sys_generic.c

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

		 */
		bzero(data, size);
	else if (com&IOC_VOID)
		*(caddr_t *)data = SCARG(uap, data);

	switch (com) {

	case FIONBIO:
		if ((tmp = *(int *)data) != 0)
			fp->f_flag |= FNONBLOCK;
		else
			fp->f_flag &= ~FNONBLOCK;
		error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p);
		break;

	case FIOASYNC:
		if ((tmp = *(int *)data) != 0)
			fp->f_flag |= FASYNC;
		else
			fp->f_flag &= ~FASYNC;
		error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p);
		break;

	case FIOSETOWN:
		tmp = *(int *)data;
		if (fp->f_type == DTYPE_SOCKET) {
			struct socket *so = (struct socket *)fp->f_data;

			so->so_pgid = tmp;
#ifdef NOTUSE_BY_PMON
			so->so_siguid = p->p_cred->p_ruid;
			so->so_sigeuid = p->p_ucred->cr_uid;
#else
			so->so_siguid = 0;
			so->so_sigeuid = 0;
#endif
			error = 0;
			break;
		}
		if (tmp <= 0) {
			tmp = -tmp;
		} else {
#ifdef NOTUSED_BY_PMON
			struct proc *p1 = pfind(tmp);
			if (p1 == 0) {
				error = ESRCH;
				break;
			}
			tmp = p1->p_pgrp->pg_id;
#else
			tmp = 0;
#endif
		}
		error = (*fp->f_ops->fo_ioctl)
			(fp, TIOCSPGRP, (caddr_t)&tmp, p);
		break;

	case FIOGETOWN:
		if (fp->f_type == DTYPE_SOCKET) {
			error = 0;
			*(int *)data = ((struct socket *)fp->f_data)->so_pgid;
			break;
		}
		error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p);
		*(int *)data = -*(int *)data;
		break;

	default:
		error = (*fp->f_ops->fo_ioctl)(fp, com, data, p);
		/*
		 * Copy any data to user, size was
		 * already set and checked above.
		 */
		if (error == 0 && (com&IOC_OUT) && size)
			error = copyout(data, SCARG(uap, data), (u_int)size);
		break;
	}
	if (memp)
		free(memp, M_IOCTLOPS);
	return (error);
}

int	selwait, nselcoll;

/*
 * Select system call.
 */
int
sys_select(p, v, retval)
	register struct proc *p;
	void *v;
	register_t *retval;
{
	register struct sys_select_args /* {
		syscallarg(int) nd;
		syscallarg(fd_set *) in;
		syscallarg(fd_set *) ou;
		syscallarg(fd_set *) ex;
		syscallarg(struct timeval *) tv;
	} */ *uap = v;
	fd_set bits[6], *pibits[3], *pobits[3];
	struct timeval atv;
	int s, ncoll, error = 0, timo;
	u_int ni;

	if (SCARG(uap, nd) > p->p_fd->fd_nfiles) {
		/* forgiving; slightly wrong */
		SCARG(uap, nd) = p->p_fd->fd_nfiles;
	}
	ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask);
	if (SCARG(uap, nd) > FD_SETSIZE) {
		caddr_t mbits;

		if ((mbits = malloc(ni * 6, M_TEMP, M_WAITOK)) == NULL) {
			error = EINVAL;
			goto cleanup;
		}
		bzero(mbits, ni * 6);
		pibits[0] = (fd_set *)&mbits[ni * 0];
		pibits[1] = (fd_set *)&mbits[ni * 1];
		pibits[2] = (fd_set *)&mbits[ni * 2];
		pobits[0] = (fd_set *)&mbits[ni * 3];
		pobits[1] = (fd_set *)&mbits[ni * 4];
		pobits[2] = (fd_set *)&mbits[ni * 5];
	} else {
		bzero((caddr_t)bits, sizeof(bits));
		pibits[0] = &bits[0];
		pibits[1] = &bits[1];
		pibits[2] = &bits[2];
		pobits[0] = &bits[3];
		pobits[1] = &bits[4];
		pobits[2] = &bits[5];
	}

