[linux-2.6-block.git] / arch / microblaze / kernel / process.c

/*
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/bitops.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h> /* for USER_DS macros */
#include <asm/cacheflush.h>

void show_regs(struct pt_regs *regs)
{
	printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode);
	printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
				regs->r1, regs->r2, regs->r3, regs->r4);
	printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
				regs->r5, regs->r6, regs->r7, regs->r8);
	printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
				regs->r9, regs->r10, regs->r11, regs->r12);
	printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
				regs->r13, regs->r14, regs->r15, regs->r16);
	printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
				regs->r17, regs->r18, regs->r19, regs->r20);
	printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
				regs->r21, regs->r22, regs->r23, regs->r24);
	printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
				regs->r25, regs->r26, regs->r27, regs->r28);
	printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
				regs->r29, regs->r30, regs->r31, regs->pc);
	printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
				regs->msr, regs->ear, regs->esr, regs->fsr);
}

void (*pm_idle)(void);
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);

static int hlt_counter = 1;

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 (likely(hlt_counter)) {
		local_irq_disable();
		stop_critical_timings();
		cpu_relax();
		start_critical_timings();
		local_irq_enable();
	} else {
		clear_thread_flag(TIF_POLLING_NRFLAG);
		smp_mb__after_clear_bit();
		local_irq_disable();
		while (!need_resched())
			cpu_sleep();
		local_irq_enable();
		set_thread_flag(TIF_POLLING_NRFLAG);
	}
}

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_idle_enter();
		rcu_idle_enter();
		while (!need_resched())
			idle();
		rcu_idle_exit();
		tick_nohz_idle_exit();

		schedule_preempt_disabled();
		check_pgt_cache();
	}
}

void flush_thread(void)
{
}

int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long unused,
		struct task_struct *p, struct pt_regs *regs)
{
	struct pt_regs *childregs = task_pt_regs(p);
	struct thread_info *ti = task_thread_info(p);

	*childregs = *regs;
	if (user_mode(regs))
		childregs->r1 = usp;
	else
		childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;

#ifndef CONFIG_MMU
	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
	ti->cpu_context.r1 = (unsigned long)childregs;
	ti->cpu_context.msr = (unsigned long)childregs->msr;
#else

	/* if creating a kernel thread then update the current reg (we don't
	 * want to use the parent's value when restoring by POP_STATE) */
	if (kernel_mode(regs))
		/* save new current on stack to use POP_STATE */
		childregs->CURRENT_TASK = (unsigned long)p;
	/* if returning to user then use the parent's value of this register */

	/* if we're creating a new kernel thread then just zeroing all
	 * the registers. That's OK for a brand new thread.*/
	/* Pls. note that some of them will be restored in POP_STATE */
	if (kernel_mode(regs))
		memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
	/* if this thread is created for fork/vfork/clone, then we want to
	 * restore all the parent's context */
	/* in addition to the registers which will be restored by POP_STATE */
	else {
		ti->cpu_context = *(struct cpu_context *)regs;
		childregs->msr |= MSR_UMS;
	}

	/* FIXME STATE_SAVE_PT_OFFSET; */
	ti->cpu_context.r1  = (unsigned long)childregs;
	/* we should consider the fact that childregs is a copy of the parent
	 * regs which were saved immediately after entering the kernel state
	 * before enabling VM. This MSR will be restored in switch_to and
	 * RETURN() and we want to have the right machine state there
	 * specifically this state must have INTs disabled before and enabled
	 * after performing rtbd
	 * compose the right MSR for RETURN(). It will work for switch_to also
	 * excepting for VM and UMS
	 * don't touch UMS , CARRY and cache bits
	 * right now MSR is a copy of parent one */
	childregs->msr |= MSR_BIP;
	childregs->msr &= ~MSR_EIP;
	childregs->msr |= MSR_IE;
	childregs->msr &= ~MSR_VM;
	childregs->msr |= MSR_VMS;
	childregs->msr |= MSR_EE; /* exceptions will be enabled*/

	ti->cpu_context.msr = (childregs->msr|MSR_VM);
	ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
	ti->cpu_context.msr &= ~MSR_IE;
#endif
	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;

