/* $NetBSD: uvm_km.c,v 1.3 1998/02/07 02:29:21 chs Exp $ */ /* * XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE! * >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<< */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * Copyright (c) 1991, 1993, The Regents of the University of California. * * All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * 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 Charles D. Cranor, * Washington University, 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. * * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * uvm_km.c: handle kernel memory allocation and management */ #include #include #include #include #include #include #include /* * global data structures */ vm_map_t kernel_map = NULL; /* * local functions */ static int uvm_km_get __P((struct uvm_object *, vm_offset_t, vm_page_t *, int *, int, vm_prot_t, int, int)); /* * local data structues */ static struct vm_map kernel_map_store; static struct uvm_object kmem_object_store; static struct uvm_object mb_object_store; static struct uvm_pagerops km_pager = { NULL, /* init */ NULL, /* attach */ NULL, /* reference */ NULL, /* detach */ NULL, /* fault */ NULL, /* flush */ uvm_km_get, /* get */ /* ... rest are NULL */ }; /* * uvm_km_get: pager get function for kernel objects * * => currently we do not support pageout to the swap area, so this * pager is very simple. eventually we may want an anonymous * object pager which will do paging. */ static int uvm_km_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags) struct uvm_object *uobj; vm_offset_t offset; struct vm_page **pps; int *npagesp; int centeridx, advice, flags; vm_prot_t access_type; { vm_offset_t current_offset; vm_page_t ptmp; int lcv, gotpages, maxpages; boolean_t done; UVMHIST_FUNC("uvm_km_get"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist, "flags=%d", flags,0,0,0); /* * get number of pages */ maxpages = *npagesp; /* * step 1: handled the case where fault data structures are locked. */ if (flags & PGO_LOCKED) { /* * step 1a: get pages that are already resident. only do this * if the data structures are locked (i.e. the first time through). */ done = TRUE; /* be optimistic */ gotpages = 0; /* # of pages we got so far */ for (lcv = 0, current_offset = offset ; lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) { /* do we care about this page? if not, skip it */ if (pps[lcv] == PGO_DONTCARE) continue; /* lookup page */ ptmp = uvm_pagelookup(uobj, current_offset); /* null? attempt to allocate the page */ if (ptmp == NULL) { ptmp = uvm_pagealloc(uobj, current_offset, NULL); if (ptmp) { ptmp->flags &= ~(PG_BUSY|PG_FAKE); /* new page */ UVM_PAGE_OWN(ptmp, NULL); ptmp->wire_count = 1; /* XXX: prevents pageout attempts */ uvm_pagezero(ptmp); } } /* to be useful must get a non-busy, non-released page */ if (ptmp == NULL || (ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) { if (lcv == centeridx || (flags & PGO_ALLPAGES) != 0) done = FALSE; /* need to do a wait or I/O! */ continue; } /* useful page: busy/lock it and plug it in our result array */ ptmp->flags |= PG_BUSY; /* caller must un-busy this page */ UVM_PAGE_OWN(ptmp, "uvm_km_get1"); pps[lcv] = ptmp; gotpages++; } /* "for" lcv loop */ /* * step 1b: now we've either done everything needed or we to unlock * and do some waiting or I/O. */ UVMHIST_LOG(maphist, "<- done (done=%d)", done, 0,0,0); *npagesp = gotpages; if (done) return(VM_PAGER_OK); /* bingo! */ else return(VM_PAGER_UNLOCK); /* EEK! Need to unlock and I/O */ } /* * step 2: get non-resident or busy pages. * object is locked. data structures are unlocked. */ for (lcv = 0, current_offset = offset ; lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) { /* skip over pages we've already gotten or don't want */ /* skip over pages we don't _have_ to get */ if (pps[lcv] != NULL || (lcv != centeridx && (flags & PGO_ALLPAGES) == 0)) continue; /* * we have yet to locate the current page (pps[lcv]). we first * look for a page that is already at the current offset. if we * find a page, we check to see if it is busy or released. if that * is the case, then we sleep on the page until it is no longer busy * or released and repeat the lookup. if the page we found is * neither busy nor released, then we busy it (so we own it) and * plug it into pps[lcv]. this 'break's the following while loop * and indicates we are ready to move on to the next page in the * "lcv" loop above. * * if we exit the while loop with pps[lcv] still set to NULL, then * it