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freebsd/sys/kern/subr_autoconf.c
Justin T. Gibbs ab36c06737 init_main.c subr_autoconf.c:
Add support for "interrupt driven configuration hooks".
	A component of the kernel can register a hook, most likely
	during auto-configuration, and receive a callback once
	interrupt services are available.  This callback will occur before
	the root and dump devices are configured, so the configuration
	task can affect the selection of those two devices or complete
	any tasks that need to be performed prior to launching init.
	System boot is posponed so long as a hook is registered.  The
	hook owner is responsible for removing the hook once their task
	is complete or the system boot can continue.

kern_acct.c kern_clock.c kern_exit.c kern_synch.c kern_time.c:
	Change the interface and implementation for the kernel callout
	service.  The new implemntaion is based on the work of
	Adam M. Costello and George Varghese, published in a technical
	report entitled "Redesigning the BSD Callout and Timer Facilities".
	The interface used in FreeBSD is a little different than the one
	outlined in the paper.  The new function prototypes are:

	struct callout_handle timeout(void (*func)(void *),
				      void *arg, int ticks);

	void untimeout(void (*func)(void *), void *arg,
		       struct callout_handle handle);

	If a client wishes to remove a timeout, it must store the
	callout_handle returned by timeout and pass it to untimeout.

	The new implementation gives 0(1) insert and removal of callouts
	making this interface scale well even for applications that
	keep 100s of callouts outstanding.

