/* * linux/arch/m68k/kernel/process.c * * Copyright (C) 1995 Hamish Macdonald * * 68060 fixes by Jesper Skov */ /* * This file handles the architecture-dependent parts of process handling.. */ #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/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/a.out.h> #include <linux/reboot.h> #include <linux/init_task.h> #include <linux/mqueue.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/traps.h> #include <asm/machdep.h> #include <asm/setup.h> #include <asm/pgtable.h> /* * Initial task/thread structure. Make this a per-architecture thing, * because different architectures tend to have different * alignment requirements and potentially different initial * setup. */ static struct fs_struct init_fs = INIT_FS; static struct files_struct init_files = INIT_FILES; static struct signal_struct init_signals = INIT_SIGNALS(init_signals); static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); struct mm_struct init_mm = INIT_MM(init_mm); EXPORT_SYMBOL(init_mm); union thread_union init_thread_union __attribute__((section(".data.init_task"), aligned(THREAD_SIZE))) = { INIT_THREAD_INFO(init_task) }; /* initial task structure */ struct task_struct init_task = INIT_TASK(init_task); EXPORT_SYMBOL(init_task); asmlinkage void ret_from_fork(void); /* * Return saved PC from a blocked thread */ unsigned long thread_saved_pc(struct task_struct *tsk) { struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; /* Check whether the thread is blocked in resume() */ if (in_sched_functions(sw->retpc)) return ((unsigned long *)sw->a6)[1]; else return sw->retpc; } /* * The idle loop on an m68k.. */ void default_idle(void) { if (!need_resched()) #if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES) /* block out HSYNC on the atari (falcon) */ __asm__("stop #0x2200" : : : "cc"); #else __asm__("stop #0x2000" : : : "cc"); #endif } void (*idle)(void) = default_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()) idle(); preempt_enable_no_resched(); schedule(); preempt_disable(); } } void machine_restart(char * __unused) { if (mach_reset) mach_reset(); for (;;); } void machine_halt(void) { if (mach_halt) mach_halt(); for (;;); } void machine_power_off(void) { if (mach_power_off) mach_power_off(); for (;;); } void show_regs(struct pt_regs * regs) { printk("\n"); printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", regs->orig_d0, regs->d0, regs->a2, regs->a1); printk("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5, regs->d4); printk("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2, regs->d1); if (!(regs->sr & PS_S)) printk("USP: %08lx\n", rdusp()); } /* * Create a kernel thread */ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) { int pid; mm_segment_t fs; fs = get_fs(); set_fs (KERNEL_DS); { register long retval __asm__ ("d0"); register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; retval = __NR_clone; __asm__ __volatile__ ("clrl %%d2\n\t" "trap #0\n\t" /* Linux/m68k system call */ "tstl %0\n\t" /* child or parent */ "jne 1f\n\t" /* parent - jump */ "lea %%sp@(%c7),%6\n\t" /* reload current */ "movel %6@,%6\n\t" "movel %3,%%sp@-\n\t" /* push argument */ "jsr %4@\n\t" /* call fn */ "movel %0,%%d1\n\t" /* pass exit value */ "movel %2,%%d0\n\t" /* exit */ "trap #0\n" "1:" : "+d" (retval) : "i" (__NR_clone), "i" (__NR_exit), "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), "i" (-THREAD_SIZE) : "d2"); pid = retval; } set_fs (fs); return pid; } void flush_thread(void) { unsigned long zero = 0; set_fs(USER_DS); current->thread.fs = __USER_DS; if (!FPU_IS_EMU) asm volatile (".chip 68k/68881\n\t" "frestore %0@\n\t" ".chip 68k" : : "a" (&zero)); } /* * "m68k_fork()".. By the time we get here, the * non-volatile registers have also been saved on the * stack. We do some ugly pointer stuff here.. (see * also copy_thread) */ asmlinkage int m68k_fork(struct pt_regs *regs) { return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); } asmlinkage int m68k_vfork(struct pt_regs *regs) { return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL); } asmlinkage int m68k_clone(struct pt_regs *regs) { unsigned long clone_flags; unsigned long newsp; int *parent_tidptr, *child_tidptr; /* syscall2 puts clone_flags in d1 and usp in d2 */ clone_flags = regs->d1; newsp = regs->d2; parent_tidptr = (int *)regs->d3; child_tidptr = (int *)regs->d4; if (!newsp) newsp = rdusp(); return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); } int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, unsigned long unused, struct task_struct * p, struct pt_regs * regs) { struct pt_regs * childregs; struct switch_stack * childstack, *stack; unsigned long stack_offset, *retp; stack_offset = THREAD_SIZE - sizeof(struct pt_regs); childregs = (struct pt_regs *) ((unsigned long) (p->thread_info) + stack_offset); *childregs = *regs; childregs->d0 = 0; retp = ((unsigned long *) regs); stack = ((struct switch_stack *) retp) - 1; childstack = ((struct switch_stack *) childregs) - 1; *childstack = *stack; childstack->retpc = (unsigned long)ret_from_fork; p->thread.usp = usp; p->thread.ksp = (unsigned long)childstack; /* * Must save the current SFC/DFC value, NOT the value when * the parent was last descheduled - RGH 10-08-96 */ p->thread.fs = get_fs().seg; if (!FPU_IS_EMU) { /* Copy the current fpu state */ asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0]) : "memory"); /* Restore the state in case the fpu was busy */ asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); } return 0; } /* Fill in the fpu structure for a core dump. */ int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) { char fpustate[216]; if (FPU_IS_EMU) { int i; memcpy(fpu->fpcntl, current->thread.fpcntl, 12); memcpy(fpu->fpregs, current->thread.fp, 96); /* Convert internal fpu reg representation * into long double format */ for (i = 0; i < 24; i += 3) fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | ((fpu->fpregs[i] & 0x0000ffff) << 16); return 1; } /* First dump the fpu context to avoid protocol violation. */ asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) return 0; asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" :: "m" (fpu->fpcntl[0]) : "memory"); asm volatile ("fmovemx %/fp0-%/fp7,%0" :: "m" (fpu->fpregs[0]) : "memory"); return 1; } /* * fill in the user structure for a core dump.. */ void dump_thread(struct pt_regs * regs, struct user * dump) { struct switch_stack *sw; /* changed the size calculations - should hopefully work better. lbt */ dump->magic = CMAGIC; dump->start_code = 0; dump->start_stack = rdusp() & ~(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->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump); sw = ((struct switch_stack *)regs) - 1; dump->regs.d1 = regs->d1; dump->regs.d2 = regs->d2; dump->regs.d3 = regs->d3; dump->regs.d4 = regs->d4; dump->regs.d5 = regs->d5; dump->regs.d6 = sw->d6; dump->regs.d7 = sw->d7; dump->regs.a0 = regs->a0; dump->regs.a1 = regs->a1; dump->regs.a2 = regs->a2; dump->regs.a3 = sw->a3; dump->regs.a4 = sw->a4; dump->regs.a5 = sw->a5; dump->regs.a6 = sw->a6; dump->regs.d0 = regs->d0; dump->regs.orig_d0 = regs->orig_d0; dump->regs.stkadj = regs->stkadj; dump->regs.sr = regs->sr; dump->regs.pc = regs->pc; dump->regs.fmtvec = (regs->format << 12) | regs->vector; /* dump floating point stuff */ dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp); } /* * sys_execve() executes a new program. */ asmlinkage int sys_execve(char *name, char **argv, char **envp) { int error; char * filename; struct pt_regs *regs = (struct pt_regs *) &name; lock_kernel(); filename = getname(name); error = PTR_ERR(filename); if (IS_ERR(filename)) goto out; error = do_execve(filename, argv, envp, regs); putname(filename); out: unlock_kernel(); return error; } unsigned long get_wchan(struct task_struct *p) { unsigned long fp, pc; unsigned long stack_page; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; stack_page = (unsigned long)(p->thread_info); fp = ((struct switch_stack *)p->thread.ksp)->a6; do { if (fp < stack_page+sizeof(struct thread_info) || fp >= 8184+stack_page) return 0; pc = ((unsigned long *)fp)[1]; if (!in_sched_functions(pc)) return pc; fp = *(unsigned long *) fp; } while (count++ < 16); return 0; }