means that we allocated a new busy/fake/clean page ptmp in the * object and we need to do I/O to fill in the data. */ while (pps[lcv] == NULL) { /* top of "pps" while loop */ /* look for a current page */ ptmp = uvm_pagelookup(uobj, current_offset); /* nope? allocate one now (if we can) */ if (ptmp == NULL) { ptmp = uvm_pagealloc(uobj, current_offset, NULL); /* alloc */ /* out of RAM? */ if (ptmp == NULL) { simple_unlock(&uobj->vmobjlock); uvm_wait("kmgetwait1"); simple_lock(&uobj->vmobjlock); continue; /* goto top of pps while loop */ } /* * got new page ready for I/O. break pps while loop. pps[lcv] is * still NULL. */ break; } /* page is there, see if we need to wait on it */ if ((ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) { ptmp->flags |= PG_WANTED; UVM_UNLOCK_AND_WAIT(ptmp,&uobj->vmobjlock,0,"uvn_get",0); simple_lock(&uobj->vmobjlock); continue; /* goto top of pps while loop */ } /* * if we get here then the page has become resident and unbusy * between steps 1 and 2. we busy it now (so we own it) and set * pps[lcv] (so that we exit the while loop). */ ptmp->flags |= PG_BUSY; /* we own it, caller must un-busy */ UVM_PAGE_OWN(ptmp, "uvm_km_get2"); pps[lcv] = ptmp; } /* * if we own the a valid page at the correct offset, pps[lcv] will * point to it. nothing more to do except go to the next page. */ if (pps[lcv]) continue; /* next lcv */ /* * we have a "fake/busy/clean" page that we just allocated. * do the needed "i/o" (in this case that means zero it). */ uvm_pagezero(ptmp); ptmp->flags &= ~(PG_FAKE); ptmp->wire_count = 1; /* XXX: prevents pageout attempts */ pps[lcv] = ptmp; } /* lcv loop */ /* * finally, unlock object and return. */ simple_unlock(&uobj->vmobjlock); UVMHIST_LOG(maphist, "<- done (OK)",0,0,0,0); return(VM_PAGER_OK); } /* * uvm_km_init: init kernel maps and objects to reflect reality (i.e. * KVM already allocated for text, data, bss, and static data structures). * * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. * we assume that [min -> start] has already been allocated and that * "end" is the end. */ void uvm_km_init(start, end) vm_offset_t start, end; { vm_offset_t base = VM_MIN_KERNEL_ADDRESS; /* * first, init kernel memory objects. */ /* kernel_object: for pageable anonymous kernel memory */ uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); /* kmem_object: for malloc'd memory (always wired) */ simple_lock_init(&kmem_object_store.vmobjlock); kmem_object_store.pgops = &km_pager; TAILQ_INIT(&kmem_object_store.memq); kmem_object_store.uo_npages = 0; kmem_object_store.uo_refs = UVM_OBJ_KERN; /* we are special. we never die */ uvmexp.kmem_object = &kmem_object_store; /* mb_object: for mbuf memory (always wired) */ simple_lock_init(&mb_object_store.vmobjlock); mb_object_store.pgops = &km_pager; TAILQ_INIT(&mb_object_store.memq); mb_object_store.uo_npages = 0; mb_object_store.uo_refs = UVM_OBJ_KERN; /* we are special. we never die */ uvmexp.mb_object = &mb_object_store; /* * init the map and reserve kernel space before installing. */ uvm_map_setup(&kernel_map_store, base, end, FALSE); kernel_map_store.pmap = pmap_kernel(); if (uvm_map(&kernel_map_store, &base, start - base, NULL, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != KERN_SUCCESS) panic("uvm_km_init: could not reserve space for kernel"); /* * install! */ kernel_map = &kernel_map_store; } /* * uvm_km_suballoc: allocate a submap in the kernel map. once a submap * is allocated all references to that area of VM must go through it. this * allows the locking of VAs in kernel_map to be broken up into regions. * * => if submap is non NULL we use that as the submap, otherwise we * alloc a new map */ struct vm_map *uvm_km_suballoc(map, min, max, size, pageable, submap) struct vm_map *map; vm_offset_t *min, *max; /* OUT, OUT */ vm_size_t size; boolean_t pageable; struct vm_map *submap; { size = round_page(size); /* round up to pagesize */ /* * first allocate a blank spot in the parent map */ if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != