arch/microblaze/kernel/process.c - maze/linux - Git at Google

 /*
  * 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/system.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_stop_sched_tick(1);
 		while (!need_resched())
 			idle();
 		tick_nohz_restart_sched_tick();

 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();
 		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 - STATE_SAVE_ARG_SPACE;
 	/* 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 */
 #endif
 	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;

 	if (clone_flags & CLONE_SETTLS)
 		;

 	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)
 {
 	set_fs(USER_DS);
 	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 */
	/*
	* 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/system.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_stop_sched_tick(1);
	while (!need_resched())
	idle();
	tick_nohz_restart_sched_tick();

	preempt_enable_no_resched();
	schedule();
	preempt_disable();
	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 - STATE_SAVE_ARG_SPACE;
	/* 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 */
	#endif
	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;

	if (clone_flags & CLONE_SETTLS)
	;

	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)
	{
	set_fs(USER_DS);
	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 */