[mirror_ubuntu-zesty-kernel.git] / arch / sh / kernel / process.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 - 2006  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 <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/ubc.h>

static int hlt_counter;
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", 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;
}

/*
 * 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 wrote last, for checking update */
	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 (current_cpu_data.type != CPU_SH7604)
		ctrl_outb(asid, UBC_BASRA);
#endif

	ctrl_outl(0, UBC_BAMRA);

	if (current_cpu_data.type == CPU_SH7729 ||
	    current_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 |= 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)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
#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)
{
	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 *ufilename, char **uargv,
			  char **uenvp, unsigned long r7,
			  struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	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)p->thread.sp;
		return ((unsigned long *)schedule_frame)[21];
	}

	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);
}

/*
 * Generic trap handler.
 */
asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
				   unsigned long r6, unsigned long r7,
				   struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);

	/* Rewind */
	regs->pc -= 2;

	force_sig(SIGTRAP, current);
}

/*
 * Special handler for BUG() traps.
 */
asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5,
				 unsigned long r6, unsigned long r7,
				 struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);

	/* Rewind */
	regs->pc -= 2;

#ifdef CONFIG_BUG
	if (__kernel_text_address(instruction_pointer(regs))) {
		u16 insn = *(u16 *)instruction_pointer(regs);
		if (insn == TRAPA_BUG_OPCODE)
			handle_BUG(regs);
	}
#endif

