[mirror_ubuntu-zesty-kernel.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>
#include <asm/fpu.h>

static int hlt_counter;
int ubc_usercnt = 0;

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

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);

static 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(1);
		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);
	printk("CPU : %d    %s  (%s %.*s)\n",
	       smp_processor_id(), print_tainted(), init_utsname()->release,
	       (int)strcspn(init_utsname()->version, " "),
	       init_utsname()->version);

	print_symbol("PC is at %s\n", instruction_pointer(regs));
	print_symbol("PR is at %s\n", regs->pr);

	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
	       regs->pc, regs->regs[15], regs->sr);
#ifdef CONFIG_MMU
	printk("TEA : %08x\n", ctrl_inl(MMU_TEA));
#else
	printk("\n");
#endif

	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

#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>
9bbafce2	28	#include <asm/fpu.h>
1da177e4	29
aec5e0e1	30	static int hlt_counter;
1da177e4 LT	31	int ubc_usercnt = 0;
1da177e4 LT	32
a3310bbd	33	void (*pm_idle)(void);
a3310bbd PM	34	void (*pm_power_off)(void);
	35	EXPORT_SYMBOL(pm_power_off);
	36
f3a9022f PM	37	static int __init nohlt_setup(char *__unused)
	38	{
	39	hlt_counter = 1;
	40	return 1;
	41	}
	42	__setup("nohlt", nohlt_setup);
	43
	44	static int __init hlt_setup(char *__unused)
	45	{
	46	hlt_counter = 0;
	47	return 1;
	48	}
	49	__setup("hlt", hlt_setup);
	50
4c1cfab1	51	static void default_idle(void)
a3310bbd	52	{
f3a9022f PM	53	if (!hlt_counter) {
	54	clear_thread_flag(TIF_POLLING_NRFLAG);
	55	smp_mb__after_clear_bit();
	56	set_bl_bit();
	57	while (!need_resched())
	58	cpu_sleep();
	59	clear_bl_bit();
	60	set_thread_flag(TIF_POLLING_NRFLAG);
	61	} else
	62	while (!need_resched())
	63	cpu_relax();
a3310bbd PM	64	}
a3310bbd PM	65
64c7c8f8	66	void cpu_idle(void)
1da177e4	67	{
f3a9022f PM	68	set_thread_flag(TIF_POLLING_NRFLAG);
f3a9022f PM	69
1da177e4 LT	70	/* endless idle loop with no priority at all */
1da177e4 LT	71	while (1) {
a3310bbd PM	72	void (*idle)(void) = pm_idle;
	73
	74	if (!idle)
	75	idle = default_idle;
	76
b8f8c3cf	77	tick_nohz_stop_sched_tick(1);
a3310bbd PM	78	while (!need_resched())
a3310bbd PM	79	idle();
57be2b48	80	tick_nohz_restart_sched_tick();
1da177e4	81
5bfb5d69	82	preempt_enable_no_resched();
1da177e4	83	schedule();
5bfb5d69	84	preempt_disable();
5f8c9908	85	check_pgt_cache();
1da177e4 LT	86	}
	87	}
	88
1da177e4 LT	89	void machine_restart(char * __unused)
	90	{
	91	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	92	asm volatile("ldc %0, sr\n\t"
	93	"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
	94	}
	95
1da177e4 LT	96	void machine_halt(void)
1da177e4 LT	97	{
a3310bbd	98	local_irq_disable();
1da177e4	99
1da177e4 LT	100	while (1)
	101	cpu_sleep();
	102	}
	103
1da177e4 LT	104	void machine_power_off(void)
1da177e4 LT	105	{
a3310bbd PM	106	if (pm_power_off)
a3310bbd PM	107	pm_power_off();
1da177e4 LT	108	}
1da177e4 LT	109
1da177e4 LT	110	void show_regs(struct pt_regs * regs)
	111	{
	112	printk("\n");
19c5870c	113	printk("Pid : %d, Comm: %20s\n", task_pid_nr(current), current->comm);
7d96169c PM	114	printk("CPU : %d %s (%s %.*s)\n",
	115	smp_processor_id(), print_tainted(), init_utsname()->release,
	116	(int)strcspn(init_utsname()->version, " "),
	117	init_utsname()->version);
	118
6b002230	119	print_symbol("PC is at %s\n", instruction_pointer(regs));
7d96169c PM	120	print_symbol("PR is at %s\n", regs->pr);
