[deliverable/linux.git] / arch / m68k / kernel / process.c

/*
 *  linux/arch/m68k/kernel/process.c
 *
 *  Copyright (C) 1995  Hamish Macdonald
 *
 *  68060 fixes by Jesper Skov
 */

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

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/reboot.h>
#include <linux/init_task.h>
#include <linux/mqueue.h>

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/machdep.h>
#include <asm/setup.h>
#include <asm/pgtable.h>

/*
 * Initial task/thread structure. Make this a per-architecture thing,
 * because different architectures tend to have different
 * alignment requirements and potentially different initial
 * setup.
 */
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
struct mm_struct init_mm = INIT_MM(init_mm);

EXPORT_SYMBOL(init_mm);

union thread_union init_thread_union
__attribute__((section(".data.init_task"), aligned(THREAD_SIZE)))
       = { INIT_THREAD_INFO(init_task) };

/* initial task structure */
struct task_struct init_task = INIT_TASK(init_task);

EXPORT_SYMBOL(init_task);

asmlinkage void ret_from_fork(void);


/*
 * Return saved PC from a blocked thread
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
	struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
	/* Check whether the thread is blocked in resume() */
	if (in_sched_functions(sw->retpc))
		return ((unsigned long *)sw->a6)[1];
	else
		return sw->retpc;
}

/*
 * The idle loop on an m68k..
 */
static void default_idle(void)
{
	if (!need_resched())
#if defined(MACH_ATARI_ONLY)
		/* block out HSYNC on the atari (falcon) */
		__asm__("stop #0x2200" : : : "cc");
#else
		__asm__("stop #0x2000" : : : "cc");
#endif
}

void (*idle)(void) = default_idle;

/*
 * The idle thread. There's no useful work to be
 * done, so just try to conserve power and have a
 * low exit latency (ie sit in a loop waiting for
 * somebody to say that they'd like to reschedule)
 */
void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		while (!need_resched())
			idle();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

void machine_restart(char * __unused)
{
	if (mach_reset)
		mach_reset();
	for (;;);
}

void machine_halt(void)
{
	if (mach_halt)
		mach_halt();
	for (;;);
}

void machine_power_off(void)
{
	if (mach_power_off)
		mach_power_off();
	for (;;);
}

void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);

void show_regs(struct pt_regs * regs)
{
	printk("\n");
	printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
	printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
	       regs->orig_d0, regs->d0, regs->a2, regs->a1);
	printk("A0: %08lx  D5: %08lx  D4: %08lx\n",
	       regs->a0, regs->d5, regs->d4);
	printk("D3: %08lx  D2: %08lx  D1: %08lx\n",
	       regs->d3, regs->d2, regs->d1);
	if (!(regs->sr & PS_S))
		printk("USP: %08lx\n", rdusp());
}

/*
 * Create a kernel thread
 */
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
	int pid;
	mm_segment_t fs;

	fs = get_fs();
	set_fs (KERNEL_DS);

	{
	register long retval __asm__ ("d0");
	register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;

	retval = __NR_clone;
	__asm__ __volatile__
	  ("clrl %%d2\n\t"
	   "trap #0\n\t"		/* Linux/m68k system call */
	   "tstl %0\n\t"		/* child or parent */
	   "jne 1f\n\t"			/* parent - jump */
	   "lea %%sp@(%c7),%6\n\t"	/* reload current */
	   "movel %6@,%6\n\t"
	   "movel %3,%%sp@-\n\t"	/* push argument */
	   "jsr %4@\n\t"		/* call fn */
	   "movel %0,%%d1\n\t"		/* pass exit value */
	   "movel %2,%%d0\n\t"		/* exit */
	   "trap #0\n"
	   "1:"
	   : "+d" (retval)
	   : "i" (__NR_clone), "i" (__NR_exit),
	     "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
	     "i" (-THREAD_SIZE)
	   : "d2");

	pid = retval;
	}

	set_fs (fs);
	return pid;
}
EXPORT_SYMBOL(kernel_thread);

void flush_thread(void)
{
	unsigned long zero = 0;
	set_fs(USER_DS);
	current->thread.fs = __USER_DS;
	if (!FPU_IS_EMU)
		asm volatile (".chip 68k/68881\n\t"
			      "frestore %0@\n\t"
			      ".chip 68k" : : "a" (&zero));
}

