);
	183
	184	/* Ok, create the new process.. */
aec5e0e1 PM	185	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0,
aec5e0e1 PM	186	&regs, 0, NULL, NULL);
1da177e4 LT	187	}
	188
	189	/*
	190	* Free current thread data structures etc..
	191	*/
	192	void exit_thread(void)
	193	{
	194	if (current->thread.ubc_pc) {
	195	current->thread.ubc_pc = 0;
	196	ubc_usercnt -= 1;
	197	}
	198	}
	199
	200	void flush_thread(void)
	201	{
	202	#if defined(CONFIG_SH_FPU)
	203	struct task_struct *tsk = current;
1da177e4	204	/* Forget lazy FPU state */
3cf0f4ec	205	clear_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	206	clear_used_math();
	207	#endif
	208	}
	209
	210	void release_thread(struct task_struct *dead_task)
	211	{
	212	/* do nothing */
	213	}
	214
	215	/* Fill in the fpu structure for a core dump.. */
	216	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	217	{
	218	int fpvalid = 0;
	219
	220	#if defined(CONFIG_SH_FPU)
	221	struct task_struct *tsk = current;
	222
	223	fpvalid = !!tsk_used_math(tsk);
	224	if (fpvalid) {
	225	unlazy_fpu(tsk, regs);
	226	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
1da177e4 LT	227	}
	228	#endif
	229
	230	return fpvalid;
	231	}
	232
	233	asmlinkage void ret_from_fork(void);
	234
	235	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	236	unsigned long unused,
	237	struct task_struct p, struct pt_regs regs)
	238	{
2991be72	239	struct thread_info *ti = task_thread_info(p);
1da177e4 LT	240	struct pt_regs *childregs;
	241	#if defined(CONFIG_SH_FPU)
	242	struct task_struct *tsk = current;
	243
	244	unlazy_fpu(tsk, regs);
	245	p->thread.fpu = tsk->thread.fpu;
	246	copy_to_stopped_child_used_math(p);
	247	#endif
	248
3cf0f4ec	249	childregs = task_pt_regs(p);
1da177e4 LT	250	childregs = regs;
	251
	252	if (user_mode(regs)) {
	253	childregs->regs[15] = usp;
2991be72	254	ti->addr_limit = USER_DS;
1da177e4	255	} else {
e6bcf562	256	childregs->regs[15] = (unsigned long)childregs;
2991be72	257	ti->addr_limit = KERNEL_DS;
1da177e4	258	}
aec5e0e1	259
e6bcf562	260	if (clone_flags & CLONE_SETTLS)
1da177e4	261	childregs->gbr = childregs->regs[0];
aec5e0e1	262
1da177e4 LT	263	childregs->regs[0] = 0; /* Set return value for child */
	264
	265	p->thread.sp = (unsigned long) childregs;
	266	p->thread.pc = (unsigned long) ret_from_fork;
	267
	268	p->thread.ubc_pc = 0;
	269
	270	return 0;
	271	}
	272
1da177e4	273	/* Tracing by user break controller. */
aec5e0e1	274	static void ubc_set_tracing(int asid, unsigned long pc)
1da177e4	275	{
8ae91b9a RS	276	#if defined(CONFIG_CPU_SH4A)
	277	unsigned long val;
	278
	279	val = (UBC_CBR_ID_INST \| UBC_CBR_RW_READ \| UBC_CBR_CE);
	280	val \|= (UBC_CBR_AIE \| UBC_CBR_AIV_SET(asid));
	281
	282	ctrl_outl(val, UBC_CBR0);
	283	ctrl_outl(pc, UBC_CAR0);
	284	ctrl_outl(0x0, UBC_CAMR0);
	285	ctrl_outl(0x0, UBC_CBCR);
	286
	287	val = (UBC_CRR_RES \| UBC_CRR_PCB \| UBC_CRR_BIE);
	288	ctrl_outl(val, UBC_CRR0);
	289
aec5e0e1	290	/* Read UBC register that we wrote last, for checking update */
8ae91b9a RS	291	val = ctrl_inl(UBC_CRR0);
	292
	293	#else /* CONFIG_CPU_SH4A */
1da177e4 LT	294	ctrl_outl(pc, UBC_BARA);
1da177e4 LT	295
a2d1a5fa	296	#ifdef CONFIG_MMU
357d5946	297	ctrl_outb(asid, UBC_BASRA);
a2d1a5fa	298	#endif
1da177e4 LT	299
	300	ctrl_outl(0, UBC_BAMRA);
	301
11c19656	302	if (current_cpu_data.type == CPU_SH7729 \|\|
3a2e117e PM	303	current_cpu_data.type == CPU_SH7710 \|\|
