NetBSD/sys/uvm/uvm_map.c

4950 lines
122 KiB
C

/* $NetBSD: uvm_map.c,v 1.226 2006/05/25 14:27:28 yamt 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_map.c 8.3 (Berkeley) 1/12/94
* from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 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.
*/
/*
* uvm_map.c: uvm map operations
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.226 2006/05/25 14:27:28 yamt Exp $");
#include "opt_ddb.h"
#include "opt_uvmhist.h"
#include "opt_uvm.h"
#include "opt_sysv.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#ifdef SYSVSHM
#include <sys/shm.h>
#endif
#include <uvm/uvm.h>
#undef RB_AUGMENT
#define RB_AUGMENT(x) uvm_rb_augment(x)
#ifdef DDB
#include <uvm/uvm_ddb.h>
#endif
#if defined(UVMMAP_NOCOUNTERS)
#define UVMMAP_EVCNT_DEFINE(name) /* nothing */
#define UVMMAP_EVCNT_INCR(ev) /* nothing */
#define UVMMAP_EVCNT_DECR(ev) /* nothing */
#else /* defined(UVMMAP_NOCOUNTERS) */
#include <sys/device.h>
#define UVMMAP_EVCNT_DEFINE(name) \
struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \
"uvmmap", #name); \
EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name);
#define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++
#define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count--
#endif /* defined(UVMMAP_NOCOUNTERS) */
UVMMAP_EVCNT_DEFINE(ubackmerge)
UVMMAP_EVCNT_DEFINE(uforwmerge)
UVMMAP_EVCNT_DEFINE(ubimerge)
UVMMAP_EVCNT_DEFINE(unomerge)
UVMMAP_EVCNT_DEFINE(kbackmerge)
UVMMAP_EVCNT_DEFINE(kforwmerge)
UVMMAP_EVCNT_DEFINE(kbimerge)
UVMMAP_EVCNT_DEFINE(knomerge)
UVMMAP_EVCNT_DEFINE(map_call)
UVMMAP_EVCNT_DEFINE(mlk_call)
UVMMAP_EVCNT_DEFINE(mlk_hint)
UVMMAP_EVCNT_DEFINE(uke_alloc)
UVMMAP_EVCNT_DEFINE(uke_free)
UVMMAP_EVCNT_DEFINE(ukh_alloc)
UVMMAP_EVCNT_DEFINE(ukh_free)
const char vmmapbsy[] = "vmmapbsy";
/*
* pool for vmspace structures.
*/
POOL_INIT(uvm_vmspace_pool, sizeof(struct vmspace), 0, 0, 0, "vmsppl",
&pool_allocator_nointr);
/*
* pool for dynamically-allocated map entries.
*/
POOL_INIT(uvm_map_entry_pool, sizeof(struct vm_map_entry), 0, 0, 0, "vmmpepl",
&pool_allocator_nointr);
MALLOC_DEFINE(M_VMMAP, "VM map", "VM map structures");
MALLOC_DEFINE(M_VMPMAP, "VM pmap", "VM pmap");
#ifdef PMAP_GROWKERNEL
/*
* This global represents the end of the kernel virtual address
* space. If we want to exceed this, we must grow the kernel
* virtual address space dynamically.
*
* Note, this variable is locked by kernel_map's lock.
*/
vaddr_t uvm_maxkaddr;
#endif
/*
* macros
*/
/*
* VM_MAP_USE_KMAPENT: determine if uvm_kmapent_alloc/free is used
* for the vm_map.
*/
extern struct vm_map *pager_map; /* XXX */
#define VM_MAP_USE_KMAPENT_FLAGS(flags) \
(((flags) & VM_MAP_INTRSAFE) != 0)
#define VM_MAP_USE_KMAPENT(map) \
(VM_MAP_USE_KMAPENT_FLAGS((map)->flags) || (map) == kernel_map)
/*
* UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging
*/
#define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \
prot, maxprot, inh, adv, wire) \
((ent)->etype == (type) && \
(((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE | UVM_MAP_QUANTUM)) \
== 0 && \
(ent)->object.uvm_obj == (uobj) && \
(ent)->protection == (prot) && \
(ent)->max_protection == (maxprot) && \
(ent)->inheritance == (inh) && \
(ent)->advice == (adv) && \
(ent)->wired_count == (wire))
/*
* uvm_map_entry_link: insert entry into a map
*
* => map must be locked
*/
#define uvm_map_entry_link(map, after_where, entry) do { \
uvm_mapent_check(entry); \
(map)->nentries++; \
(entry)->prev = (after_where); \
(entry)->next = (after_where)->next; \
(entry)->prev->next = (entry); \
(entry)->next->prev = (entry); \
uvm_rb_insert((map), (entry)); \
} while (/*CONSTCOND*/ 0)
/*
* uvm_map_entry_unlink: remove entry from a map
*
* => map must be locked
*/
#define uvm_map_entry_unlink(map, entry) do { \
KASSERT((entry) != (map)->first_free); \
KASSERT((entry) != (map)->hint); \
uvm_mapent_check(entry); \
(map)->nentries--; \
(entry)->next->prev = (entry)->prev; \
(entry)->prev->next = (entry)->next; \
uvm_rb_remove((map), (entry)); \
} while (/*CONSTCOND*/ 0)
/*
* SAVE_HINT: saves the specified entry as the hint for future lookups.
