[mirror_ubuntu-zesty-kernel.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 <linux/rcupdate.h>

#include <asm/io.h>
#include <asm/asm-offsets.h>
#include <asm/assembly.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) {
		rcu_idle_enter();
		while (!need_resched())
			barrier();
		rcu_idle_exit();
		schedule_preempt_disabled();
		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);

/*
 * 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".
	*/
}

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;
}

int
copy_thread(unsigned long clone_flags, unsigned long usp,
	    unsigned long arg, struct task_struct *p)
{
	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
	if (unlikely(p->flags & PF_KTHREAD)) {
		memset(cregs, 0, sizeof(struct pt_regs));
		if (!usp) /* idle thread */
			return 0;

		/* kernel thread */
		/* Must exit via ret_from_kernel_thread in order
		 * to call schedule_tail()
		 */
		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
		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] = ((unsigned long *)usp)[3];
		cregs->gr[26] = ((unsigned long *)usp)[2];
#else
		cregs->gr[26] = usp;
#endif
		cregs->gr[25] = arg;
	} else {
		/* user thread */
		/* 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) */
		if (usp) {
			usp = ALIGN(usp, 4);
			if (likely(usp))
				cregs->gr[30] = usp;
		}
		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
		if (personality(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 = cregs->gr[23];
	}

