[net-next-2.6.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 - 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 <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", 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)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
	/* 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 ||
	    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_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 __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 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 -= instruction_size(ctrl_inw(regs->pc - 4));

	if (notify_die(DIE_TRAP, "debug trap", regs, 0, regs->tra & 0xff,
		       SIGTRAP) == NOTIFY_STOP)
		return;

	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 -= instruction_size(ctrl_inw(regs->pc - 4));

	if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
		       SIGTRAP) == NOTIFY_STOP)
		return;

#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
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>
1da177e4 LT	21	#include <asm/uaccess.h>
1da177e4 LT	22	#include <asm/mmu_context.h>
5f8c9908	23	#include <asm/pgalloc.h>
bd079997	24	#include <asm/system.h>
b5233d07	25	#include <asm/ubc.h>
1da177e4	26
aec5e0e1	27	static int hlt_counter;
1da177e4 LT	28	int ubc_usercnt = 0;
1da177e4 LT	29
a3310bbd	30	void (*pm_idle)(void);
a3310bbd PM	31	void (*pm_power_off)(void);
	32	EXPORT_SYMBOL(pm_power_off);
	33
1da177e4 LT	34	void disable_hlt(void)
	35	{
	36	hlt_counter++;
	37	}
1da177e4 LT	38	EXPORT_SYMBOL(disable_hlt);
	39
	40	void enable_hlt(void)
	41	{
	42	hlt_counter--;
	43	}
1da177e4 LT	44	EXPORT_SYMBOL(enable_hlt);
1da177e4 LT	45
f3a9022f PM	46	static int __init nohlt_setup(char *__unused)
	47	{
	48	hlt_counter = 1;
	49	return 1;
	50	}
	51	__setup("nohlt", nohlt_setup);
	52
	53	static int __init hlt_setup(char *__unused)
	54	{
	55	hlt_counter = 0;
	56	return 1;
	57	}
	58	__setup("hlt", hlt_setup);
	59
a3310bbd PM	60	void default_idle(void)
a3310bbd PM	61	{
f3a9022f PM	62	if (!hlt_counter) {
	63	clear_thread_flag(TIF_POLLING_NRFLAG);
	64	smp_mb__after_clear_bit();
	65	set_bl_bit();
	66	while (!need_resched())
	67	cpu_sleep();
	68	clear_bl_bit();
	69	set_thread_flag(TIF_POLLING_NRFLAG);
	70	} else
	71	while (!need_resched())
	72	cpu_relax();
a3310bbd PM	73	}
a3310bbd PM	74
64c7c8f8	75	void cpu_idle(void)
1da177e4	76	{
f3a9022f PM	77	set_thread_flag(TIF_POLLING_NRFLAG);
f3a9022f PM	78
1da177e4 LT	79	/* endless idle loop with no priority at all */
1da177e4 LT	80	while (1) {
a3310bbd PM	81	void (*idle)(void) = pm_idle;
	82
	83	if (!idle)
	84	idle = default_idle;
	85
57be2b48	86	tick_nohz_stop_sched_tick();
a3310bbd PM	87	while (!need_resched())
a3310bbd PM	88	idle();
57be2b48	89	tick_nohz_restart_sched_tick();
1da177e4	90
5bfb5d69	91	preempt_enable_no_resched();
1da177e4	92	schedule();
5bfb5d69	93	preempt_disable();
5f8c9908	94	check_pgt_cache();
1da177e4 LT	95	}
	96	}
	97
1da177e4 LT	98	void machine_restart(char * __unused)
	99	{
	100	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
	101	asm volatile("ldc %0, sr\n\t"
	102	"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
	103	}
	104
1da177e4 LT	105	void machine_halt(void)
1da177e4 LT	106	{
a3310bbd	107	local_irq_disable();
1da177e4	108
1da177e4 LT	109	while (1)
	110	cpu_sleep();
	111	}
	112
1da177e4 LT	113	void machine_power_off(void)
1da177e4 LT	114	{