	/*
	 *  r21 is the thread reg, r10 is 6th arg to clone
	 *  which contains TLS area
	 */
	if (clone_flags & CLONE_SETTLS)
		childregs->r21 = childregs->r10;

	return 0;
}

#ifndef CONFIG_MMU
/*
 * Return saved PC of a blocked thread.
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
	struct cpu_context *ctx =
		&(((struct thread_info *)(tsk->stack))->cpu_context);

	/* Check whether the thread is blocked in resume() */
	if (in_sched_functions(ctx->r15))
		return (unsigned long)ctx->r15;
	else
		return ctx->r14;
}
#endif

static void kernel_thread_helper(int (*fn)(void *), void *arg)
{
	fn(arg);
	do_exit(-1);
}

int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));
	/* store them in non-volatile registers */
	regs.r5 = (unsigned long)fn;
	regs.r6 = (unsigned long)arg;
	local_save_flags(regs.msr);
	regs.pc = (unsigned long)kernel_thread_helper;
	regs.pt_mode = 1;

	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
			&regs, 0, NULL, NULL);
}
EXPORT_SYMBOL_GPL(kernel_thread);

unsigned long get_wchan(struct task_struct *p)
{
/* TBD (used by procfs) */
	return 0;
}

/* Set up a thread for executing a new program */
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
{
	regs->pc = pc;
	regs->r1 = usp;
	regs->pt_mode = 0;
#ifdef CONFIG_MMU
	regs->msr |= MSR_UMS;
#endif
}

