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

 /* 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/config.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.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 <asm/uaccess.h>
 #include <asm/system.h>
 #include <asm/setup.h>
 #include <asm/pgtable.h>
 #include <asm/gdb-stub.h>
 #include <asm/mb-regs.h>

 #include "local.h"

 asmlinkage void ret_from_fork(void);

 #include <asm/pgalloc.h>

 struct task_struct *alloc_task_struct(void)
 {
 	struct task_struct *p = kmalloc(THREAD_SIZE, GFP_KERNEL);
 	if (p)
 		atomic_set((atomic_t *)(p+1), 1);
 	return p;
 }

 void free_task_struct(struct task_struct *p)
 {
 	if (atomic_dec_and_test((atomic_t *)(p+1)))
 		kfree(p);
 }

 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) {
 		while (!need_resched()) {
 			irq_stat[smp_processor_id()].idle_timestamp = jiffies;

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

 		schedule();
 	}
 }

 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)
 {
 #if 0 //ndef NO_FPU
 	unsigned long zero = 0;
 #endif
 	set_fs(USER_DS);
 }

 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;
 }

 asmlinkage int sys_fork(void)
 {
 #ifndef CONFIG_MMU
 	/* fork almost works, enough to trick you into looking elsewhere:-( */
 	return -EINVAL;
 #else
 	return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
 #endif
 }

 asmlinkage int sys_vfork(void)
 {
 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
 		       NULL, NULL);
 }

 /*****************************************************************************/
 /*
  * clone a process
  * - tlsptr is retrieved by copy_thread()
  */
 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 			 int __user *parent_tidptr, int __user *child_tidptr,
 			 int __user *tlsptr)
 {
 	if (!newsp)
 		newsp = user_stack(__frame);
 	return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
 } /* end sys_clone() */

 /*****************************************************************************/
 /*
  * This gets called before we allocate a new thread and copy
  * the current task into it.
  */
 void prepare_to_copy(struct task_struct *tsk)
 {
 	//unlazy_fpu(tsk);
 } /* end prepare_to_copy() */

 /*****************************************************************************/
 /*
  * set up the kernel stack and exception frames for a new process
  */
 int copy_thread(int nr, unsigned long clone_flags,
 		unsigned long usp, unsigned long topstk,
 		struct task_struct *p, struct pt_regs *regs)
 {
 	struct pt_regs *childregs0, *childregs, *regs0;

 	regs0 = __kernel_frame0_ptr;
 	childregs0 = (struct pt_regs *)
 		((unsigned long) p->thread_info + THREAD_SIZE - USER_CONTEXT_SIZE);
 	childregs = childregs0;

 	/* set up the userspace frame (the only place that the USP is stored) */
 	*childregs0 = *regs0;

 	childregs0->gr8		= 0;
 	childregs0->sp		= usp;
 	childregs0->next_frame	= NULL;

 	/* set up the return kernel frame if called from kernel_thread() */
 	if (regs != regs0) {
 		childregs--;
 		*childregs = *regs;
 		childregs->sp = (unsigned long) childregs0;
 		childregs->next_frame = childregs0;
 		childregs->gr15 = (unsigned long) p->thread_info;
 		childregs->gr29 = (unsigned long) p;
 	}

 	p->set_child_tid = p->clear_child_tid = NULL;

 	p->thread.frame	 = childregs;
 	p->thread.curr	 = p;
 	p->thread.sp	 = (unsigned long) childregs;
 	p->thread.fp	 = 0;
 	p->thread.lr	 = 0;
 	p->thread.pc	 = (unsigned long) ret_from_fork;
 	p->thread.frame0 = childregs0;

 	/* 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() */

 /*
  * fill in the user structure for a core dump..
  */
 void dump_thread(struct pt_regs *regs, struct user *dump)
 {
 #if 0
 	/* changed the size calculations - should hopefully work better. lbt */
 	dump->magic = CMAGIC;
 	dump->start_code = 0;
 	dump->start_stack = user_stack(regs) & ~(PAGE_SIZE - 1);
 	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
 	dump->u_dsize -= dump->u_tsize;
 	dump->u_ssize = 0;

 	if (dump->start_stack < TASK_SIZE)
 		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;

 	dump->regs = *(struct user_context *) regs;
 #endif
 }

 /*
  * sys_execve() executes a new program.
  */
 asmlinkage int sys_execve(char *name, char **argv, char **envp)
 {
 	int error;
 	char * filename;

 	lock_kernel();
 	filename = getname(name);
 	error = PTR_ERR(filename);
 	if (IS_ERR(filename))
 		goto out;
 	error = do_execve(filename, argv, envp, __frame);
 	putname(filename);
  out:
 	unlock_kernel();
 	return error;
 }