*
* => map need not be locked (protected by hint_lock).
*/
#define SAVE_HINT(map,check,value) do { \
simple_lock(&(map)->hint_lock); \
if ((map)->hint == (check)) \
(map)->hint = (value); \
simple_unlock(&(map)->hint_lock); \
} while (/*CONSTCOND*/ 0)
/*
* clear_hints: ensure that hints don't point to the entry.
*
* => map must be write-locked.
*/
static void
clear_hints(struct vm_map *map, struct vm_map_entry *ent)
{
SAVE_HINT(map, ent, ent->prev);
if (map->first_free == ent) {
map->first_free = ent->prev;
}
}
/*
* VM_MAP_RANGE_CHECK: check and correct range
*
* => map must at least be read locked
*/
#define VM_MAP_RANGE_CHECK(map, start, end) do { \
if (start < vm_map_min(map)) \
start = vm_map_min(map); \
if (end > vm_map_max(map)) \
end = vm_map_max(map); \
if (start > end) \
start = end; \
} while (/*CONSTCOND*/ 0)
/*
* local prototypes
*/
static struct vm_map_entry *
uvm_mapent_alloc(struct vm_map *, int);
static struct vm_map_entry *
uvm_mapent_alloc_split(struct vm_map *,
const struct vm_map_entry *, int,
struct uvm_mapent_reservation *);
static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *);
static void uvm_mapent_free(struct vm_map_entry *);
#if defined(DEBUG)
static void _uvm_mapent_check(const struct vm_map_entry *, const char *,
int);
#define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__)
#else /* defined(DEBUG) */
#define uvm_mapent_check(e) /* nothing */
#endif /* defined(DEBUG) */
static struct vm_map_entry *
uvm_kmapent_alloc(struct vm_map *, int);
static void uvm_kmapent_free(struct vm_map_entry *);
static vsize_t uvm_kmapent_overhead(vsize_t);
static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *);
static void uvm_map_reference_amap(struct vm_map_entry *, int);
static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int,
struct vm_map_entry *);
static void uvm_map_unreference_amap(struct vm_map_entry *, int);
int _uvm_map_sanity(struct vm_map *);
int _uvm_tree_sanity(struct vm_map *);
static vsize_t uvm_rb_subtree_space(const struct vm_map_entry *);
static inline int
uvm_compare(const struct vm_map_entry *a, const struct vm_map_entry *b)
{
if (a->start < b->start)
return (-1);
else if (a->start > b->start)
return (1);
return (0);
}
static inline void
uvm_rb_augment(struct vm_map_entry *entry)
{
entry->space = uvm_rb_subtree_space(entry);
}
RB_PROTOTYPE(uvm_tree, vm_map_entry, rb_entry, uvm_compare);
RB_GENERATE(uvm_tree, vm_map_entry, rb_entry, uvm_compare);
static inline vsize_t
uvm_rb_space(const struct vm_map *map, const struct vm_map_entry *entry)
{
/* XXX map is not used */
KASSERT(entry->next != NULL);
return entry->next->start - entry->end;
}
static vsize_t
uvm_rb_subtree_space(const struct vm_map_entry *entry)
{
vaddr_t space, tmp;
space = entry->ownspace;
if (RB_LEFT(entry, rb_entry)) {
tmp = RB_LEFT(entry, rb_entry)->space;
if (tmp > space)
space = tmp;
}
if (RB_RIGHT(entry, rb_entry)) {
tmp = RB_RIGHT(entry, rb_entry)->space;
if (tmp > space)
space = tmp;
}
return (space);
}
static inline void
uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry)
{
/* We need to traverse to the very top */
do {
entry->ownspace = uvm_rb_space(map, entry);
entry->space = uvm_rb_subtree_space(entry);
} while ((entry = RB_PARENT(entry, rb_entry)) != NULL);
}
static void
uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry)
{
vaddr_t space = uvm_rb_space(map, entry);
struct vm_map_entry *tmp;
entry->ownspace = entry->space = space;
tmp = RB_INSERT(uvm_tree, &(map)->rbhead, entry);
#ifdef DIAGNOSTIC
if (tmp != NULL)
panic("uvm_rb_insert: duplicate entry?");
#endif
uvm_rb_fixup(map, entry);
if (entry->prev != &map->header)
uvm_rb_fixup(map, entry->prev);
}
static void
uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry)
{
struct vm_map_entry *parent;
parent = RB_PARENT(entry, rb_entry);
RB_REMOVE(uvm_tree, &(map)->rbhead, entry);
if (entry->prev != &map->header)
uvm_rb_fixup(map, entry->prev);
if (parent)
uvm_rb_fixup(map, parent);
}
#if defined(DEBUG)
int uvm_debug_check_map = 0;
int uvm_debug_check_rbtree = 0;