7d96169c PM	121
1da177e4 LT	122	printk("PC : %08lx SP : %08lx SR : %08lx ",
	123	regs->pc, regs->regs[15], regs->sr);
	124	#ifdef CONFIG_MMU
7d96169c	125	printk("TEA : %08x\n", ctrl_inl(MMU_TEA));
1da177e4	126	#else
7d96169c	127	printk("\n");
1da177e4	128	#endif
1da177e4 LT	129
	130	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
	131	regs->regs[0],regs->regs[1],
	132	regs->regs[2],regs->regs[3]);
	133	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
	134	regs->regs[4],regs->regs[5],
	135	regs->regs[6],regs->regs[7]);
	136	printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
	137	regs->regs[8],regs->regs[9],
	138	regs->regs[10],regs->regs[11]);
	139	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	140	regs->regs[12],regs->regs[13],
	141	regs->regs[14]);
	142	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
	143	regs->mach, regs->macl, regs->gbr, regs->pr);
	144
6b002230	145	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
1da177e4 LT	146	}
	147
	148	/*
	149	* Create a kernel thread
	150	*/
	151
	152	/*
	153	* This is the mechanism for creating a new kernel thread.
	154	*
	155	*/
	156	extern void kernel_thread_helper(void);
	157	__asm__(".align 5\n"
	158	"kernel_thread_helper:\n\t"
	159	"jsr @r5\n\t"
	160	" nop\n\t"
	161	"mov.l 1f, r1\n\t"
	162	"jsr @r1\n\t"
	163	" mov r0, r4\n\t"
	164	".align 2\n\t"
	165	"1:.long do_exit");
	166
aec5e0e1	167	/* Don't use this in BL=1(cli). Or else, CPU resets! */
1da177e4	168	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
aec5e0e1	169	{
1da177e4 LT	170	struct pt_regs regs;
	171
	172	memset(&regs, 0, sizeof(regs));
aec5e0e1 PM	173	regs.regs[4] = (unsigned long)arg;
aec5e0e1 PM	174	regs.regs[5] = (unsigned long)fn;
1da177e4	175
aec5e0e1	176	regs.pc = (unsigned long)kernel_thread_helper;
1da177e4 LT	177	regs.sr = (1 << 30);
	178
	179	/* Ok, create the new process.. */
aec5e0e1 PM	180	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0,
aec5e0e1 PM	181	&regs, 0, NULL, NULL);
1da177e4 LT	182	}
	183
	184	/*
	185	* Free current thread data structures etc..
	186	*/
	187	void exit_thread(void)
	188	{
	189	if (current->thread.ubc_pc) {
	190	current->thread.ubc_pc = 0;
	191	ubc_usercnt -= 1;
	192	}
	193	}
	194
	195	void flush_thread(void)
	196	{
	197	#if defined(CONFIG_SH_FPU)
	198	struct task_struct *tsk = current;
1da177e4	199	/* Forget lazy FPU state */
3cf0f4ec	200	clear_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	201	clear_used_math();
	202	#endif
	203	}
	204
	205	void release_thread(struct task_struct *dead_task)
	206	{
	207	/* do nothing */
	208	}
	209
	210	/* Fill in the fpu structure for a core dump.. */
	211	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	212	{
	213	int fpvalid = 0;
	214
	215	#if defined(CONFIG_SH_FPU)
	216	struct task_struct *tsk = current;
	217
	218	fpvalid = !!tsk_used_math(tsk);
	219	if (fpvalid) {
	220	unlazy_fpu(tsk, regs);
	221	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
1da177e4 LT	222	}
	223	#endif
	224
	225	return fpvalid;
	226	}
	227
	228	asmlinkage void ret_from_fork(void);
	229
	230	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	231	unsigned long unused,
	232	struct task_struct p, struct pt_regs regs)
	233	{
2991be72	234	struct thread_info *ti = task_thread_info(p);
1da177e4 LT	235	struct pt_regs *childregs;
	236	#if defined(CONFIG_SH_FPU)
	237	struct task_struct *tsk = current;
	238
	239	unlazy_fpu(tsk, regs);
	240	p->thread.fpu = tsk->thread.fpu;
	241	copy_to_stopped_child_used_math(p);
	242	#endif
	243
