[net-next-2.6.git] / arch / parisc / kernel / process.c

/*
 *    PARISC Architecture-dependent parts of process handling
 *    based on the work for i386
 *
 *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
 *    Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
 *    Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
 *    Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
 *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
 *    Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
 *    Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
 *    Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
 *    Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
 *    Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
 *    Copyright (C) 2001-2007 Helge Deller <deller at parisc-linux.org>
 *    Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdarg.h>

#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>

#include <asm/io.h>
#include <asm/asm-offsets.h>
#include <asm/pdc.h>
#include <asm/pdc_chassis.h>
#include <asm/pgalloc.h>
#include <asm/unwind.h>
#include <asm/sections.h>

/*
 * 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)
{
	set_thread_flag(TIF_POLLING_NRFLAG);

	/* endless idle loop with no priority at all */
	while (1) {
		while (!need_resched())
			barrier();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
		check_pgt_cache();
	}
}


#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
#define CMD_RESET       5       /* reset any module */

/*
** The Wright Brothers and Gecko systems have a H/W problem
** (Lasi...'nuf said) may cause a broadcast reset to lockup
** the system. An HVERSION dependent PDC call was developed
** to perform a "safe", platform specific broadcast reset instead
** of kludging up all the code.
**
** Older machines which do not implement PDC_BROADCAST_RESET will
** return (with an error) and the regular broadcast reset can be
** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
** the PDC call will not return (the system will be reset).
*/
void machine_restart(char *cmd)
{
#ifdef FASTBOOT_SELFTEST_SUPPORT
	/*
	 ** If user has modified the Firmware Selftest Bitmap,
	 ** run the tests specified in the bitmap after the
	 ** system is rebooted w/PDC_DO_RESET.
	 **
	 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	 **
	 ** Using "directed resets" at each processor with the MEM_TOC
	 ** vector cleared will also avoid running destructive
	 ** memory self tests. (Not implemented yet)
	 */
	if (ftc_bitmap) {
		pdc_do_firm_test_reset(ftc_bitmap);
	}
#endif
	/* set up a new led state on systems shipped with a LED State panel */
	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	
	/* "Normal" system reset */
	pdc_do_reset();

	/* Nope...box should reset with just CMD_RESET now */
	gsc_writel(CMD_RESET, COMMAND_GLOBAL);

	/* Wait for RESET to lay us to rest. */
	while (1) ;

}

void machine_halt(void)
{
	/*
	** The LED/ChassisCodes are updated by the led_halt()
	** function, called by the reboot notifier chain.
	*/
}

void (*chassis_power_off)(void);

/*
 * This routine is called from sys_reboot to actually turn off the
 * machine 
 */
void machine_power_off(void)
{
	/* If there is a registered power off handler, call it. */
	if (chassis_power_off)
		chassis_power_off();

	/* Put the soft power button back under hardware control.
	 * If the user had already pressed the power button, the
	 * following call will immediately power off. */
	pdc_soft_power_button(0);
	
	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
		
	/* It seems we have no way to power the system off via
	 * software. The user has to press the button himself. */

	printk(KERN_EMERG "System shut down completed.\n"
	       "Please power this system off now.");
}

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

/*
 * Create a kernel thread
 */

extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{

	/*
	 * FIXME: Once we are sure we don't need any debug here,
	 *	  kernel_thread can become a #define.
	 */

	return __kernel_thread(fn, arg, flags);
}
EXPORT_SYMBOL(kernel_thread);

/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
}

void flush_thread(void)
{
	/* Only needs to handle fpu stuff or perf monitors.
	** REVISIT: several arches implement a "lazy fpu state".
	*/
	set_fs(USER_DS);
}

void release_thread(struct task_struct *dead_task)
{
}

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

int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
{
	if (regs == NULL)
		return 0;

	memcpy(r, regs->fr, sizeof *r);
	return 1;
}

int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
{
	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	return 1;
}

/* Note that "fork()" is implemented in terms of clone, with
   parameters (SIGCHLD, regs->gr[30], regs). */
int
sys_clone(unsigned long clone_flags, unsigned long usp,
	  struct pt_regs *regs)
{
  	/* Arugments from userspace are:
	   r26 = Clone flags.
	   r25 = Child stack.
	   r24 = parent_tidptr.
	   r23 = Is the TLS storage descriptor 
	   r22 = child_tidptr 
	   
	   However, these last 3 args are only examined
	   if the proper flags are set. */
	int __user *parent_tidptr = (int __user *)regs->gr[24];
	int __user *child_tidptr  = (int __user *)regs->gr[22];