#define uvm_map_check(map, name) \
_uvm_map_check((map), (name), __FILE__, __LINE__)
static void
_uvm_map_check(struct vm_map *map, const char *name,
const char *file, int line)
{
if ((uvm_debug_check_map && _uvm_map_sanity(map)) ||
(uvm_debug_check_rbtree && _uvm_tree_sanity(map))) {
panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)",
name, map, file, line);
}
}
#else /* defined(DEBUG) */
#define uvm_map_check(map, name) /* nothing */
#endif /* defined(DEBUG) */
#if defined(DEBUG) || defined(DDB)
int
_uvm_map_sanity(struct vm_map *map)
{
boolean_t first_free_found = FALSE;
boolean_t hint_found = FALSE;
const struct vm_map_entry *e;
e = &map->header;
for (;;) {
if (map->first_free == e) {
first_free_found = TRUE;
} else if (!first_free_found && e->next->start > e->end) {
printf("first_free %p should be %p\n",
map->first_free, e);
return -1;
}
if (map->hint == e) {
hint_found = TRUE;
}
e = e->next;
if (e == &map->header) {
break;
}
}
if (!first_free_found) {
printf("stale first_free\n");
return -1;
}
if (!hint_found) {
printf("stale hint\n");
return -1;
}
return 0;
}
int
_uvm_tree_sanity(struct vm_map *map)
{
struct vm_map_entry *tmp, *trtmp;
int n = 0, i = 1;
RB_FOREACH(tmp, uvm_tree, &map->rbhead) {
if (tmp->ownspace != uvm_rb_space(map, tmp)) {
printf("%d/%d ownspace %lx != %lx %s\n",
n + 1, map->nentries,
(ulong)tmp->ownspace, (ulong)uvm_rb_space(map, tmp),
tmp->next == &map->header ? "(last)" : "");
goto error;
}
}
trtmp = NULL;
RB_FOREACH(tmp, uvm_tree, &map->rbhead) {
if (tmp->space != uvm_rb_subtree_space(tmp)) {
printf("space %lx != %lx\n",
(ulong)tmp->space,
(ulong)uvm_rb_subtree_space(tmp));
goto error;
}
if (trtmp != NULL && trtmp->start >= tmp->start) {
printf("corrupt: 0x%lx >= 0x%lx\n",
trtmp->start, tmp->start);
goto error;
}
n++;
trtmp = tmp;
}
if (n != map->nentries) {
printf("nentries: %d vs %d\n", n, map->nentries);
goto error;
}
for (tmp = map->header.next; tmp && tmp != &map->header;
tmp = tmp->next, i++) {
trtmp = RB_FIND(uvm_tree, &map->rbhead, tmp);
if (trtmp != tmp) {
printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp,
RB_PARENT(tmp, rb_entry));
goto error;
}
}
return (0);
error:
return (-1);
}
#endif /* defined(DEBUG) || defined(DDB) */
#ifdef DIAGNOSTIC
static struct vm_map *uvm_kmapent_map(struct vm_map_entry *);
#endif
/*
* uvm_mapent_alloc: allocate a map entry
*/
static struct vm_map_entry *
uvm_mapent_alloc(struct vm_map *map, int flags)
{
struct vm_map_entry *me;
int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK;
UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist);
if (VM_MAP_USE_KMAPENT(map)) {
me = uvm_kmapent_alloc(map, flags);
} else {
me = pool_get(&uvm_map_entry_pool, pflags);
if (__predict_false(me == NULL))
return NULL;
me->flags = 0;
}
UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me,
((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0);
return (me);
}
/*
* uvm_mapent_alloc_split: allocate a map entry for clipping.
*/
static struct vm_map_entry *
uvm_mapent_alloc_split(struct vm_map *map,
const struct vm_map_entry *old_entry, int flags,
struct uvm_mapent_reservation *umr)
{
struct vm_map_entry *me;
KASSERT(!VM_MAP_USE_KMAPENT(map) ||
(old_entry->flags & UVM_MAP_QUANTUM) || !UMR_EMPTY(umr));
if (old_entry->flags & UVM_MAP_QUANTUM) {
int s;
struct vm_map_kernel *vmk = vm_map_to_kernel(map);
s = splvm();
simple_lock(&uvm.kentry_lock);
me = vmk->vmk_merged_entries;
KASSERT(me);
vmk->vmk_merged_entries = me->next;
simple_unlock(&uvm.kentry_lock);
splx(s);
KASSERT(me->flags & UVM_MAP_QUANTUM);
} else {
me = uvm_mapent_alloc(map, flags);
}
return me;
}
/*
* uvm_mapent_free: free map entry
*/
static void
uvm_mapent_free(struct vm_map_entry *me)
{
UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]",
me, me->flags, 0, 0);
if (me->flags & UVM_MAP_KERNEL) {
uvm_kmapent_free(me);
} else {
pool_put(&uvm_map_entry_pool, me);
}
}
/*
* uvm_mapent_free_merged: free merged map entry
*
* => keep the entry if needed.
* => caller shouldn't hold map locked if VM_MAP_USE_KMAPENT(map) is true.
