/* linux/arch/sparc/kernel/process.c * * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) */ /* * This file handles the architecture-dependent parts of process handling.. */ #include <stdarg.h> #include <linux/elfcore.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/ptrace.h> #include <linux/user.h> #include <linux/smp.h> #include <linux/reboot.h> #include <linux/delay.h> #include <linux/pm.h> #include <linux/slab.h> #include <linux/cpu.h> #include <asm/auxio.h> #include <asm/oplib.h> #include <asm/uaccess.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> #include <asm/delay.h> #include <asm/processor.h> #include <asm/psr.h> #include <asm/elf.h> #include <asm/prom.h> #include <asm/unistd.h> #include <asm/setup.h> #include "kernel.h" /* * Power management idle function * Set in pm platform drivers (apc.c and pmc.c) */ void (*sparc_idle)(void); /* * Power-off handler instantiation for pm.h compliance * This is done via auxio, but could be used as a fallback * handler when auxio is not present-- unused for now... */ void (*pm_power_off)(void) = machine_power_off; EXPORT_SYMBOL(pm_power_off); /* * sysctl - toggle power-off restriction for serial console * systems in machine_power_off() */ int scons_pwroff = 1; extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); struct task_struct *last_task_used_math = NULL; struct thread_info *current_set[NR_CPUS]; /* Idle loop support. */ void arch_cpu_idle(void) { if (sparc_idle) (*sparc_idle)(); local_irq_enable(); } /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ void machine_halt(void) { local_irq_enable(); mdelay(8); local_irq_disable(); prom_halt(); panic("Halt failed!"); } void machine_restart(char * cmd) { char *p; local_irq_enable(); mdelay(8); local_irq_disable(); p = strchr (reboot_command, '\n'); if (p) *p = 0; if (cmd) prom_reboot(cmd); if (*reboot_command) prom_reboot(reboot_command); prom_feval ("reset"); panic("Reboot failed!"); } void machine_power_off(void) { if (auxio_power_register && (strcmp(of_console_device->type, "serial") || scons_pwroff)) { u8 power_register = sbus_readb(auxio_power_register); power_register |= AUXIO_POWER_OFF; sbus_writeb(power_register, auxio_power_register); } machine_halt(); } void show_regs(struct pt_regs *r) { struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; show_regs_print_info(KERN_DEFAULT); printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", r->psr, r->pc, r->npc, r->y, print_tainted()); printk("PC: <%pS>\n", (void *) r->pc); printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); printk("RPC: <%pS>\n", (void *) r->u_regs[15]); printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); } /* * The show_stack is an external API which we do not use ourselves. * The oops is printed in die_if_kernel. */ void show_stack(struct task_struct *tsk, unsigned long *_ksp) { unsigned long pc, fp; unsigned long task_base; struct reg_window32 *rw; int count = 0; if (!tsk) tsk = current; if (tsk == current && !_ksp) __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); task_base = (unsigned long) task_stack_page(tsk); fp = (unsigned long) _ksp; do { /* Bogus frame pointer? */ if (fp < (task_base + sizeof(struct thread_info)) || fp >= (task_base + (PAGE_SIZE << 1))) break; rw = (struct reg_window32 *) fp; pc = rw->ins[7]; printk("[%08lx : ", pc); printk("%pS ] ", (void *) pc); fp = rw->ins[6]; } while (++count < 16); printk("\n"); } /* * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. */ unsigned long thread_saved_pc(struct task_struct *tsk) { return task_thread_info(tsk)->kpc; } /* * Free current thread data structures etc.. */ void exit_thread(void) { #ifndef CONFIG_SMP