a3310bbd PM	115	if (pm_power_off)
a3310bbd PM	116	pm_power_off();
1da177e4 LT	117	}
1da177e4 LT	118
1da177e4 LT	119	void show_regs(struct pt_regs * regs)
	120	{
	121	printk("\n");
	122	printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
6b002230	123	print_symbol("PC is at %s\n", instruction_pointer(regs));
1da177e4 LT	124	printk("PC : %08lx SP : %08lx SR : %08lx ",
	125	regs->pc, regs->regs[15], regs->sr);
	126	#ifdef CONFIG_MMU
	127	printk("TEA : %08x ", ctrl_inl(MMU_TEA));
	128	#else
	129	printk(" ");
	130	#endif
	131	printk("%s\n", print_tainted());
	132
	133	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
	134	regs->regs[0],regs->regs[1],
	135	regs->regs[2],regs->regs[3]);
	136	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
	137	regs->regs[4],regs->regs[5],
	138	regs->regs[6],regs->regs[7]);
	139	printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
	140	regs->regs[8],regs->regs[9],
	141	regs->regs[10],regs->regs[11]);
	142	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	143	regs->regs[12],regs->regs[13],
	144	regs->regs[14]);
	145	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
	146	regs->mach, regs->macl, regs->gbr, regs->pr);
	147
6b002230	148	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
1da177e4 LT	149	}
	150
	151	/*
	152	* Create a kernel thread
	153	*/
	154
	155	/*
	156	* This is the mechanism for creating a new kernel thread.
	157	*
	158	*/
	159	extern void kernel_thread_helper(void);
	160	__asm__(".align 5\n"
	161	"kernel_thread_helper:\n\t"
	162	"jsr @r5\n\t"
	163	" nop\n\t"
	164	"mov.l 1f, r1\n\t"
	165	"jsr @r1\n\t"
	166	" mov r0, r4\n\t"
	167	".align 2\n\t"
	168	"1:.long do_exit");
	169
aec5e0e1	170	/* Don't use this in BL=1(cli). Or else, CPU resets! */
1da177e4	171	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
aec5e0e1	172	{
1da177e4 LT	173	struct pt_regs regs;
	174
	175	memset(&regs, 0, sizeof(regs));
aec5e0e1 PM	176	regs.regs[4] = (unsigned long)arg;
aec5e0e1 PM	177	regs.regs[5] = (unsigned long)fn;
1da177e4	178
aec5e0e1	179	regs.pc = (unsigned long)kernel_thread_helper;
1da177e4 LT	180	regs.sr = (1 << 30);
	181
	182	/* Ok, create the new process.. */
aec5e0e1 PM	183	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0,
aec5e0e1 PM	184	&regs, 0, NULL, NULL);
1da177e4 LT	185	}
	186
	187	/*
	188	* Free current thread data structures etc..
	189	*/
	190	void exit_thread(void)
	191	{
	192	if (current->thread.ubc_pc) {
	193	current->thread.ubc_pc = 0;
	194	ubc_usercnt -= 1;
	195	}
	196	}
	197
	198	void flush_thread(void)
	199	{
	200	#if defined(CONFIG_SH_FPU)
	201	struct task_struct *tsk = current;
1da177e4	202	/* Forget lazy FPU state */
3cf0f4ec	203	clear_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	204	clear_used_math();
	205	#endif
	206	}
	207
	208	void release_thread(struct task_struct *dead_task)
	209	{
	210	/* do nothing */
	211	}
	212
	213	/* Fill in the fpu structure for a core dump.. */
	214	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	215	{
	216	int fpvalid = 0;
	217
	218	#if defined(CONFIG_SH_FPU)
	219	struct task_struct *tsk = current;
	220
	221	fpvalid = !!tsk_used_math(tsk);
	222	if (fpvalid) {
	223	unlazy_fpu(tsk, regs);
	224	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	225	}
	226	#endif
	227
	228	return fpvalid;
	229	}
	230
aec5e0e1	231	/*
1da177e4 LT	232	* Capture the user space registers if the task is not running (in user space)