#ifdef CONFIG_MMU
#include <linux/elfcore.h>
/*
 * Set up a thread for executing a new program
 */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
	return 0; /* MicroBlaze has no separate FPU registers */
}
#endif /* CONFIG_MMU */
Commit	Line	Data
6496a23a MS	1	/*
	2	* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
	3	* Copyright (C) 2008-2009 PetaLogix
	4	* Copyright (C) 2006 Atmark Techno, Inc.
	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file "COPYING" in the main directory of this archive
	8	* for more details.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/sched.h>
	13	#include <linux/pm.h>
	14	#include <linux/tick.h>
	15	#include <linux/bitops.h>
6496a23a	16	#include <asm/pgalloc.h>
40db0834	17	#include <asm/uaccess.h> /* for USER_DS macros */
a1f55113	18	#include <asm/cacheflush.h>
6496a23a MS	19
	20	void show_regs(struct pt_regs *regs)
	21	{
ac3efab5	22	printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode);
6496a23a MS	23	printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
	24	regs->r1, regs->r2, regs->r3, regs->r4);
	25	printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
	26	regs->r5, regs->r6, regs->r7, regs->r8);
	27	printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
	28	regs->r9, regs->r10, regs->r11, regs->r12);
	29	printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
	30	regs->r13, regs->r14, regs->r15, regs->r16);
	31	printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
	32	regs->r17, regs->r18, regs->r19, regs->r20);
	33	printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
	34	regs->r21, regs->r22, regs->r23, regs->r24);
	35	printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
	36	regs->r25, regs->r26, regs->r27, regs->r28);
	37	printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
	38	regs->r29, regs->r30, regs->r31, regs->pc);
	39	printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
	40	regs->msr, regs->ear, regs->esr, regs->fsr);
6496a23a MS	41	}
	42
	43	void (*pm_idle)(void);
	44	void (*pm_power_off)(void) = NULL;
	45	EXPORT_SYMBOL(pm_power_off);
	46
	47	static int hlt_counter = 1;
	48
	49	void disable_hlt(void)
	50	{
	51	hlt_counter++;
	52	}
	53	EXPORT_SYMBOL(disable_hlt);
	54
	55	void enable_hlt(void)
	56	{
	57	hlt_counter--;
	58	}
	59	EXPORT_SYMBOL(enable_hlt);
	60
	61	static int __init nohlt_setup(char *__unused)
	62	{
	63	hlt_counter = 1;
	64	return 1;
	65	}
	66	__setup("nohlt", nohlt_setup);
	67
	68	static int __init hlt_setup(char *__unused)
	69	{
	70	hlt_counter = 0;
	71	return 1;
	72	}
	73	__setup("hlt", hlt_setup);
	74
	75	void default_idle(void)
	76	{
78ebfa88	77	if (likely(hlt_counter)) {
d0f140e0 MS	78	local_irq_disable();
	79	stop_critical_timings();
	80	cpu_relax();
	81	start_critical_timings();
	82	local_irq_enable();
78ebfa88	83	} else {
6496a23a MS	84	clear_thread_flag(TIF_POLLING_NRFLAG);
	85	smp_mb__after_clear_bit();
	86	local_irq_disable();
	87	while (!need_resched())
	88	cpu_sleep();
	89	local_irq_enable();
	90	set_thread_flag(TIF_POLLING_NRFLAG);
78ebfa88	91	}
6496a23a MS	92	}
	93
	94	void cpu_idle(void)
	95	{
	96	set_thread_flag(TIF_POLLING_NRFLAG);
	97
	98	/* endless idle loop with no priority at all */
	99	while (1) {
	100	void (*idle)(void) = pm_idle;
	101
	102	if (!idle)
	103	idle = default_idle;
	104
1268fbc7 FW	105	tick_nohz_idle_enter();
1268fbc7 FW	106	rcu_idle_enter();
6496a23a MS	107	while (!need_resched())
6496a23a MS	108	idle();
1268fbc7 FW	109	rcu_idle_exit();
1268fbc7 FW	110	tick_nohz_idle_exit();
6496a23a	111
bd2f5536	112	schedule_preempt_disabled();
6496a23a MS	113	check_pgt_cache();
	114	}
	115	}
	116
	117	void flush_thread(void)
	118	{
	119	}
	120
a8fb748e	121	int copy_thread(unsigned long clone_flags, unsigned long usp,
6496a23a MS	122	unsigned long unused,
	123	struct task_struct p, struct pt_regs regs)
	124	{
	125	struct pt_regs *childregs = task_pt_regs(p);
	126	struct thread_info *ti = task_thread_info(p);
	127
	128	childregs = regs;
	129	if (user_mode(regs))
	130	childregs->r1 = usp;
	131	else
	132	childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
	133
5233806d	134	#ifndef CONFIG_MMU
6496a23a MS	135	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
	136	ti->cpu_context.r1 = (unsigned long)childregs;
	137	ti->cpu_context.msr = (unsigned long)childregs->msr;