/*
 * "m68k_fork()".. By the time we get here, the
 * non-volatile registers have also been saved on the
 * stack. We do some ugly pointer stuff here.. (see
 * also copy_thread)
 */

asmlinkage int m68k_fork(struct pt_regs *regs)
{
	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
}

asmlinkage int m68k_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
		       NULL, NULL);
}

asmlinkage int m68k_clone(struct pt_regs *regs)
{
	unsigned long clone_flags;
	unsigned long newsp;
	int __user *parent_tidptr, *child_tidptr;

	/* syscall2 puts clone_flags in d1 and usp in d2 */
	clone_flags = regs->d1;
	newsp = regs->d2;
	parent_tidptr = (int __user *)regs->d3;
	child_tidptr = (int __user *)regs->d4;
	if (!newsp)
		newsp = rdusp();
	return do_fork(clone_flags, newsp, regs, 0,
		       parent_tidptr, child_tidptr);
}

int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
		 unsigned long unused,
		 struct task_struct * p, struct pt_regs * regs)
{
	struct pt_regs * childregs;
	struct switch_stack * childstack, *stack;
	unsigned long *retp;

	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;

	*childregs = *regs;
	childregs->d0 = 0;

	retp = ((unsigned long *) regs);
	stack = ((struct switch_stack *) retp) - 1;

	childstack = ((struct switch_stack *) childregs) - 1;
	*childstack = *stack;
	childstack->retpc = (unsigned long)ret_from_fork;

	p->thread.usp = usp;
	p->thread.ksp = (unsigned long)childstack;
	/*
	 * Must save the current SFC/DFC value, NOT the value when
	 * the parent was last descheduled - RGH  10-08-96
	 */
	p->thread.fs = get_fs().seg;

	if (!FPU_IS_EMU) {
		/* Copy the current fpu state */
		asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");

		if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2])
		  asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
				"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
				: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
				: "memory");
		/* Restore the state in case the fpu was busy */
		asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
	}

	return 0;
}

/* Fill in the fpu structure for a core dump.  */

int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
{
	char fpustate[216];

	if (FPU_IS_EMU) {
		int i;

		memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
		memcpy(fpu->fpregs, current->thread.fp, 96);
		/* Convert internal fpu reg representation
		 * into long double format
		 */
		for (i = 0; i < 24; i += 3)
			fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
			                 ((fpu->fpregs[i] & 0x0000ffff) << 16);
		return 1;
	}

	/* First dump the fpu context to avoid protocol violation.  */
	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
	if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
		return 0;

	asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
		:: "m" (fpu->fpcntl[0])
		: "memory");
	asm volatile ("fmovemx %/fp0-%/fp7,%0"
		:: "m" (fpu->fpregs[0])
		: "memory");
	return 1;
}
EXPORT_SYMBOL(dump_fpu);

/*
 * sys_execve() executes a new program.
 */
asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
{
	int error;
	char * filename;
	struct pt_regs *regs = (struct pt_regs *) &name;

	lock_kernel();
	filename = getname(name);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
out:
	unlock_kernel();
	return error;
}