	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
aec5e0e1	10	* Copyright (C) 2002 - 2006 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>
1da177e4 LT	18	#include <asm/uaccess.h>
1da177e4 LT	19	#include <asm/mmu_context.h>
b5233d07	20	#include <asm/ubc.h>
1da177e4	21
aec5e0e1	22	static int hlt_counter;
1da177e4 LT	23	int ubc_usercnt = 0;
	24
	25	#define HARD_IDLE_TIMEOUT (HZ / 3)
	26
a3310bbd	27	void (*pm_idle)(void);
a3310bbd PM	28	void (*pm_power_off)(void);
	29	EXPORT_SYMBOL(pm_power_off);
	30
1da177e4 LT	31	void disable_hlt(void)
	32	{
	33	hlt_counter++;
	34	}
1da177e4 LT	35	EXPORT_SYMBOL(disable_hlt);
	36
	37	void enable_hlt(void)
	38	{
	39	hlt_counter--;
	40	}
1da177e4 LT	41	EXPORT_SYMBOL(enable_hlt);
1da177e4 LT	42
a3310bbd PM	43	void default_idle(void)
	44	{
	45	if (!hlt_counter)
	46	cpu_sleep();
	47	else
	48	cpu_relax();
	49	}
	50
64c7c8f8	51	void cpu_idle(void)
1da177e4 LT	52	{
	53	/* endless idle loop with no priority at all */
	54	while (1) {
a3310bbd PM	55	void (*idle)(void) = pm_idle;
	56
	57	if (!idle)
	58	idle = default_idle;
	59
	60	while (!need_resched())
	61	idle();
1da177e4	62
5bfb5d69	63	preempt_enable_no_resched();
1da177e4	64	schedule();
5bfb5d69	65	preempt_disable();
1da177e4 LT	66	}
	67	}
	68
1da177e4 LT	69	void machine_restart(char * __unused)
	70	{
	71	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	72	asm volatile("ldc %0, sr\n\t"
	73	"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
	74	}
	75
1da177e4 LT	76	void machine_halt(void)
1da177e4 LT	77	{
a3310bbd	78	local_irq_disable();
1da177e4	79
1da177e4 LT	80	while (1)
	81	cpu_sleep();
	82	}
	83
1da177e4 LT	84	void machine_power_off(void)
1da177e4 LT	85	{
a3310bbd PM	86	if (pm_power_off)
a3310bbd PM	87	pm_power_off();
1da177e4 LT	88	}
1da177e4 LT	89
1da177e4 LT	90	void show_regs(struct pt_regs * regs)
	91	{
	92	printk("\n");
	93	printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
6b002230	94	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	95	printk("PC : %08lx SP : %08lx SR : %08lx ",
	96	regs->pc, regs->regs[15], regs->sr);
	97	#ifdef CONFIG_MMU
	98	printk("TEA : %08x ", ctrl_inl(MMU_TEA));
	99	#else
	100	printk(" ");
	101	#endif
	102	printk("%s\n", print_tainted());
	103
	104	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
	105	regs->regs[0],regs->regs[1],
	106	regs->regs[2],regs->regs[3]);
	107	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
	108	regs->regs[4],regs->regs[5],
	109	regs->regs[6],regs->regs[7]);
	110	printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
	111	regs->regs[8],regs->regs[9],
	112	regs->regs[10],regs->regs[11]);
	113	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	114	regs->regs[12],regs->regs[13],
	115	regs->regs[14]);
	116	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
	117	regs->mach, regs->macl, regs->gbr, regs->pr);
	118
6b002230	119	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
1da177e4 LT	120	}
	121
	122	/*
	123	* Create a kernel thread
	124	*/
	125
	126	/*
	127	* This is the mechanism for creating a new kernel thread.
	128	*
	129	*/
	130	extern void kernel_thread_helper(void);
	131	__asm__(".align 5\n"
	132	"kernel_thread_helper:\n\t"
	133	"jsr @r5\n\t"
	134	" nop\n\t"
	135	"mov.l 1f, r1\n\t"
	136	"jsr @r1\n\t"
	137	" mov r0, r4\n\t"
	138	".align 2\n\t"
	139	"1:.long do_exit");
	140
aec5e0e1	141	/* Don't use this in BL=1(cli). Or else, CPU resets! */
1da177e4	142	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
aec5e0e1	143	{
1da177e4 LT	144	struct pt_regs regs;
	145
	146	memset(&regs, 0, sizeof(regs));
aec5e0e1 PM	147	regs.regs[4] = (unsigned long)arg;
aec5e0e1 PM	148	regs.regs[5] = (unsigned long)fn;
1da177e4	149
aec5e0e1	150	regs.pc = (unsigned long)kernel_thread_helper;
1da177e4 LT	151	regs.sr = (1 << 30);
	152
	153	/* Ok, create the new process.. */
aec5e0e1 PM	154	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0,
