/*  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/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/init.h>#include <linux/slab.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> /*  * 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))		*auxio_power_register |= AUXIO_POWER_OFF;	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(&current->thread.float_regs[0], &current->thread.fsr,		       &current->thread.fpqueue[0], &current->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(&current->thread.float_regs[0], &current->thread.fsr,		       &current->thread.fpqueue[0], &current->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(&current->thread.float_regs[0], &current->thread.fsr,		       &current->thread.fpqueue[0], &current->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(&current->thread.float_regs[0], &current->thread.fsr,		       &current->thread.fpqueue[0], &current->thread.fpqdepth);		if (regs != NULL) {			regs->psr &= ~(PSR_EF);			last_task_used_math = NULL;		}	}#endif	memcpy(&fpregs->pr_fr.pr_regs[0],	       &current->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],		       &current->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;}