	/* usp must be word aligned.  This also prevents users from
	 * passing in the value 1 (which is the signal for a special
	 * return for a kernel thread) */
	usp = ALIGN(usp, 4);

	/* A zero value for usp means use the current stack */
	if (usp == 0)
	  usp = regs->gr[30];

	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
}

int
sys_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
}

int
copy_thread(unsigned long clone_flags, unsigned long usp,
	    unsigned long unused,	/* in ia64 this is "user_stack_size" */
	    struct task_struct * p, struct pt_regs * pregs)
{
	struct pt_regs * cregs = &(p->thread.regs);
	void *stack = task_stack_page(p);
	
	/* We have to use void * instead of a function pointer, because
	 * function pointers aren't a pointer to the function on 64-bit.
	 * Make them const so the compiler knows they live in .text */
	extern void * const ret_from_kernel_thread;
	extern void * const child_return;
#ifdef CONFIG_HPUX
	extern void * const hpux_child_return;
#endif

	*cregs = *pregs;

	/* Set the return value for the child.  Note that this is not
           actually restored by the syscall exit path, but we put it
           here for consistency in case of signals. */
	cregs->gr[28] = 0; /* child */

	/*
	 * We need to differentiate between a user fork and a
	 * kernel fork. We can't use user_mode, because the
	 * the syscall path doesn't save iaoq. Right now
	 * We rely on the fact that kernel_thread passes
	 * in zero for usp.
	 */
	if (usp == 1) {
		/* kernel thread */
		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
		/* Must exit via ret_from_kernel_thread in order
		 * to call schedule_tail()
		 */
		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
		/*
		 * Copy function and argument to be called from
		 * ret_from_kernel_thread.
		 */
#ifdef CONFIG_64BIT
		cregs->gr[27] = pregs->gr[27];
#endif
		cregs->gr[26] = pregs->gr[26];
		cregs->gr[25] = pregs->gr[25];
	} else {
		/* user thread */
		/*
		 * Note that the fork wrappers are responsible
		 * for setting gr[21].
		 */

		/* Use same stack depth as parent */
		cregs->ksp = (unsigned long)stack
			+ (pregs->gr[21] & (THREAD_SIZE - 1));
		cregs->gr[30] = usp;
		if (p->personality == PER_HPUX) {
#ifdef CONFIG_HPUX
			cregs->kpc = (unsigned long) &hpux_child_return;
#else
			BUG();
#endif
		} else {
			cregs->kpc = (unsigned long) &child_return;
		}
		/* Setup thread TLS area from the 4th parameter in clone */
		if (clone_flags & CLONE_SETTLS)
		  cregs->cr27 = pregs->gr[23];
	
	}

	return 0;
}

unsigned long thread_saved_pc(struct task_struct *t)
{
	return t->thread.regs.kpc;
}

/*
 * sys_execve() executes a new program.
 */

asmlinkage int sys_execve(struct pt_regs *regs)
{
	int error;
	char *filename;

	filename = getname((const char __user *) regs->gr[26]);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename,
			  (const char __user *const __user *) regs->gr[25],
			  (const char __user *const __user *) regs->gr[24],
			  regs);
	putname(filename);
out:

	return error;
}

extern int __execve(const char *filename,
		    const char *const argv[],
		    const char *const envp[], struct task_struct *task);
int kernel_execve(const char *filename,
		  const char *const argv[],
		  const char *const envp[])
{
	return __execve(filename, argv, envp, current);
}

unsigned long
get_wchan(struct task_struct *p)
{
	struct unwind_frame_info info;
	unsigned long ip;
	int count = 0;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	/*
	 * These bracket the sleeping functions..
	 */

	unwind_frame_init_from_blocked_task(&info, p);
	do {
		if (unwind_once(&info) < 0)
			return 0;
		ip = info.ip;
		if (!in_sched_functions(ip))
			return ip;
	} while (count++ < 16);
	return 0;
}

