subr_autoconf.c

来自「MIPS处理器的bootloader,龙芯就是用的修改过的PMON2」· C语言 代码 · 共 943 行 · 第 1/2 页

	lname = strlen(cd->cd_name);
	xunit = number(&num[sizeof num], dev->dv_unit);
	lunit = &num[sizeof num] - xunit;
	if (lname + lunit >= sizeof(dev->dv_xname))
		panic("config_make_softc: device name too long");

	bcopy(cd->cd_name, dev->dv_xname, lname);
	bcopy(xunit, dev->dv_xname + lname, lunit);
	dev->dv_parent = parent;

	/* put this device in the devices array */
	if (dev->dv_unit >= cd->cd_ndevs) {
		/*
		 * Need to expand the array.
		 */
		int old = cd->cd_ndevs, new;
		void **nsp;

		if (old == 0)
			new = MINALLOCSIZE / sizeof(void *);
		else
			new = old * 2;
		while (new <= dev->dv_unit)
			new *= 2;
		cd->cd_ndevs = new;
		nsp = malloc(new * sizeof(void *), M_DEVBUF, M_NOWAIT);	
		if (nsp == 0)
			panic("config_make_softc: %sing dev array",
			    old != 0 ? "expand" : "creat");
		bzero(nsp + old, (new - old) * sizeof(void *));
		if (old != 0) {
			bcopy(cd->cd_devs, nsp, old * sizeof(void *));
			free(cd->cd_devs, M_DEVBUF);
		}
		cd->cd_devs = nsp;
	}
	if (cd->cd_devs[dev->dv_unit])
		panic("config_make_softc: duplicate %s", dev->dv_xname);

	dev->dv_ref = 1;

	return (dev);
}

/*
 * Detach a device.  Optionally forced (e.g. because of hardware
 * removal) and quiet.  Returns zero if successful, non-zero
 * (an error code) otherwise.
 *
 * Note that this code wants to be run from a process context, so
 * that the detach can sleep to allow processes which have a device
 * open to run and unwind their stacks.
 */
int
config_detach(dev, flags)
	struct device *dev;
	int flags;
{
	struct cfdata *cf;
	struct cfattach *ca;
	struct cfdriver *cd;
#ifdef DIAGNOSTIC
	struct device *d;
#endif
	int rv = 0, i;

	cf = dev->dv_cfdata;
#ifdef DIAGNOSTIC
	if (cf->cf_fstate != FSTATE_FOUND && cf->cf_fstate != FSTATE_STAR)
		panic("config_detach: bad device fstate");
#endif
	ca = cf->cf_attach;
	cd = cf->cf_driver;

	/*
	 * Ensure the device is deactivated.  If the device doesn't
	 * have an activation entry point, we allow DVF_ACTIVE to
	 * remain set.  Otherwise, if DVF_ACTIVE is still set, the
	 * device is busy, and the detach fails.
	 */
	if (ca->ca_activate != NULL)
		rv = config_deactivate(dev);

	/*
	 * Try to detach the device.  If that's not possible, then
	 * we either panic() (for the forced but failed case), or
	 * return an error.
	 */
	if (rv == 0) {
		if (ca->ca_detach != NULL)
			rv = (*ca->ca_detach)(dev, flags);
		else
			rv = EOPNOTSUPP;
	}
	if (rv != 0) {
		if ((flags & DETACH_FORCE) == 0)
			return (rv);
		else
			panic("config_detach: forced detach of %s failed (%d)",
			    dev->dv_xname, rv);
	}

	/*
	 * The device has now been successfully detached.
	 */

#ifdef DIAGNOSTIC
	/*
	 * Sanity: If you're successfully detached, you should have no
	 * children.  (Note that because children must be attached
	 * after parents, we only need to search the latter part of
	 * the list.)
	 */
	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
	     d = TAILQ_NEXT(d, dv_list)) {
		if (d->dv_parent == dev)
			panic("config_detach: detached device has children");
	}
#endif

	/*
	 * Mark cfdata to show that the unit can be reused, if possible.
	 * Note that we can only re-use a starred unit number if the unit
	 * being detached had the last assigned unit number.
	 */
	for (cf = cfdata; cf->cf_driver; cf++) {
		if (cf->cf_driver == cd) {
			if (cf->cf_fstate == FSTATE_FOUND &&
			    cf->cf_unit == dev->dv_unit)
				cf->cf_fstate = FSTATE_NOTFOUND;
			if (cf->cf_fstate == FSTATE_STAR &&
			    cf->cf_unit == dev->dv_unit + 1)
				cf->cf_unit--;
		}
	}

