[deliverable/linux.git] / arch / sparc / kernel / process_32.c

/*  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(&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;
}
Commit	Line	Data
64d329ee	1	/* linux/arch/sparc/kernel/process.c
1da177e4	2	*
4fe3ebec	3	* Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	4	* Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
	5	*/
	6
	7	/*
	8	* This file handles the architecture-dependent parts of process handling..
	9	*/
	10
	11	#include <stdarg.h>
	12
8bdd5a1b	13	#include <linux/elfcore.h>
1da177e4 LT	14	#include <linux/errno.h>
	15	#include <linux/module.h>
	16	#include <linux/sched.h>
	17	#include <linux/kernel.h>
1da177e4 LT	18	#include <linux/mm.h>
	19	#include <linux/stddef.h>
	20	#include <linux/ptrace.h>
1da177e4	21	#include <linux/user.h>
1da177e4	22	#include <linux/smp.h>
1da177e4 LT	23	#include <linux/reboot.h>
	24	#include <linux/delay.h>
	25	#include <linux/pm.h>
5a0e3ad6	26	#include <linux/slab.h>
8bdd5a1b	27	#include <linux/cpu.h>
1da177e4 LT	28
	29	#include <asm/auxio.h>
	30	#include <asm/oplib.h>
	31	#include <asm/uaccess.h>
1da177e4 LT	32	#include <asm/page.h>
	33	#include <asm/pgalloc.h>
	34	#include <asm/pgtable.h>
	35	#include <asm/delay.h>
	36	#include <asm/processor.h>
	37	#include <asm/psr.h>
	38	#include <asm/elf.h>
c73fcc84	39	#include <asm/prom.h>
1da177e4	40	#include <asm/unistd.h>
d550bbd4	41	#include <asm/setup.h>
1da177e4	42
8bdd5a1b SR	43	#include "kernel.h"
8bdd5a1b SR	44
1da177e4 LT	45	/*
	46	* Power management idle function
	47	* Set in pm platform drivers (apc.c and pmc.c)
	48	*/
d472ba84	49	void (*sparc_idle)(void);
1da177e4 LT	50
	51	/*
	52	* Power-off handler instantiation for pm.h compliance
	53	* This is done via auxio, but could be used as a fallback
	54	* handler when auxio is not present-- unused for now...
	55	*/
304cd3ef	56	void (*pm_power_off)(void) = machine_power_off;
89eb1693	57	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	58
	59	/*
	60	* sysctl - toggle power-off restriction for serial console
	61	* systems in machine_power_off()
	62	*/
	63	int scons_pwroff = 1;
	64
	65	extern void fpsave(unsigned long , unsigned long , void , unsigned long );
	66
	67	struct task_struct *last_task_used_math = NULL;
	68	struct thread_info *current_set[NR_CPUS];
	69
87fa05ae SR	70	/* Idle loop support. */
87fa05ae SR	71	void arch_cpu_idle(void)
1da177e4	72	{
87fa05ae SR	73	if (sparc_idle)
	74	(*sparc_idle)();
	75	local_irq_enable();
1da177e4 LT	76	}
1da177e4 LT	77
1da177e4 LT	78	/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
	79	void machine_halt(void)
	80	{
	81	local_irq_enable();
	82	mdelay(8);
	83	local_irq_disable();
1da177e4 LT	84	prom_halt();
	85	panic("Halt failed!");
	86	}
	87
1da177e4 LT	88	void machine_restart(char * cmd)
	89	{
	90	char *p;
	91
	92	local_irq_enable();
	93	mdelay(8);
	94	local_irq_disable();
	95
	96	p = strchr (reboot_command, '\n');
	97	if (p) *p = 0;
1da177e4 LT	98	if (cmd)
	99	prom_reboot(cmd);
	100	if (*reboot_command)
	101	prom_reboot(reboot_command);
