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

/* process.c: FRV specific parts of process handling
 *
 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 * - Derived from arch/m68k/kernel/process.c
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/rcupdate.h>

#include <asm/asm-offsets.h>
#include <asm/uaccess.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/gdb-stub.h>
#include <asm/mb-regs.h>

#include "local.h"

asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);

#include <asm/pgalloc.h>

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

static void core_sleep_idle(void)
{
#ifdef LED_DEBUG_SLEEP
	/* Show that we're sleeping... */
	__set_LEDS(0x55aa);
#endif
	frv_cpu_core_sleep();
#ifdef LED_DEBUG_SLEEP
	/* ... and that we woke up */
	__set_LEDS(0);
#endif
	mb();
}

void (*idle)(void) = core_sleep_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) {
		rcu_idle_enter();
		while (!need_resched()) {
			check_pgt_cache();

			if (!frv_dma_inprogress && idle)
				idle();
		}
		rcu_idle_exit();

		schedule_preempt_disabled();
	}
}

void machine_restart(char * __unused)
{
	unsigned long reset_addr;
#ifdef CONFIG_GDBSTUB
	gdbstub_exit(0);
#endif

	if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
		reset_addr = 0xfefff500;
	else
		reset_addr = 0xfeff0500;

	/* Software reset. */
	asm volatile("      dcef @(gr0,gr0),1 ! membar !"
		     "      sti     %1,@(%0,0) !"
		     "      nop ! nop ! nop ! nop ! nop ! "
		     "      nop ! nop ! nop ! nop ! nop ! "
		     "      nop ! nop ! nop ! nop ! nop ! "
		     "      nop ! nop ! nop ! nop ! nop ! "
		     : : "r" (reset_addr), "r" (1) );

	for (;;)
		;
}

void machine_halt(void)
{
#ifdef CONFIG_GDBSTUB
	gdbstub_exit(0);
#endif

	for (;;);
}

void machine_power_off(void)
{
#ifdef CONFIG_GDBSTUB
	gdbstub_exit(0);
#endif

	for (;;);
}

void flush_thread(void)
{
	/* nothing */
}

inline unsigned long user_stack(const struct pt_regs *regs)
{
	while (regs->next_frame)
		regs = regs->next_frame;
	return user_mode(regs) ? regs->sp : 0;
}

/*
 * set up the kernel stack and exception frames for a new process
 */
int copy_thread(unsigned long clone_flags,
		unsigned long usp, unsigned long arg,
		struct task_struct *p)
{
	struct pt_regs *childregs;

	childregs = (struct pt_regs *)
		(task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);

	/* set up the userspace frame (the only place that the USP is stored) */
	*childregs = *current_pt_regs();

	p->thread.frame	 = childregs;
	p->thread.curr	 = p;
	p->thread.sp	 = (unsigned long) childregs;
	p->thread.fp	 = 0;
	p->thread.lr	 = 0;
	p->thread.frame0 = childregs;

	if (unlikely(p->flags & PF_KTHREAD)) {
		childregs->gr9 = usp; /* function */
		childregs->gr8 = arg;
		p->thread.pc = (unsigned long) ret_from_kernel_thread;
		save_user_regs(p->thread.user);
		return 0;
	}
	if (usp)
		childregs->sp = usp;
	childregs->next_frame	= NULL;

	p->thread.pc = (unsigned long) ret_from_fork;

	/* the new TLS pointer is passed in as arg #5 to sys_clone() */
	if (clone_flags & CLONE_SETTLS)
		childregs->gr29 = childregs->gr12;

	save_user_regs(p->thread.user);

	return 0;
} /* end copy_thread() */

unsigned long get_wchan(struct task_struct *p)
{
	struct pt_regs *regs0;
	unsigned long fp, pc;
	unsigned long stack_limit;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	stack_limit = (unsigned long) (p + 1);
	fp = p->thread.fp;
	regs0 = p->thread.frame0;

	do {
		if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
			return 0;

		pc = ((unsigned long *) fp)[2];

