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Diffstat (limited to 'sys/kern/subr_rman.c')
-rw-r--r--sys/kern/subr_rman.c591
1 files changed, 0 insertions, 591 deletions
diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c
deleted file mode 100644
index e0526bb5badc..000000000000
--- a/sys/kern/subr_rman.c
+++ /dev/null
@@ -1,591 +0,0 @@
-/*
- * Copyright 1998 Massachusetts Institute of Technology
- *
- * Permission to use, copy, modify, and distribute this software and
- * its documentation for any purpose and without fee is hereby
- * granted, provided that both the above copyright notice and this
- * permission notice appear in all copies, that both the above
- * copyright notice and this permission notice appear in all
- * supporting documentation, and that the name of M.I.T. not be used
- * in advertising or publicity pertaining to distribution of the
- * software without specific, written prior permission. M.I.T. makes
- * no representations about the suitability of this software for any
- * purpose. It is provided "as is" without express or implied
- * warranty.
- *
- * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
- * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
- * SHALL M.I.T. 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.
- *
- * $Id: subr_rman.c,v 1.3 1998/12/07 21:58:29 archie Exp $
- */
-
-/*
- * The kernel resource manager. This code is responsible for keeping track
- * of hardware resources which are apportioned out to various drivers.
- * It does not actually assign those resources, and it is not expected
- * that end-device drivers will call into this code directly. Rather,
- * the code which implements the buses that those devices are attached to,
- * and the code which manages CPU resources, will call this code, and the
- * end-device drivers will make upcalls to that code to actually perform
- * the allocation.
- *
- * There are two sorts of resources managed by this code. The first is
- * the more familiar array (RMAN_ARRAY) type; resources in this class
- * consist of a sequence of individually-allocatable objects which have
- * been numbered in some well-defined order. Most of the resources
- * are of this type, as it is the most familiar. The second type is
- * called a gauge (RMAN_GAUGE), and models fungible resources (i.e.,
- * resources in which each instance is indistinguishable from every
- * other instance). The principal anticipated application of gauges
- * is in the context of power consumption, where a bus may have a specific
- * power budget which all attached devices share. RMAN_GAUGE is not
- * implemented yet.
- *
- * For array resources, we make one simplifying assumption: two clients
- * sharing the same resource must use the same range of indices. That
- * is to say, sharing of overlapping-but-not-identical regions is not
- * permitted.
- */
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/kernel.h>
-#include <sys/lock.h>
-#include <sys/malloc.h>
-#include <sys/rman.h>
-#include <sys/bus.h> /* XXX debugging */
-
-MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
-
-struct rman_head rman_head;
-#ifndef NULL_SIMPLELOCKS
-static struct simplelock rman_lock; /* mutex to protect rman_head */
-#endif
-static int int_rman_activate_resource(struct rman *rm, struct resource *r,
- struct resource **whohas);
-static int int_rman_release_resource(struct rman *rm, struct resource *r);
-
-#define CIRCLEQ_TERMCOND(var, head) (var == (void *)&(head))
-
-int
-rman_init(struct rman *rm)
-{
- static int once;
-
- if (once == 0) {
- once = 1;
- TAILQ_INIT(&rman_head);
- simple_lock_init(&rman_lock);
- }
-
- if (rm->rm_type == RMAN_UNINIT)
- panic("rman_init");
- if (rm->rm_type == RMAN_GAUGE)
- panic("implement RMAN_GAUGE");
-
- CIRCLEQ_INIT(&rm->rm_list);
- rm->rm_slock = malloc(sizeof *rm->rm_slock, M_RMAN, M_NOWAIT);
- if (rm->rm_slock == 0)
- return ENOMEM;
- simple_lock_init(rm->rm_slock);
-
- simple_lock(&rman_lock);
- TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
- simple_unlock(&rman_lock);
- return 0;
-}
-
-/*
- * NB: this interface is not robust against programming errors which
- * add multiple copies of the same region.
- */
-int
-rman_manage_region(struct rman *rm, u_long start, u_long end)
-{
- struct resource *r, *s;
-
- r = malloc(sizeof *r, M_RMAN, M_NOWAIT);
- if (r == 0)
- return ENOMEM;
- r->r_sharehead = 0;
- r->r_start = start;
- r->r_end = end;
- r->r_flags = 0;
- r->r_dev = 0;
- r->r_rm = rm;
-
- simple_lock(rm->rm_slock);
- for (s = rm->rm_list.cqh_first;
- !CIRCLEQ_TERMCOND(s, rm->rm_list) && s->r_end < r->r_start;
- s = s->r_link.cqe_next)
- ;
-
- if (CIRCLEQ_TERMCOND(s, rm->rm_list)) {
- CIRCLEQ_INSERT_TAIL(&rm->rm_list, r, r_link);
- } else {
- CIRCLEQ_INSERT_BEFORE(&rm->rm_list, s, r, r_link);
- }
-
- simple_unlock(rm->rm_slock);
- return 0;
-}
-
-int
-rman_fini(struct rman *rm)
-{
- struct resource *r;
-
- simple_lock(rm->rm_slock);
- for (r = rm->rm_list.cqh_first; !CIRCLEQ_TERMCOND(r, rm->rm_list);
- r = r->r_link.cqe_next) {
- if (r->r_flags & RF_ALLOCATED)
- return EBUSY;
- }
-
- /*
- * There really should only be one of these if we are in this
- * state and the code is working properly, but it can't hurt.