*/
static void
uvm_mapent_free_merged(struct vm_map *map, struct vm_map_entry *me)
{
KASSERT(!(me->flags & UVM_MAP_KERNEL) || uvm_kmapent_map(me) == map);
if (me->flags & UVM_MAP_QUANTUM) {
/*
* keep this entry for later splitting.
*/
struct vm_map_kernel *vmk;
int s;
KASSERT(VM_MAP_IS_KERNEL(map));
KASSERT(!VM_MAP_USE_KMAPENT(map) ||
(me->flags & UVM_MAP_KERNEL));
vmk = vm_map_to_kernel(map);
s = splvm();
simple_lock(&uvm.kentry_lock);
me->next = vmk->vmk_merged_entries;
vmk->vmk_merged_entries = me;
simple_unlock(&uvm.kentry_lock);
splx(s);
} else {
uvm_mapent_free(me);
}
}
/*
* uvm_mapent_copy: copy a map entry, preserving flags
*/
static inline void
uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst)
{
memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) -
((char *)src));
}
/*
* uvm_mapent_overhead: calculate maximum kva overhead necessary for
* map entries.
*
* => size and flags are the same as uvm_km_suballoc's ones.
*/
vsize_t
uvm_mapent_overhead(vsize_t size, int flags)
{
if (VM_MAP_USE_KMAPENT_FLAGS(flags)) {
return uvm_kmapent_overhead(size);
}
return 0;
}
#if defined(DEBUG)
static void
_uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line)
{
if (entry->start >= entry->end) {
goto bad;
}
if (UVM_ET_ISOBJ(entry)) {
if (entry->object.uvm_obj == NULL) {
goto bad;
}
} else if (UVM_ET_ISSUBMAP(entry)) {
if (entry->object.sub_map == NULL) {
goto bad;
}
} else {
if (entry->object.uvm_obj != NULL ||
entry->object.sub_map != NULL) {
goto bad;
}
}
if (!UVM_ET_ISOBJ(entry)) {
if (entry->offset != 0) {
goto bad;
}
}
return;
bad:
panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line);
}
#endif /* defined(DEBUG) */
/*
* uvm_map_entry_unwire: unwire a map entry
*
* => map should be locked by caller
*/
static inline void
uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry)
{
entry->wired_count = 0;
uvm_fault_unwire_locked(map, entry->start, entry->end);
}
/*
* wrapper for calling amap_ref()
*/
static inline void
uvm_map_reference_amap(struct vm_map_entry *entry, int flags)
{
amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff,
(entry->end - entry->start) >> PAGE_SHIFT, flags);
}
/*
* wrapper for calling amap_unref()
*/
static inline void
uvm_map_unreference_amap(struct vm_map_entry *entry, int flags)
{
amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff,
(entry->end - entry->start) >> PAGE_SHIFT, flags);
}
/*
* uvm_map_init: init mapping system at boot time. note that we allocate
* and init the static pool of struct vm_map_entry *'s for the kernel here.
*/
void
uvm_map_init(void)
{
#if defined(UVMHIST)
static struct uvm_history_ent maphistbuf[100];
static struct uvm_history_ent pdhistbuf[100];
#endif
/*
* first, init logging system.
*/
UVMHIST_FUNC("uvm_map_init");
UVMHIST_INIT_STATIC(maphist, maphistbuf);
UVMHIST_INIT_STATIC(pdhist, pdhistbuf);
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0);
/*
* initialize the global lock for kernel map entry.
*
* XXX is it worth to have per-map lock instead?
*/
simple_lock_init(&uvm.kentry_lock);
}
/*
* clippers
*/
/*
* uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy.
*/
static void
uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2,
vaddr_t splitat)
{
vaddr_t adj;
KASSERT(entry1->start < splitat);
KASSERT(splitat < entry1->end);
adj = splitat - entry1->start;
entry1->end = entry2->start = splitat;
if (entry1->aref.ar_amap) {
amap_splitref(&entry1->aref, &entry2->aref, adj);
}
if (UVM_ET_ISSUBMAP(entry1)) {
/* ... unlikely to happen, but play it safe */
uvm_map_reference(entry1->object.sub_map);
} else if (UVM_ET_ISOBJ(entry1)) {
KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */
entry2->offset += adj;
if (entry1->object.uvm_obj->pgops &&
entry1->object.uvm_obj->pgops->pgo_reference)
entry1->object.uvm_obj->pgops->pgo_reference(
entry1->object.uvm_obj);
}
}
/*
* uvm_map_clip_start: ensure that the entry begins at or after
* the starting address, if it doesn't we split the entry.
*
* => caller should use UVM_MAP_CLIP_START macro rather than calling
* this directly
* => map must be locked by caller
*/
void
uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry,
vaddr_t start, struct uvm_mapent_reservation *umr)
{
struct vm_map_entry *new_entry;
/* uvm_map_simplify_entry(map, entry); */ /* XXX */
uvm_map_check(map, "clip_start entry");
uvm_mapent_check(entry);
/*
* Split off the front portion. note that we must insert the new
* entry BEFORE this one, so that this entry has the specified
* starting address.