		/* FIXME: This depends on the order of these functions. */
		if (!in_sched_functions(pc))
			return pc;

		fp = *(unsigned long *) fp;
	} while (count++ < 16);

	return 0;
}

unsigned long thread_saved_pc(struct task_struct *tsk)
{
	/* Check whether the thread is blocked in resume() */
	if (in_sched_functions(tsk->thread.pc))
		return ((unsigned long *)tsk->thread.fp)[2];
	else
		return tsk->thread.pc;
}

int elf_check_arch(const struct elf32_hdr *hdr)
{
	unsigned long hsr0 = __get_HSR(0);
	unsigned long psr = __get_PSR();

	if (hdr->e_machine != EM_FRV)
		return 0;

	switch (hdr->e_flags & EF_FRV_GPR_MASK) {
	case EF_FRV_GPR64:
		if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
			return 0;
	case EF_FRV_GPR32:
	case 0:
		break;
	default:
		return 0;
	}

	switch (hdr->e_flags & EF_FRV_FPR_MASK) {
	case EF_FRV_FPR64:
		if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
			return 0;
	case EF_FRV_FPR32:
	case EF_FRV_FPR_NONE:
	case 0:
		break;
	default:
		return 0;
	}

	if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
		if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
		    PSR_IMPLE(psr) != PSR_IMPLE_FR451)
			return 0;

	switch (hdr->e_flags & EF_FRV_CPU_MASK) {
	case EF_FRV_CPU_GENERIC:
		break;
	case EF_FRV_CPU_FR300:
	case EF_FRV_CPU_SIMPLE:
	case EF_FRV_CPU_TOMCAT:
	default:
		return 0;
	case EF_FRV_CPU_FR400:
		if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
		    PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
		    PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
		    PSR_IMPLE(psr) != PSR_IMPLE_FR551)
			return 0;
		break;
	case EF_FRV_CPU_FR450:
		if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
			return 0;
		break;
	case EF_FRV_CPU_FR500:
		if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
			return 0;
		break;
	case EF_FRV_CPU_FR550:
		if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
			return 0;
		break;
	}