	233	*/
	234	int dump_task_regs(struct task_struct tsk, elf_gregset_t regs)
	235	{
	236	struct pt_regs ptregs;
aec5e0e1	237
3cf0f4ec	238	ptregs = *task_pt_regs(tsk);
1da177e4 LT	239	elf_core_copy_regs(regs, &ptregs);
	240
	241	return 1;
	242	}
	243
aec5e0e1	244	int dump_task_fpu(struct task_struct tsk, elf_fpregset_t fpu)
1da177e4 LT	245	{
	246	int fpvalid = 0;
	247
	248	#if defined(CONFIG_SH_FPU)
	249	fpvalid = !!tsk_used_math(tsk);
	250	if (fpvalid) {
3cf0f4ec	251	unlazy_fpu(tsk, task_pt_regs(tsk));
1da177e4 LT	252	memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
	253	}
	254	#endif
	255
	256	return fpvalid;
	257	}
	258
	259	asmlinkage void ret_from_fork(void);
	260
	261	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	262	unsigned long unused,
	263	struct task_struct p, struct pt_regs regs)
	264	{
2991be72	265	struct thread_info *ti = task_thread_info(p);
1da177e4 LT	266	struct pt_regs *childregs;
	267	#if defined(CONFIG_SH_FPU)
	268	struct task_struct *tsk = current;
	269
	270	unlazy_fpu(tsk, regs);
	271	p->thread.fpu = tsk->thread.fpu;
	272	copy_to_stopped_child_used_math(p);
	273	#endif
	274
3cf0f4ec	275	childregs = task_pt_regs(p);
1da177e4 LT	276	childregs = regs;
	277
	278	if (user_mode(regs)) {
	279	childregs->regs[15] = usp;
2991be72	280	ti->addr_limit = USER_DS;
1da177e4	281	} else {
e6bcf562	282	childregs->regs[15] = (unsigned long)childregs;
2991be72	283	ti->addr_limit = KERNEL_DS;
1da177e4	284	}
aec5e0e1	285
e6bcf562	286	if (clone_flags & CLONE_SETTLS)
1da177e4	287	childregs->gbr = childregs->regs[0];
aec5e0e1	288
1da177e4 LT	289	childregs->regs[0] = 0; /* Set return value for child */
	290
	291	p->thread.sp = (unsigned long) childregs;
	292	p->thread.pc = (unsigned long) ret_from_fork;
	293
	294	p->thread.ubc_pc = 0;
	295
	296	return 0;
	297	}
	298
1da177e4	299	/* Tracing by user break controller. */
aec5e0e1	300	static void ubc_set_tracing(int asid, unsigned long pc)
1da177e4	301	{
8ae91b9a RS	302	#if defined(CONFIG_CPU_SH4A)
	303	unsigned long val;
	304
	305	val = (UBC_CBR_ID_INST \| UBC_CBR_RW_READ \| UBC_CBR_CE);
	306	val \|= (UBC_CBR_AIE \| UBC_CBR_AIV_SET(asid));
	307
	308	ctrl_outl(val, UBC_CBR0);
	309	ctrl_outl(pc, UBC_CAR0);
	310	ctrl_outl(0x0, UBC_CAMR0);
	311	ctrl_outl(0x0, UBC_CBCR);
	312
	313	val = (UBC_CRR_RES \| UBC_CRR_PCB \| UBC_CRR_BIE);
	314	ctrl_outl(val, UBC_CRR0);
	315
aec5e0e1	316	/* Read UBC register that we wrote last, for checking update */
8ae91b9a RS	317	val = ctrl_inl(UBC_CRR0);
	318
	319	#else /* CONFIG_CPU_SH4A */
1da177e4 LT	320	ctrl_outl(pc, UBC_BARA);
1da177e4 LT	321
a2d1a5fa	322	#ifdef CONFIG_MMU
1da177e4	323	/* We don't have any ASID settings for the SH-2! */
11c19656	324	if (current_cpu_data.type != CPU_SH7604)
1da177e4	325	ctrl_outb(asid, UBC_BASRA);
a2d1a5fa	326	#endif
1da177e4 LT	327
	328	ctrl_outl(0, UBC_BAMRA);
	329
11c19656	330	if (current_cpu_data.type == CPU_SH7729 \|\|
3a2e117e PM	331	current_cpu_data.type == CPU_SH7710 \|\|
3a2e117e PM	332	current_cpu_data.type == CPU_SH7712) {
1da177e4 LT	333	ctrl_outw(BBR_INST \| BBR_READ \| BBR_CPU, UBC_BBRA);
	334	ctrl_outl(BRCR_PCBA \| BRCR_PCTE, UBC_BRCR);
	335	} else {
	336	ctrl_outw(BBR_INST \| BBR_READ, UBC_BBRA);
	337	ctrl_outw(BRCR_PCBA, UBC_BRCR);
	338	}
8ae91b9a	339	#endif /* CONFIG_CPU_SH4A */
1da177e4 LT	340	}
	341
	342	/*
	343	* switch_to(x,y) should switch tasks from x to y.