if(last_task_used_math == current) { #else if (test_thread_flag(TIF_USEDFPU)) { #endif /* Keep process from leaving FPU in a bogon state. */ put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); #ifndef CONFIG_SMP last_task_used_math = NULL; #else clear_thread_flag(TIF_USEDFPU); #endif } } void flush_thread(void) { current_thread_info()->w_saved = 0; #ifndef CONFIG_SMP if(last_task_used_math == current) { #else if (test_thread_flag(TIF_USEDFPU)) { #endif /* Clean the fpu. */ put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); #ifndef CONFIG_SMP last_task_used_math = NULL; #else clear_thread_flag(TIF_USEDFPU); #endif } /* This task is no longer a kernel thread. */ if (current->thread.flags & SPARC_FLAG_KTHREAD) { current->thread.flags &= ~SPARC_FLAG_KTHREAD; /* We must fixup kregs as well. */ /* XXX This was not fixed for ti for a while, worked. Unused? */ current->thread.kregs = (struct pt_regs *) (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); } } static inline struct sparc_stackf __user * clone_stackframe(struct sparc_stackf __user *dst, struct sparc_stackf __user *src) { unsigned long size, fp; struct sparc_stackf *tmp; struct sparc_stackf __user *sp; if (get_user(tmp, &src->fp)) return NULL; fp = (unsigned long) tmp; size = (fp - ((unsigned long) src)); fp = (unsigned long) dst; sp = (struct sparc_stackf __user *)(fp - size); /* do_fork() grabs the parent semaphore, we must release it * temporarily so we can build the child clone stack frame * without deadlocking. */ if (__copy_user(sp, src, size)) sp = NULL; else if (put_user(fp, &sp->fp)) sp = NULL; return sp; } asmlinkage int sparc_do_fork(unsigned long clone_flags, unsigned long stack_start, struct pt_regs *regs, unsigned long stack_size) { unsigned long parent_tid_ptr, child_tid_ptr; unsigned long orig_i1 = regs->u_regs[UREG_I1]; long ret; parent_tid_ptr = regs->u_regs[UREG_I2]; child_tid_ptr = regs->u_regs[UREG_I4]; ret = do_fork(clone_flags, stack_start, stack_size, (int __user *) parent_tid_ptr, (int __user *) child_tid_ptr); /* If we get an error and potentially restart the system * call, we're screwed because copy_thread() clobbered * the parent's %o1. So detect that case and restore it * here. */ if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) regs->u_regs[UREG_I1] = orig_i1; return ret; } /* Copy a Sparc thread. The fork() return value conventions * under SunOS are nothing short of bletcherous: * Parent --> %o0 == childs pid, %o1 == 0 * Child --> %o0 == parents pid, %o1 == 1 * * NOTE: We have a separate fork kpsr/kwim because * the parent could change these values between * sys_fork invocation and when we reach here * if the parent should sleep while trying to * allocate the task_struct and kernel stack in * do_fork(). * XXX See comment above sys_vfork in sparc64. todo. */ extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, struct task_struct *p) { struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs, *regs = current_pt_regs(); char *new_stack; #ifndef CONFIG_SMP if(last_task_used_math == current) { #else if (test_thread_flag(TIF_USEDFPU)) { #endif put_psr(get_psr() | PSR_EF); fpsave(&p->thread.float_regs[0], &p->thread.fsr, &p->thread.fpqueue[0], &p->thread.fpqdepth); } /* * p->thread_info new_stack childregs stack bottom * ! ! ! ! * V V (stk.fr.) V (pt_regs) V * +----- - - - - - ------+===========+=============+ */ new_stack = task_stack_page(p) + THREAD_SIZE; new_stack -= STACKFRAME_SZ + TRACEREG_SZ; childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); /* * A new process must start with interrupts closed in 2.5, * because this is how Mingo's scheduler works (see schedule_tail * and finish_arch_switch). If