	return 1;
}

int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
	memcpy(fpregs,
	       &current->thread.user->f,
	       sizeof(current->thread.user->f));
	return 1;
}
Commit	Line	Data
1da177e4 LT	1	/* process.c: FRV specific parts of process handling
	2	*
	3	* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	* - Derived from arch/m68k/kernel/process.c
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
9dec17eb	13	#include <linux/module.h>
1da177e4 LT	14	#include <linux/errno.h>
	15	#include <linux/sched.h>
	16	#include <linux/kernel.h>
	17	#include <linux/mm.h>
	18	#include <linux/smp.h>
1da177e4 LT	19	#include <linux/stddef.h>
	20	#include <linux/unistd.h>
	21	#include <linux/ptrace.h>
	22	#include <linux/slab.h>
	23	#include <linux/user.h>
	24	#include <linux/elf.h>
	25	#include <linux/reboot.h>
	26	#include <linux/interrupt.h>
8defab33	27	#include <linux/pagemap.h>
41d8fe5b	28	#include <linux/rcupdate.h>
1da177e4	29
84e8cd6d	30	#include <asm/asm-offsets.h>
1da177e4	31	#include <asm/uaccess.h>
1da177e4 LT	32	#include <asm/setup.h>
1da177e4 LT	33	#include <asm/pgtable.h>
8defab33	34	#include <asm/tlb.h>
1da177e4 LT	35	#include <asm/gdb-stub.h>
	36	#include <asm/mb-regs.h>
	37
	38	#include "local.h"
	39
	40	asmlinkage void ret_from_fork(void);
02ce496f	41	asmlinkage void ret_from_kernel_thread(void);
1da177e4 LT	42
	43	#include <asm/pgalloc.h>
	44
9dec17eb DH	45	void (*pm_power_off)(void);
	46	EXPORT_SYMBOL(pm_power_off);
	47
1da177e4 LT	48	static void core_sleep_idle(void)
	49	{
	50	#ifdef LED_DEBUG_SLEEP
	51	/* Show that we're sleeping... */
	52	__set_LEDS(0x55aa);
	53	#endif
	54	frv_cpu_core_sleep();
	55	#ifdef LED_DEBUG_SLEEP
	56	/* ... and that we woke up */
	57	__set_LEDS(0);
	58	#endif
	59	mb();
	60	}
	61
	62	void (*idle)(void) = core_sleep_idle;
	63
	64	/*
	65	* The idle thread. There's no useful work to be
	66	* done, so just try to conserve power and have a
	67	* low exit latency (ie sit in a loop waiting for
	68	* somebody to say that they'd like to reschedule)
	69	*/
	70	void cpu_idle(void)
	71	{
	72	/* endless idle loop with no priority at all */
	73	while (1) {
41d8fe5b	74	rcu_idle_enter();
1da177e4	75	while (!need_resched()) {
8defab33 CL	76	check_pgt_cache();
8defab33 CL	77
1da177e4 LT	78	if (!frv_dma_inprogress && idle)
	79	idle();
	80	}
41d8fe5b	81	rcu_idle_exit();
1da177e4	82
bd2f5536	83	schedule_preempt_disabled();
1da177e4 LT	84	}
	85	}
	86
	87	void machine_restart(char * __unused)
	88	{
	89	unsigned long reset_addr;
	90	#ifdef CONFIG_GDBSTUB
	91	gdbstub_exit(0);
	92	#endif
	93
	94	if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
	95	reset_addr = 0xfefff500;
	96	else
	97	reset_addr = 0xfeff0500;
	98
	99	/* Software reset. */
	100	asm volatile(" dcef @(gr0,gr0),1 ! membar !"
	101	" sti %1,@(%0,0) !"
	102	" nop ! nop ! nop ! nop ! nop ! "
	103	" nop ! nop ! nop ! nop ! nop ! "
	104	" nop ! nop ! nop ! nop ! nop ! "
	105	" nop ! nop ! nop ! nop ! nop ! "
	106	: : "r" (reset_addr), "r" (1) );
	107
	108	for (;;)
	109	;
	110	}
	111
	112	void machine_halt(void)
	113	{
	114	#ifdef CONFIG_GDBSTUB
	115	gdbstub_exit(0);
	116	#endif
	117
	118	for (;;);
	119	}
	120
	121	void machine_power_off(void)
	122	{
	123	#ifdef CONFIG_GDBSTUB
	124	gdbstub_exit(0);
	125	#endif
	126
	127	for (;;);
	128	}
	129
	130	void flush_thread(void)
	131	{
adc400f6	132	/* nothing */
1da177e4 LT	133	}
	134
	135	inline unsigned long user_stack(const struct pt_regs *regs)
	136	{
	137	while (regs->next_frame)
	138	regs = regs->next_frame;
	139	return user_mode(regs) ? regs->sp : 0;
	140	}
	141
1da177e4 LT	142	/*
	143	* set up the kernel stack and exception frames for a new process
	144	*/
6f2c55b8	145	int copy_thread(unsigned long clone_flags,
49ed3398	146	unsigned long usp, unsigned long arg,
afa86fc4	147	struct task_struct *p)
1da177e4	148	{
02ce496f	149	struct pt_regs *childregs;
1da177e4	150
02ce496f	151	childregs = (struct pt_regs *)
84e8cd6d	152	(task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