- */
- for (r = rm->rm_list.cqh_first; !CIRCLEQ_TERMCOND(r, rm->rm_list);
- r = rm->rm_list.cqh_first) {
- CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
- free(r, M_RMAN);
- }
- simple_unlock(rm->rm_slock);
- simple_lock(&rman_lock);
- TAILQ_REMOVE(&rman_head, rm, rm_link);
- simple_unlock(&rman_lock);
- free(rm->rm_slock, M_RMAN);
-
- return 0;
-}
-
-struct resource *
-rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
- u_int flags, struct device *dev)
-{
- u_int want_activate;
- struct resource *r, *s, *rv;
- u_long rstart, rend;
-
- rv = 0;
-
-#ifdef RMAN_DEBUG
- printf("rman_reserve_resource: <%s> request: [%#lx, %#lx], length "
- "%#lx, flags %u, device %s%d\n", rm->rm_descr, start, end,
- count, flags, device_get_name(dev), device_get_unit(dev));
-#endif /* RMAN_DEBUG */
- want_activate = (flags & RF_ACTIVE);
- flags &= ~RF_ACTIVE;
-
- simple_lock(rm->rm_slock);
-
- for (r = rm->rm_list.cqh_first;
- !CIRCLEQ_TERMCOND(r, rm->rm_list) && r->r_end < start;
- r = r->r_link.cqe_next)
- ;
-
- if (CIRCLEQ_TERMCOND(r, rm->rm_list)) {
-#ifdef RMAN_DEBUG
- printf("could not find a region\n");
-#endif RMAN_DEBUG
- goto out;
- }
-
- /*
- * First try to find an acceptable totally-unshared region.
- */
- for (s = r; !CIRCLEQ_TERMCOND(s, rm->rm_list);
- s = s->r_link.cqe_next) {
-#ifdef RMAN_DEBUG
- printf("considering [%#lx, %#lx]\n", s->r_start, s->r_end);
-#endif /* RMAN_DEBUG */
- if (s->r_start > end) {
-#ifdef RMAN_DEBUG
- printf("s->r_start (%#lx) > end (%#lx)\n", s->r_start, end);
-#endif /* RMAN_DEBUG */
- break;
- }
- if (s->r_flags & RF_ALLOCATED) {
-#ifdef RMAN_DEBUG
- printf("region is allocated\n");
-#endif /* RMAN_DEBUG */
- continue;
- }
- rstart = max(s->r_start, start);
- rend = min(s->r_end, max(start + count, end));
-#ifdef RMAN_DEBUG
- printf("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
- rstart, rend, (rend - rstart + 1), count);
-#endif /* RMAN_DEBUG */
-
- if ((rend - rstart + 1) >= count) {
-#ifdef RMAN_DEBUG
- printf("candidate region: [%#lx, %#lx], size %#lx\n",
- rend, rstart, (rend - rstart + 1));
-#endif /* RMAN_DEBUG */
- if ((s->r_end - s->r_start + 1) == count) {
-#ifdef RMAN_DEBUG
- printf("candidate region is entire chunk\n");
-#endif /* RMAN_DEBUG */
- rv = s;
- rv->r_flags |= RF_ALLOCATED;
- rv->r_dev = dev;
- goto out;
- }
-
- /*
- * If s->r_start < rstart and
- * s->r_end > rstart + count - 1, then
- * we need to split the region into three pieces
- * (the middle one will get returned to the user).
- * Otherwise, we are allocating at either the
- * beginning or the end of s, so we only need to
- * split it in two. The first case requires
- * two new allocations; the second requires but one.
- */
- rv = malloc(sizeof *r, M_RMAN, M_NOWAIT);
- if (rv == 0)
- goto out;
- rv->r_start = rstart;
- rv->r_end = rstart + count - 1;
- rv->r_flags = flags | RF_ALLOCATED;
- rv->r_dev = dev;
- rv->r_sharehead = 0;
-
- if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
-#ifdef RMAN_DEBUG
- printf("splitting region in three parts: "
- "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
- s->r_start, rv->r_start - 1,
- rv->r_start, rv->r_end,
- rv->r_end + 1, s->r_end);
-#endif /* RMAN_DEBUG */
- /*
- * We are allocating in the middle.