3a2e117e PM	304	current_cpu_data.type == CPU_SH7712) {
1da177e4 LT	305	ctrl_outw(BBR_INST \| BBR_READ \| BBR_CPU, UBC_BBRA);
	306	ctrl_outl(BRCR_PCBA \| BRCR_PCTE, UBC_BRCR);
	307	} else {
	308	ctrl_outw(BBR_INST \| BBR_READ, UBC_BBRA);
	309	ctrl_outw(BRCR_PCBA, UBC_BRCR);
	310	}
8ae91b9a	311	#endif /* CONFIG_CPU_SH4A */
1da177e4 LT	312	}
	313
	314	/*
	315	* switch_to(x,y) should switch tasks from x to y.
	316	*
	317	*/
aec5e0e1 PM	318	struct task_struct __switch_to(struct task_struct prev,
aec5e0e1 PM	319	struct task_struct *next)
1da177e4 LT	320	{
1da177e4 LT	321	#if defined(CONFIG_SH_FPU)
3cf0f4ec	322	unlazy_fpu(prev, task_pt_regs(prev));
1da177e4 LT	323	#endif
1da177e4 LT	324
83662461	325	#if defined(CONFIG_GUSA) && defined(CONFIG_PREEMPT)
1da177e4	326	{
1da177e4 LT	327	struct pt_regs *regs;
1da177e4 LT	328
995bb781	329	preempt_disable();
3cf0f4ec	330	regs = task_pt_regs(prev);
1da177e4 LT	331	if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
	332	int offset = (int)regs->regs[15];
	333
	334	/* Reset stack pointer: clear critical region mark */
	335	regs->regs[15] = regs->regs[1];
	336	if (regs->pc < regs->regs[0])
	337	/* Go to rewind point */
	338	regs->pc = regs->regs[0] + offset;
	339	}
995bb781	340	preempt_enable_no_resched();
1da177e4 LT	341	}
	342	#endif
	343
a2d1a5fa	344	#ifdef CONFIG_MMU
1da177e4 LT	345	/*
1da177e4 LT	346	* Restore the kernel mode register
aec5e0e1	347	* k7 (r7_bank1)
1da177e4 LT	348	*/
	349	asm volatile("ldc %0, r7_bank"
	350	: /* no output */
cafcfcaa	351	: "r" (task_thread_info(next)));
a2d1a5fa	352	#endif
1da177e4	353
1da177e4 LT	354	/* If no tasks are using the UBC, we're done */
	355	if (ubc_usercnt == 0)
	356	/* If no tasks are using the UBC, we're done */;
	357	else if (next->thread.ubc_pc && next->mm) {
a2d1a5fa YS	358	int asid = 0;
a2d1a5fa YS	359	#ifdef CONFIG_MMU
aec5e0e1	360	asid \|= cpu_asid(smp_processor_id(), next->mm);
a2d1a5fa YS	361	#endif
a2d1a5fa YS	362	ubc_set_tracing(asid, next->thread.ubc_pc);
1da177e4	363	} else {
8ae91b9a RS	364	#if defined(CONFIG_CPU_SH4A)
	365	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	366	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	367	#else
1da177e4 LT	368	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	369	ctrl_outw(0, UBC_BBRB);
8ae91b9a	370	#endif
1da177e4	371	}
1da177e4 LT	372
	373	return prev;
	374	}
	375
	376	asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
	377	unsigned long r6, unsigned long r7,
f0bc814c	378	struct pt_regs __regs)
1da177e4 LT	379	{
1da177e4 LT	380	#ifdef CONFIG_MMU
882c12c4	381	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c	382	return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
1da177e4 LT	383	#else
	384	/* fork almost works, enough to trick you into looking elsewhere :-( */
	385	return -EINVAL;
	386	#endif
	387	}
	388
	389	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
	390	unsigned long parent_tidptr,
	391	unsigned long child_tidptr,
f0bc814c	392	struct pt_regs __regs)
1da177e4	393	{
f0bc814c	394	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4	395	if (!newsp)
f0bc814c SM	396	newsp = regs->regs[15];
f0bc814c SM	397	return do_fork(clone_flags, newsp, regs, 0,
aec5e0e1 PM	398	(int __user *)parent_tidptr,
aec5e0e1 PM	399	(int __user *)child_tidptr);
1da177e4 LT	400	}
	401
	402	/*
	403	* This is trivial, and on the face of it looks like it
	404	* could equally well be done in user mode.
