/* * 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) 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 <asm/bootinfo.h> #include <asm/cpu.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> /* * We use this if we don't have any better idle routine.. * (This to kill: kernel/platform.c. */ void default_idle (void) { } /* * 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()) if (cpu_wait) (*cpu_wait)(); schedule(); } } 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(); 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 = p->thread_info; struct pt_regs *childregs; long childksp; childksp = (unsigned long)ti + THREAD_SIZE - 32; preempt_disable(); if (is_fpu_owner()) { save_fp(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); return 0; } /* Fill in the fpu structure for a core dump.. */ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) { memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); return 1; } void 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_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(®s, 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, ®s, 0, NULL, NULL); } struct mips_frame_info { int frame_offset; int pc_offset; }; static struct mips_frame_info schedule_frame; static struct mips_frame_info schedule_timeout_frame; static struct mips_frame_info sleep_on_frame; static struct mips_frame_info sleep_on_timeout_frame; static struct mips_frame_info wait_for_completion_frame; static int mips_frame_info_initialized; static int __init get_frame_info(struct mips_frame_info *info, void *func) { int i; union mips_instruction *ip = (union mips_instruction *)func; info->pc_offset = -1; info->frame_offset = -1; 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 ( #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) { /* sw / sd $ra, offset($sp) */ if (ip->i_format.rt == 31) { if (info->pc_offset != -1) break; info->pc_offset = ip->i_format.simmediate / sizeof(long); } /* sw / sd $s8, offset($sp) */ if (ip->i_format.rt == 30) { if (info->frame_offset != -1) break; info->frame_offset = ip->i_format.simmediate / sizeof(long); } } } if (info->pc_offset == -1 || info->frame_offset == -1) { printk("Can't analyze prologue code at %p\n", func); info->pc_offset = -1; info->frame_offset = -1; return -1; } return 0; } static int __init frame_info_init(void) { mips_frame_info_initialized = !get_frame_info(&schedule_frame, schedule) && !get_frame_info(&schedule_timeout_frame, schedule_timeout) && !get_frame_info(&sleep_on_frame, sleep_on) && !get_frame_info(&sleep_on_timeout_frame, sleep_on_timeout) && !get_frame_info(&wait_for_completion_frame, wait_for_completion); 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.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 frame, pc; if (!p || p == current || p->state == TASK_RUNNING) return 0; if (!mips_frame_info_initialized) return 0; pc = thread_saved_pc(p); if (!in_sched_functions(pc)) goto out; if (pc >= (unsigned long) sleep_on_timeout) goto schedule_timeout_caller; if (pc >= (unsigned long) sleep_on) goto schedule_caller; if (pc >= (unsigned long) interruptible_sleep_on_timeout) goto schedule_timeout_caller; if (pc >= (unsigned long)interruptible_sleep_on) goto schedule_caller; if (pc >= (unsigned long)wait_for_completion) goto schedule_caller; goto schedule_timeout_caller; schedule_caller: frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; if (pc >= (unsigned long) sleep_on) pc = ((unsigned long *)frame)[sleep_on_frame.pc_offset]; else pc = ((unsigned long *)frame)[wait_for_completion_frame.pc_offset]; goto out; schedule_timeout_caller: /* * The schedule_timeout frame */ frame = ((unsigned long *)p->thread.reg30)[schedule_frame.frame_offset]; /* * frame now points to sleep_on_timeout's frame */ pc = ((unsigned long *)frame)[schedule_timeout_frame.pc_offset]; if (in_sched_functions(pc)) { /* schedule_timeout called by [interruptible_]sleep_on_timeout */ frame = ((unsigned long *)frame)[schedule_timeout_frame.frame_offset]; pc = ((unsigned long *)frame)[sleep_on_timeout_frame.pc_offset]; } out: #ifdef CONFIG_64BIT if (current->thread.mflags & MF_32BIT_REGS) /* Kludge for 32-bit ps */ pc &= 0xffffffffUL; #endif return pc; } EXPORT_SYMBOL(get_wchan);