*/
new_entry = uvm_mapent_alloc_split(map, entry, 0, umr);
uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
uvm_mapent_splitadj(new_entry, entry, start);
uvm_map_entry_link(map, entry->prev, new_entry);
uvm_map_check(map, "clip_start leave");
}
/*
* uvm_map_clip_end: ensure that the entry ends at or before
* the ending address, if it does't we split the reference
*
* => caller should use UVM_MAP_CLIP_END macro rather than calling
* this directly
* => map must be locked by caller
*/
void
uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end,
struct uvm_mapent_reservation *umr)
{
struct vm_map_entry *new_entry;
uvm_map_check(map, "clip_end entry");
uvm_mapent_check(entry);
/*
* Create a new entry and insert it
* AFTER the specified entry
*/
new_entry = uvm_mapent_alloc_split(map, entry, 0, umr);
uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
uvm_mapent_splitadj(entry, new_entry, end);
uvm_map_entry_link(map, entry, new_entry);
uvm_map_check(map, "clip_end leave");
}
static void
vm_map_drain(struct vm_map *map, uvm_flag_t flags)
{
if (!VM_MAP_IS_KERNEL(map)) {
return;
}
uvm_km_va_drain(map, flags);
}
/*
* M A P - m a i n e n t r y p o i n t
*/
/*
* uvm_map: establish a valid mapping in a map
*
* => assume startp is page aligned.
* => assume size is a multiple of PAGE_SIZE.
* => assume sys_mmap provides enough of a "hint" to have us skip
* over text/data/bss area.
* => map must be unlocked (we will lock it)
* => <uobj,uoffset> value meanings (4 cases):
* [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER
* [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER
* [3] <uobj,uoffset> == normal mapping
* [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA
*
* case [4] is for kernel mappings where we don't know the offset until
* we've found a virtual address. note that kernel object offsets are
* always relative to vm_map_min(kernel_map).
*
* => if `align' is non-zero, we align the virtual address to the specified
* alignment.
* this is provided as a mechanism for large pages.
*
* => XXXCDC: need way to map in external amap?
*/
int
uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size,
struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags)
{
struct uvm_map_args args;
struct vm_map_entry *new_entry;
int error;
KASSERT((flags & UVM_FLAG_QUANTUM) == 0 || VM_MAP_IS_KERNEL(map));
KASSERT((size & PAGE_MASK) == 0);
/*
* for pager_map, allocate the new entry first to avoid sleeping
* for memory while we have the map locked.
*
* besides, because we allocates entries for in-kernel maps
* a bit differently (cf. uvm_kmapent_alloc/free), we need to
* allocate them before locking the map.
*/
new_entry = NULL;
if (VM_MAP_USE_KMAPENT(map) || (flags & UVM_FLAG_QUANTUM) ||
map == pager_map) {
new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT));
if (__predict_false(new_entry == NULL))
return ENOMEM;
if (flags & UVM_FLAG_QUANTUM)
new_entry->flags |= UVM_MAP_QUANTUM;
}
if (map == pager_map)
flags |= UVM_FLAG_NOMERGE;
error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align,
flags, &args);
if (!error) {
error = uvm_map_enter(map, &args, new_entry);
*startp = args.uma_start;
} else if (new_entry) {
uvm_mapent_free(new_entry);
}
#if defined(DEBUG)
if (!error && VM_MAP_IS_KERNEL(map)) {
uvm_km_check_empty(*startp, *startp + size,
(map->flags & VM_MAP_INTRSAFE) != 0);
}
#endif /* defined(DEBUG) */
return error;
}
int
uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size,
struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags,
struct uvm_map_args *args)
{
struct vm_map_entry *prev_entry;
vm_prot_t prot = UVM_PROTECTION(flags);
vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
UVMHIST_FUNC("uvm_map_prepare");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)",
map, start, size, flags);
UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0);
/*
* detect a popular device driver bug.
*/
KASSERT(doing_shutdown || curlwp != NULL ||
(map->flags & VM_MAP_INTRSAFE));
/*
* zero-sized mapping doesn't make any sense.
*/
KASSERT(size > 0);
KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0);
uvm_map_check(map, "map entry");
/*
* check sanity of protection code
*/
if ((prot & maxprot) != prot) {
UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x",
prot, maxprot,0,0);
return EACCES;
}
/*
* figure out where to put new VM range
*/
retry:
if (vm_map_lock_try(map) == FALSE) {
if (flags & UVM_FLAG_TRYLOCK) {
return EAGAIN;
}
vm_map_lock(map); /* could sleep here */
}
prev_entry = uvm_map_findspace(map, start, size, &start,
uobj, uoffset, align, flags);
if (prev_entry == NULL) {
unsigned int timestamp;
timestamp = map->timestamp;
UVMHIST_LOG(maphist,"waiting va timestamp=0x%x",
timestamp,0,0,0);
simple_lock(&map->flags_lock);
map->flags |= VM_MAP_WANTVA;
simple_unlock(&map->flags_lock);
vm_map_unlock(map);
/*
* try to reclaim kva and wait until someone does unmap.