#ifdef CONFIG_64BIT
void *dereference_function_descriptor(void *ptr)
{
	Elf64_Fdesc *desc = ptr;
	void *p;

	if (!probe_kernel_address(&desc->addr, p))
		ptr = p;
	return ptr;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* PARISC Architecture-dependent parts of process handling
	3	* based on the work for i386
	4	*
	5	* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
	6	* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
	7	* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
	8	* Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
	9	* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
	10	* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
	11	* Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
b2450cc1	12	* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
1da177e4 LT	13	* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
	14	* Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
	15	* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
a8f44e38	16	* Copyright (C) 2001-2007 Helge Deller <deller at parisc-linux.org>
1da177e4 LT	17	* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
	18	*
	19	*
	20	* This program is free software; you can redistribute it and/or modify
	21	* it under the terms of the GNU General Public License as published by
	22	* the Free Software Foundation; either version 2 of the License, or
	23	* (at your option) any later version.
	24	*
	25	* This program is distributed in the hope that it will be useful,
	26	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	27	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	28	* GNU General Public License for more details.
	29	*
	30	* You should have received a copy of the GNU General Public License
	31	* along with this program; if not, write to the Free Software
	32	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	33	*/
	34
	35	#include <stdarg.h>
	36
	37	#include <linux/elf.h>
	38	#include <linux/errno.h>
	39	#include <linux/kernel.h>
	40	#include <linux/mm.h>
4e950f6f	41	#include <linux/fs.h>
1da177e4 LT	42	#include <linux/module.h>
	43	#include <linux/personality.h>
	44	#include <linux/ptrace.h>
	45	#include <linux/sched.h>
5a0e3ad6	46	#include <linux/slab.h>
1da177e4 LT	47	#include <linux/stddef.h>
	48	#include <linux/unistd.h>
	49	#include <linux/kallsyms.h>
b609308e	50	#include <linux/uaccess.h>
1da177e4 LT	51
1da177e4 LT	52	#include <asm/io.h>
0013a854	53	#include <asm/asm-offsets.h>
1da177e4 LT	54	#include <asm/pdc.h>
	55	#include <asm/pdc_chassis.h>
	56	#include <asm/pgalloc.h>
1da177e4	57	#include <asm/unwind.h>
b609308e	58	#include <asm/sections.h>
1da177e4	59
1da177e4 LT	60	/*
	61	* The idle thread. There's no useful work to be
	62	* done, so just try to conserve power and have a
	63	* low exit latency (ie sit in a loop waiting for
	64	* somebody to say that they'd like to reschedule)
	65	*/
	66	void cpu_idle(void)
	67	{
64c7c8f8 NP	68	set_thread_flag(TIF_POLLING_NRFLAG);
64c7c8f8 NP	69
1da177e4 LT	70	/* endless idle loop with no priority at all */
	71	while (1) {
	72	while (!need_resched())
	73	barrier();
5bfb5d69	74	preempt_enable_no_resched();
1da177e4	75	schedule();
5bfb5d69	76	preempt_disable();
1da177e4 LT	77	check_pgt_cache();
	78	}
	79	}
	80
	81
10992092	82	#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
1da177e4 LT	83	#define CMD_RESET 5 /* reset any module */
	84
	85	/*
	86	** The Wright Brothers and Gecko systems have a H/W problem
	87	** (Lasi...'nuf said) may cause a broadcast reset to lockup
	88	** the system. An HVERSION dependent PDC call was developed
	89	** to perform a "safe", platform specific broadcast reset instead
	90	** of kludging up all the code.
	91	**
	92	** Older machines which do not implement PDC_BROADCAST_RESET will
	93	** return (with an error) and the regular broadcast reset can be
	94	** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
	95	** the PDC call will not return (the system will be reset).
	96	*/
	97	void machine_restart(char *cmd)
	98	{
	99	#ifdef FASTBOOT_SELFTEST_SUPPORT
	100	/*
	101	** If user has modified the Firmware Selftest Bitmap,
	102	** run the tests specified in the bitmap after the
	103	** system is rebooted w/PDC_DO_RESET.
	104	**
	105	** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	106	**