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long fp, pc;
	unsigned long stack_page;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	stack_page = (unsigned long)task_stack_page(p);
	fp = ((struct switch_stack *)p->thread.ksp)->a6;
	do {
		if (fp < stack_page+sizeof(struct thread_info) ||
		    fp >= 8184+stack_page)
			return 0;
		pc = ((unsigned long *)fp)[1];
		if (!in_sched_functions(pc))
			return pc;
		fp = *(unsigned long *) fp;
	} while (count++ < 16);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/m68k/kernel/process.c
	3	*
	4	* Copyright (C) 1995 Hamish Macdonald
	5	*
	6	* 68060 fixes by Jesper Skov
	7	*/
	8
	9	/*
	10	* This file handles the architecture-dependent parts of process handling..
	11	*/
	12
1da177e4 LT	13	#include <linux/errno.h>
	14	#include <linux/module.h>
	15	#include <linux/sched.h>
	16	#include <linux/kernel.h>
	17	#include <linux/mm.h>
4e950f6f	18	#include <linux/fs.h>
1da177e4 LT	19	#include <linux/smp.h>
	20	#include <linux/smp_lock.h>
	21	#include <linux/stddef.h>
	22	#include <linux/unistd.h>
	23	#include <linux/ptrace.h>
	24	#include <linux/slab.h>
	25	#include <linux/user.h>
1da177e4 LT	26	#include <linux/reboot.h>
	27	#include <linux/init_task.h>
	28	#include <linux/mqueue.h>
	29
	30	#include <asm/uaccess.h>
	31	#include <asm/system.h>
	32	#include <asm/traps.h>
	33	#include <asm/machdep.h>
	34	#include <asm/setup.h>
	35	#include <asm/pgtable.h>
	36
	37	/*
	38	* Initial task/thread structure. Make this a per-architecture thing,
	39	* because different architectures tend to have different
	40	* alignment requirements and potentially different initial
	41	* setup.
	42	*/
1da177e4 LT	43	static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
	44	static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
	45	struct mm_struct init_mm = INIT_MM(init_mm);
	46
	47	EXPORT_SYMBOL(init_mm);
	48
	49	union thread_union init_thread_union
	50	__attribute__((section(".data.init_task"), aligned(THREAD_SIZE)))
	51	= { INIT_THREAD_INFO(init_task) };
	52
	53	/* initial task structure */
	54	struct task_struct init_task = INIT_TASK(init_task);
	55
	56	EXPORT_SYMBOL(init_task);
	57
	58	asmlinkage void ret_from_fork(void);
	59
	60
	61	/*
	62	* Return saved PC from a blocked thread
	63	*/
	64	unsigned long thread_saved_pc(struct task_struct *tsk)
	65	{
	66	struct switch_stack sw = (struct switch_stack )tsk->thread.ksp;
	67	/* Check whether the thread is blocked in resume() */
	68	if (in_sched_functions(sw->retpc))
	69	return ((unsigned long *)sw->a6)[1];
	70	else
	71	return sw->retpc;
	72	}
	73
	74	/*
	75	* The idle loop on an m68k..
	76	*/
cdb04527	77	static void default_idle(void)
1da177e4 LT	78	{
1da177e4 LT	79	if (!need_resched())
29c8a246	80	#if defined(MACH_ATARI_ONLY)
1da177e4 LT	81	/* block out HSYNC on the atari (falcon) */
	82	__asm__("stop #0x2200" : : : "cc");
	83	#else
	84	__asm__("stop #0x2000" : : : "cc");
	85	#endif
	86	}
	87
	88	void (*idle)(void) = default_idle;
	89
	90	/*
	91	* The idle thread. There's no useful work to be
	92	* done, so just try to conserve power and have a
	93	* low exit latency (ie sit in a loop waiting for
	94	* somebody to say that they'd like to reschedule)
	95	*/
	96	void cpu_idle(void)
	97	{
	98	/* endless idle loop with no priority at all */
	99	while (1) {
	100	while (!need_resched())
	101	idle();
5bfb5d69	102	preempt_enable_no_resched();
1da177e4	103	schedule();
5bfb5d69	104	preempt_disable();
1da177e4 LT	105	}
	106	}
	107
	108	void machine_restart(char * __unused)
	109	{