we do not do it, a timer interrupt hits * before we unlock, attempts to re-take the rq->lock, and then we die. * Thus, kpsr|=PSR_PIL. */ ti->ksp = (unsigned long) new_stack; p->thread.kregs = childregs; if (unlikely(p->flags & PF_KTHREAD)) { extern int nwindows; unsigned long psr; memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); p->thread.flags |= SPARC_FLAG_KTHREAD; p->thread.current_ds = KERNEL_DS; ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); childregs->u_regs[UREG_G1] = sp; /* function */ childregs->u_regs[UREG_G2] = arg; psr = childregs->psr = get_psr(); ti->kpsr = psr | PSR_PIL; ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); return 0; } memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); childregs->u_regs[UREG_FP] = sp; p->thread.flags &= ~SPARC_FLAG_KTHREAD; p->thread.current_ds = USER_DS; ti->kpc = (((unsigned long) ret_from_fork) - 0x8); ti->kpsr = current->thread.fork_kpsr | PSR_PIL; ti->kwim = current->thread.fork_kwim; if (sp != regs->u_regs[UREG_FP]) { struct sparc_stackf __user *childstack; struct sparc_stackf __user *parentstack; /* * This is a clone() call with supplied user stack. * Set some valid stack frames to give to the child. */ childstack = (struct sparc_stackf __user *) (sp & ~0xfUL); parentstack = (struct sparc_stackf __user *) regs->u_regs[UREG_FP]; #if 0 printk("clone: parent stack:\n"); show_stackframe(parentstack); #endif childstack = clone_stackframe(childstack, parentstack); if (!childstack) return -EFAULT; #if 0 printk("clone: child stack:\n"); show_stackframe(childstack); #endif childregs->u_regs[UREG_FP] = (unsigned long)childstack; } #ifdef CONFIG_SMP /* FPU must be disabled on SMP. */ childregs->psr &= ~PSR_EF; clear_tsk_thread_flag(p, TIF_USEDFPU); #endif /* Set the return value for the child. */ childregs->u_regs[UREG_I0] = current->pid; childregs->u_regs[UREG_I1] = 1; /* Set the return value for the parent. */ regs->u_regs[UREG_I1] = 0; if (clone_flags & CLONE_SETTLS) childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; return 0; } /* * fill in the fpu structure for a core dump. */ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) { if (used_math()) { memset(fpregs, 0, sizeof(*fpregs)); fpregs->pr_q_entrysize = 8; return 1; } #ifdef CONFIG_SMP if (test_thread_flag(TIF_USEDFPU)) { put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); if (regs != NULL) { regs->psr &= ~(PSR_EF); clear_thread_flag(TIF_USEDFPU); } } #else if (current == last_task_used_math) { put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); if (regs != NULL) { regs->psr &= ~(PSR_EF); last_task_used_math = NULL; } } #endif memcpy(&fpregs->pr_fr.pr_regs[0], ¤t->thread.float_regs[0], (sizeof(unsigned long) * 32)); fpregs->pr_fsr = current->thread.fsr; fpregs->pr_qcnt = current->thread.fpqdepth; fpregs->pr_q_entrysize = 8; fpregs->pr_en = 1; if(fpregs->pr_qcnt != 0) { memcpy(&fpregs->pr_q[0], ¤t->thread.fpqueue[0], sizeof(struct fpq) * fpregs->pr_qcnt); } /* Zero out the rest. */ memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); return 1; } unsigned long get_wchan(struct task_struct *task) { unsigned long pc, fp, bias = 0; unsigned long task_base = (unsigned long) task; unsigned long ret = 0; struct reg_window32 *rw; int count = 0; if (!task || task == current || task->state == TASK_RUNNING) goto out; fp = task_thread_info(task)->ksp + bias; do { /* Bogus frame pointer? */ if (fp < (task_base + sizeof(struct thread_info)) || fp >= (task_base + (2 * PAGE_SIZE))) break; rw = (struct reg_window32 *) fp; pc = rw->ins[7]; if (!in_sched_functions(pc)) { ret = pc; goto out; } fp = rw->ins[6] + bias; } while (++count < 16); out: return ret; }