	107	** Using "directed resets" at each processor with the MEM_TOC
	108	** vector cleared will also avoid running destructive
	109	** memory self tests. (Not implemented yet)
	110	*/
	111	if (ftc_bitmap) {
	112	pdc_do_firm_test_reset(ftc_bitmap);
	113	}
	114	#endif
	115	/* set up a new led state on systems shipped with a LED State panel */
	116	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	117
	118	/* "Normal" system reset */
	119	pdc_do_reset();
	120
	121	/* Nope...box should reset with just CMD_RESET now */
	122	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
	123
	124	/* Wait for RESET to lay us to rest. */
	125	while (1) ;
	126
	127	}
	128
1da177e4 LT	129	void machine_halt(void)
	130	{
	131	/*
	132	** The LED/ChassisCodes are updated by the led_halt()
	133	** function, called by the reboot notifier chain.
	134	*/
	135	}
	136
85509c00	137	void (*chassis_power_off)(void);
1da177e4 LT	138
	139	/*
	140	* This routine is called from sys_reboot to actually turn off the
	141	* machine
	142	*/
	143	void machine_power_off(void)
	144	{
	145	/* If there is a registered power off handler, call it. */
85509c00 KM	146	if (chassis_power_off)
85509c00 KM	147	chassis_power_off();
1da177e4 LT	148
	149	/* Put the soft power button back under hardware control.
	150	* If the user had already pressed the power button, the
	151	* following call will immediately power off. */
	152	pdc_soft_power_button(0);
	153
	154	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	155
	156	/* It seems we have no way to power the system off via
	157	* software. The user has to press the button himself. */
	158
	159	printk(KERN_EMERG "System shut down completed.\n"
ad361c98	160	"Please power this system off now.");
1da177e4 LT	161	}
1da177e4 LT	162
85509c00 KM	163	void (*pm_power_off)(void) = machine_power_off;
85509c00 KM	164	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	165
	166	/*
	167	* Create a kernel thread
	168	*/
	169
	170	extern pid_t __kernel_thread(int (fn)(void ), void *arg, unsigned long flags);
	171	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	172	{
	173
	174	/*
	175	* FIXME: Once we are sure we don't need any debug here,
	176	* kernel_thread can become a #define.
	177	*/
	178
	179	return __kernel_thread(fn, arg, flags);
	180	}
	181	EXPORT_SYMBOL(kernel_thread);
	182
	183	/*
	184	* Free current thread data structures etc..
	185	*/
	186	void exit_thread(void)
	187	{
	188	}
	189
	190	void flush_thread(void)
	191	{
	192	/* Only needs to handle fpu stuff or perf monitors.
	193	** REVISIT: several arches implement a "lazy fpu state".
	194	*/
	195	set_fs(USER_DS);
	196	}
	197
	198	void release_thread(struct task_struct *dead_task)
	199	{
	200	}
	201
	202	/*
	203	* Fill in the FPU structure for a core dump.
	204	*/
	205
	206	int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
	207	{
	208	if (regs == NULL)
	209	return 0;
	210
	211	memcpy(r, regs->fr, sizeof *r);
	212	return 1;
	213	}
	214
	215	int dump_task_fpu (struct task_struct tsk, elf_fpregset_t r)
	216	{
	217	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	218	return 1;
	219	}
	220
	221	/* Note that "fork()" is implemented in terms of clone, with
	222	parameters (SIGCHLD, regs->gr[30], regs). */
	223	int
	224	sys_clone(unsigned long clone_flags, unsigned long usp,
	225	struct pt_regs *regs)
	226	{
b2450cc1 CD	227	/* Arugments from userspace are:
	228	r26 = Clone flags.
	229	r25 = Child stack.
	230	r24 = parent_tidptr.
	231	r23 = Is the TLS storage descriptor
	232	r22 = child_tidptr
	233
	234	However, these last 3 args are only examined
	235	if the proper flags are set. */
803094f4 HD	236	int __user parent_tidptr = (int __user )regs->gr[24];
803094f4 HD	237	int __user child_tidptr = (int __user )regs->gr[22];
1da177e4 LT	238
	239	/* usp must be word aligned. This also prevents users from
	240	* passing in the value 1 (which is the signal for a special
	241	* return for a kernel thread) */
	242	usp = ALIGN(usp, 4);
	243
	244	/* A zero value for usp means use the current stack */
b2450cc1 CD	245	if (usp == 0)
b2450cc1 CD	246	usp = regs->gr[30];
1da177e4	247
b2450cc1	248	return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
1da177e4 LT	249	}
	250
	251	int
	252	sys_vfork(struct pt_regs *regs)
	253	{
	254	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