	/*
	 * Unlink from device list.
	 */
	TAILQ_REMOVE(&alldevs, dev, dv_list);
	device_unref(dev);

	/*
	 * Remove from cfdriver's array, tell the world, and free softc.
	 */
	cd->cd_devs[dev->dv_unit] = NULL;
	if ((flags & DETACH_QUIET) == 0)
		printf("%s detached\n", dev->dv_xname);

	device_unref(dev);
	/*
	 * If the device now has no units in use, deallocate its softc array.
	 */
	for (i = 0; i < cd->cd_ndevs; i++)
		if (cd->cd_devs[i] != NULL)
			break;
	if (i == cd->cd_ndevs) {		/* nothing found; deallocate */
		free(cd->cd_devs, M_DEVBUF);
		cd->cd_devs = NULL;
		cd->cd_ndevs = 0;
	}

	/*
	 * Return success.
	 */
	return (0);
}

int
config_activate(dev)
	struct device *dev;
{
	struct cfattach *ca = dev->dv_cfdata->cf_attach;
	int rv = 0, oflags = dev->dv_flags;

	if (ca->ca_activate == NULL)
		return (EOPNOTSUPP);

	if ((dev->dv_flags & DVF_ACTIVE) == 0) {
		dev->dv_flags |= DVF_ACTIVE;
		rv = (*ca->ca_activate)(dev, DVACT_ACTIVATE);
		if (rv)
			dev->dv_flags = oflags;
	}
	return (rv);
}

int
config_deactivate(dev)
	struct device *dev;
{
	struct cfattach *ca = dev->dv_cfdata->cf_attach;
	int rv = 0, oflags = dev->dv_flags;

	if (ca->ca_activate == NULL)
		return (EOPNOTSUPP);

	if (dev->dv_flags & DVF_ACTIVE) {
		dev->dv_flags &= ~DVF_ACTIVE;
		rv = (*ca->ca_activate)(dev, DVACT_DEACTIVATE);
		if (rv)
			dev->dv_flags = oflags;
	}
	return (rv);
}

/*
 * Defer the configuration of the specified device until all
 * of its parent's devices have been attached.
 */
void
config_defer(dev, func)
	struct device *dev;
	void (*func) __P((struct device *));
{
	struct deferred_config *dc;

	if (dev->dv_parent == NULL)
		panic("config_defer: can't defer config of a root device");

#ifdef DIAGNOSTIC
	for (dc = TAILQ_FIRST(&deferred_config_queue); dc != NULL;
	     dc = TAILQ_NEXT(dc, dc_queue)) {
		if (dc->dc_dev == dev)
			panic("config_defer: deferred twice");
	}
#endif

	if ((dc = malloc(sizeof(*dc), M_DEVBUF, M_NOWAIT)) == NULL)
		panic("config_defer: can't allocate defer structure");

	dc->dc_dev = dev;
	dc->dc_func = func;
	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
}

/*
 * Process the deferred configuration queue for a device.
 */
void
config_process_deferred_children(parent)
	struct device *parent;
{
	struct deferred_config *dc, *ndc;

	for (dc = TAILQ_FIRST(&deferred_config_queue);
	     dc != NULL; dc = ndc) {
		ndc = TAILQ_NEXT(dc, dc_queue);
		if (dc->dc_dev->dv_parent == parent) {
			TAILQ_REMOVE(&deferred_config_queue, dc, dc_queue);
			(*dc->dc_func)(dc->dc_dev);
			free(dc, M_DEVBUF);
		}
	}
}

int
config_detach_children(parent, flags)
	struct device *parent;
	int flags;
{
	struct device *dev, *next_dev;
	int  rv = 0;

	/* The config_detach routine may sleep, meaning devices
	   may be added to the queue. However, all devices will
	   be added to the tail of the queue, the queue won't
	   be re-organized, and the subtree of parent here should be locked
	   for purposes of adding/removing children.
	*/
	for (dev  = TAILQ_FIRST(&alldevs);
	     dev != NULL; dev = next_dev) {
		next_dev = TAILQ_NEXT(dev, dv_list);
		if (dev->dv_parent == parent &&
		    (rv = config_detach(dev, flags)))
			return (rv);
	}

	return  (rv);
}

int
config_activate_children(parent, act)
	struct device *parent;
	enum devact act;
{
	struct device *dev, *next_dev;
	int  rv = 0;