aec5e0e1 PM	155	&regs, 0, NULL, NULL);
1da177e4 LT	156	}
	157
	158	/*
	159	* Free current thread data structures etc..
	160	*/
	161	void exit_thread(void)
	162	{
	163	if (current->thread.ubc_pc) {
	164	current->thread.ubc_pc = 0;
	165	ubc_usercnt -= 1;
	166	}
	167	}
	168
	169	void flush_thread(void)
	170	{
	171	#if defined(CONFIG_SH_FPU)
	172	struct task_struct *tsk = current;
1da177e4	173	/* Forget lazy FPU state */
3cf0f4ec	174	clear_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	175	clear_used_math();
	176	#endif
	177	}
	178
	179	void release_thread(struct task_struct *dead_task)
	180	{
	181	/* do nothing */
	182	}
	183
	184	/* Fill in the fpu structure for a core dump.. */
	185	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	186	{
	187	int fpvalid = 0;
	188
	189	#if defined(CONFIG_SH_FPU)
	190	struct task_struct *tsk = current;
	191
	192	fpvalid = !!tsk_used_math(tsk);
	193	if (fpvalid) {
	194	unlazy_fpu(tsk, regs);
	195	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	196	}
	197	#endif
	198
	199	return fpvalid;
	200	}
	201
aec5e0e1	202	/*
1da177e4 LT	203	* Capture the user space registers if the task is not running (in user space)
	204	*/
	205	int dump_task_regs(struct task_struct tsk, elf_gregset_t regs)
	206	{
	207	struct pt_regs ptregs;
aec5e0e1	208
3cf0f4ec	209	ptregs = *task_pt_regs(tsk);
1da177e4 LT	210	elf_core_copy_regs(regs, &ptregs);
	211
	212	return 1;
	213	}
	214
aec5e0e1	215	int dump_task_fpu(struct task_struct tsk, elf_fpregset_t fpu)
1da177e4 LT	216	{
	217	int fpvalid = 0;
	218
	219	#if defined(CONFIG_SH_FPU)
	220	fpvalid = !!tsk_used_math(tsk);
	221	if (fpvalid) {
3cf0f4ec	222	unlazy_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	223	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	224	}
	225	#endif
	226
	227	return fpvalid;
	228	}
	229
	230	asmlinkage void ret_from_fork(void);
	231
	232	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	233	unsigned long unused,
	234	struct task_struct p, struct pt_regs regs)
	235	{
2991be72	236	struct thread_info *ti = task_thread_info(p);
1da177e4 LT	237	struct pt_regs *childregs;
	238	#if defined(CONFIG_SH_FPU)
	239	struct task_struct *tsk = current;
	240
	241	unlazy_fpu(tsk, regs);
	242	p->thread.fpu = tsk->thread.fpu;
	243	copy_to_stopped_child_used_math(p);
	244	#endif
	245
3cf0f4ec	246	childregs = task_pt_regs(p);
1da177e4 LT	247	childregs = regs;
	248
	249	if (user_mode(regs)) {
	250	childregs->regs[15] = usp;
2991be72	251	ti->addr_limit = USER_DS;
1da177e4	252	} else {
aec5e0e1 PM	253	childregs->regs[15] = (unsigned long)task_stack_page(p) +
aec5e0e1 PM	254	THREAD_SIZE;
2991be72	255	ti->addr_limit = KERNEL_DS;
1da177e4	256	}
aec5e0e1 PM	257
aec5e0e1 PM	258	if (clone_flags & CLONE_SETTLS)
1da177e4	259	childregs->gbr = childregs->regs[0];
aec5e0e1	260
1da177e4 LT	261	childregs->regs[0] = 0; /* Set return value for child */
	262
	263	p->thread.sp = (unsigned long) childregs;
	264	p->thread.pc = (unsigned long) ret_from_fork;
	265
	266	p->thread.ubc_pc = 0;
	267
	268	return 0;
	269	}
	270
1da177e4	271	/* Tracing by user break controller. */
aec5e0e1	272	static void ubc_set_tracing(int asid, unsigned long pc)
1da177e4	273	{
8ae91b9a RS	274	#if defined(CONFIG_CPU_SH4A)
	275	unsigned long val;
	276
	277	val = (UBC_CBR_ID_INST \| UBC_CBR_RW_READ \| UBC_CBR_CE);
	278	val \|= (UBC_CBR_AIE \| UBC_CBR_AIV_SET(asid));
	279
	280	ctrl_outl(val, UBC_CBR0);
	281	ctrl_outl(pc, UBC_CAR0);
	282	ctrl_outl(0x0, UBC_CAMR0);
	283	ctrl_outl(0x0, UBC_CBCR);
	284
	285	val = (UBC_CRR_RES \| UBC_CRR_PCB \| UBC_CRR_BIE);
	286	ctrl_outl(val, UBC_CRR0);
	287
aec5e0e1	288	/* Read UBC register that we wrote last, for checking update */
8ae91b9a RS	289	val = ctrl_inl(UBC_CRR0);
	290
	291	#else /* CONFIG_CPU_SH4A */
1da177e4 LT	292	ctrl_outl(pc, UBC_BARA);
1da177e4 LT	293
a2d1a5fa	294	#ifdef CONFIG_MMU
1da177e4	295	/* We don't have any ASID settings for the SH-2! */