- */
- r = malloc(sizeof *r, M_RMAN, M_NOWAIT);
- if (r == 0) {
- free(rv, M_RMAN);
- rv = 0;
- goto out;
- }
- r->r_start = rv->r_end + 1;
- r->r_end = s->r_end;
- r->r_flags = s->r_flags;
- r->r_dev = 0;
- r->r_sharehead = 0;
- s->r_end = rv->r_start - 1;
- CIRCLEQ_INSERT_AFTER(&rm->rm_list, s, rv,
- r_link);
- CIRCLEQ_INSERT_AFTER(&rm->rm_list, rv, r,
- r_link);
- } else if (s->r_start == rv->r_start) {
-#ifdef RMAN_DEBUG
- printf("allocating from the beginning\n");
-#endif /* RMAN_DEBUG */
- /*
- * We are allocating at the beginning.
- */
- s->r_start = rv->r_end + 1;
- CIRCLEQ_INSERT_BEFORE(&rm->rm_list, s, rv,
- r_link);
- } else {
-#ifdef RMAN_DEBUG
- printf("allocating at the end\n");
-#endif /* RMAN_DEBUG */
- /*
- * We are allocating at the end.
- */
- s->r_end = rv->r_start - 1;
- CIRCLEQ_INSERT_AFTER(&rm->rm_list, s, rv,
- r_link);
- }
- goto out;
- }
- }
-
- /*
- * Now find an acceptable shared region, if the client's requirements
- * allow sharing. By our implementation restriction, a candidate
- * region must match exactly by both size and sharing type in order
- * to be considered compatible with the client's request. (The
- * former restriction could probably be lifted without too much
- * additional work, but this does not seem warranted.)
- */
-#ifdef RMAN_DEBUG
- printf("no unshared regions found\n");
-#endif /* RMAN_DEBUG */
- if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
- goto out;
-
- for (s = r; !CIRCLEQ_TERMCOND(s, rm->rm_list);
- s = s->r_link.cqe_next) {
- if (s->r_start > end)
- break;
- if ((s->r_flags & flags) != flags)
- continue;
- rstart = max(s->r_start, start);
- rend = min(s->r_end, max(start + count, end));
- if (s->r_start >= start && s->r_end <= end
- && (s->r_end - s->r_start + 1) == count) {
- rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT);
- if (rv == 0)
- goto out;
- rv->r_start = s->r_start;
- rv->r_end = s->r_end;
- rv->r_flags = s->r_flags &
- (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
- rv->r_dev = dev;
- rv->r_rm = rm;
- if (s->r_sharehead == 0) {
- s->r_sharehead = malloc(sizeof *s->r_sharehead,
- M_RMAN, M_NOWAIT);
- if (s->r_sharehead == 0) {
- free(rv, M_RMAN);
- rv = 0;
- goto out;
- }
- LIST_INIT(s->r_sharehead);
- LIST_INSERT_HEAD(s->r_sharehead, s,
- r_sharelink);
- s->r_flags = RF_FIRSTSHARE;
- }
- rv->r_sharehead = s->r_sharehead;
- LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
- goto out;
- }
- }
-
- /*
- * We couldn't find anything.
- */
-out:
- /*
- * If the user specified RF_ACTIVE in the initial flags,
- * which is reflected in `want_activate', we attempt to atomically
- * activate the resource. If this fails, we release the resource
- * and indicate overall failure. (This behavior probably doesn't
- * make sense for RF_TIMESHARE-type resources.)
- */
- if (rv && want_activate) {
- struct resource *whohas;
- if (int_rman_activate_resource(rm, rv, &whohas)) {
- int_rman_release_resource(rm, rv);
- rv = 0;
- }
- }
-
- simple_unlock(rm->rm_slock);
- return (rv);
-}
-
-static int
-int_rman_activate_resource(struct rman *rm, struct resource *r,
- struct resource **whohas)
-{
- struct resource *s;
- int ok;
-
- /*
- * If we are not timesharing, then there is nothing much to do.
- * If we already have the resource, then there is nothing at all to do.
- * If we are not on a sharing list with anybody else, then there is
- * little to do.