#define	getbits(name, x) \
	if (SCARG(uap, name) && (error = copyin((caddr_t)SCARG(uap, name), \
	    (caddr_t)pibits[x], ni))) \
		goto done;
	getbits(in, 0);
	getbits(ou, 1);
	getbits(ex, 2);
#undef	getbits

	if (SCARG(uap, tv)) {
		error = copyin((caddr_t)SCARG(uap, tv), (caddr_t)&atv,
			sizeof (atv));
		if (error)
			goto done;
		if (itimerfix(&atv)) {
			error = EINVAL;
			goto done;
		}
		s = splclock();
		timeradd(&atv, &time, &atv);
		timo = hzto(&atv);
		/*
		 * Avoid inadvertently sleeping forever.
		 */
		if (timo == 0)
			timo = 1;
		splx(s);
	} else
		timo = 0;
retry:
	ncoll = nselcoll;
	p->p_flag |= P_SELECT;
	error = selscan(p, pibits[0], pobits[0], SCARG(uap, nd), retval);
	if (error || *retval)
		goto done;
	s = splhigh();
	/* this should be timercmp(&time, &atv, >=) */
	if (SCARG(uap, tv) && (time.tv_sec > atv.tv_sec ||
	    (time.tv_sec == atv.tv_sec && time.tv_usec >= atv.tv_usec))) {
		splx(s);
		goto done;
	}
	if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) {
		splx(s);
		goto retry;
	}
	p->p_flag &= ~P_SELECT;
	error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo);
	splx(s);
	if (error == 0)
		goto retry;
done:
	p->p_flag &= ~P_SELECT;
	/* select is not restarted after signals... */
	if (error == ERESTART)
		error = EINTR;
	if (error == EWOULDBLOCK)
		error = 0;
#define	putbits(name, x) \
	if (SCARG(uap, name) && (error2 = copyout((caddr_t)pobits[x], \
	    (caddr_t)SCARG(uap, name), ni))) \
		error = error2;
	if (error == 0) {
		int error2;

		putbits(in, 0);
		putbits(ou, 1);
		putbits(ex, 2);
#undef putbits
	}
	
cleanup:
	if (pibits[0] != &bits[0])
		free(pibits[0], M_TEMP);
	return (error);
}

int
selscan(p, ibits, obits, nfd, retval)
	struct proc *p;
	fd_set *ibits, *obits;
	int nfd;
	register_t *retval;
{
	caddr_t cibits = (caddr_t)ibits, cobits = (caddr_t)obits;
	register struct filedesc *fdp = p->p_fd;
	register int msk, i, j, fd;
	register fd_mask bits;
	struct file *fp;
	int ni, n = 0;
	static int flag[3] = { FREAD, FWRITE, 0 };

	/*
	 * if nfd > FD_SETSIZE then the fd_set's contain nfd bits (rounded
	 * up to the next byte) otherwise the fd_set's are normal sized.
	 */
	ni = sizeof(fd_set);
	if (nfd > FD_SETSIZE)
		ni = howmany(nfd, NFDBITS) * sizeof(fd_mask);

	for (msk = 0; msk < 3; msk++) {
		fd_set *pibits = (fd_set *)&cibits[msk*ni];
		fd_set *pobits = (fd_set *)&cobits[msk*ni];

		for (i = 0; i < nfd; i += NFDBITS) {
			bits = pibits->fds_bits[i/NFDBITS];
			while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
				bits &= ~(1 << j);
				fp = fdp->fd_ofiles[fd];
				if (fp == NULL)
					return (EBADF);
				if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) {
					FD_SET(fd, pobits);
					n++;
				}
			}
		}
	}
	*retval = n;
	return (0);
}

/*ARGSUSED*/
int
seltrue(dev, flag, p)
	dev_t dev;
	int flag;
	struct proc *p;
{

	return (1);
}

/*
 * Record a select request.
 */
void
selrecord(selector, sip)
	struct proc *selector;
	struct selinfo *sip;
{
	struct proc *p;
	pid_t mypid;

	mypid = selector->p_pid;
	if (sip->si_selpid == mypid)
		return;
	if (sip->si_selpid && (p = pfind(sip->si_selpid)) &&
	    p->p_wchan == (caddr_t)&selwait)
		sip->si_flags |= SI_COLL;
	else
		sip->si_selpid = mypid;
}