	344	*
	345	*/
aec5e0e1 PM	346	struct task_struct __switch_to(struct task_struct prev,
aec5e0e1 PM	347	struct task_struct *next)
1da177e4 LT	348	{
1da177e4 LT	349	#if defined(CONFIG_SH_FPU)
3cf0f4ec	350	unlazy_fpu(prev, task_pt_regs(prev));
1da177e4 LT	351	#endif
	352
	353	#ifdef CONFIG_PREEMPT
	354	{
	355	unsigned long flags;
	356	struct pt_regs *regs;
	357
	358	local_irq_save(flags);
3cf0f4ec	359	regs = task_pt_regs(prev);
1da177e4 LT	360	if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
	361	int offset = (int)regs->regs[15];
	362
	363	/* Reset stack pointer: clear critical region mark */
	364	regs->regs[15] = regs->regs[1];
	365	if (regs->pc < regs->regs[0])
	366	/* Go to rewind point */
	367	regs->pc = regs->regs[0] + offset;
	368	}
	369	local_irq_restore(flags);
	370	}
	371	#endif
	372
a2d1a5fa	373	#ifdef CONFIG_MMU
1da177e4 LT	374	/*
1da177e4 LT	375	* Restore the kernel mode register
aec5e0e1	376	* k7 (r7_bank1)
1da177e4 LT	377	*/
	378	asm volatile("ldc %0, r7_bank"
	379	: /* no output */
cafcfcaa	380	: "r" (task_thread_info(next)));
a2d1a5fa	381	#endif
1da177e4	382
1da177e4 LT	383	/* If no tasks are using the UBC, we're done */
	384	if (ubc_usercnt == 0)
	385	/* If no tasks are using the UBC, we're done */;
	386	else if (next->thread.ubc_pc && next->mm) {
a2d1a5fa YS	387	int asid = 0;
a2d1a5fa YS	388	#ifdef CONFIG_MMU
aec5e0e1	389	asid \|= cpu_asid(smp_processor_id(), next->mm);
a2d1a5fa YS	390	#endif
a2d1a5fa YS	391	ubc_set_tracing(asid, next->thread.ubc_pc);
1da177e4	392	} else {
8ae91b9a RS	393	#if defined(CONFIG_CPU_SH4A)
	394	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	395	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	396	#else
1da177e4 LT	397	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	398	ctrl_outw(0, UBC_BBRB);
8ae91b9a	399	#endif
1da177e4	400	}
1da177e4 LT	401
	402	return prev;
	403	}
	404
	405	asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
	406	unsigned long r6, unsigned long r7,
f0bc814c	407	struct pt_regs __regs)
1da177e4	408	{
f0bc814c	409	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4	410	#ifdef CONFIG_MMU
f0bc814c	411	return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
1da177e4 LT	412	#else
	413	/* fork almost works, enough to trick you into looking elsewhere :-( */
	414	return -EINVAL;
	415	#endif
	416	}
	417
	418	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
	419	unsigned long parent_tidptr,
	420	unsigned long child_tidptr,
f0bc814c	421	struct pt_regs __regs)
1da177e4	422	{
f0bc814c	423	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4	424	if (!newsp)
f0bc814c SM	425	newsp = regs->regs[15];
f0bc814c SM	426	return do_fork(clone_flags, newsp, regs, 0,
aec5e0e1 PM	427	(int __user *)parent_tidptr,
aec5e0e1 PM	428	(int __user *)child_tidptr);
1da177e4 LT	429	}
	430
	431	/*
	432	* This is trivial, and on the face of it looks like it
	433	* could equally well be done in user mode.
	434	*
	435	* Not so, for quite unobvious reasons - register pressure.