5233806d MS	138	#else
	139
	140	/* if creating a kernel thread then update the current reg (we don't
	141	* want to use the parent's value when restoring by POP_STATE) */
	142	if (kernel_mode(regs))
	143	/* save new current on stack to use POP_STATE */
	144	childregs->CURRENT_TASK = (unsigned long)p;
	145	/* if returning to user then use the parent's value of this register */
	146
	147	/* if we're creating a new kernel thread then just zeroing all
	148	* the registers. That's OK for a brand new thread.*/
	149	/* Pls. note that some of them will be restored in POP_STATE */
	150	if (kernel_mode(regs))
	151	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
	152	/* if this thread is created for fork/vfork/clone, then we want to
	153	* restore all the parent's context */
	154	/* in addition to the registers which will be restored by POP_STATE */
	155	else {
	156	ti->cpu_context = (struct cpu_context )regs;
	157	childregs->msr \|= MSR_UMS;
	158	}
	159
	160	/* FIXME STATE_SAVE_PT_OFFSET; */
6e83557c	161	ti->cpu_context.r1 = (unsigned long)childregs;
5233806d MS	162	/* we should consider the fact that childregs is a copy of the parent
	163	* regs which were saved immediately after entering the kernel state
	164	* before enabling VM. This MSR will be restored in switch_to and
	165	* RETURN() and we want to have the right machine state there
	166	* specifically this state must have INTs disabled before and enabled
	167	* after performing rtbd
	168	* compose the right MSR for RETURN(). It will work for switch_to also
	169	* excepting for VM and UMS
	170	* don't touch UMS , CARRY and cache bits
	171	* right now MSR is a copy of parent one */
	172	childregs->msr \|= MSR_BIP;
	173	childregs->msr &= ~MSR_EIP;
	174	childregs->msr \|= MSR_IE;
	175	childregs->msr &= ~MSR_VM;
	176	childregs->msr \|= MSR_VMS;
	177	childregs->msr \|= MSR_EE; /* exceptions will be enabled*/
	178
	179	ti->cpu_context.msr = (childregs->msr\|MSR_VM);
	180	ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
84ac218f	181	ti->cpu_context.msr &= ~MSR_IE;
5233806d	182	#endif
6496a23a MS	183	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
6496a23a MS	184
d5c15f17 EI	185	/*
	186	* r21 is the thread reg, r10 is 6th arg to clone
	187	* which contains TLS area
	188	*/
6496a23a	189	if (clone_flags & CLONE_SETTLS)
d5c15f17	190	childregs->r21 = childregs->r10;
6496a23a MS	191
	192	return 0;
	193	}
	194
5233806d	195	#ifndef CONFIG_MMU
6496a23a MS	196	/*
	197	* Return saved PC of a blocked thread.
	198	*/
	199	unsigned long thread_saved_pc(struct task_struct *tsk)
	200	{
	201	struct cpu_context *ctx =
	202	&(((struct thread_info *)(tsk->stack))->cpu_context);
	203
	204	/* Check whether the thread is blocked in resume() */
	205	if (in_sched_functions(ctx->r15))
	206	return (unsigned long)ctx->r15;
	207	else
	208	return ctx->r14;
	209	}
5233806d	210	#endif
6496a23a MS	211
	212	static void kernel_thread_helper(int (fn)(void ), void *arg)
	213	{
	214	fn(arg);
	215	do_exit(-1);
	216	}
	217
	218	int kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
	219	{
	220	struct pt_regs regs;
6496a23a MS	221
	222	memset(&regs, 0, sizeof(regs));
	223	/* store them in non-volatile registers */
	224	regs.r5 = (unsigned long)fn;
	225	regs.r6 = (unsigned long)arg;
	226	local_save_flags(regs.msr);
	227	regs.pc = (unsigned long)kernel_thread_helper;
ac3efab5	228	regs.pt_mode = 1;
6496a23a	229
6714fcc3	230	return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0,
6496a23a	231	&regs, 0, NULL, NULL);
6496a23a	232	}
5af7fa68	233	EXPORT_SYMBOL_GPL(kernel_thread);
6496a23a MS	234
	235	unsigned long get_wchan(struct task_struct *p)
	236	{
	237	/* TBD (used by procfs) */
	238	return 0;
	239	}
e1c4bd08 MS	240
	241	/* Set up a thread for executing a new program */
	242	void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
	243	{
e1c4bd08 MS	244	regs->pc = pc;
	245	regs->r1 = usp;
	246	regs->pt_mode = 0;
f1ae3f69	247	#ifdef CONFIG_MMU
866d7229	248	regs->msr \|= MSR_UMS;
f1ae3f69	249	#endif
e1c4bd08	250	}
5233806d MS	251
	252	#ifdef CONFIG_MMU
	253	#include <linux/elfcore.h>
	254	/*
	255	* Set up a thread for executing a new program
	256	*/
	257	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpregs)
	258	{
	259	return 0; /* MicroBlaze has no separate FPU registers */
	260	}
	261	#endif /* CONFIG_MMU */