3cf0f4ec	244	childregs = task_pt_regs(p);
1da177e4 LT	245	childregs = regs;
	246
	247	if (user_mode(regs)) {
	248	childregs->regs[15] = usp;
2991be72	249	ti->addr_limit = USER_DS;
1da177e4	250	} else {
e6bcf562	251	childregs->regs[15] = (unsigned long)childregs;
2991be72	252	ti->addr_limit = KERNEL_DS;
1da177e4	253	}
aec5e0e1	254
e6bcf562	255	if (clone_flags & CLONE_SETTLS)
1da177e4	256	childregs->gbr = childregs->regs[0];
aec5e0e1	257
1da177e4 LT	258	childregs->regs[0] = 0; /* Set return value for child */
	259
	260	p->thread.sp = (unsigned long) childregs;
	261	p->thread.pc = (unsigned long) ret_from_fork;
	262
	263	p->thread.ubc_pc = 0;
	264
	265	return 0;
	266	}
	267
1da177e4	268	/* Tracing by user break controller. */
aec5e0e1	269	static void ubc_set_tracing(int asid, unsigned long pc)
1da177e4	270	{
8ae91b9a RS	271	#if defined(CONFIG_CPU_SH4A)
	272	unsigned long val;
	273
	274	val = (UBC_CBR_ID_INST \| UBC_CBR_RW_READ \| UBC_CBR_CE);
	275	val \|= (UBC_CBR_AIE \| UBC_CBR_AIV_SET(asid));
	276
	277	ctrl_outl(val, UBC_CBR0);
	278	ctrl_outl(pc, UBC_CAR0);
	279	ctrl_outl(0x0, UBC_CAMR0);
	280	ctrl_outl(0x0, UBC_CBCR);
	281
	282	val = (UBC_CRR_RES \| UBC_CRR_PCB \| UBC_CRR_BIE);
	283	ctrl_outl(val, UBC_CRR0);
	284
aec5e0e1	285	/* Read UBC register that we wrote last, for checking update */
8ae91b9a RS	286	val = ctrl_inl(UBC_CRR0);
	287
	288	#else /* CONFIG_CPU_SH4A */
1da177e4 LT	289	ctrl_outl(pc, UBC_BARA);
1da177e4 LT	290
a2d1a5fa	291	#ifdef CONFIG_MMU
357d5946	292	ctrl_outb(asid, UBC_BASRA);
a2d1a5fa	293	#endif
1da177e4 LT	294
	295	ctrl_outl(0, UBC_BAMRA);
	296
11c19656	297	if (current_cpu_data.type == CPU_SH7729 \|\|
3a2e117e PM	298	current_cpu_data.type == CPU_SH7710 \|\|
3a2e117e PM	299	current_cpu_data.type == CPU_SH7712) {
1da177e4 LT	300	ctrl_outw(BBR_INST \| BBR_READ \| BBR_CPU, UBC_BBRA);
	301	ctrl_outl(BRCR_PCBA \| BRCR_PCTE, UBC_BRCR);
	302	} else {
	303	ctrl_outw(BBR_INST \| BBR_READ, UBC_BBRA);
	304	ctrl_outw(BRCR_PCBA, UBC_BRCR);
	305	}
8ae91b9a	306	#endif /* CONFIG_CPU_SH4A */
1da177e4 LT	307	}
	308
	309	/*
	310	* switch_to(x,y) should switch tasks from x to y.
	311	*
	312	*/
aec5e0e1 PM	313	struct task_struct __switch_to(struct task_struct prev,
aec5e0e1 PM	314	struct task_struct *next)
1da177e4 LT	315	{
1da177e4 LT	316	#if defined(CONFIG_SH_FPU)
3cf0f4ec	317	unlazy_fpu(prev, task_pt_regs(prev));
1da177e4 LT	318	#endif
1da177e4 LT	319
a2d1a5fa	320	#ifdef CONFIG_MMU
1da177e4 LT	321	/*
1da177e4 LT	322	* Restore the kernel mode register
aec5e0e1	323	* k7 (r7_bank1)
1da177e4 LT	324	*/
	325	asm volatile("ldc %0, r7_bank"
	326	: /* no output */
cafcfcaa	327	: "r" (task_thread_info(next)));
a2d1a5fa	328	#endif
1da177e4	329
1da177e4 LT	330	/* If no tasks are using the UBC, we're done */
	331	if (ubc_usercnt == 0)
	332	/* If no tasks are using the UBC, we're done */;
	333	else if (next->thread.ubc_pc && next->mm) {
a2d1a5fa YS	334	int asid = 0;
a2d1a5fa YS	335	#ifdef CONFIG_MMU
aec5e0e1	336	asid \|= cpu_asid(smp_processor_id(), next->mm);
a2d1a5fa YS	337	#endif
a2d1a5fa YS	338	ubc_set_tracing(asid, next->thread.ubc_pc);
1da177e4	339	} else {
8ae91b9a RS	340	#if defined(CONFIG_CPU_SH4A)
	341	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	342	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	343	#else
1da177e4 LT	344	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	345	ctrl_outw(0, UBC_BBRB);
8ae91b9a	346	#endif
1da177e4	347	}
1da177e4 LT	348
	349	return prev;
	350	}
	351
	352	asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