* XXX fragile locking
*/
vm_map_drain(map, flags);
simple_lock(&map->flags_lock);
while ((map->flags & VM_MAP_WANTVA) != 0 &&
map->timestamp == timestamp) {
if ((flags & UVM_FLAG_WAITVA) == 0) {
simple_unlock(&map->flags_lock);
UVMHIST_LOG(maphist,
"<- uvm_map_findspace failed!", 0,0,0,0);
return ENOMEM;
} else {
ltsleep(&map->header, PVM, "vmmapva", 0,
&map->flags_lock);
}
}
simple_unlock(&map->flags_lock);
goto retry;
}
#ifdef PMAP_GROWKERNEL
/*
* If the kernel pmap can't map the requested space,
* then allocate more resources for it.
*/
if (map == kernel_map && uvm_maxkaddr < (start + size))
uvm_maxkaddr = pmap_growkernel(start + size);
#endif
UVMMAP_EVCNT_INCR(map_call);
/*
* if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER
* [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in
* either case we want to zero it before storing it in the map entry
* (because it looks strange and confusing when debugging...)
*
* if uobj is not null
* if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping
* and we do not need to change uoffset.
* if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset
* now (based on the starting address of the map). this case is
* for kernel object mappings where we don't know the offset until
* the virtual address is found (with uvm_map_findspace). the
* offset is the distance we are from the start of the map.
*/
if (uobj == NULL) {
uoffset = 0;
} else {
if (uoffset == UVM_UNKNOWN_OFFSET) {
KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj));
uoffset = start - vm_map_min(kernel_map);
}
}
args->uma_flags = flags;
args->uma_prev = prev_entry;
args->uma_start = start;
args->uma_size = size;
args->uma_uobj = uobj;
args->uma_uoffset = uoffset;
return 0;
}
int
uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args,
struct vm_map_entry *new_entry)
{
struct vm_map_entry *prev_entry = args->uma_prev;
struct vm_map_entry *dead = NULL;
const uvm_flag_t flags = args->uma_flags;
const vm_prot_t prot = UVM_PROTECTION(flags);
const vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
const vm_inherit_t inherit = UVM_INHERIT(flags);
const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ?
AMAP_EXTEND_NOWAIT : 0;
const int advice = UVM_ADVICE(flags);
const int meflagval = (flags & UVM_FLAG_QUANTUM) ?
UVM_MAP_QUANTUM : 0;
vaddr_t start = args->uma_start;
vsize_t size = args->uma_size;
struct uvm_object *uobj = args->uma_uobj;
voff_t uoffset = args->uma_uoffset;
const int kmap = (vm_map_pmap(map) == pmap_kernel());
int merged = 0;
int error;
int newetype;
UVMHIST_FUNC("uvm_map_enter");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)",
map, start, size, flags);
UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0);
KASSERT(map->hint == prev_entry); /* bimerge case assumes this */
if (flags & UVM_FLAG_QUANTUM) {
KASSERT(new_entry);
KASSERT(new_entry->flags & UVM_MAP_QUANTUM);
}
if (uobj)
newetype = UVM_ET_OBJ;
else
newetype = 0;
if (flags & UVM_FLAG_COPYONW) {
newetype |= UVM_ET_COPYONWRITE;
if ((flags & UVM_FLAG_OVERLAY) == 0)
newetype |= UVM_ET_NEEDSCOPY;
}
/*
* try and insert in map by extending previous entry, if possible.
* XXX: we don't try and pull back the next entry. might be useful
* for a stack, but we are currently allocating our stack in advance.
*/
if (flags & UVM_FLAG_NOMERGE)
goto nomerge;
if (prev_entry->end == start &&
prev_entry != &map->header &&
UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, meflagval,
prot, maxprot, inherit, advice, 0)) {
if (uobj && prev_entry->offset +
(prev_entry->end - prev_entry->start) != uoffset)
goto forwardmerge;
/*
* can't extend a shared amap. note: no need to lock amap to
* look at refs since we don't care about its exact value.
* if it is one (i.e. we have only reference) it will stay there
*/
if (prev_entry->aref.ar_amap &&
amap_refs(prev_entry->aref.ar_amap) != 1) {
goto forwardmerge;
}
if (prev_entry->aref.ar_amap) {
error = amap_extend(prev_entry, size,
amapwaitflag | AMAP_EXTEND_FORWARDS);
if (error)
goto nomerge;
}
if (kmap)
UVMMAP_EVCNT_INCR(kbackmerge);
else
UVMMAP_EVCNT_INCR(ubackmerge);
UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0);
/*
* drop our reference to uobj since we are extending a reference
* that we already have (the ref count can not drop to zero).
*/
if (uobj && uobj->pgops->pgo_detach)
uobj->pgops->pgo_detach(uobj);
prev_entry->end += size;
uvm_rb_fixup(map, prev_entry);
uvm_map_check(map, "map backmerged");
UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0);
merged++;
}
forwardmerge:
if (prev_entry->next->start == (start + size) &&
prev_entry->next != &map->header &&
UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, meflagval,
prot, maxprot, inherit, advice, 0)) {
if (uobj && prev_entry->next->offset != uoffset + size)
goto nomerge;
/*
* can't extend a shared amap. note: no need to lock amap to
* look at refs since we don't care about its exact value.