	102	prom_feval ("reset");
	103	panic("Reboot failed!");
	104	}
	105
1da177e4 LT	106	void machine_power_off(void)
1da177e4 LT	107	{
c73fcc84	108	if (auxio_power_register &&
d2aca8f9 SR	109	(strcmp(of_console_device->type, "serial") \|\| scons_pwroff)) {
	110	u8 power_register = sbus_readb(auxio_power_register);
	111	power_register \|= AUXIO_POWER_OFF;
	112	sbus_writeb(power_register, auxio_power_register);
	113	}
	114
1da177e4 LT	115	machine_halt();
	116	}
	117
1da177e4 LT	118	void show_regs(struct pt_regs *r)
1da177e4 LT	119	{
4d7b92ad	120	struct reg_window32 rw = (struct reg_window32 ) r->u_regs[14];
1da177e4	121
a43cb95d TH	122	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	123
1da177e4 LT	124	printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
1da177e4 LT	125	r->psr, r->pc, r->npc, r->y, print_tainted());
4fe3ebec	126	printk("PC: <%pS>\n", (void *) r->pc);
1da177e4 LT	127	printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
	128	r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
	129	r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
	130	printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
	131	r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
	132	r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
4fe3ebec	133	printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
1da177e4 LT	134
	135	printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
	136	rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
	137	rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
	138	printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
	139	rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
	140	rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
	141	}
	142
	143	/*
	144	* The show_stack is an external API which we do not use ourselves.
	145	* The oops is printed in die_if_kernel.
	146	*/
	147	void show_stack(struct task_struct tsk, unsigned long _ksp)
	148	{
	149	unsigned long pc, fp;
	150	unsigned long task_base;
4d7b92ad	151	struct reg_window32 *rw;
1da177e4 LT	152	int count = 0;
1da177e4 LT	153
89e3f23d TH	154	if (!tsk)
89e3f23d TH	155	tsk = current;
1da177e4	156
89e3f23d TH	157	if (tsk == current && !_ksp)
	158	__asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
	159
	160	task_base = (unsigned long) task_stack_page(tsk);
1da177e4 LT	161	fp = (unsigned long) _ksp;
	162	do {
	163	/* Bogus frame pointer? */
	164	if (fp < (task_base + sizeof(struct thread_info)) \|\|
	165	fp >= (task_base + (PAGE_SIZE << 1)))
	166	break;
4d7b92ad	167	rw = (struct reg_window32 *) fp;
1da177e4 LT	168	pc = rw->ins[7];
1da177e4 LT	169	printk("[%08lx : ", pc);
4fe3ebec	170	printk("%pS ] ", (void *) pc);
1da177e4 LT	171	fp = rw->ins[6];
	172	} while (++count < 16);
	173	printk("\n");
	174	}
	175
	176	/*
	177	* Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
	178	*/
	179	unsigned long thread_saved_pc(struct task_struct *tsk)
	180	{
d562ef6a	181	return task_thread_info(tsk)->kpc;
1da177e4 LT	182	}
	183
	184	/*
	185	* Free current thread data structures etc..
