From owner-p4-projects@FreeBSD.ORG Mon Mar 7 22:23:14 2011 Return-Path: Delivered-To: p4-projects@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 32767) id A161F1065674; Mon, 7 Mar 2011 22:23:14 +0000 (UTC) Delivered-To: perforce@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 62ADB1065673 for ; Mon, 7 Mar 2011 22:23:14 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from skunkworks.freebsd.org (skunkworks.freebsd.org [IPv6:2001:4f8:fff6::2d]) by mx1.freebsd.org (Postfix) with ESMTP id 4D1FE8FC17 for ; Mon, 7 Mar 2011 22:23:14 +0000 (UTC) Received: from skunkworks.freebsd.org (localhost [127.0.0.1]) by skunkworks.freebsd.org (8.14.4/8.14.4) with ESMTP id p27MNE4h090594 for ; Mon, 7 Mar 2011 22:23:14 GMT (envelope-from jhb@freebsd.org) Received: (from perforce@localhost) by skunkworks.freebsd.org (8.14.4/8.14.4/Submit) id p27MNEaq090591 for perforce@freebsd.org; Mon, 7 Mar 2011 22:23:14 GMT (envelope-from jhb@freebsd.org) Date: Mon, 7 Mar 2011 22:23:14 GMT Message-Id: <201103072223.p27MNEaq090591@skunkworks.freebsd.org> X-Authentication-Warning: skunkworks.freebsd.org: perforce set sender to jhb@freebsd.org using -f From: John Baldwin To: Perforce Change Reviews Precedence: bulk Cc: Subject: PERFORCE change 189686 for review X-BeenThere: p4-projects@freebsd.org X-Mailman-Version: 2.1.5 List-Id: p4 projects tree changes List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Mar 2011 22:23:14 -0000 http://p4web.freebsd.org/@@189686?ac=10 Change 189686 by jhb@jhb_jhbbsd on 2011/03/07 22:22:32 First cut at an 'rman_adjust_region()'. Affected files ... .. //depot/projects/pci/sys/kern/subr_rman.c#2 edit .. //depot/projects/pci/sys/sys/rman.h#2 edit Differences ... ==== //depot/projects/pci/sys/kern/subr_rman.c#2 (text+ko) ==== @@ -268,6 +268,128 @@ return 0; } +/* Shrink or extend one or both ends of an allocated resource. */ +int +rman_adjust_resource(struct resource *rr, u_long start, u_long end) +{ + struct resource_i *r, *s, *t, *new; + struct rman *rm; + + /* Not supported for shared resources. */ + r = rr->__r_i; + if (r->r_flags & (RF_TIMESHARE | RF_SHAREABLE)) + return (EINVAL); + + /* + * This does not support wholesale moving of a resource. At + * least part of the desired new range must overlap with the + * existing resource. + */ + if (end < r->r_start || r->r_end < start) + return (EINVAL); + + /* + * Find the two resource regions immediately adjacent to the + * allocated resource. + */ + rm = r->r_rm; + mtx_lock(rm->rm_mtx); +#ifdef INVARIANTS + TAILQ_FOREACH(s, &rm->rm_list, r_link) { + if (s == r) + break; + } + if (s == NULL) + panic("resource not in list"); +#endif + s = TAILQ_PREV(r, resource_head, r_link); + t = TAILQ_NEXT(r, r_link); + KASSERT(s == NULL || s->r_end + 1 == r->r_start, + ("prev resource mismatch")); + KASSERT(t == NULL || r->r_end + 1 == t->r_start, + ("next resource mismatch")); + + /* + * See if the changes are permitted. Shrinking is always allowed, + * but growing requires sufficient room in the adjacent region. + */ + if (start < r->r_start && (s == NULL || (s->r_flags & RF_ALLOCATED) || + s->r_start > start)) { + mtx_unlock(rm->rm_mtx); + return (EBUSY); + } + if (end > r->r_end && (t == NULL || (t->r_flags & RF_ALLOCATED) || + t->r_end < end)) { + mtx_unlock(rm->rm_mtx); + return (EBUSY); + } + + /* + * While holding the lock, grow either end of the resource as + * needed and shrink either end if the shrinking does not require + * allocating a new resource. We can safely drop the lock and then + * insert a new range to handle the shrinking case afterwards. + */ + if (start < r->r_start || + (start > r->r_start && s != NULL && !(s->r_flags & RF_ALLOCATED))) { + KASSERT(s->r_flags == 0, ("prev is busy")); + r->r_start = start; + if (s->r_start == start) { + TAILQ_REMOVE(&rm->rm_list, s, r_link); + free(s, M_RMAN); + } else + s->r_end = start - 1; + } + if (end > r->r_end || + (end < t->r_end && t != NULL && !(t->r_flags & RF_ALLOCATED))) { + KASSERT(t->r_flags == 0, ("next is busy")); + r->r_end = end; + if (t->r_end == end) { + TAILQ_REMOVE(&rm->rm_list, t, r_link); + free(t, M_RMAN); + } else + t->r_start = end + 1; + } + mtx_unlock(rm->rm_mtx); + + /* + * Handle the shrinking cases that require allocating a new + * resource to hold the newly-free region. We have to recheck + * if we still need this new region after acquiring the lock. + */ + if (start > r->r_start) { + new = int_alloc_resource(M_WAITOK); + new->r_start = r->r_start; + new->r_end = start - 1; + new->r_rm = rm; + mtx_lock(rm->rm_mtx); + r->r_start = start; + s = TAILQ_PREV(r, resource_head, r_link); + if (s != NULL && !(s->r_flags & RF_ALLOCATED)) { + s->r_end = start - 1; + free(new, M_RMAN); + } else + TAILQ_INSERT_BEFORE(r, new, r_link); + mtx_unlock(rm->rm_mtx); + } + if (end < r->r_end) { + new = int_alloc_resource(M_WAITOK); + new->r_start = end + 1; + new->r_end = r->r_end; + new->r_rm = rm; + mtx_lock(rm->rm_mtx); + r->r_end = end; + t = TAILQ_NEXT(r, r_link); + if (t != NULL && !(t->r_flags & RF_ALLOCATED)) { + t->r_start = end + 1; + free(new, M_RMAN); + } else + TAILQ_INSERT_AFTER(&rm->rm_list, r, new, r_link); + mtx_unlock(rm->rm_mtx); + } + return (0); +} + struct resource * rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, u_long count, u_long bound, u_int flags, ==== //depot/projects/pci/sys/sys/rman.h#2 (text+ko) ==== @@ -116,6 +116,7 @@ TAILQ_HEAD(rman_head, rman); int rman_activate_resource(struct resource *r); +int rman_adjust_resource(struct resource *r, u_long start, u_long end); int rman_await_resource(struct resource *r, int pri, int timo); bus_space_handle_t rman_get_bushandle(struct resource *); bus_space_tag_t rman_get_bustag(struct resource *);