* if it is one (i.e. we have only reference) it will stay there.
*
* note that we also can't merge two amaps, so if we
* merged with the previous entry which has an amap,
* and the next entry also has an amap, we give up.
*
* Interesting cases:
* amap, new, amap -> give up second merge (single fwd extend)
* amap, new, none -> double forward extend (extend again here)
* none, new, amap -> double backward extend (done here)
* uobj, new, amap -> single backward extend (done here)
*
* XXX should we attempt to deal with someone refilling
* the deallocated region between two entries that are
* backed by the same amap (ie, arefs is 2, "prev" and
* "next" refer to it, and adding this allocation will
* close the hole, thus restoring arefs to 1 and
* deallocating the "next" vm_map_entry)? -- @@@
*/
if (prev_entry->next->aref.ar_amap &&
(amap_refs(prev_entry->next->aref.ar_amap) != 1 ||
(merged && prev_entry->aref.ar_amap))) {
goto nomerge;
}
if (merged) {
/*
* Try to extend the amap of the previous entry to
* cover the next entry as well. If it doesn't work
* just skip on, don't actually give up, since we've
* already completed the back merge.
*/
if (prev_entry->aref.ar_amap) {
if (amap_extend(prev_entry,
prev_entry->next->end -
prev_entry->next->start,
amapwaitflag | AMAP_EXTEND_FORWARDS))
goto nomerge;
}
/*
* Try to extend the amap of the *next* entry
* back to cover the new allocation *and* the
* previous entry as well (the previous merge
* didn't have an amap already otherwise we
* wouldn't be checking here for an amap). If
* it doesn't work just skip on, again, don't
* actually give up, since we've already
* completed the back merge.
*/
else if (prev_entry->next->aref.ar_amap) {
if (amap_extend(prev_entry->next,
prev_entry->end -
prev_entry->start,
amapwaitflag | AMAP_EXTEND_BACKWARDS))
goto nomerge;
}
} else {
/*
* Pull the next entry's amap backwards to cover this
* new allocation.
*/
if (prev_entry->next->aref.ar_amap) {
error = amap_extend(prev_entry->next, size,
amapwaitflag | AMAP_EXTEND_BACKWARDS);
if (error)
goto nomerge;
}
}
if (merged) {
if (kmap) {
UVMMAP_EVCNT_DECR(kbackmerge);
UVMMAP_EVCNT_INCR(kbimerge);
} else {
UVMMAP_EVCNT_DECR(ubackmerge);
UVMMAP_EVCNT_INCR(ubimerge);
}
} else {
if (kmap)
UVMMAP_EVCNT_INCR(kforwmerge);
else
UVMMAP_EVCNT_INCR(uforwmerge);
}
UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0);
/*
* drop our reference to uobj since we are extending a reference
* that we already have (the ref count can not drop to zero).
* (if merged, we've already detached)
*/
if (uobj && uobj->pgops->pgo_detach && !merged)
uobj->pgops->pgo_detach(uobj);
if (merged) {
dead = prev_entry->next;
prev_entry->end = dead->end;
uvm_map_entry_unlink(map, dead);
if (dead->aref.ar_amap != NULL) {
prev_entry->aref = dead->aref;
dead->aref.ar_amap = NULL;
}
} else {
prev_entry->next->start -= size;
if (prev_entry != &map->header)
uvm_rb_fixup(map, prev_entry);
if (uobj)
prev_entry->next->offset = uoffset;
}
uvm_map_check(map, "map forwardmerged");
UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0);
merged++;
}
nomerge:
if (!merged) {
UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0);
if (kmap)
UVMMAP_EVCNT_INCR(knomerge);
else
UVMMAP_EVCNT_INCR(unomerge);
/*
* allocate new entry and link it in.
*/
if (new_entry == NULL) {
new_entry = uvm_mapent_alloc(map,
(flags & UVM_FLAG_NOWAIT));
if (__predict_false(new_entry == NULL)) {
error = ENOMEM;
goto done;
}
}
new_entry->start = start;
new_entry->end = new_entry->start + size;
new_entry->object.uvm_obj = uobj;
new_entry->offset = uoffset;
new_entry->etype = newetype;
if (flags & UVM_FLAG_NOMERGE) {
new_entry->flags |= UVM_MAP_NOMERGE;
}
new_entry->protection = prot;
new_entry->max_protection = maxprot;
new_entry->inheritance = inherit;
new_entry->wired_count = 0;
new_entry->advice = advice;
if (flags & UVM_FLAG_OVERLAY) {
/*
* to_add: for BSS we overallocate a little since we
* are likely to extend
*/
vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ?