	See the updated timeout.9 man page for more details.
1997-09-21 22:00:25 +00:00

422 lines
11 KiB
C

/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Lawrence Berkeley Laboratories.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)subr_autoconf.c 8.1 (Berkeley) 6/10/93
*
* $Id: subr_autoconf.c,v 1.4 1997/02/22 09:39:15 peter Exp $
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>
/*
* Autoconfiguration subroutines.
*/
#ifdef UNUSED
/*
* ioconf.c exports exactly two names: cfdata and cfroots. All system
* devices and drivers are found via these tables.
*/
extern struct cfdata cfdata[];
extern short cfroots[];
#define ROOT ((struct device *)NULL)
struct matchinfo {
cfmatch_t fn;
struct device *parent;
void *aux;
struct cfdata *match;
int pri;
};
/*
* Apply the matching function and choose the best. This is used
* a few times and we want to keep the code small.
*/
static void
mapply(m, cf)
register struct matchinfo *m;
register struct cfdata *cf;
{
register int pri;
if (m->fn != NULL)
pri = (*m->fn)(m->parent, cf, m->aux);
else
pri = (*cf->cf_driver->cd_match)(m->parent, cf, m->aux);
if (pri > m->pri) {
m->match = cf;
m->pri = pri;
}
}
/*
* Iterate over all potential children of some device, calling the given
* function (default being the child's match function) for each one.
* Nonzero returns are matches; the highest value returned is considered
* the best match. Return the `found child' if we got a match, or NULL
* otherwise. The `aux' pointer is simply passed on through.
*
* Note that this function is designed so that it can be used to apply
* an arbitrary function to all potential children (its return value
* can be ignored).
*/
struct cfdata *
config_search(fn, parent, aux)
cfmatch_t fn;
register struct device *parent;
void *aux;
{
register struct cfdata *cf;
register short *p;
struct matchinfo m;
m.fn = fn;
m.parent = parent;
m.aux = aux;
m.match = NULL;
m.pri = 0;
for (cf = cfdata; cf->cf_driver; cf++) {
/*
* Skip cf if no longer eligible, otherwise scan through
* parents for one matching `parent', and try match function.
*/
if (cf->cf_fstate == FSTATE_FOUND)
continue;
for (p = cf->cf_parents; *p >= 0; p++)
if (parent->dv_cfdata == &cfdata[*p])
mapply(&m, cf);
}
return (m.match);
}
/*
* Find the given root device.
* This is much like config_search, but there is no parent.
*/
struct cfdata *
config_rootsearch(fn, rootname, aux)
register cfmatch_t fn;
register char *rootname;
register void *aux;
{
register struct cfdata *cf;
register short *p;
struct matchinfo m;
m.fn = fn;
m.parent = ROOT;
m.aux = aux;
m.match = NULL;
m.pri = 0;
/*
* Look at root entries for matching name. We do not bother
* with found-state here since only one root should ever be
* searched (and it must be done first).
*/
for (p = cfroots; *p >= 0; p++) {
cf = &cfdata[*p];
if (strcmp(cf->cf_driver->cd_name, rootname) == 0)
mapply(&m, cf);
}
return (m.match);
}
static char *msgs[3] = { "", " not configured\n", " unsupported\n" };
/*
* The given `aux' argument describes a device that has been found
* on the given parent, but not necessarily configured. Locate the
* configuration data for that device (using the cd_match configuration
* driver function) and attach it, and return true. If the device was
* not configured, call the given `print' function and return 0.
*/
int
config_found(parent, aux, print)
struct device *parent;
void *aux;
cfprint_t print;
{
struct cfdata *cf;
if ((cf = config_search((cfmatch_t)NULL, parent, aux)) != NULL) {
config_attach(parent, cf, aux, print);
return (1);
}
printf(msgs[(*print)(aux, parent->dv_xname)]);
return (0);
}
/*
* As above, but for root devices.
*/
int
config_rootfound(rootname, aux)
char *rootname;
void *aux;
{
struct cfdata *cf;
if ((cf = config_rootsearch((cfmatch_t)NULL, rootname, aux)) != NULL) {
config_attach(ROOT, cf, aux, (cfprint_t)NULL);
return (1);
}
printf("root device %s not configured\n", rootname);
return (0);
}
/* just like sprintf(buf, "%d") except that it works from the end */
static char *
number(ep, n)
register char *ep;
register int n;
{
*--ep = 0;
while (n >= 10) {
*--ep = (n % 10) + '0';
n /= 10;
}
*--ep = n + '0';
return (ep);
}
/*
* Attach a found device. Allocates memory for device variables.
*/
void
config_attach(parent, cf, aux, print)
register struct device *parent;
register struct cfdata *cf;
register void *aux;
cfprint_t print;
{
register struct device *dev;
register struct cfdriver *cd;
register size_t lname, lunit;
register char *xunit;
int myunit;
char num[10];
static struct device **nextp = &alldevs;
cd = cf->cf_driver;
if (cd->cd_devsize < sizeof(struct device))
panic("config_attach");
myunit = cf->cf_unit;
if (cf->cf_fstate == FSTATE_NOTFOUND)
cf->cf_fstate = FSTATE_FOUND;
else
cf->cf_unit++;
/* compute length of name and decimal expansion of unit number */
lname = strlen(cd->cd_name);
xunit = number(&num[sizeof num], myunit);
lunit = &num[sizeof num] - xunit;
if (lname + lunit >= sizeof(dev->dv_xname))
panic("config_attach: device name too long");
/* get memory for all device vars */
dev = (struct device *)malloc(cd->cd_devsize, M_DEVBUF, M_WAITOK);
/* XXX cannot wait! */
bzero(dev, cd->cd_devsize);
*nextp = dev; /* link up */
nextp = &dev->dv_next;
dev->dv_class = cd->cd_class;
dev->dv_cfdata = cf;
dev->dv_unit = myunit;
bcopy(cd->cd_name, dev->dv_xname, lname);
bcopy(xunit, dev->dv_xname + lname, lunit);
dev->dv_parent = parent;
if (parent == ROOT)
printf("%s (root)", dev->dv_xname);
else {
printf("%s at %s", dev->dv_xname, parent->dv_xname);
(void) (*print)(aux, (char *)0);
}
/* put this device in the devices array */
if (dev->dv_unit >= cd->cd_ndevs) {
/*
* Need to expand the array.
*/
int old = cd->cd_ndevs, oldbytes, new, newbytes;
void **nsp;
if (old == 0) {
nsp = malloc(MINALLOCSIZE, M_DEVBUF, M_WAITOK); /*XXX*/
bzero(nsp, MINALLOCSIZE);
cd->cd_ndevs = MINALLOCSIZE / sizeof(void *);
} else {
new = cd->cd_ndevs;
do {
new *= 2;
} while (new <= dev->dv_unit);
cd->cd_ndevs = new;
oldbytes = old * sizeof(void *);
newbytes = new * sizeof(void *);
nsp = malloc(newbytes, M_DEVBUF, M_WAITOK); /*XXX*/
bcopy(cd->cd_devs, nsp, oldbytes);
bzero(&nsp[old], newbytes - oldbytes);
free(cd->cd_devs, M_DEVBUF);
}
cd->cd_devs = nsp;
}
if (cd->cd_devs[dev->dv_unit])
panic("config_attach: duplicate %s", dev->dv_xname);
cd->cd_devs[dev->dv_unit] = dev;
/*
* Before attaching, clobber any unfound devices that are
* otherwise identical.
*/
for (cf = cfdata; cf->cf_driver; cf++)
if (cf->cf_driver == cd && cf->cf_unit == dev->dv_unit &&
cf->cf_fstate == FSTATE_NOTFOUND)
cf->cf_fstate = FSTATE_FOUND;
(*cd->cd_attach)(parent, dev, aux);
}
/*
* 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;
{
static struct evcnt **nextp = &allevents;
#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);
*nextp = ev;
nextp = &ev->ev_next;
}
#endif
/*
* "Interrupt driven config" functions.
*/
static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
/* ARGSUSED */
static void run_interrupt_driven_config_hooks __P((void *dummy));
static void
run_interrupt_driven_config_hooks(dummy)
void *dummy;
{
struct intr_config_hook *hook;
for (hook = intr_config_hook_list.tqh_first; hook != NULL;
hook = hook->ich_links.tqe_next) {
(*hook->ich_func)(hook->ich_arg);
}
while (intr_config_hook_list.tqh_first != NULL) {
tsleep(&intr_config_hook_list, PCONFIG, "conifhk", 0);
}
}
SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
run_interrupt_driven_config_hooks, NULL)
/*
* Register a hook that will be called after "cold"
* autoconfiguration is complete and interrupts can
* be used to complete initialization.
*/
int
config_intrhook_establish(hook)
struct intr_config_hook *hook;
{
struct intr_config_hook *hook_entry;
for (hook_entry = intr_config_hook_list.tqh_first; hook_entry != NULL;
hook_entry = hook_entry->ich_links.tqe_next)
if (hook_entry == hook)
break;
if (hook_entry != NULL) {
printf("config_intrhook_establish: establishing an "
"already established hook.\n");
return (1);
}
TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
if (cold == 0)
/* XXX Sufficient for LKMs loaded after initial config??? */
run_interrupt_driven_config_hooks(NULL);
return (0);
}
void
config_intrhook_disestablish(hook)
struct intr_config_hook *hook;
{
struct intr_config_hook *hook_entry;
for (hook_entry = intr_config_hook_list.tqh_first; hook_entry != NULL;
hook_entry = hook_entry->ich_links.tqe_next)
if (hook_entry == hook)
break;
if (hook_entry == NULL)
panic("config_intrhook_disestablish: disestablishing an "
"unestablished hook");
TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
/* Wakeup anyone watching the list */
wakeup(&intr_config_hook_list);
}