KERN_SUCCESS) { panic("uvm_km_suballoc: unable to allocate space in parent map"); } /* * set VM bounds (min is filled in by uvm_map) */ *max = *min + size; /* * add references to pmap and create or init the submap */ pmap_reference(vm_map_pmap(map)); if (submap == NULL) { submap = uvm_map_create(vm_map_pmap(map), *min, *max, pageable); if (submap == NULL) panic("uvm_km_suballoc: unable to create submap"); } else { uvm_map_setup(submap, *min, *max, pageable); submap->pmap = vm_map_pmap(map); } /* * now let uvm_map_submap plug in it... */ if (uvm_map_submap(map, *min, *max, submap) != KERN_SUCCESS) panic("uvm_km_suballoc: submap allocation failed"); return(submap); } /* * uvm_km_pgremove: remove pages from a kernel uvm_object. * * => when you unmap a part of anonymous kernel memory you want to toss * the pages right away. (this gets called from uvm_unmap_...). */ #define UKM_HASH_PENALTY 4 /* a guess */ void uvm_km_pgremove(uobj, start, end) struct uvm_object *uobj; vm_offset_t start, end; { boolean_t by_list, is_aobj; struct vm_page *pp, *ppnext; vm_offset_t curoff; UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); simple_lock(&uobj->vmobjlock); /* lock object */ /* is uobj an aobj? */ is_aobj = uobj->pgops == &aobj_pager; /* choose cheapest traversal */ by_list = (uobj->uo_npages <= ((end - start) / PAGE_SIZE) * UKM_HASH_PENALTY); if (by_list) goto loop_by_list; /* by hash */ for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { pp = uvm_pagelookup(uobj, curoff); if (pp == NULL) continue; UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0); /* now do the actual work */ if (pp->flags & PG_BUSY) pp->flags |= PG_RELEASED; /* owner must check for this when done */ else { pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); /* * if this kernel object is an aobj, free the swap slot. */ if (is_aobj) { int slot = uao_set_swslot(uobj, curoff / PAGE_SIZE, 0); if (slot) uvm_swap_free(slot, 1); } uvm_lock_pageq(); uvm_pagefree(pp); uvm_unlock_pageq(); } /* done */ } simple_unlock(&uobj->vmobjlock); return; loop_by_list: for (pp = uobj->memq.tqh_first ; pp != NULL ; pp = ppnext) { ppnext = pp->listq.tqe_next; if (pp->offset < start || pp->offset >= end) { continue; } UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0); /* now do the actual work */ if (pp->flags & PG_BUSY) pp->flags |= PG_RELEASED; /* owner must check for this when done */ else { pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); /* * if this kernel object is an aobj, free the swap slot. */ if (is_aobj) { int slot = uao_set_swslot(uobj, pp->offset / PAGE_SIZE, 0); if (slot) uvm_swap_free(slot, 1); } uvm_lock_pageq(); uvm_pagefree(pp); uvm_unlock_pageq(); } /* done */ } simple_unlock(&uobj->vmobjlock); return; } /* * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() * * => we map wired memory into the specified map using the obj passed in * => NOTE: we can return NULL even if we can wait if there is not enough * free VM space in the map... caller should be prepared to handle * this case. * => we return KVA of memory allocated * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't * lock the map */ vm_offset_t uvm_km_kmemalloc(map, obj, size, flags) vm_map_t map; struct uvm_object *obj; vm_size_t size; int flags; { vm_offset_t kva, loopva; vm_offset_t offset; struct vm_page *pg; UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", map, obj, size, flags); #ifdef DIAGNOSTIC /* sanity check */ if (vm_map_pmap(map) != pmap_kernel()) panic("uvm_km_kmemalloc: invalid map"); #endif /* * setup for call */ size = round_page(size); kva = vm_map_min(map); /* hint */ /* * allocate some virtual space */ if (uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) != KERN_SUCCESS) { UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); return(0); } /* * if all we wanted was VA, return now */ if (flags & UVM_KMF_VALLOC) { UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); return(kva); } /* * recover object offset from virtual address */ offset = kva - vm_map_min(map); UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); /* * now allocate and map in the memory... note that we are the only ones * whom should ever get a handle on this area of VM. */ loopva = kva; while (size) { simple_lock(&obj->vmobjlock); pg = uvm_pagealloc(obj, offset, NULL); if (pg) { pg->flags &= ~PG_BUSY; /* new page */ UVM_PAGE_OWN(pg, NULL); pg->wire_count = 1; uvmexp.wired++; } simple_unlock(&obj->vmobjlock); /* * out of memory? */ if (pg == NULL) { if (flags & UVM_KMF_NOWAIT) { uvm_unmap(map, kva, kva + size, 0); /* free everything! */ return(0); } else { uvm_wait("km_getwait2"); /* sleep here */ continue; } } /* * map it in: note that we call pmap_enter with the map and object * unlocked in case we are kmem_map/kmem_object (because if pmap_enter * wants to allocate out of kmem_object it will need to lock it itself!) */ #if defined(PMAP_NEW) pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), VM_PROT_ALL); #else pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE); #endif