	255	}
	256
	257	int
6f2c55b8	258	copy_thread(unsigned long clone_flags, unsigned long usp,
1da177e4 LT	259	unsigned long unused, /* in ia64 this is "user_stack_size" */
	260	struct task_struct * p, struct pt_regs * pregs)
	261	{
	262	struct pt_regs * cregs = &(p->thread.regs);
40f1f0de	263	void *stack = task_stack_page(p);
1da177e4 LT	264
	265	/* We have to use void * instead of a function pointer, because
	266	* function pointers aren't a pointer to the function on 64-bit.
	267	* Make them const so the compiler knows they live in .text */
	268	extern void * const ret_from_kernel_thread;
	269	extern void * const child_return;
	270	#ifdef CONFIG_HPUX
	271	extern void * const hpux_child_return;
	272	#endif
	273
	274	cregs = pregs;
	275
	276	/* Set the return value for the child. Note that this is not
	277	actually restored by the syscall exit path, but we put it
	278	here for consistency in case of signals. */
	279	cregs->gr[28] = 0; /* child */
	280
	281	/*
	282	* We need to differentiate between a user fork and a
	283	* kernel fork. We can't use user_mode, because the
	284	* the syscall path doesn't save iaoq. Right now
	285	* We rely on the fact that kernel_thread passes
	286	* in zero for usp.
	287	*/
	288	if (usp == 1) {
	289	/* kernel thread */
40f1f0de	290	cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
1da177e4 LT	291	/* Must exit via ret_from_kernel_thread in order
	292	* to call schedule_tail()
	293	*/
	294	cregs->kpc = (unsigned long) &ret_from_kernel_thread;
	295	/*
	296	* Copy function and argument to be called from
	297	* ret_from_kernel_thread.
	298	*/
a8f44e38	299	#ifdef CONFIG_64BIT
1da177e4 LT	300	cregs->gr[27] = pregs->gr[27];
	301	#endif
	302	cregs->gr[26] = pregs->gr[26];
	303	cregs->gr[25] = pregs->gr[25];
	304	} else {
	305	/* user thread */
	306	/*
	307	* Note that the fork wrappers are responsible
	308	* for setting gr[21].
	309	*/
	310
	311	/* Use same stack depth as parent */
40f1f0de	312	cregs->ksp = (unsigned long)stack
1da177e4 LT	313	+ (pregs->gr[21] & (THREAD_SIZE - 1));
	314	cregs->gr[30] = usp;
	315	if (p->personality == PER_HPUX) {
	316	#ifdef CONFIG_HPUX
	317	cregs->kpc = (unsigned long) &hpux_child_return;
	318	#else
	319	BUG();
	320	#endif
	321	} else {
	322	cregs->kpc = (unsigned long) &child_return;
	323	}
b2450cc1 CD	324	/* Setup thread TLS area from the 4th parameter in clone */
	325	if (clone_flags & CLONE_SETTLS)
	326	cregs->cr27 = pregs->gr[23];
	327
1da177e4 LT	328	}
	329
	330	return 0;
	331	}
	332
	333	unsigned long thread_saved_pc(struct task_struct *t)
	334	{
	335	return t->thread.regs.kpc;
	336	}
	337
	338	/*
	339	* sys_execve() executes a new program.
	340	*/
	341
	342	asmlinkage int sys_execve(struct pt_regs *regs)
	343	{
	344	int error;
	345	char *filename;
	346
	347	filename = getname((const char __user *) regs->gr[26]);
	348	error = PTR_ERR(filename);
	349	if (IS_ERR(filename))
	350	goto out;
d7627467 DH	351	error = do_execve(filename,
	352	(const char __user const __user ) regs->gr[25],
	353	(const char __user const __user ) regs->gr[24],
	354	regs);
1da177e4 LT	355	putname(filename);
	356	out:
	357
	358	return error;
	359	}
	360
d7627467 DH	361	extern int __execve(const char *filename,
	362	const char *const argv[],
	363	const char const envp[], struct task_struct task);
	364	int kernel_execve(const char *filename,
	365	const char *const argv[],
	366	const char *const envp[])
3db03b4a AB	367	{
	368	return __execve(filename, argv, envp, current);
	369	}
	370
	371	unsigned long
1da177e4 LT	372	get_wchan(struct task_struct *p)
	373	{
	374	struct unwind_frame_info info;
	375	unsigned long ip;
	376	int count = 0;
cc650a7a KM	377
	378	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	379	return 0;
	380
1da177e4 LT	381	/*
	382	* These bracket the sleeping functions..
	383	*/
	384
	385	unwind_frame_init_from_blocked_task(&info, p);
	386	do {
	387	if (unwind_once(&info) < 0)
	388	return 0;
	389	ip = info.ip;
	390	if (!in_sched_functions(ip))
	391	return ip;
	392	} while (count++ < 16);
	393	return 0;
	394	}
b609308e KM	395
	396	#ifdef CONFIG_64BIT
	397	void dereference_function_descriptor(void ptr)
	398	{
	399	Elf64_Fdesc *desc = ptr;
	400	void *p;
	401
	402	if (!probe_kernel_address(&desc->addr, p))
	403	ptr = p;
	404	return ptr;
	405	}
	406	#endif