	/* The config_deactivate routine may sleep, meaning devices
	   may be added to the queue. However, all devices will
	   be added to the tail of the queue, the queue won't
	   be re-organized, and the subtree of parent here should be locked
	   for purposes of adding/removing children.
	*/
	for (dev = TAILQ_FIRST(&alldevs);
	     dev != NULL; dev = next_dev) {
		next_dev = TAILQ_NEXT(dev, dv_list);
		if (dev->dv_parent == parent) {
			switch (act) {
			case DVACT_ACTIVATE:
				rv = config_activate(dev);
				break;
			case DVACT_DEACTIVATE:
				rv = config_deactivate(dev);
				break;
			default:
#ifdef DIAGNOSTIC
				printf ("config_activate_children: shouldn't get here");
#endif
				rv = EOPNOTSUPP;
				break;

			}
						
			if (rv)
				break;
		}
	}

	return  (rv);
}

/* 
 * Lookup a device in the cfdriver device array.  Does not return a
 * device if it is not active.
 *
 * Increments ref count on the device by one, reflecting the
 * new reference created on the stack.
 *
 * Context: process only 
 */
struct device *
device_lookup(cd, unit)
	struct cfdriver *cd;
	int unit;
{
	struct device *dv = NULL;

	if (unit >= 0 && unit < cd->cd_ndevs)
		dv = (struct device *)(cd->cd_devs[unit]);
	
	if (!dv)
		return (NULL);

	if (!(dv->dv_flags & DVF_ACTIVE))
		dv = NULL;

	if (dv != NULL)
		device_ref(dv);

	return (dv);
}


/*
 * Increments the ref count on the device structure. The device
 * structure is freed when the ref count hits 0.
 *
 * Context: process or interrupt
 */
void
device_ref(dv)
	struct device *dv;
{
	dv->dv_ref++;
}

/*
 * Decrement the ref count on the device structure.
 *
 * free's the structure when the ref count hits zero and calls the zeroref
 * function.
 *
 * Context: process or interrupt
 */
void
device_unref(dv)
	struct device *dv;
{
	dv->dv_ref--;
	if (dv->dv_ref == 0) {
		if (dv->dv_cfdata->cf_attach->ca_zeroref)
			(*dv->dv_cfdata->cf_attach->ca_zeroref)(dv);
		
		free(dv, M_DEVBUF);
	}
}

/*
 * Attach an event.  These must come from initially-zero space (see
 * commented-out assignments below), but that occurs naturally for
 * device instance variables.
 */
void
evcnt_attach(dev, name, ev)
	struct device *dev;
	const char *name;
	struct evcnt *ev;
{

#ifdef DIAGNOSTIC
	if (strlen(name) >= sizeof(ev->ev_name))
		panic("evcnt_attach");
#endif
	/* ev->ev_next = NULL; */
	ev->ev_dev = dev;
	/* ev->ev_count = 0; */
	strcpy(ev->ev_name, name);
	TAILQ_INSERT_TAIL(&allevents, ev, ev_list);
}

#if 0
int
attach_loadable(parentname, parentunit, cftable)
	char *parentname;
	int parentunit;
	struct cftable *cftable;
{
	int found = 0;
	struct device *d;

	TAILQ_INSERT_TAIL(&allcftables, cftable, list);

	for(d = alldevs.tqh_first; d != NULL; d = d->dv_list.tqe_next) {
		struct cfdriver *drv = d->dv_cfdata->cf_driver;

		if (strcmp(parentname, drv->cd_name) == NULL &&
		    (parentunit == -1 || parentunit == d->dv_unit)) {
			int s;

			s = splhigh(); /* ??? */
			found |= (*d->dv_cfdata->cf_attach->ca_reprobe)(d,
			    &(cftable->tab[0]));
			splx(s);
		}
	}
	if (!found)
		TAILQ_REMOVE(&allcftables, cftable, list);
	return(found);
}

int
devcf_intable __P((struct device *, void *));

int
devcf_intable(dev, arg)
	struct device *dev;
	void *arg;
{
	struct cftable *tbl = arg;
	struct cfdata *cf;

	for(cf = tbl->tab; cf->cf_driver; cf++) {
		if (dev->dv_cfdata == cf)
			return(1);
	}
	return(0);
}

int
detach_loadable(cftable)
	struct cftable *cftable;
{
	if (!detach_devices(devcf_intable, cftable, 0, 0))
		return(0);
	TAILQ_REMOVE(&allcftables, cftable, list);
	return(1);
}
#endif