1da177e4	153
e7aa51b2	154	/* set up the userspace frame (the only place that the USP is stored) */
b9763ce3	155	childregs = current_pt_regs();
1da177e4 LT	156
	157	p->thread.frame = childregs;
	158	p->thread.curr = p;
	159	p->thread.sp = (unsigned long) childregs;
	160	p->thread.fp = 0;
	161	p->thread.lr = 0;
02ce496f	162	p->thread.frame0 = childregs;
1da177e4	163
b9763ce3	164	if (unlikely(p->flags & PF_KTHREAD)) {
49ed3398 AV	165	childregs->gr9 = usp; /* function */
49ed3398 AV	166	childregs->gr8 = arg;
49ed3398 AV	167	p->thread.pc = (unsigned long) ret_from_kernel_thread;
	168	save_user_regs(p->thread.user);
	169	return 0;
	170	}
b9763ce3 AV	171	if (usp)
b9763ce3 AV	172	childregs->sp = usp;
49ed3398 AV	173	childregs->next_frame = NULL;
	174
	175	p->thread.pc = (unsigned long) ret_from_fork;
1da177e4 LT	176
	177	/* the new TLS pointer is passed in as arg #5 to sys_clone() */
	178	if (clone_flags & CLONE_SETTLS)
	179	childregs->gr29 = childregs->gr12;
	180
	181	save_user_regs(p->thread.user);
	182
	183	return 0;
	184	} /* end copy_thread() */
	185
1da177e4 LT	186	unsigned long get_wchan(struct task_struct *p)
	187	{
	188	struct pt_regs *regs0;
	189	unsigned long fp, pc;
	190	unsigned long stack_limit;
	191	int count = 0;
	192	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	193	return 0;
	194
	195	stack_limit = (unsigned long) (p + 1);
	196	fp = p->thread.fp;
	197	regs0 = p->thread.frame0;
	198
	199	do {
	200	if (fp < stack_limit \|\| fp >= (unsigned long) regs0 \|\| fp & 3)
	201	return 0;
	202
	203	pc = ((unsigned long *) fp)[2];
	204
	205	/* FIXME: This depends on the order of these functions. */
	206	if (!in_sched_functions(pc))
	207	return pc;
	208
	209	fp = (unsigned long ) fp;
	210	} while (count++ < 16);
	211
	212	return 0;
	213	}
	214
	215	unsigned long thread_saved_pc(struct task_struct *tsk)
	216	{
	217	/* Check whether the thread is blocked in resume() */
	218	if (in_sched_functions(tsk->thread.pc))
	219	return ((unsigned long *)tsk->thread.fp)[2];
	220	else
	221	return tsk->thread.pc;
	222	}
	223
	224	int elf_check_arch(const struct elf32_hdr *hdr)
	225	{
	226	unsigned long hsr0 = __get_HSR(0);
	227	unsigned long psr = __get_PSR();
	228
	229	if (hdr->e_machine != EM_FRV)
	230	return 0;
	231
	232	switch (hdr->e_flags & EF_FRV_GPR_MASK) {
	233	case EF_FRV_GPR64:
	234	if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
	235	return 0;
	236	case EF_FRV_GPR32:
	237	case 0:
	238	break;
	239	default:
	240	return 0;
	241	}
	242
	243	switch (hdr->e_flags & EF_FRV_FPR_MASK) {
	244	case EF_FRV_FPR64:
	245	if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
	246	return 0;
	247	case EF_FRV_FPR32:
	248	case EF_FRV_FPR_NONE:
	249	case 0:
250	break;
251	default:
252	return 0;
253	}
254
255	if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
256	if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
257	PSR_IMPLE(psr) != PSR_IMPLE_FR451)
258	return 0;
259
260	switch (hdr->e_flags & EF_FRV_CPU_MASK) {
261	case EF_FRV_CPU_GENERIC:
262	break;
263	case EF_FRV_CPU_FR300:
264	case EF_FRV_CPU_SIMPLE:
265	case EF_FRV_CPU_TOMCAT:
266	default:
267	return 0;
268	case EF_FRV_CPU_FR400:
269	if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
270	PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
271	PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
272	PSR_IMPLE(psr) != PSR_IMPLE_FR551)
273	return 0;
274	break;
275	case EF_FRV_CPU_FR450:
276	if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
277	return 0;
278	break;
279	case EF_FRV_CPU_FR500:
280	if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
281	return 0;
282	break;
283	case EF_FRV_CPU_FR550:
284	if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
285	return 0;
286	break;
287	}
288
289	return 1;
290	}
6d8c4e3b DH	291
	292	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpregs)
	293	{
	294	memcpy(fpregs,
	295	&current->thread.user->f,
	296	sizeof(current->thread.user->f));
	297	return 1;
	298	}