process.c

广州斯道2410普及版II的源代码

		ia32_save_state(p);
#endif
#ifdef CONFIG_PERFMON
	if (p->thread.pfm_context)
		retval = pfm_inherit(p, child_ptregs);
#endif
	return retval;
}

void
do_copy_regs (struct unw_frame_info *info, void *arg)
{
	unsigned long mask, sp, nat_bits = 0, ip, ar_rnat, urbs_end, cfm;
	elf_greg_t *dst = arg;
	struct pt_regs *pt;
	char nat;
	int i;

	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */

	if (unw_unwind_to_user(info) < 0)
		return;

	unw_get_sp(info, &sp);
	pt = (struct pt_regs *) (sp + 16);

	urbs_end = ia64_get_user_rbs_end(current, pt, &cfm);

	if (ia64_sync_user_rbs(current, info->sw, pt->ar_bspstore, urbs_end) < 0)
		return;

	ia64_peek(current, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
		  &ar_rnat);

	/*
	 * coredump format:
	 *	r0-r31
	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
	 *	predicate registers (p0-p63)
	 *	b0-b7
	 *	ip cfm user-mask
	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
	 */

	/* r0 is zero */
	for (i = 1, mask = (1UL << i); i < 32; ++i) {
		unw_get_gr(info, i, &dst[i], &nat);
		if (nat)
			nat_bits |= mask;
		mask <<= 1;
	}
	dst[32] = nat_bits;
	unw_get_pr(info, &dst[33]);

	for (i = 0; i < 8; ++i)
		unw_get_br(info, i, &dst[34 + i]);

	unw_get_rp(info, &ip);
	dst[42] = ip + ia64_psr(pt)->ri;
	dst[43] = cfm;
	dst[44] = pt->cr_ipsr & IA64_PSR_UM;

	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
	/*
	 * For bsp and bspstore, unw_get_ar() would return the kernel
	 * addresses, but we need the user-level addresses instead:
	 */
	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
	dst[47] = pt->ar_bspstore;
	dst[48] = ar_rnat;
	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
	unw_get_ar(info, UNW_AR_LC, &dst[53]);
	unw_get_ar(info, UNW_AR_EC, &dst[54]);
}

void
do_dump_fpu (struct unw_frame_info *info, void *arg)
{
	elf_fpreg_t *dst = arg;
	int i;

	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */

	if (unw_unwind_to_user(info) < 0)
		return;

	/* f0 is 0.0, f1 is 1.0 */

	for (i = 2; i < 32; ++i)
		unw_get_fr(info, i, dst + i);

	ia64_flush_fph(current);
	if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0)
		memcpy(dst + 32, current->thread.fph, 96*16);
}

void
ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
{
	unw_init_running(do_copy_regs, dst);
}

int
dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
{
	unw_init_running(do_dump_fpu, dst);
	return 1;	/* f0-f31 are always valid so we always return 1 */
}

asmlinkage long
sys_execve (char *filename, char **argv, char **envp, struct pt_regs *regs)
{
	int error;

	filename = getname(filename);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		goto out;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
out:
	return error;
}

pid_t
kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
{
	struct task_struct *parent = current;
	int result, tid;

	tid = clone(flags | CLONE_VM, 0);
	if (parent != current) {
		result = (*fn)(arg);
		_exit(result);
	}
	return tid;
}

/*
 * Flush thread state.  This is called when a thread does an execve().
 */
void
flush_thread (void)
{
	/* drop floating-point and debug-register state if it exists: */
	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);

#ifndef CONFIG_SMP
	if (ia64_get_fpu_owner() == current)
		ia64_set_fpu_owner(0);
#endif
}

#ifdef CONFIG_PERFMON
/*
 * By the time we get here, the task is detached from the tasklist. This is important
 * because it means that no other tasks can ever find it as a notifiied task, therfore
 * there is no race condition between this code and let's say a pfm_context_create().
 * Conversely, the pfm_cleanup_notifiers() cannot try to access a task's pfm context if
 * this other task is in the middle of its own pfm_context_exit() because it would alreayd
 * be out of the task list. Note that this case is very unlikely between a direct child
 * and its parents (if it is the notified process) because of the way the exit is notified
 * via SIGCHLD.
 */
void
release_thread (struct task_struct *task)
{
	if (task->thread.pfm_context)
		pfm_context_exit(task);

	if (atomic_read(&task->thread.pfm_notifiers_check) > 0)
		pfm_cleanup_notifiers(task);
}
#endif

/*
 * Clean up state associated with current thread.  This is called when
 * the thread calls exit().
 */
void
exit_thread (void)
{
#ifndef CONFIG_SMP
	if (ia64_get_fpu_owner() == current)
		ia64_set_fpu_owner(0);
#endif
#ifdef CONFIG_PERFMON
       /* stop monitoring */
	if ((current->thread.flags & IA64_THREAD_PM_VALID) != 0) {
		/*
		 * we cannot rely on switch_to() to save the PMU
		 * context for the last time. There is a possible race
		 * condition in SMP mode between the child and the
		 * parent.  by explicitly saving the PMU context here
		 * we garantee no race.  this call we also stop
		 * monitoring
		 */
		pfm_flush_regs(current);
		/*
		 * make sure that switch_to() will not save context again
		 */
		current->thread.flags &= ~IA64_THREAD_PM_VALID;
	}
#endif
}

unsigned long
get_wchan (struct task_struct *p)
{
	struct unw_frame_info info;
	unsigned long ip;
	int count = 0;
	/*
	 * These bracket the sleeping functions..
	 */
	extern void scheduling_functions_start_here(void);
	extern void scheduling_functions_end_here(void);
#	define first_sched	((unsigned long) scheduling_functions_start_here)
#	define last_sched	((unsigned long) scheduling_functions_end_here)

	/*
	 * Note: p may not be a blocked task (it could be current or
	 * another process running on some other CPU.  Rather than
	 * trying to determine if p is really blocked, we just assume
	 * it's blocked and rely on the unwind routines to fail
	 * gracefully if the process wasn't really blocked after all.
	 * --davidm 99/12/15
	 */
	unw_init_from_blocked_task(&info, p);
	do {
		if (unw_unwind(&info) < 0)
			return 0;
		unw_get_ip(&info, &ip);
		if (ip < first_sched || ip >= last_sched)
			return ip;
	} while (count++ < 16);
	return 0;
#	undef first_sched
#	undef last_sched
}

void
cpu_halt (void)
{
	pal_power_mgmt_info_u_t power_info[8];
	unsigned long min_power;
	int i, min_power_state;

	if (ia64_pal_halt_info(power_info) != 0)
		return;

	min_power_state = 0;
	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
	for (i = 1; i < 8; ++i)
		if (power_info[i].pal_power_mgmt_info_s.im
		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
			min_power_state = i;
		}

	while (1)
		ia64_pal_halt(min_power_state);
}

void
machine_restart (char *restart_cmd)
{
	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, 0);
}

void
machine_halt (void)
{
	cpu_halt();
}

void
machine_power_off (void)
{
	if (pm_power_off)
		pm_power_off();
	machine_halt();
}