 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;
 }
	/* 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/config.h>
	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/smp_lock.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 <asm/uaccess.h>
	#include <asm/system.h>
	#include <asm/setup.h>
	#include <asm/pgtable.h>
	#include <asm/gdb-stub.h>
	#include <asm/mb-regs.h>

	#include "local.h"

	asmlinkage void ret_from_fork(void);

	#include <asm/pgalloc.h>

	struct task_struct *alloc_task_struct(void)
	{
	struct task_struct *p = kmalloc(THREAD_SIZE, GFP_KERNEL);
	if (p)
	atomic_set((atomic_t *)(p+1), 1);
	return p;
	}

	void free_task_struct(struct task_struct *p)
	{
	if (atomic_dec_and_test((atomic_t *)(p+1)))
	kfree(p);
	}

	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) {
	while (!need_resched()) {
	irq_stat[smp_processor_id()].idle_timestamp = jiffies;

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

	schedule();
	}
	}

	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)
	{
	#if 0 //ndef NO_FPU
	unsigned long zero = 0;
	#endif
	set_fs(USER_DS);
	}

	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;
	}

	asmlinkage int sys_fork(void)
	{
	#ifndef CONFIG_MMU
	/* fork almost works, enough to trick you into looking elsewhere:-( */
	return -EINVAL;
	#else
	return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
	#endif
	}

	asmlinkage int sys_vfork(void)
	{
	return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, user_stack(__frame), __frame, 0,
	NULL, NULL);
	}

	/*****************************************************************************/
	/*
	* clone a process
	* - tlsptr is retrieved by copy_thread()
	*/
	asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
	int __user parent_tidptr, int __user child_tidptr,
	int __user *tlsptr)
	{
	if (!newsp)
	newsp = user_stack(__frame);
	return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
	} /* end sys_clone() */

	/*****************************************************************************/
	/*
	* This gets called before we allocate a new thread and copy
	* the current task into it.
	*/
	void prepare_to_copy(struct task_struct *tsk)
	{
	//unlazy_fpu(tsk);
	} /* end prepare_to_copy() */

	/*****************************************************************************/
	/*
	* set up the kernel stack and exception frames for a new process
	*/
	int copy_thread(int nr, unsigned long clone_flags,
	unsigned long usp, unsigned long topstk,
	struct task_struct p, struct pt_regs regs)
	{
	struct pt_regs childregs0, childregs, *regs0;

	regs0 = __kernel_frame0_ptr;
	childregs0 = (struct pt_regs *)
	((unsigned long) p->thread_info + THREAD_SIZE - USER_CONTEXT_SIZE);
	childregs = childregs0;

	/* set up the userspace frame (the only place that the USP is stored) */
	childregs0 = regs0;

	childregs0->gr8 = 0;
	childregs0->sp = usp;
	childregs0->next_frame = NULL;

	/* set up the return kernel frame if called from kernel_thread() */
	if (regs != regs0) {
	childregs--;
	childregs = regs;
	childregs->sp = (unsigned long) childregs0;
	childregs->next_frame = childregs0;
	childregs->gr15 = (unsigned long) p->thread_info;
	childregs->gr29 = (unsigned long) p;
	}

	p->set_child_tid = p->clear_child_tid = NULL;

	p->thread.frame = childregs;
	p->thread.curr = p;
	p->thread.sp = (unsigned long) childregs;
	p->thread.fp = 0;
	p->thread.lr = 0;
	p->thread.pc = (unsigned long) ret_from_fork;
	p->thread.frame0 = childregs0;

	/* 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() */

	/*
	* fill in the user structure for a core dump..
	*/
	void dump_thread(struct pt_regs regs, struct user dump)
	{
	#if 0
	/* changed the size calculations - should hopefully work better. lbt */
	dump->magic = CMAGIC;
	dump->start_code = 0;
	dump->start_stack = user_stack(regs) & ~(PAGE_SIZE - 1);
	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
	dump->u_dsize -= dump->u_tsize;
	dump->u_ssize = 0;

	if (dump->start_stack < TASK_SIZE)
	dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;

	dump->regs = (struct user_context ) regs;
	#endif
	}

	/*
	* sys_execve() executes a new program.
	*/
	asmlinkage int sys_execve(char name, char argv, char *envp)
	{
	int error;
	char * filename;

	lock_kernel();
	filename = getname(name);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
	goto out;
	error = do_execve(filename, argv, envp, __frame);
	putname(filename);
	out:
	unlock_kernel();
	return error;
	}

	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;
	}