- */
- if ((r->r_flags & RF_TIMESHARE) == 0
- || (r->r_flags & RF_ACTIVE) != 0
- || r->r_sharehead == 0) {
- r->r_flags |= RF_ACTIVE;
- return 0;
- }
-
- ok = 1;
- for (s = r->r_sharehead->lh_first; s && ok;
- s = s->r_sharelink.le_next) {
- if ((s->r_flags & RF_ACTIVE) != 0) {
- ok = 0;
- *whohas = s;
- }
- }
- if (ok) {
- r->r_flags |= RF_ACTIVE;
- return 0;
- }
- return EBUSY;
-}
-
-int
-rman_activate_resource(struct resource *r)
-{
- int rv;
- struct resource *whohas;
- struct rman *rm;
-
- rm = r->r_rm;
- simple_lock(rm->rm_slock);
- rv = int_rman_activate_resource(rm, r, &whohas);
- simple_unlock(rm->rm_slock);
- return rv;
-}
-
-int
-rman_await_resource(struct resource *r, int pri, int timo)
-{
- int rv, s;
- struct resource *whohas;
- struct rman *rm;
-
- rm = r->r_rm;
- for (;;) {
- simple_lock(rm->rm_slock);
- rv = int_rman_activate_resource(rm, r, &whohas);
- if (rv != EBUSY)
- return (rv);
-
- if (r->r_sharehead == 0)
- panic("rman_await_resource");
- /*
- * splhigh hopefully will prevent a race between
- * simple_unlock and tsleep where a process
- * could conceivably get in and release the resource
- * before we have a chance to sleep on it.
- */
- s = splhigh();
- whohas->r_flags |= RF_WANTED;
- simple_unlock(rm->rm_slock);
- rv = tsleep(r->r_sharehead, pri, "rmwait", timo);
- if (rv) {
- splx(s);
- return rv;
- }
- simple_lock(rm->rm_slock);
- splx(s);
- }
-}
-
-int
-rman_deactivate_resource(struct resource *r)
-{
- struct rman *rm;
-
- rm = r->r_rm;
- simple_lock(rm->rm_slock);
- r->r_flags &= ~RF_ACTIVE;
- if (r->r_flags & RF_WANTED) {
- r->r_flags &= ~RF_WANTED;
- wakeup(r->r_sharehead);
- }
- simple_unlock(rm->rm_slock);
- return 0;
-}
-
-static int
-int_rman_release_resource(struct rman *rm, struct resource *r)
-{
- struct resource *s, *t;
-
- if (r->r_flags & RF_ACTIVE)
- return EBUSY;
-
- /*
- * Check for a sharing list first. If there is one, then we don't
- * have to think as hard.
- */
- if (r->r_sharehead) {
- /*
- * If a sharing list exists, then we know there are at
- * least two sharers.
- *
- * If we are in the main circleq, appoint someone else.
- */
- LIST_REMOVE(r, r_sharelink);
- s = r->r_sharehead->lh_first;
- if (r->r_flags & RF_FIRSTSHARE) {
- s->r_flags |= RF_FIRSTSHARE;
- CIRCLEQ_INSERT_BEFORE(&rm->rm_list, r, s, r_link);
- CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
- }
-
- /*
- * Make sure that the sharing list goes away completely
- * if the resource is no longer being shared at all.
- */
- if (s->r_sharelink.le_next == 0) {
- free(s->r_sharehead, M_RMAN);
- s->r_sharehead = 0;
- s->r_flags &= ~RF_FIRSTSHARE;
- }
- goto out;
- }
-
- /*
- * Look at the adjacent resources in the list and see if our
- * segment can be merged with any of them.
- */
- s = r->r_link.cqe_prev;
- t = r->r_link.cqe_next;
-
- if (s != (void *)&rm->rm_list && (s->r_flags & RF_ALLOCATED) == 0
- && t != (void *)&rm->rm_list && (t->r_flags & RF_ALLOCATED) == 0) {
- /*
- * Merge all three segments.
- */
- s->r_end = t->r_end;
- CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
- CIRCLEQ_REMOVE(&rm->rm_list, t, r_link);
- free(t, M_RMAN);
- } else if (s != (void *)&rm->rm_list
- && (s->r_flags & RF_ALLOCATED) == 0) {
- /*
- * Merge previous segment with ours.
- */
- s->r_end = r->r_end;
- CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
- } else if (t != (void *)&rm->rm_list
- && (t->r_flags & RF_ALLOCATED) == 0) {
- /*
- * Merge next segment with ours.
- */
- t->r_start = r->r_start;
- CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
- } else {
- /*
- * At this point, we know there is nothing we
- * can potentially merge with, because on each
- * side, there is either nothing there or what is
- * there is still allocated. In that case, we don't
- * want to remove r from the list; we simply want to
- * change it to an unallocated region and return
- * without freeing anything.
- */
- r->r_flags &= ~RF_ALLOCATED;
- return 0;
- }
-
-out:
- free(r, M_RMAN);
- return 0;
-}
-
-int
-rman_release_resource(struct resource *r)
-{
- int rv;
- struct rman *rm = r->r_rm;
-
- simple_lock(rm->rm_slock);
- rv = int_rman_release_resource(rm, r);
- simple_unlock(rm->rm_slock);
- return (rv);
-}
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