	return 0;
}

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

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>
fbe75218	51	#include <linux/rcupdate.h>
1da177e4 LT	52
1da177e4 LT	53	#include <asm/io.h>
0013a854	54	#include <asm/asm-offsets.h>
ff0ab8af	55	#include <asm/assembly.h>
1da177e4 LT	56	#include <asm/pdc.h>
	57	#include <asm/pdc_chassis.h>
	58	#include <asm/pgalloc.h>
1da177e4	59	#include <asm/unwind.h>
b609308e	60	#include <asm/sections.h>
1da177e4	61
1da177e4 LT	62	/*
	63	* The idle thread. There's no useful work to be
	64	* done, so just try to conserve power and have a
	65	* low exit latency (ie sit in a loop waiting for
	66	* somebody to say that they'd like to reschedule)
	67	*/
	68	void cpu_idle(void)
	69	{
64c7c8f8 NP	70	set_thread_flag(TIF_POLLING_NRFLAG);
64c7c8f8 NP	71
1da177e4 LT	72	/* endless idle loop with no priority at all */
1da177e4 LT	73	while (1) {
fbe75218	74	rcu_idle_enter();
1da177e4 LT	75	while (!need_resched())
1da177e4 LT	76	barrier();
fbe75218	77	rcu_idle_exit();
bd2f5536	78	schedule_preempt_disabled();
1da177e4 LT	79	check_pgt_cache();
	80	}
	81	}
	82
	83
10992092	84	#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
1da177e4 LT	85	#define CMD_RESET 5 /* reset any module */
	86
	87	/*
	88	** The Wright Brothers and Gecko systems have a H/W problem
	89	** (Lasi...'nuf said) may cause a broadcast reset to lockup
	90	** the system. An HVERSION dependent PDC call was developed
	91	** to perform a "safe", platform specific broadcast reset instead
	92	** of kludging up all the code.
	93	**
	94	** Older machines which do not implement PDC_BROADCAST_RESET will
	95	** return (with an error) and the regular broadcast reset can be
	96	** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
	97	** the PDC call will not return (the system will be reset).
	98	*/
	99	void machine_restart(char *cmd)
	100	{
	101	#ifdef FASTBOOT_SELFTEST_SUPPORT
	102	/*
	103	** If user has modified the Firmware Selftest Bitmap,
	104	** run the tests specified in the bitmap after the
	105	** system is rebooted w/PDC_DO_RESET.
	106	**
	107	** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
	108	**
	109	** Using "directed resets" at each processor with the MEM_TOC
	110	** vector cleared will also avoid running destructive
	111	** memory self tests. (Not implemented yet)
	112	*/
	113	if (ftc_bitmap) {
	114	pdc_do_firm_test_reset(ftc_bitmap);
	115	}
	116	#endif
	117	/* set up a new led state on systems shipped with a LED State panel */
	118	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	119
	120	/* "Normal" system reset */
	121	pdc_do_reset();
	122
	123	/* Nope...box should reset with just CMD_RESET now */
	124	gsc_writel(CMD_RESET, COMMAND_GLOBAL);
	125
	126	/* Wait for RESET to lay us to rest. */
	127	while (1) ;
	128
	129	}
	130
1da177e4 LT	131	void machine_halt(void)
	132	{
	133	/*
	134	** The LED/ChassisCodes are updated by the led_halt()
	135	** function, called by the reboot notifier chain.
	136	*/
	137	}
	138
85509c00	139	void (*chassis_power_off)(void);
1da177e4 LT	140
	141	/*
	142	* This routine is called from sys_reboot to actually turn off the
	143	* machine
	144	*/
	145	void machine_power_off(void)
	146	{
	147	/* If there is a registered power off handler, call it. */
85509c00 KM	148	if (chassis_power_off)
85509c00 KM	149	chassis_power_off();
1da177e4 LT	150
	151	/* Put the soft power button back under hardware control.
	152	* If the user had already pressed the power button, the
	153	* following call will immediately power off. */
	154	pdc_soft_power_button(0);
	155
	156	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
	157
	158	/* It seems we have no way to power the system off via
	159	* software. The user has to press the button himself. */
	160
	161	printk(KERN_EMERG "System shut down completed.\n"
ad361c98	162	"Please power this system off now.");
1da177e4 LT	163	}
1da177e4 LT	164
85509c00 KM	165	void (*pm_power_off)(void) = machine_power_off;
85509c00 KM	166	EXPORT_SYMBOL(pm_power_off);
1da177e4	167
1da177e4 LT	168	/*
	169	* Free current thread data structures etc..
	170	*/
	171	void exit_thread(void)
	172	{
	173	}
	174
	175	void flush_thread(void)
	176	{
	177	/* Only needs to handle fpu stuff or perf monitors.
	178	** REVISIT: several arches implement a "lazy fpu state".
	179	*/
1da177e4 LT	180	}
	181
	182	void release_thread(struct task_struct *dead_task)
	183	{
	184	}
	185
	186	/*
	187	* Fill in the FPU structure for a core dump.
	188	*/
	189
	190	int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
	191	{
	192	if (regs == NULL)
	193	return 0;
	194
	195	memcpy(r, regs->fr, sizeof *r);
	196	return 1;
	197	}
	198
	199	int dump_task_fpu (struct task_struct tsk, elf_fpregset_t r)
	200	{
	201	memcpy(r, tsk->thread.regs.fr, sizeof(*r));
	202	return 1;
	203	}
	204
1da177e4	205	int
6f2c55b8	206	copy_thread(unsigned long clone_flags, unsigned long usp,
afa86fc4	207	unsigned long arg, struct task_struct *p)
1da177e4	208	{
afa86fc4	209	struct pt_regs *cregs = &(p->thread.regs);
40f1f0de	210	void *stack = task_stack_page(p);
1da177e4 LT	211
	212	/* We have to use void * instead of a function pointer, because
	213	* function pointers aren't a pointer to the function on 64-bit.
	214	* Make them const so the compiler knows they live in .text */
	215	extern void * const ret_from_kernel_thread;
	216	extern void * const child_return;
	217	#ifdef CONFIG_HPUX
	218	extern void * const hpux_child_return;
	219	#endif
ff0ab8af	220	if (unlikely(p->flags & PF_KTHREAD)) {
a44e060f	221	memset(cregs, 0, sizeof(struct pt_regs));
ff0ab8af AV	222	if (!usp) /* idle thread */
	223	return 0;
	224
1da177e4	225	/* kernel thread */
1da177e4 LT	226	/* Must exit via ret_from_kernel_thread in order
	227	* to call schedule_tail()
	228	*/
ff0ab8af	229	cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
1da177e4 LT	230	cregs->kpc = (unsigned long) &ret_from_kernel_thread;
	231	/*
	232	* Copy function and argument to be called from
	233	* ret_from_kernel_thread.
	234	*/
a8f44e38	235	#ifdef CONFIG_64BIT
a44e060f AV	236	cregs->gr[27] = ((unsigned long *)usp)[3];
	237	cregs->gr[26] = ((unsigned long *)usp)[2];
	238	#else
	239	cregs->gr[26] = usp;
1da177e4	240	#endif
a44e060f	241	cregs->gr[25] = arg;
1da177e4 LT	242	} else {
1da177e4 LT	243	/* user thread */
415bfae9 AV	244	/* usp must be word aligned. This also prevents users from
	245	* passing in the value 1 (which is the signal for a special
	246	* return for a kernel thread) */
	247	if (usp) {
	248	usp = ALIGN(usp, 4);
	249	if (likely(usp))
	250	cregs->gr[30] = usp;
	251	}
ff0ab8af	252	cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
5b24c421	253	if (personality(p->personality) == PER_HPUX) {
1da177e4 LT	254	#ifdef CONFIG_HPUX
	255	cregs->kpc = (unsigned long) &hpux_child_return;
	256	#else
	257	BUG();
	258	#endif
	259	} else {
	260	cregs->kpc = (unsigned long) &child_return;
	261	}
b2450cc1 CD	262	/* Setup thread TLS area from the 4th parameter in clone */
b2450cc1 CD	263	if (clone_flags & CLONE_SETTLS)
415bfae9	264	cregs->cr27 = cregs->gr[23];
1da177e4 LT	265	}
	266
	267	return 0;
	268	}
	269
	270	unsigned long thread_saved_pc(struct task_struct *t)
	271	{
	272	return t->thread.regs.kpc;
	273	}
	274
3db03b4a	275	unsigned long
1da177e4 LT	276	get_wchan(struct task_struct *p)
	277	{
	278	struct unwind_frame_info info;
	279	unsigned long ip;
	280	int count = 0;
cc650a7a KM	281
	282	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	283	return 0;
	284
1da177e4 LT	285	/*
	286	* These bracket the sleeping functions..
	287	*/
	288
	289	unwind_frame_init_from_blocked_task(&info, p);
	290	do {
	291	if (unwind_once(&info) < 0)
	292	return 0;
	293	ip = info.ip;
	294	if (!in_sched_functions(ip))
	295	return ip;
	296	} while (count++ < 16);
	297	return 0;
	298	}
b609308e KM	299
	300	#ifdef CONFIG_64BIT
	301	void dereference_function_descriptor(void ptr)
	302	{
	303	Elf64_Fdesc *desc = ptr;
	304	void *p;
	305
	306	if (!probe_kernel_address(&desc->addr, p))
	307	ptr = p;
	308	return ptr;
	309	}
	310	#endif