/*
 * Do a wakeup when a selectable event occurs.
 */
void
selwakeup(sip)
	register struct selinfo *sip;
{
	register struct proc *p;
	int s;

	if (sip->si_selpid == 0)
		return;
	if (sip->si_flags & SI_COLL) {
		nselcoll++;
		sip->si_flags &= ~SI_COLL;
		wakeup((caddr_t)&selwait);
	}
	p = pfind(sip->si_selpid);
	sip->si_selpid = 0;
	if (p != NULL) {
		s = splhigh();
		if (p->p_wchan == (caddr_t)&selwait) {
			if (p->p_stat == SSLEEP)
				setrunnable(p);
			else
				unsleep(p);
		} else if (p->p_flag & P_SELECT)
			p->p_flag &= ~P_SELECT;
		splx(s);
	}
}

void
pollscan(p, pl, nfd, retval)
	struct proc *p;
	struct pollfd *pl;
	int nfd;
	register_t *retval;
{
	register struct filedesc *fdp = p->p_fd;
	register int msk, i;
	struct file *fp;
	int x, n = 0;
	static int flag[3] = { FREAD, FWRITE, 0 };
	static int pflag[3] = { POLLIN|POLLRDNORM, POLLOUT, POLLERR };

	/* 
	 * XXX: We need to implement the rest of the flags.
	 */
	for (i = 0; i < nfd; i++) {
		fp = fdp->fd_ofiles[pl[i].fd];
		if (fp == NULL) {
			if (pl[i].events & POLLNVAL) {
				pl[i].revents |= POLLNVAL;
				n++;
			}
			continue;
		}
		for (x = msk = 0; msk < 3; msk++) {
			if (pl[i].events & pflag[msk]) {
				if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) {
					pl[i].revents |= pflag[msk] &
					    pl[i].events;
					x++;
				}
			}
		}
		if (x)
			n++;
	}
	*retval = n;
}

/*
 * We are using the same mechanism as select only we encode/decode args
 * differently.
 */
int
sys_poll(p, v, retval)
	register struct proc *p;
	void *v;
	register_t *retval;
{
	struct sys_poll_args *uap = v;
	size_t sz;
	struct pollfd pfds[4], *pl = pfds;
	int msec = SCARG(uap, timeout);
	struct timeval atv;
	int timo, ncoll, i, s, error, error2;
	extern int nselcoll, selwait;

	/* XXX constrain; This may not match standards */
	if (SCARG(uap, nfds) > p->p_fd->fd_nfiles)
		SCARG(uap, nfds) = p->p_fd->fd_nfiles;
	sz = sizeof(struct pollfd) * SCARG(uap, nfds);
	
	/* optimize for the default case, of a small nfds value */
	if (sz > sizeof(pfds))
		pl = (struct pollfd *) malloc(sz, M_TEMP, M_WAITOK);

	if ((error = copyin(SCARG(uap, fds), pl, sz)) != 0)
		goto bad;

	for (i = 0; i < SCARG(uap, nfds); i++)
		pl[i].revents = 0;

	if (msec != -1) {
		atv.tv_sec = msec / 1000;
		atv.tv_usec = (msec - (atv.tv_sec * 1000)) * 1000;

		if (itimerfix(&atv)) {
			error = EINVAL;
			goto done;
		}
		s = splclock();
		timeradd(&atv, &time, &atv);
		timo = hzto(&atv);
		/*
		 * Avoid inadvertently sleeping forever.
		 */
		if (timo == 0)
			timo = 1;
		splx(s);
	} else
		timo = 0;

retry:
	ncoll = nselcoll;
	p->p_flag |= P_SELECT;
	pollscan(p, pl, SCARG(uap, nfds), retval);
	if (*retval)
		goto done;
	s = splhigh();
	if (timo && timercmp(&time, &atv, >=)) {
		splx(s);
		goto done;
	}
	if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) {
		splx(s);
		goto retry;
	}
	p->p_flag &= ~P_SELECT;
	error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "poll", timo);
	splx(s);
	if (error == 0)
		goto retry;

done:
	p->p_flag &= ~P_SELECT;
	/* poll is not restarted after signals... */
	if (error == ERESTART)
		error = EINTR;
	if (error == EWOULDBLOCK)
		error = 0;
	if ((error2 = copyout(pl, SCARG(uap, fds), sz)) != 0)
		error = error2;
bad:
	if (pl != pfds)
		free((char *) pl, M_TEMP);
	return (error);
}