	405	*
	406	* Not so, for quite unobvious reasons - register pressure.
	407	* In user mode vfork() cannot have a stack frame, and if
	408	* done by calling the "clone()" system call directly, you
	409	* do not have enough call-clobbered registers to hold all
	410	* the information you need.
	411	*/
	412	asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
	413	unsigned long r6, unsigned long r7,
f0bc814c	414	struct pt_regs __regs)
1da177e4	415	{
f0bc814c SM	416	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c SM	417	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->regs[15], regs,
1da177e4 LT	418	0, NULL, NULL);
	419	}
	420
	421	/*
	422	* sys_execve() executes a new program.
	423	*/
e08f457c PM	424	asmlinkage int sys_execve(char __user ufilename, char __user __user *uargv,
e08f457c PM	425	char __user * __user *uenvp, unsigned long r7,
f0bc814c	426	struct pt_regs __regs)
1da177e4	427	{
f0bc814c	428	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4 LT	429	int error;
	430	char *filename;
	431
e08f457c	432	filename = getname(ufilename);
1da177e4 LT	433	error = PTR_ERR(filename);
	434	if (IS_ERR(filename))
	435	goto out;
	436
e08f457c	437	error = do_execve(filename, uargv, uenvp, regs);
1da177e4 LT	438	if (error == 0) {
	439	task_lock(current);
	440	current->ptrace &= ~PT_DTRACE;
	441	task_unlock(current);
	442	}
	443	putname(filename);
	444	out:
	445	return error;
	446	}
	447
	448	unsigned long get_wchan(struct task_struct *p)
	449	{
1da177e4 LT	450	unsigned long pc;
	451
	452	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	453	return 0;
	454
	455	/*
	456	* The same comment as on the Alpha applies here, too ...
	457	*/
	458	pc = thread_saved_pc(p);
c64ac9f0 DM	459
c64ac9f0 DM	460	#ifdef CONFIG_FRAME_POINTER
1da177e4	461	if (in_sched_functions(pc)) {
c64ac9f0	462	unsigned long schedule_frame = (unsigned long)p->thread.sp;
b652c23c	463	return ((unsigned long *)schedule_frame)[21];
1da177e4	464	}
c64ac9f0	465	#endif
b652c23c	466
1da177e4 LT	467	return pc;
	468	}
	469
f0bc814c	470	asmlinkage void break_point_trap(void)
1da177e4 LT	471	{
1da177e4 LT	472	/* Clear tracing. */
8ae91b9a RS	473	#if defined(CONFIG_CPU_SH4A)
	474	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	475	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	476	#else
1da177e4 LT	477	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	478	ctrl_outw(0, UBC_BBRB);
8ae91b9a	479	#endif
1da177e4 LT	480	current->thread.ubc_pc = 0;
	481	ubc_usercnt -= 1;
	482
	483	force_sig(SIGTRAP, current);
	484	}