	186	*/
	187	void exit_thread(void)
	188	{
	189	#ifndef CONFIG_SMP
	190	if(last_task_used_math == current) {
	191	#else
54f565ea	192	if (test_thread_flag(TIF_USEDFPU)) {
1da177e4 LT	193	#endif
	194	/* Keep process from leaving FPU in a bogon state. */
	195	put_psr(get_psr() \| PSR_EF);
	196	fpsave(&current->thread.float_regs[0], &current->thread.fsr,
	197	&current->thread.fpqueue[0], &current->thread.fpqdepth);
	198	#ifndef CONFIG_SMP
	199	last_task_used_math = NULL;
	200	#else
54f565ea	201	clear_thread_flag(TIF_USEDFPU);
1da177e4 LT	202	#endif
	203	}
	204	}
	205
	206	void flush_thread(void)
	207	{
	208	current_thread_info()->w_saved = 0;
	209
1da177e4 LT	210	#ifndef CONFIG_SMP
	211	if(last_task_used_math == current) {
	212	#else
54f565ea	213	if (test_thread_flag(TIF_USEDFPU)) {
1da177e4 LT	214	#endif
	215	/* Clean the fpu. */
	216	put_psr(get_psr() \| PSR_EF);
	217	fpsave(&current->thread.float_regs[0], &current->thread.fsr,
	218	&current->thread.fpqueue[0], &current->thread.fpqdepth);
	219	#ifndef CONFIG_SMP
	220	last_task_used_math = NULL;
	221	#else
54f565ea	222	clear_thread_flag(TIF_USEDFPU);
1da177e4 LT	223	#endif
	224	}
	225
ddd53bf1	226	/* This task is no longer a kernel thread. */
1da177e4 LT	227	if (current->thread.flags & SPARC_FLAG_KTHREAD) {
	228	current->thread.flags &= ~SPARC_FLAG_KTHREAD;
	229
	230	/* We must fixup kregs as well. */
	231	/* XXX This was not fixed for ti for a while, worked. Unused? */
	232	current->thread.kregs = (struct pt_regs *)
36483c6b	233	(task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
1da177e4 LT	234	}
	235	}
	236
64d329ee	237	static inline struct sparc_stackf __user *
1da177e4 LT	238	clone_stackframe(struct sparc_stackf __user *dst,
	239	struct sparc_stackf __user *src)
	240	{
	241	unsigned long size, fp;
	242	struct sparc_stackf *tmp;
	243	struct sparc_stackf __user *sp;
	244
	245	if (get_user(tmp, &src->fp))
	246	return NULL;
	247
	248	fp = (unsigned long) tmp;
	249	size = (fp - ((unsigned long) src));
	250	fp = (unsigned long) dst;
	251	sp = (struct sparc_stackf __user *)(fp - size);
	252
	253	/* do_fork() grabs the parent semaphore, we must release it
	254	* temporarily so we can build the child clone stack frame
	255	* without deadlocking.
	256	*/
	257	if (__copy_user(sp, src, size))
	258	sp = NULL;
	259	else if (put_user(fp, &sp->fp))
	260	sp = NULL;
	261
	262	return sp;
	263	}
	264
	265	asmlinkage int sparc_do_fork(unsigned long clone_flags,
	266	unsigned long stack_start,
	267	struct pt_regs *regs,
	268	unsigned long stack_size)
	269	{
	270	unsigned long parent_tid_ptr, child_tid_ptr;
1e38c126 DM	271	unsigned long orig_i1 = regs->u_regs[UREG_I1];
1e38c126 DM	272	long ret;
1da177e4 LT	273
	274	parent_tid_ptr = regs->u_regs[UREG_I2];
	275	child_tid_ptr = regs->u_regs[UREG_I4];
	276
e80d6661	277	ret = do_fork(clone_flags, stack_start, stack_size,
1e38c126 DM	278	(int __user *) parent_tid_ptr,
	279	(int __user *) child_tid_ptr);
	280
	281	/* If we get an error and potentially restart the system
	282	* call, we're screwed because copy_thread() clobbered
	283	* the parent's %o1. So detect that case and restore it
	284	* here.
	285	*/
	286	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
	287	regs->u_regs[UREG_I1] = orig_i1;
	288
	289	return ret;
1da177e4 LT	290	}
	291
	292	/* Copy a Sparc thread. The fork() return value conventions
	293	* under SunOS are nothing short of bletcherous:
	294	* Parent --> %o0 == childs pid, %o1 == 0
	295	* Child --> %o0 == parents pid, %o1 == 1
	296	*
	297	* NOTE: We have a separate fork kpsr/kwim because
	298	* the parent could change these values between
	299	* sys_fork invocation and when we reach here
	300	* if the parent should sleep while trying to
	301	* allocate the task_struct and kernel stack in
	302	* do_fork().
	303	* XXX See comment above sys_vfork in sparc64. todo.