loopva += PAGE_SIZE; offset += PAGE_SIZE; size -= PAGE_SIZE; } UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); return(kva); } /* * uvm_km_free: free an area of kernel memory */ void uvm_km_free(map, addr, size) vm_map_t map; vm_offset_t addr; vm_size_t size; { uvm_unmap(map, trunc_page(addr), round_page(addr+size), 1); } /* * uvm_km_free_wakeup: free an area of kernel memory and wake up * anyone waiting for vm space. * * => XXX: "wanted" bit + unlock&wait on other end? */ void uvm_km_free_wakeup(map, addr, size) vm_map_t map; vm_offset_t addr; vm_size_t size; { vm_map_entry_t dead_entries; vm_map_lock(map); (void)uvm_unmap_remove(map, trunc_page(addr), round_page(addr+size), 1, &dead_entries); thread_wakeup(map); vm_map_unlock(map); if (dead_entries != NULL) uvm_unmap_detach(dead_entries, 0); } /* * uvm_km_alloc1: allocate wired down memory in the kernel map. * * => we can sleep if needed */ vm_offset_t uvm_km_alloc1(map, size, zeroit) vm_map_t map; vm_size_t size; boolean_t zeroit; { vm_offset_t kva, loopva, offset; struct vm_page *pg; UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); #ifdef DIAGNOSTIC if (vm_map_pmap(map) != pmap_kernel()) panic("uvm_km_alloc1"); #endif size = round_page(size); kva = vm_map_min(map); /* hint */ /* * allocate some virtual space */ if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) { UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); return(0); } /* * recover object offset from virtual address */ offset = kva - vm_map_min(map); UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); /* * now allocate the memory. we must be careful about released pages. */ loopva = kva; while (size) { simple_lock(&uvm.kernel_object->vmobjlock); pg = uvm_pagelookup(uvm.kernel_object, offset); /* if we found a page in an unallocated region, it must be released */ if (pg) { if ((pg->flags & PG_RELEASED) == 0) panic("uvm_km_alloc1: non-released page"); pg->flags |= PG_WANTED; UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock,0,"km_alloc",0); continue; /* retry */ } /* allocate ram */ pg = uvm_pagealloc(uvm.kernel_object, offset, NULL); if (pg) { pg->flags &= ~PG_BUSY; /* new page */ UVM_PAGE_OWN(pg, NULL); } simple_unlock(&uvm.kernel_object->vmobjlock); if (pg == NULL) { uvm_wait("km_alloc1w"); /* wait for memory */ continue; } /* map it in */ #if defined(PMAP_NEW) pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL); #else pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE); #endif loopva += PAGE_SIZE; offset += PAGE_SIZE; size -= PAGE_SIZE; } /* * zero on request (note that "size" is now zero due to the above loop * so we need to subtract kva from loopva to reconstruct the size). */ if (zeroit) bzero((caddr_t)kva, loopva - kva); UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); return(kva); } /* * uvm_km_valloc: allocate zero-fill memory in the kernel's address space * * => memory is not allocated until fault time */ vm_offset_t uvm_km_valloc(map, size) vm_map_t map; vm_size_t size; { vm_offset_t kva; UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); #ifdef DIAGNOSTIC if (vm_map_pmap(map) != pmap_kernel()) panic("uvm_km_valloc"); #endif size = round_page(size); kva = vm_map_min(map); /* hint */ /* * allocate some virtual space. will be demand filled by kernel_object. */ if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) { UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); return(0); } UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); return(kva); } /* * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space * * => memory is not allocated until fault time * => if no room in map, wait for space to free, unless requested size * is larger than map (in which case we return 0) */ vm_offset_t uvm_km_valloc_wait(map, size) vm_map_t map; vm_size_t size; { vm_offset_t kva; UVMHIST_FUNC("uvm_km_valloc_wait"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); #ifdef DIAGNOSTIC if (vm_map_pmap(map) != pmap_kernel()) panic("uvm_km_valloc_wait"); #endif size = round_page(size); if (size > vm_map_max(map) - vm_map_min(map)) return(0); while (1) { kva = vm_map_min(map); /* hint */ /* * allocate some virtual space. will be demand filled by kernel_object. */ if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) == KERN_SUCCESS){ UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); return(kva); } /* * failed. sleep for a while (on map) */ UVMHIST_LOG(maphist,"<<>>",0,0,0,0); tsleep((caddr_t)map, PVM, "vallocwait", 0); } /*NOTREACHED*/ }