	110	if (mach_reset)
	111	mach_reset();
	112	for (;;);
	113	}
	114
1da177e4 LT	115	void machine_halt(void)
	116	{
	117	if (mach_halt)
	118	mach_halt();
	119	for (;;);
	120	}
	121
1da177e4 LT	122	void machine_power_off(void)
	123	{
	124	if (mach_power_off)
	125	mach_power_off();
	126	for (;;);
	127	}
	128
cead14da AV	129	void (*pm_power_off)(void) = machine_power_off;
	130	EXPORT_SYMBOL(pm_power_off);
	131
1da177e4 LT	132	void show_regs(struct pt_regs * regs)
	133	{
	134	printk("\n");
	135	printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
	136	regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
	137	printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
	138	regs->orig_d0, regs->d0, regs->a2, regs->a1);
	139	printk("A0: %08lx D5: %08lx D4: %08lx\n",
	140	regs->a0, regs->d5, regs->d4);
	141	printk("D3: %08lx D2: %08lx D1: %08lx\n",
	142	regs->d3, regs->d2, regs->d1);
	143	if (!(regs->sr & PS_S))
	144	printk("USP: %08lx\n", rdusp());
	145	}
	146
	147	/*
	148	* Create a kernel thread
	149	*/
	150	int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
	151	{
	152	int pid;
	153	mm_segment_t fs;
	154
	155	fs = get_fs();
	156	set_fs (KERNEL_DS);
	157
	158	{
	159	register long retval __asm__ ("d0");
	160	register long clone_arg __asm__ ("d1") = flags \| CLONE_VM \| CLONE_UNTRACED;
	161
	162	retval = __NR_clone;
	163	__asm__ __volatile__
	164	("clrl %%d2\n\t"
	165	"trap #0\n\t" /* Linux/m68k system call */
	166	"tstl %0\n\t" /* child or parent */
	167	"jne 1f\n\t" /* parent - jump */
	168	"lea %%sp@(%c7),%6\n\t" /* reload current */
	169	"movel %6@,%6\n\t"
	170	"movel %3,%%sp@-\n\t" /* push argument */
	171	"jsr %4@\n\t" /* call fn */
	172	"movel %0,%%d1\n\t" /* pass exit value */
	173	"movel %2,%%d0\n\t" /* exit */
	174	"trap #0\n"
	175	"1:"
	176	: "+d" (retval)
	177	: "i" (__NR_clone), "i" (__NR_exit),
	178	"r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
	179	"i" (-THREAD_SIZE)
	180	: "d2");
	181
	182	pid = retval;
	183	}
	184
	185	set_fs (fs);
	186	return pid;
	187	}
2e811488	188	EXPORT_SYMBOL(kernel_thread);
1da177e4 LT	189
	190	void flush_thread(void)
	191	{
	192	unsigned long zero = 0;
	193	set_fs(USER_DS);
	194	current->thread.fs = __USER_DS;
	195	if (!FPU_IS_EMU)
	196	asm volatile (".chip 68k/68881\n\t"
	197	"frestore %0@\n\t"
	198	".chip 68k" : : "a" (&zero));
	199	}
	200
	201	/*
	202	* "m68k_fork()".. By the time we get here, the
	203	* non-volatile registers have also been saved on the
	204	* stack. We do some ugly pointer stuff here.. (see
	205	* also copy_thread)
	206	*/
	207
	208	asmlinkage int m68k_fork(struct pt_regs *regs)
	209	{
	210	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
	211	}
	212
	213	asmlinkage int m68k_vfork(struct pt_regs *regs)
	214	{
	215	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), regs, 0,
	216	NULL, NULL);
	217	}
	218
	219	asmlinkage int m68k_clone(struct pt_regs *regs)
	220	{
	221	unsigned long clone_flags;
	222	unsigned long newsp;
1e5c374d	223	int __user parent_tidptr, child_tidptr;
1da177e4 LT	224
	225	/* syscall2 puts clone_flags in d1 and usp in d2 */
	226	clone_flags = regs->d1;
	227	newsp = regs->d2;
1e5c374d AV	228	parent_tidptr = (int __user *)regs->d3;
1e5c374d AV	229	child_tidptr = (int __user *)regs->d4;
1da177e4 LT	230	if (!newsp)
	231	newsp = rdusp();
	232	return do_fork(clone_flags, newsp, regs, 0,
	233	parent_tidptr, child_tidptr);
	234	}
	235
	236	int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
	237	unsigned long unused,
	238	struct task_struct * p, struct pt_regs * regs)