	304	*/
	305	extern void ret_from_fork(void);
c78e0643	306	extern void ret_from_kernel_thread(void);
1da177e4	307
6f2c55b8	308	int copy_thread(unsigned long clone_flags, unsigned long sp,
afa86fc4	309	unsigned long arg, struct task_struct *p)
1da177e4	310	{
36483c6b	311	struct thread_info *ti = task_thread_info(p);
afa86fc4	312	struct pt_regs childregs, regs = current_pt_regs();
1da177e4 LT	313	char *new_stack;
	314
	315	#ifndef CONFIG_SMP
	316	if(last_task_used_math == current) {
	317	#else
54f565ea	318	if (test_thread_flag(TIF_USEDFPU)) {
1da177e4 LT	319	#endif
	320	put_psr(get_psr() \| PSR_EF);
	321	fpsave(&p->thread.float_regs[0], &p->thread.fsr,
	322	&p->thread.fpqueue[0], &p->thread.fpqdepth);
1da177e4 LT	323	}
	324
	325	/*
c78e0643 AV	326	* p->thread_info new_stack childregs stack bottom
	327	* ! ! ! !
	328	* V V (stk.fr.) V (pt_regs) V
	329	* +----- - - - - - ------+===========+=============+
1da177e4	330	*/
36483c6b	331	new_stack = task_stack_page(p) + THREAD_SIZE;
1da177e4	332	new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
1da177e4 LT	333	childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
	334
	335	/*
	336	* A new process must start with interrupts closed in 2.5,
	337	* because this is how Mingo's scheduler works (see schedule_tail
	338	* and finish_arch_switch). If we do not do it, a timer interrupt hits
	339	* before we unlock, attempts to re-take the rq->lock, and then we die.
	340	* Thus, kpsr\|=PSR_PIL.
	341	*/
	342	ti->ksp = (unsigned long) new_stack;
c78e0643 AV	343	p->thread.kregs = childregs;
	344
	345	if (unlikely(p->flags & PF_KTHREAD)) {
	346	extern int nwindows;
	347	unsigned long psr;
	348	memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
	349	p->thread.flags \|= SPARC_FLAG_KTHREAD;
	350	p->thread.current_ds = KERNEL_DS;
	351	ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
	352	childregs->u_regs[UREG_G1] = sp; /* function */
	353	childregs->u_regs[UREG_G2] = arg;
	354	psr = childregs->psr = get_psr();
	355	ti->kpsr = psr \| PSR_PIL;
	356	ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
	357	return 0;
	358	}
	359	memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
	360	childregs->u_regs[UREG_FP] = sp;
	361	p->thread.flags &= ~SPARC_FLAG_KTHREAD;
	362	p->thread.current_ds = USER_DS;
1da177e4 LT	363	ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
	364	ti->kpsr = current->thread.fork_kpsr \| PSR_PIL;
	365	ti->kwim = current->thread.fork_kwim;
	366
c78e0643 AV	367	if (sp != regs->u_regs[UREG_FP]) {
	368	struct sparc_stackf __user *childstack;
	369	struct sparc_stackf __user *parentstack;
1da177e4	370
c78e0643 AV	371	/*
	372	* This is a clone() call with supplied user stack.
	373	* Set some valid stack frames to give to the child.
	374	*/
	375	childstack = (struct sparc_stackf __user *)
	376	(sp & ~0xfUL);
	377	parentstack = (struct sparc_stackf __user *)
	378	regs->u_regs[UREG_FP];
1da177e4 LT	379
1da177e4 LT	380	#if 0
c78e0643 AV	381	printk("clone: parent stack:\n");
c78e0643 AV	382	show_stackframe(parentstack);
1da177e4 LT	383	#endif
1da177e4 LT	384
c78e0643 AV	385	childstack = clone_stackframe(childstack, parentstack);
	386	if (!childstack)
	387	return -EFAULT;
1da177e4 LT	388
1da177e4 LT	389	#if 0
c78e0643 AV	390	printk("clone: child stack:\n");
c78e0643 AV	391	show_stackframe(childstack);
1da177e4 LT	392	#endif
1da177e4 LT	393
c78e0643	394	childregs->u_regs[UREG_FP] = (unsigned long)childstack;
1da177e4 LT	395	}
	396
	397	#ifdef CONFIG_SMP
	398	/* FPU must be disabled on SMP. */
	399	childregs->psr &= ~PSR_EF;
427f23cb	400	clear_tsk_thread_flag(p, TIF_USEDFPU);
1da177e4 LT	401	#endif
	402
	403	/* Set the return value for the child. */
	404	childregs->u_regs[UREG_I0] = current->pid;
	405	childregs->u_regs[UREG_I1] = 1;
	406
	407	/* Set the return value for the parent. */
	408	regs->u_regs[UREG_I1] = 0;
	409
	410	if (clone_flags & CLONE_SETTLS)
	411	childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
	412
	413	return 0;
	414	}
	415
1da177e4 LT	416	/*
	417	* fill in the fpu structure for a core dump.