	353	unsigned long r6, unsigned long r7,
f0bc814c	354	struct pt_regs __regs)
1da177e4 LT	355	{
1da177e4 LT	356	#ifdef CONFIG_MMU
882c12c4	357	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c	358	return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
1da177e4 LT	359	#else
	360	/* fork almost works, enough to trick you into looking elsewhere :-( */
	361	return -EINVAL;
	362	#endif
	363	}
	364
	365	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
	366	unsigned long parent_tidptr,
	367	unsigned long child_tidptr,
f0bc814c	368	struct pt_regs __regs)
1da177e4	369	{
f0bc814c	370	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4	371	if (!newsp)
f0bc814c SM	372	newsp = regs->regs[15];
f0bc814c SM	373	return do_fork(clone_flags, newsp, regs, 0,
aec5e0e1 PM	374	(int __user *)parent_tidptr,
aec5e0e1 PM	375	(int __user *)child_tidptr);
1da177e4 LT	376	}
	377
	378	/*
	379	* This is trivial, and on the face of it looks like it
	380	* could equally well be done in user mode.
	381	*
	382	* Not so, for quite unobvious reasons - register pressure.
	383	* In user mode vfork() cannot have a stack frame, and if
	384	* done by calling the "clone()" system call directly, you
	385	* do not have enough call-clobbered registers to hold all
	386	* the information you need.
	387	*/
	388	asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
	389	unsigned long r6, unsigned long r7,
f0bc814c	390	struct pt_regs __regs)
1da177e4	391	{
f0bc814c SM	392	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c SM	393	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->regs[15], regs,
1da177e4 LT	394	0, NULL, NULL);
	395	}
	396
	397	/*
	398	* sys_execve() executes a new program.
	399	*/
e08f457c PM	400	asmlinkage int sys_execve(char __user ufilename, char __user __user *uargv,
e08f457c PM	401	char __user * __user *uenvp, unsigned long r7,
f0bc814c	402	struct pt_regs __regs)
1da177e4	403	{
f0bc814c	404	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4 LT	405	int error;
	406	char *filename;
	407
e08f457c	408	filename = getname(ufilename);
1da177e4 LT	409	error = PTR_ERR(filename);
	410	if (IS_ERR(filename))
	411	goto out;
	412
e08f457c	413	error = do_execve(filename, uargv, uenvp, regs);
1da177e4 LT	414	if (error == 0) {
	415	task_lock(current);
	416	current->ptrace &= ~PT_DTRACE;
	417	task_unlock(current);
	418	}
	419	putname(filename);
	420	out:
	421	return error;
	422	}
	423
	424	unsigned long get_wchan(struct task_struct *p)
	425	{
1da177e4 LT	426	unsigned long pc;
	427
	428	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	429	return 0;
	430
	431	/*
	432	* The same comment as on the Alpha applies here, too ...
	433	*/
	434	pc = thread_saved_pc(p);
c64ac9f0 DM	435
c64ac9f0 DM	436	#ifdef CONFIG_FRAME_POINTER
1da177e4	437	if (in_sched_functions(pc)) {
c64ac9f0	438	unsigned long schedule_frame = (unsigned long)p->thread.sp;
b652c23c	439	return ((unsigned long *)schedule_frame)[21];
1da177e4	440	}
c64ac9f0	441	#endif
b652c23c	442
1da177e4 LT	443	return pc;
	444	}
	445
f0bc814c	446	asmlinkage void break_point_trap(void)
1da177e4 LT	447	{
1da177e4 LT	448	/* Clear tracing. */
8ae91b9a RS	449	#if defined(CONFIG_CPU_SH4A)
	450	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	451	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	452	#else
1da177e4 LT	453	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	454	ctrl_outw(0, UBC_BBRB);
8ae91b9a	455	#endif
1da177e4 LT	456	current->thread.ubc_pc = 0;
	457	ubc_usercnt -= 1;
	458
	459	force_sig(SIGTRAP, current);
	460	}