/* * 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. * * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others. * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2004 Thiemo Seufer */#include <linux/config.h>#include <linux/errno.h>#include <linux/module.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/ptrace.h>#include <linux/slab.h>#include <linux/mman.h>#include <linux/personality.h>#include <linux/sys.h>#include <linux/user.h>#include <linux/a.out.h>#include <linux/init.h>#include <linux/completion.h>#include <linux/kallsyms.h> #include <asm/abi.h>#include <asm/bootinfo.h>#include <asm/cpu.h>#include <asm/dsp.h>#include <asm/fpu.h>#include <asm/pgtable.h>#include <asm/system.h>#include <asm/mipsregs.h>#include <asm/processor.h>#include <asm/uaccess.h>#include <asm/io.h>#include <asm/elf.h>#include <asm/isadep.h>#include <asm/inst.h>#ifdef CONFIG_MIPS_MT_SMTC#include <asm/mipsmtregs.h>extern void smtc_idle_loop_hook(void);#endif /* CONFIG_MIPS_MT_SMTC */ /* * 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) */ATTRIB_NORET void cpu_idle(void){	/* endless idle loop with no priority at all */	while (1) {		while (!need_resched()) {#ifdef CONFIG_MIPS_MT_SMTC			smtc_idle_loop_hook();#endif /* CONFIG_MIPS_MT_SMTC */			if (cpu_wait)				(*cpu_wait)();		}		preempt_enable_no_resched();		schedule();		preempt_disable();	}} /* * Native o32 and N64 ABI without DSP ASE */struct mips_abi mips_abi = {	.do_signal	= do_signal,#ifdef CONFIG_TRAD_SIGNALS	.setup_frame	= setup_frame,#endif	.setup_rt_frame	= setup_rt_frame}; #ifdef CONFIG_MIPS32_O32/* * o32 compatibility on 64-bit kernels, without DSP ASE */struct mips_abi mips_abi_32 = {	.do_signal	= do_signal32,	.setup_frame	= setup_frame_32,	.setup_rt_frame	= setup_rt_frame_32};#endif /* CONFIG_MIPS32_O32 */ #ifdef CONFIG_MIPS32_N32/* * N32 on 64-bit kernels, without DSP ASE */struct mips_abi mips_abi_n32 = {	.do_signal	= do_signal,	.setup_rt_frame	= setup_rt_frame_n32};#endif /* CONFIG_MIPS32_N32 */ asmlinkage void ret_from_fork(void); void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp){	unsigned long status; 	/* New thread loses kernel privileges. */	status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|KU_MASK);#ifdef CONFIG_64BIT	status &= ~ST0_FR;	status |= (current->thread.mflags & MF_32BIT_REGS) ? 0 : ST0_FR;#endif	status |= KU_USER;	regs->cp0_status = status;	clear_used_math();	lose_fpu();	if (cpu_has_dsp)		__init_dsp();	regs->cp0_epc = pc;	regs->regs[29] = sp;	current_thread_info()->addr_limit = USER_DS;} void exit_thread(void){} void flush_thread(void){} int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,	unsigned long unused, struct task_struct *p, struct pt_regs *regs){	struct thread_info *ti = task_thread_info(p);	struct pt_regs *childregs;	long childksp;	p->set_child_tid = p->clear_child_tid = NULL; 	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; 	preempt_disable(); 	if (is_fpu_owner())		save_fp(p); 	if (cpu_has_dsp)		save_dsp(p); 	preempt_enable(); 	/* set up new TSS. */	childregs = (struct pt_regs *) childksp - 1;	*childregs = *regs;	childregs->regs[7] = 0;	/* Clear error flag */ #if defined(CONFIG_BINFMT_IRIX)	if (current->personality != PER_LINUX) {		/* Under IRIX things are a little different. */		childregs->regs[3] = 1;		regs->regs[3] = 0;	}#endif	childregs->regs[2] = 0;	/* Child gets zero as return value */	regs->regs[2] = p->pid; 	if (childregs->cp0_status & ST0_CU0) {		childregs->regs[28] = (unsigned long) ti;		childregs->regs[29] = childksp;		ti->addr_limit = KERNEL_DS;	} else {		childregs->regs[29] = usp;		ti->addr_limit = USER_DS;	}	p->thread.reg29 = (unsigned long) childregs;	p->thread.reg31 = (unsigned long) ret_from_fork; 	/*	 * New tasks lose permission to use the fpu. This accelerates context	 * switching for most programs since they don't use the fpu.	 */	p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);	childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);	clear_tsk_thread_flag(p, TIF_USEDFPU); #ifdef CONFIG_MIPS_MT_FPAFF	/*	 * FPU affinity support is cleaner if we track the	 * user-visible CPU affinity from the very beginning.	 * The generic cpus_allowed mask will already have	 * been copied from the parent before copy_thread	 * is invoked.	 */	p->thread.user_cpus_allowed = p->cpus_allowed;#endif /* CONFIG_MIPS_MT_FPAFF */ 	if (clone_flags & CLONE_SETTLS)		ti->tp_value = regs->regs[7]; 	return 0;} /* Fill in the fpu structure for a core dump.. */int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r){	memcpy(r, &current->thread.fpu, sizeof(current->thread.fpu)); 	return 1;} void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs){	int i; 	for (i = 0; i < EF_R0; i++)		gp[i] = 0;	gp[EF_R0] = 0;	for (i = 1; i <= 31; i++)		gp[EF_R0 + i] = regs->regs[i];	gp[EF_R26] = 0;	gp[EF_R27] = 0;	gp[EF_LO] = regs->lo;	gp[EF_HI] = regs->hi;	gp[EF_CP0_EPC] = regs->cp0_epc;	gp[EF_CP0_BADVADDR] = regs->cp0_badvaddr;	gp[EF_CP0_STATUS] = regs->cp0_status;	gp[EF_CP0_CAUSE] = regs->cp0_cause;#ifdef EF_UNUSED0	gp[EF_UNUSED0] = 0;#endif} int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs){	elf_dump_regs(*regs, task_pt_regs(tsk));	return 1;} int dump_task_fpu (struct task_struct *t, elf_fpregset_t *fpr){	memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); 	return 1;} /* * Create a kernel thread */ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)){	do_exit(fn(arg));} long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags){	struct pt_regs regs; 	memset(&regs, 0, sizeof(regs)); 	regs.regs[4] = (unsigned long) arg;	regs.regs[5] = (unsigned long) fn;	regs.cp0_epc = (unsigned long) kernel_thread_helper;	regs.cp0_status = read_c0_status();#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)	regs.cp0_status &= ~(ST0_KUP | ST0_IEC);	regs.cp0_status |= ST0_IEP;#else	regs.cp0_status |= ST0_EXL;#endif 	/* Ok, create the new process.. */	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);} static struct mips_frame_info {	void *func;	unsigned long func_size;	int frame_size;	int pc_offset;} *schedule_frame, mfinfo[64];static int mfinfo_num; static int __init get_frame_info(struct mips_frame_info *info){	int i;	void *func = info->func;	union mips_instruction *ip = (union mips_instruction *)func;	info->pc_offset = -1;	info->frame_size = 0;	for (i = 0; i < 128; i++, ip++) {		/* if jal, jalr, jr, stop. */		if (ip->j_format.opcode == jal_op ||		    (ip->r_format.opcode == spec_op &&		     (ip->r_format.func == jalr_op ||		      ip->r_format.func == jr_op)))			break; 		if (info->func_size && i >= info->func_size / 4)			break;		if (#ifdef CONFIG_32BIT		    ip->i_format.opcode == addiu_op &&#endif#ifdef CONFIG_64BIT		    ip->i_format.opcode == daddiu_op &&#endif		    ip->i_format.rs == 29 &&		    ip->i_format.rt == 29) {			/* addiu/daddiu sp,sp,-imm */			if (info->frame_size)				continue;			info->frame_size = - ip->i_format.simmediate;		} 		if (#ifdef CONFIG_32BIT		    ip->i_format.opcode == sw_op &&#endif#ifdef CONFIG_64BIT		    ip->i_format.opcode == sd_op &&#endif		    ip->i_format.rs == 29 &&		    ip->i_format.rt == 31) {			/* sw / sd $ra, offset($sp) */			if (info->pc_offset != -1)				continue;			info->pc_offset =				ip->i_format.simmediate / sizeof(long);		}	}	if (info->pc_offset == -1 || info->frame_size == 0) {		if (func == schedule)			printk("Can't analyze prologue code at %p\n", func);		info->pc_offset = -1;		info->frame_size = 0;	} 	return 0;} static int __init frame_info_init(void){	int i;#ifdef CONFIG_KALLSYMS	char *modname;	char namebuf[KSYM_NAME_LEN + 1];	unsigned long start, size, ofs;	extern char __sched_text_start[], __sched_text_end[];	extern char __lock_text_start[], __lock_text_end[]; 	start = (unsigned long)__sched_text_start;	for (i = 0; i < ARRAY_SIZE(mfinfo); i++) {		if (start == (unsigned long)schedule)			schedule_frame = &mfinfo[i];		if (!kallsyms_lookup(start, &size, &ofs, &modname, namebuf))			break;		mfinfo[i].func = (void *)(start + ofs);		mfinfo[i].func_size = size;		start += size - ofs;		if (start >= (unsigned long)__lock_text_end)			break;		if (start == (unsigned long)__sched_text_end)			start = (unsigned long)__lock_text_start;	}#else	mfinfo[0].func = schedule;	schedule_frame = &mfinfo[0];#endif	for (i = 0; i < ARRAY_SIZE(mfinfo) && mfinfo[i].func; i++)		get_frame_info(&mfinfo[i]); 	mfinfo_num = i;	return 0;} arch_initcall(frame_info_init); /* * Return saved PC of a blocked thread. */unsigned long thread_saved_pc(struct task_struct *tsk){	struct thread_struct *t = &tsk->thread; 	/* New born processes are a special case */	if (t->reg31 == (unsigned long) ret_from_fork)		return t->reg31; 	if (!schedule_frame || schedule_frame->pc_offset < 0)		return 0;	return ((unsigned long *)t->reg29)[schedule_frame->pc_offset];} /* get_wchan - a maintenance nightmare^W^Wpain in the ass ...  */unsigned long get_wchan(struct task_struct *p){	unsigned long stack_page;	unsigned long pc;#ifdef CONFIG_KALLSYMS	unsigned long frame;#endif 	if (!p || p == current || p->state == TASK_RUNNING)		return 0; 	stack_page = (unsigned long)task_stack_page(p);	if (!stack_page || !mfinfo_num)		return 0; 	pc = thread_saved_pc(p);#ifdef CONFIG_KALLSYMS	if (!in_sched_functions(pc))		return pc; 	frame = p->thread.reg29 + schedule_frame->frame_size;	do {		int i; 		if (frame < stack_page || frame > stack_page + THREAD_SIZE - 32)			return 0; 		for (i = mfinfo_num - 1; i >= 0; i--) {			if (pc >= (unsigned long) mfinfo[i].func)				break;		}		if (i < 0)			break; 		pc = ((unsigned long *)frame)[mfinfo[i].pc_offset];		if (!mfinfo[i].frame_size)			break;		frame += mfinfo[i].frame_size;	} while (in_sched_functions(pc));#endif 	return pc;}