	239	{
	240	struct pt_regs * childregs;
	241	struct switch_stack * childstack, *stack;
768595ff	242	unsigned long *retp;
1da177e4	243
768595ff	244	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
1da177e4 LT	245
	246	childregs = regs;
	247	childregs->d0 = 0;
	248
	249	retp = ((unsigned long *) regs);
	250	stack = ((struct switch_stack *) retp) - 1;
	251
	252	childstack = ((struct switch_stack *) childregs) - 1;
	253	childstack = stack;
	254	childstack->retpc = (unsigned long)ret_from_fork;
	255
	256	p->thread.usp = usp;
	257	p->thread.ksp = (unsigned long)childstack;
	258	/*
	259	* Must save the current SFC/DFC value, NOT the value when
	260	* the parent was last descheduled - RGH 10-08-96
	261	*/
	262	p->thread.fs = get_fs().seg;
	263
	264	if (!FPU_IS_EMU) {
	265	/* Copy the current fpu state */
	266	asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
	267
	268	if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2])
	269	asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
	270	"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
	271	: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
	272	: "memory");
	273	/* Restore the state in case the fpu was busy */
	274	asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
	275	}
	276
	277	return 0;
	278	}
	279
	280	/* Fill in the fpu structure for a core dump. */
	281
	282	int dump_fpu (struct pt_regs regs, struct user_m68kfp_struct fpu)
	283	{
	284	char fpustate[216];
	285
	286	if (FPU_IS_EMU) {
	287	int i;
	288
	289	memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
	290	memcpy(fpu->fpregs, current->thread.fp, 96);
	291	/* Convert internal fpu reg representation
	292	* into long double format
	293	*/
	294	for (i = 0; i < 24; i += 3)
	295	fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) \|
	296	((fpu->fpregs[i] & 0x0000ffff) << 16);
	297	return 1;
	298	}
	299
	300	/* First dump the fpu context to avoid protocol violation. */
	301	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
	302	if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
	303	return 0;
	304
	305	asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
	306	:: "m" (fpu->fpcntl[0])
	307	: "memory");
	308	asm volatile ("fmovemx %/fp0-%/fp7,%0"
309	:: "m" (fpu->fpregs[0])
310	: "memory");
311	return 1;
312	}
2e811488	313	EXPORT_SYMBOL(dump_fpu);
1da177e4	314
1da177e4 LT	315	/*
	316	* sys_execve() executes a new program.
	317	*/
1e5c374d	318	asmlinkage int sys_execve(char __user name, char __user __user argv, char __user __user *envp)
1da177e4 LT	319	{
	320	int error;
	321	char * filename;
	322	struct pt_regs regs = (struct pt_regs ) &name;
	323
	324	lock_kernel();
	325	filename = getname(name);
	326	error = PTR_ERR(filename);
	327	if (IS_ERR(filename))
	328	goto out;
	329	error = do_execve(filename, argv, envp, regs);
	330	putname(filename);
	331	out:
	332	unlock_kernel();
	333	return error;
	334	}
	335
	336	unsigned long get_wchan(struct task_struct *p)
	337	{
	338	unsigned long fp, pc;
	339	unsigned long stack_page;
	340	int count = 0;
	341	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	342	return 0;
	343
768595ff	344	stack_page = (unsigned long)task_stack_page(p);
1da177e4 LT	345	fp = ((struct switch_stack *)p->thread.ksp)->a6;
	346	do {
	347	if (fp < stack_page+sizeof(struct thread_info) \|\|
	348	fp >= 8184+stack_page)
	349	return 0;
	350	pc = ((unsigned long *)fp)[1];
	351	if (!in_sched_functions(pc))
	352	return pc;
	353	fp = (unsigned long ) fp;
	354	} while (count++ < 16);
	355	return 0;
	356	}