	436	* In user mode vfork() cannot have a stack frame, and if
	437	* done by calling the "clone()" system call directly, you
	438	* do not have enough call-clobbered registers to hold all
	439	* the information you need.
	440	*/
	441	asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
	442	unsigned long r6, unsigned long r7,
f0bc814c	443	struct pt_regs __regs)
1da177e4	444	{
f0bc814c SM	445	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c SM	446	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->regs[15], regs,
1da177e4 LT	447	0, NULL, NULL);
	448	}
	449
	450	/*
	451	* sys_execve() executes a new program.
	452	*/
e08f457c PM	453	asmlinkage int sys_execve(char __user ufilename, char __user __user *uargv,
e08f457c PM	454	char __user * __user *uenvp, unsigned long r7,
f0bc814c	455	struct pt_regs __regs)
1da177e4	456	{
f0bc814c	457	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
1da177e4 LT	458	int error;
	459	char *filename;
	460
e08f457c	461	filename = getname(ufilename);
1da177e4 LT	462	error = PTR_ERR(filename);
	463	if (IS_ERR(filename))
	464	goto out;
	465
e08f457c	466	error = do_execve(filename, uargv, uenvp, regs);
1da177e4 LT	467	if (error == 0) {
	468	task_lock(current);
	469	current->ptrace &= ~PT_DTRACE;
	470	task_unlock(current);
	471	}
	472	putname(filename);
	473	out:
	474	return error;
	475	}
	476
	477	unsigned long get_wchan(struct task_struct *p)
	478	{
	479	unsigned long schedule_frame;
	480	unsigned long pc;
	481
	482	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	483	return 0;
	484
	485	/*
	486	* The same comment as on the Alpha applies here, too ...
	487	*/
	488	pc = thread_saved_pc(p);
	489	if (in_sched_functions(pc)) {
b652c23c PM	490	schedule_frame = (unsigned long)p->thread.sp;
b652c23c PM	491	return ((unsigned long *)schedule_frame)[21];
1da177e4	492	}
b652c23c	493
1da177e4 LT	494	return pc;
	495	}
	496
f0bc814c	497	asmlinkage void break_point_trap(void)
1da177e4 LT	498	{
1da177e4 LT	499	/* Clear tracing. */
8ae91b9a RS	500	#if defined(CONFIG_CPU_SH4A)
	501	ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
	502	ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
	503	#else
1da177e4 LT	504	ctrl_outw(0, UBC_BBRA);
1da177e4 LT	505	ctrl_outw(0, UBC_BBRB);
8ae91b9a	506	#endif
1da177e4 LT	507	current->thread.ubc_pc = 0;
	508	ubc_usercnt -= 1;
	509
	510	force_sig(SIGTRAP, current);
	511	}
	512
f413d0d9 PM	513	/*
	514	* Generic trap handler.
	515	*/
	516	asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5,
	517	unsigned long r6, unsigned long r7,
	518	struct pt_regs __regs)
	519	{
	520	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	521
	522	/* Rewind */
53f983a9	523	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
f413d0d9	524
b118ca57	525	if (notify_die(DIE_TRAP, "debug trap", regs, 0, regs->tra & 0xff,
3a2e117e PM	526	SIGTRAP) == NOTIFY_STOP)
	527	return;
	528
f413d0d9 PM	529	force_sig(SIGTRAP, current);
	530	}
	531
	532	/*
	533	* Special handler for BUG() traps.
	534	*/
	535	asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5,
	536	unsigned long r6, unsigned long r7,
	537	struct pt_regs __regs)
1da177e4	538	{
f0bc814c SM	539	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
f0bc814c SM	540
dc34d312	541	/* Rewind */
53f983a9	542	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
dc34d312	543
b118ca57	544	if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
3a2e117e PM	545	SIGTRAP) == NOTIFY_STOP)
	546	return;
	547
dc34d312 PM	548	#ifdef CONFIG_BUG
	549	if (__kernel_text_address(instruction_pointer(regs))) {
	550	u16 insn = (u16 )instruction_pointer(regs);
	551	if (insn == TRAPA_BUG_OPCODE)
	552	handle_BUG(regs);
	553	}
	554	#endif
	555
1da177e4 LT	556	force_sig(SIGTRAP, current);
1da177e4 LT	557	}