11c19656	296	if (current_cpu_data.type != CPU_SH7604)
1da177e4	297	ctrl_outb(asid, UBC_BASRA);
a2d1a5fa	298	#endif
1da177e4 LT	299
	300	ctrl_outl(0, UBC_BAMRA);
	301
11c19656 PM	302	if (current_cpu_data.type == CPU_SH7729 \|\|
11c19656 PM	303	current_cpu_data.type == CPU_SH7710) {
1da177e4 LT	304	ctrl_outw(BBR_INST \| BBR_READ \| BBR_CPU, UBC_BBRA);
	305	ctrl_outl(BRCR_PCBA \| BRCR_PCTE, UBC_BRCR);
	306	} else {
	307	ctrl_outw(BBR_INST \| BBR_READ, UBC_BBRA);
	308	ctrl_outw(BRCR_PCBA, UBC_BRCR);
	309	}
8ae91b9a	310	#endif /* CONFIG_CPU_SH4A */
1da177e4 LT	311	}
	312
	313	/*
	314	* switch_to(x,y) should switch tasks from x to y.
	315	*
	316	*/
aec5e0e1 PM	317	struct task_struct __switch_to(struct task_struct prev,
aec5e0e1 PM	318	struct task_struct *next)
1da177e4 LT	319	{
1da177e4 LT	320	#if defined(CONFIG_SH_FPU)
3cf0f4ec	321	unlazy_fpu(prev, task_pt_regs(prev));
1da177e4 LT	322	#endif
	323
	324	#ifdef CONFIG_PREEMPT
	325	{
	326	unsigned long flags;
	327	struct pt_regs *regs;
	328
	329	local_irq_save(flags);
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	}
	340	local_irq_restore(flags);
	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	379	{
f0bc814c	380	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4	381	#ifdef CONFIG_MMU
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	*/
	424	asmlinkage int sys_execve(char ufilename, char *uargv,
	425	char **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
	432	filename = getname((char __user *)ufilename);
	433	error = PTR_ERR(filename);
	434	if (IS_ERR(filename))
	435	goto out;
	436
	437	error = do_execve(filename,
	438	(char __user * __user *)uargv,
	439	(char __user * __user *)uenvp,
f0bc814c	440	regs);
1da177e4 LT	441	if (error == 0) {
	442	task_lock(current);
	443	current->ptrace &= ~PT_DTRACE;
	444	task_unlock(current);
	445	}
	446	putname(filename);
	447	out:
	448	return error;
	449	}
	450
	451	unsigned long get_wchan(struct task_struct *p)
	452	{
	453	unsigned long schedule_frame;
	454	unsigned long pc;
	455
	456	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	457	return 0;
	458
	459	/*
	460	* The same comment as on the Alpha applies here, too ...
	461	*/
	462	pc = thread_saved_pc(p);
	463	if (in_sched_functions(pc)) {
b652c23c PM	464	schedule_frame = (unsigned long)p->thread.sp;
b652c23c PM	465	return ((unsigned long *)schedule_frame)[21];
1da177e4	466	}
b652c23c	467
1da177e4 LT	468	return pc;
	469	}
	470
f0bc814c	471	asmlinkage void break_point_trap(void)
1da177e4 LT	472	{
1da177e4 LT	473	/* Clear tracing. */
8ae91b9a RS	474	#if defined(CONFIG_CPU_SH4A)
	475	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	476	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	477	#else
1da177e4 LT	478	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	479	ctrl_outw(0, UBC_BBRB);
8ae91b9a	480	#endif
1da177e4 LT	481	current->thread.ubc_pc = 0;
	482	ubc_usercnt -= 1;
	483
	484	force_sig(SIGTRAP, current);
	485	}
	486
f413d0d9 PM	487	/*
	488	* Generic trap handler.
	489	*/
	490	asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
	491	unsigned long r6, unsigned long r7,
	492	struct pt_regs __regs)
	493	{
	494	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	495
	496	/* Rewind */
	497	regs->pc -= 2;
	498
	499	force_sig(SIGTRAP, current);
	500	}
	501
	502	/*
	503	* Special handler for BUG() traps.
	504	*/
	505	asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5,
	506	unsigned long r6, unsigned long r7,
	507	struct pt_regs __regs)
1da177e4	508	{
f0bc814c SM	509	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c SM	510
dc34d312	511	/* Rewind */
f0bc814c	512	regs->pc -= 2;
dc34d312 PM	513
	514	#ifdef CONFIG_BUG
	515	if (__kernel_text_address(instruction_pointer(regs))) {
	516	u16 insn = (u16 )instruction_pointer(regs);
	517	if (insn == TRAPA_BUG_OPCODE)
	518	handle_BUG(regs);
	519	}
	520	#endif
	521
1da177e4 LT	522	force_sig(SIGTRAP, current);
1da177e4 LT	523	}