	418	*/
	419	int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
	420	{
	421	if (used_math()) {
	422	memset(fpregs, 0, sizeof(*fpregs));
	423	fpregs->pr_q_entrysize = 8;
	424	return 1;
	425	}
	426	#ifdef CONFIG_SMP
54f565ea	427	if (test_thread_flag(TIF_USEDFPU)) {
1da177e4 LT	428	put_psr(get_psr() \| PSR_EF);
	429	fpsave(&current->thread.float_regs[0], &current->thread.fsr,
	430	&current->thread.fpqueue[0], &current->thread.fpqdepth);
	431	if (regs != NULL) {
	432	regs->psr &= ~(PSR_EF);
54f565ea	433	clear_thread_flag(TIF_USEDFPU);
1da177e4 LT	434	}
	435	}
	436	#else
	437	if (current == last_task_used_math) {
	438	put_psr(get_psr() \| PSR_EF);
	439	fpsave(&current->thread.float_regs[0], &current->thread.fsr,
	440	&current->thread.fpqueue[0], &current->thread.fpqdepth);
	441	if (regs != NULL) {
	442	regs->psr &= ~(PSR_EF);
	443	last_task_used_math = NULL;
	444	}
	445	}
	446	#endif
	447	memcpy(&fpregs->pr_fr.pr_regs[0],
	448	&current->thread.float_regs[0],
	449	(sizeof(unsigned long) * 32));
	450	fpregs->pr_fsr = current->thread.fsr;
	451	fpregs->pr_qcnt = current->thread.fpqdepth;
	452	fpregs->pr_q_entrysize = 8;
	453	fpregs->pr_en = 1;
	454	if(fpregs->pr_qcnt != 0) {
	455	memcpy(&fpregs->pr_q[0],
	456	&current->thread.fpqueue[0],
	457	sizeof(struct fpq) * fpregs->pr_qcnt);
	458	}
	459	/* Zero out the rest. */
	460	memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
	461	sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
	462	return 1;
	463	}
	464
1da177e4 LT	465	unsigned long get_wchan(struct task_struct *task)
	466	{
	467	unsigned long pc, fp, bias = 0;
	468	unsigned long task_base = (unsigned long) task;
	469	unsigned long ret = 0;
4d7b92ad	470	struct reg_window32 *rw;
1da177e4 LT	471	int count = 0;
	472
	473	if (!task \|\| task == current \|\|
	474	task->state == TASK_RUNNING)
	475	goto out;
	476
d562ef6a	477	fp = task_thread_info(task)->ksp + bias;
1da177e4 LT	478	do {
	479	/* Bogus frame pointer? */
	480	if (fp < (task_base + sizeof(struct thread_info)) \|\|
	481	fp >= (task_base + (2 * PAGE_SIZE)))
	482	break;
4d7b92ad	483	rw = (struct reg_window32 *) fp;
1da177e4 LT	484	pc = rw->ins[7];
	485	if (!in_sched_functions(pc)) {
	486	ret = pc;
	487	goto out;
	488	}
	489	fp = rw->ins[6] + bias;
	490	} while (++count < 16);
	491
	492	out:
	493	return ret;
	494	}
	495