/* $NetBSD: uvm_km.c,v 1.22.2.1 1999/04/16 16:28:45 chs Exp $ */ /* * 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 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp * * * 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. */ #include "opt_uvmhist.h" #include "opt_pmap_new.h" /* * uvm_km.c: handle kernel memory allocation and management */ /* * overview of kernel memory management: * * the kernel virtual address space is mapped by "kernel_map." kernel_map * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). * * the kernel_map has several "submaps." submaps can only appear in * the kernel_map (user processes can't use them). submaps "take over" * the management of a sub-range of the kernel's address space. submaps * are typically allocated at boot time and are never released. kernel * virtual address space that is mapped by a submap is locked by the * submap's lock -- not the kernel_map's lock. * * thus, the useful feature of submaps is that they allow us to break * up the locking and protection of the kernel address space into smaller * chunks. * * the vm system has several standard kernel submaps, including: * kmem_map => contains only wired kernel memory for the kernel * malloc. *** access to kmem_map must be protected * by splimp() because we are allowed to call malloc() * at interrupt time *** * mb_map => memory for large mbufs, *** protected by splimp *** * pager_map => used to map "buf" structures into kernel space * exec_map => used during exec to handle exec args * etc... * * the kernel allocates its private memory out of special uvm_objects whose * reference count is set to UVM_OBJ_KERN (thus indicating that the objects * are "special" and never die). all kernel objects should be thought of * as large, fixed-sized, sparsely populated uvm_objects. each kernel * object is equal to the size of kernel virtual address space (i.e. the * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). * * most kernel private memory lives in kernel_object. the only exception * to this is for memory that belongs to submaps that must be protected * by splimp(). each of these submaps has their own private kernel * object (e.g. kmem_object, mb_object). * * note that just because a kernel object spans the entire kernel virutal * address space doesn't mean that it has to be mapped into the entire space. * large chunks of a kernel object's space go unused either because * that area of kernel VM is unmapped, or there is some other type of * object mapped into that range (e.g. a vnode). for submap's kernel * objects, the only part of the object that can ever be populated is the * offsets that are managed by the submap. * * note that the "offset" in a kernel object is always the kernel virtual * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). * example: * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, * then that means that the page at offset 0x235000 in kernel_object is * mapped at 0xf8235000. * * note that the offsets in kmem_object and mb_object also follow this * rule. this means that the offsets for kmem_object must fall in the * range of [vm_map_min(kmem_object) - vm_map_min(kernel_map)] to * [vm_map_max(kmem_object) - vm_map_min(kernel_map)], so the offsets * in those objects will typically not start at zero. * * kernel object have one other special property: when the kernel virtual * memory mapping them is unmapped, the backing memory in the object is * freed right away. this is done with the uvm_km_pgremove() function. * this has to be done because there is no backing store for kernel pages * and no need to save them after they are no longer referenced. */ #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 *, vaddr_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, /* 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. * => XXXCDC: this pager should be phased out in favor of the aobj pager */ static int uvm_km_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags) struct uvm_object *uobj; vaddr_t offset; struct vm_page **pps; int *npagesp; int centeridx, advice, flags; vm_prot_t access_type; { vaddr_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, 0); if (ptmp) { /* new page */ ptmp->flags &= ~(PG_BUSY|PG_FAKE); UVM_PAGE_OWN(ptmp, NULL); 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) /* need to do a wait or I/O! */ done = FALSE; continue; } /* * useful page: busy/lock it and plug it in our * result array */ /* caller must un-busy this page */ ptmp->flags |= PG_BUSY; 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, 0); /* out of RAM? */ if (ptmp == NULL) { simple_unlock(&uobj->vmobjlock); uvm_wait("kmgetwait1"); simple_lock(&uobj->vmobjlock); /* goto top of pps while loop */ continue; } /* * 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). caller must un-busy. */ ptmp->flags |= PG_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); 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) vaddr_t start, end; { vaddr_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 (wired, protected by splimp) */ 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; /* we are special. we never die */ kmem_object_store.uo_refs = UVM_OBJ_KERN; uvmexp.kmem_object = &kmem_object_store; /* mb_object: for mbuf memory (always wired, protected by splimp) */ 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; /* we are special. we never die */ mb_object_store.uo_refs = UVM_OBJ_KERN; uvmexp.mb_object = &mb_object_store; /* * init the map and reserve allready allocated 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 `fixed' is true, *min specifies where the region described * by the submap must start * => 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, fixed, submap) struct vm_map *map; vaddr_t *min, *max; /* OUT, OUT */ vsize_t size; boolean_t pageable; boolean_t fixed; struct vm_map *submap; { int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 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, mapflags)) != 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; vaddr_t start, end; { boolean_t by_list, is_aobj; struct vm_page *pp, *ppnext; vaddr_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_SHIFT) * 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) /* owner must check for this when done */ pp->flags |= PG_RELEASED; else { pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); /* * if this kernel object is an aobj, free the swap slot. */ if (is_aobj) { uao_dropswap(uobj, curoff >> PAGE_SHIFT); } 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) /* owner must check for this when done */ pp->flags |= PG_RELEASED; else { pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); /* * if this kernel object is an aobj, free the swap slot. */ if (is_aobj) { uao_dropswap(uobj, pp->offset >> PAGE_SHIFT); } 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 */ vaddr_t uvm_km_kmemalloc(map, obj, size, flags) vm_map_t map; struct uvm_object *obj; vsize_t size; int flags; { vaddr_t kva, loopva; vaddr_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(kernel_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, 0); if (pg) { pg->flags &= ~PG_BUSY; /* new page */ UVM_PAGE_OWN(pg, NULL); } simple_unlock(&obj->vmobjlock); /* * out of memory? */ if (pg == NULL) { if (flags & UVM_KMF_NOWAIT) { /* free everything! */ uvm_unmap(map, kva, kva + size); 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, 0); #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; vaddr_t addr; vsize_t size; { uvm_unmap(map, trunc_page(addr), round_page(addr+size)); } /* * 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; vaddr_t addr; vsize_t size; { vm_map_entry_t dead_entries; vm_map_lock(map); (void)uvm_unmap_remove(map, trunc_page(addr), round_page(addr+size), &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 */ vaddr_t uvm_km_alloc1(map, size, zeroit) vm_map_t map; vsize_t size; boolean_t zeroit; { vaddr_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(kernel_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, 0); 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, 0); #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) memset((caddr_t)kva, 0, 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 */ vaddr_t uvm_km_valloc(map, size) vm_map_t map; vsize_t size; { vaddr_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) */ vaddr_t uvm_km_valloc_wait(map, size) vm_map_t map; vsize_t size; { vaddr_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*/ } /* Sanity; must specify both or none. */ #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) #error Must specify MAP and UNMAP together. #endif /* * uvm_km_alloc_poolpage: allocate a page for the pool allocator * * => if the pmap specifies an alternate mapping method, we use it. */ /* ARGSUSED */ vaddr_t uvm_km_alloc_poolpage1(map, obj, waitok) vm_map_t map; struct uvm_object *obj; boolean_t waitok; { #if defined(PMAP_MAP_POOLPAGE) struct vm_page *pg; vaddr_t va; again: pg = uvm_pagealloc(NULL, 0, NULL, 0); if (pg == NULL) { if (waitok) { uvm_wait("plpg"); goto again; } else return (0); } va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); if (va == 0) uvm_pagefree(pg); return (va); #else vaddr_t va; int s; /* * NOTE: We may be called with a map that doens't require splimp * protection (e.g. kernel_map). However, it does not hurt to * go to splimp in this case (since unprocted maps will never be * accessed in interrupt context). * * XXX We may want to consider changing the interface to this * XXX function. */ s = splimp(); va = uvm_km_kmemalloc(map, obj, PAGE_SIZE, waitok ? 0 : UVM_KMF_NOWAIT); splx(s); return (va); #endif /* PMAP_MAP_POOLPAGE */ } /* * uvm_km_free_poolpage: free a previously allocated pool page * * => if the pmap specifies an alternate unmapping method, we use it. */ /* ARGSUSED */ void uvm_km_free_poolpage1(map, addr) vm_map_t map; vaddr_t addr; { #if defined(PMAP_UNMAP_POOLPAGE) paddr_t pa; pa = PMAP_UNMAP_POOLPAGE(addr); uvm_pagefree(PHYS_TO_VM_PAGE(pa)); #else int s; /* * NOTE: We may be called with a map that doens't require splimp * protection (e.g. kernel_map). However, it does not hurt to * go to splimp in this case (since unprocted maps will never be * accessed in interrupt context). * * XXX We may want to consider changing the interface to this * XXX function. */ s = splimp(); uvm_km_free(map, addr, PAGE_SIZE); splx(s); #endif /* PMAP_UNMAP_POOLPAGE */ }