Linux-2.6.33.2/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/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/slab.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 <asm/auxio.h>
#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/system.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>
/*
* Power management idle function
* Set in pm platform drivers (apc.c and pmc.c)
*/
void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
/*
* 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];
#ifndef CONFIG_SMP
#define SUN4C_FAULT_HIGH 100
/*
* the idle loop on a Sparc... ;)
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
for (;;) {
if (ARCH_SUN4C) {
static int count = HZ;
static unsigned long last_jiffies;
static unsigned long last_faults;
static unsigned long fps;
unsigned long now;
unsigned long faults;
extern unsigned long sun4c_kernel_faults;
extern void sun4c_grow_kernel_ring(void);
local_irq_disable();
now = jiffies;
count -= (now - last_jiffies);
last_jiffies = now;
if (count < 0) {
count += HZ;
faults = sun4c_kernel_faults;
fps = (fps + (faults - last_faults)) >> 1;
last_faults = faults;
#if 0
printk("kernel faults / second = %ld\n", fps);
#endif
if (fps >= SUN4C_FAULT_HIGH) {
sun4c_grow_kernel_ring();
}
}
local_irq_enable();
}
if (pm_idle) {
while (!need_resched())
(*pm_idle)();
} else {
while (!need_resched())
cpu_relax();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
#else
/* This is being executed in task 0 'user space'. */
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while(1) {
while (!need_resched())
cpu_relax();
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
#endif
/* 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();
}
#if 0
static DEFINE_SPINLOCK(sparc_backtrace_lock);
void __show_backtrace(unsigned long fp)
{
struct reg_window32 *rw;
unsigned long flags;
int cpu = smp_processor_id();
spin_lock_irqsave(&sparc_backtrace_lock, flags);
rw = (struct reg_window32 *)fp;
while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
!(((unsigned long) rw) & 0x7)) {
printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
"FP[%08lx] CALLER[%08lx]: ", cpu,
rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
rw->ins[4], rw->ins[5],
rw->ins[6],
rw->ins[7]);
printk("%pS\n", (void *) rw->ins[7]);
rw = (struct reg_window32 *) rw->ins[6];
}
spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
}
#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
#define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
void show_backtrace(void)
{
unsigned long fp;
__SAVE; __SAVE; __SAVE; __SAVE;
__SAVE; __SAVE; __SAVE; __SAVE;
__RESTORE; __RESTORE; __RESTORE; __RESTORE;
__RESTORE; __RESTORE; __RESTORE; __RESTORE;
__GET_FP(fp);
__show_backtrace(fp);
}
#ifdef CONFIG_SMP
void smp_show_backtrace_all_cpus(void)
{
xc0((smpfunc_t) show_backtrace);
show_backtrace();
}
#endif
void show_stackframe(struct sparc_stackf *sf)
{
unsigned long size;
unsigned long *stk;
int i;
printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
"l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
"i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
"x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
(unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
sf->xxargs[0]);
size = ((unsigned long)sf->fp) - ((unsigned long)sf);
size -= STACKFRAME_SZ;
stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
i = 0;
do {
printk("s%d: %08lx\n", i++, *stk++);
} while ((size -= sizeof(unsigned long)));
}
#endif
void show_regs(struct pt_regs *r)
{
struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
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 != NULL)
task_base = (unsigned long) task_stack_page(tsk);
else
task_base = (unsigned long) current_thread_info();
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");
}
void dump_stack(void)
{
unsigned long *ksp;
__asm__ __volatile__("mov %%fp, %0"
: "=r" (ksp));
show_stack(current, ksp);
}
EXPORT_SYMBOL(dump_stack);
/*
* 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
}
/* Now, this task is no longer a kernel thread. */
current->thread.current_ds = USER_DS;
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,
regs, 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);
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
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);
#ifdef CONFIG_SMP
clear_thread_flag(TIF_USEDFPU);
#endif
}
/*
* p->thread_info new_stack childregs
* ! ! ! {if(PSR_PS) }
* V V (stk.fr.) V (pt_regs) { (stk.fr.) }
* +----- - - - - - ------+===========+============={+==========}+
*/
new_stack = task_stack_page(p) + THREAD_SIZE;
if (regs->psr & PSR_PS)
new_stack -= STACKFRAME_SZ;
new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
memcpy(new_stack, (char *)regs - STACKFRAME_SZ, 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;
ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
ti->kwim = current->thread.fork_kwim;
if(regs->psr & PSR_PS) {
extern struct pt_regs fake_swapper_regs;
p->thread.kregs = &fake_swapper_regs;
new_stack += STACKFRAME_SZ + TRACEREG_SZ;
childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
p->thread.flags |= SPARC_FLAG_KTHREAD;
p->thread.current_ds = KERNEL_DS;
memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
childregs->u_regs[UREG_G6] = (unsigned long) ti;
} else {
p->thread.kregs = childregs;
childregs->u_regs[UREG_FP] = sp;
p->thread.flags &= ~SPARC_FLAG_KTHREAD;
p->thread.current_ds = USER_DS;
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;
#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;
}
/*
* sparc_execve() executes a new program after the asm stub has set
* things up for us. This should basically do what I want it to.
*/
asmlinkage int sparc_execve(struct pt_regs *regs)
{
int error, base = 0;
char *filename;
/* Check for indirect call. */
if(regs->u_regs[UREG_G1] == 0)
base = 1;
filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
error = PTR_ERR(filename);
if(IS_ERR(filename))
goto out;
error = do_execve(filename,
(char __user * __user *)regs->u_regs[base + UREG_I1],
(char __user * __user *)regs->u_regs[base + UREG_I2],
regs);
putname(filename);
out:
return error;
}
/*
* This is the mechanism for creating a new kernel thread.
*
* NOTE! Only a kernel-only process(ie the swapper or direct descendants
* who haven't done an "execve()") should use this: it will work within
* a system call from a "real" process, but the process memory space will
* not be freed until both the parent and the child have exited.
*/
pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
long retval;
__asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
"mov %5, %%g3\n\t" /* and arg. */
"mov %1, %%g1\n\t"
"mov %2, %%o0\n\t" /* Clone flags. */
"mov 0, %%o1\n\t" /* usp arg == 0 */
"t 0x10\n\t" /* Linux/Sparc clone(). */
"cmp %%o1, 0\n\t"
"be 1f\n\t" /* The parent, just return. */
" nop\n\t" /* Delay slot. */
"jmpl %%g2, %%o7\n\t" /* Call the function. */
" mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
"mov %3, %%g1\n\t"
"t 0x10\n\t" /* Linux/Sparc exit(). */
/* Notreached by child. */
"1: mov %%o0, %0\n\t" :
"=r" (retval) :
"i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
"i" (__NR_exit), "r" (fn), "r" (arg) :
"g1", "g2", "g3", "o0", "o1", "memory", "cc");
return retval;
}
EXPORT_SYMBOL(kernel_thread);
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;
}