UVM_AMAP_CHUNK << PAGE_SHIFT : 0;
struct vm_amap *amap = amap_alloc(size, to_add,
(flags & UVM_FLAG_NOWAIT) ? M_NOWAIT : M_WAITOK);
if (__predict_false(amap == NULL)) {
error = ENOMEM;
goto done;
}
new_entry->aref.ar_pageoff = 0;
new_entry->aref.ar_amap = amap;
} else {
new_entry->aref.ar_pageoff = 0;
new_entry->aref.ar_amap = NULL;
}
uvm_map_entry_link(map, prev_entry, new_entry);
/*
* Update the free space hint
*/
if ((map->first_free == prev_entry) &&
(prev_entry->end >= new_entry->start))
map->first_free = new_entry;
new_entry = NULL;
}
map->size += size;
UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
error = 0;
done:
vm_map_unlock(map);
if (new_entry) {
if (error == 0) {
KDASSERT(merged);
uvm_mapent_free_merged(map, new_entry);
} else {
uvm_mapent_free(new_entry);
}
}
if (dead) {
KDASSERT(merged);
uvm_mapent_free_merged(map, dead);
}
return error;
}
/*
* uvm_map_lookup_entry: find map entry at or before an address
*
* => map must at least be read-locked by caller
* => entry is returned in "entry"
* => return value is true if address is in the returned entry
*/
boolean_t
uvm_map_lookup_entry(struct vm_map *map, vaddr_t address,
struct vm_map_entry **entry /* OUT */)
{
struct vm_map_entry *cur;
boolean_t use_tree = FALSE;
UVMHIST_FUNC("uvm_map_lookup_entry");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)",
map, address, entry, 0);
/*
* start looking either from the head of the
* list, or from the hint.
*/
simple_lock(&map->hint_lock);
cur = map->hint;
simple_unlock(&map->hint_lock);
if (cur == &map->header)
cur = cur->next;
UVMMAP_EVCNT_INCR(mlk_call);
if (address >= cur->start) {
/*
* go from hint to end of list.
*
* but first, make a quick check to see if
* we are already looking at the entry we
* want (which is usually the case).
* note also that we don't need to save the hint
* here... it is the same hint (unless we are
* at the header, in which case the hint didn't
* buy us anything anyway).
*/
if (cur != &map->header && cur->end > address) {
UVMMAP_EVCNT_INCR(mlk_hint);
*entry = cur;
UVMHIST_LOG(maphist,"<- got it via hint (0x%x)",
cur, 0, 0, 0);
uvm_mapent_check(*entry);
return (TRUE);
}
if (map->nentries > 30)
use_tree = TRUE;
} else {
/*
* invalid hint. use tree.
*/
use_tree = TRUE;
}
uvm_map_check(map, __func__);
if (use_tree) {
struct vm_map_entry *prev = &map->header;
cur = RB_ROOT(&map->rbhead);
/*
* Simple lookup in the tree. Happens when the hint is
* invalid, or nentries reach a threshold.
*/
while (cur) {
if (address >= cur->start) {
if (address < cur->end) {
*entry = cur;
goto got;
}
prev = cur;
cur = RB_RIGHT(cur, rb_entry);
} else
cur = RB_LEFT(cur, rb_entry);
}
*entry = prev;
goto failed;
}
/*
* search linearly
*/
while (cur != &map->header) {
if (cur->end > address) {
if (address >= cur->start) {
/*
* save this lookup for future
* hints, and return
*/
*entry = cur;
got:
SAVE_HINT(map, map->hint, *entry);
UVMHIST_LOG(maphist,"<- search got it (0x%x)",
cur, 0, 0, 0);
KDASSERT((*entry)->start <= address);
KDASSERT(address < (*entry)->end);
uvm_mapent_check(*entry);
return (TRUE);
}
break;
}
cur = cur->next;
}
*entry = cur->prev;
failed:
SAVE_HINT(map, map->hint, *entry);
UVMHIST_LOG(maphist,"<- failed!",0,0,0,0);
KDASSERT((*entry) == &map->header || (*entry)->end <= address);
KDASSERT((*entry)->next == &map->header ||
address < (*entry)->next->start);
return (FALSE);
}
/*
* See if the range between start and start + length fits in the gap
* entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't
* fit, and -1 address wraps around.
*/
static int
uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset,
vsize_t align, int topdown, struct vm_map_entry *entry)
{
vaddr_t end;
#ifdef PMAP_PREFER
/*
* push start address forward as needed to avoid VAC alias problems.
* we only do this if a valid offset is specified.
*/
if (uoffset != UVM_UNKNOWN_OFFSET)
PMAP_PREFER(uoffset, start, length, topdown);
#endif
if (align != 0) {
if ((*start & (align - 1)) != 0) {
if (topdown)
*start &= ~(align - 1);
else
*start = roundup(*start, align);
}
/*
* XXX Should we PMAP_PREFER() here again?
* eh...i think we're okay
*/
}
/*
* Find the end of the proposed new region. Be sure we didn't
* wrap around the address; if so, we lose. Otherwise, if the
* proposed new region fits before the next entry, we win.
*/
end = *start + length;
if (end < *start)
return (-1);
if (entry->next->start >= end && *start >= entry->end)
return (1);
return (0);
}
/*
* uvm_map_findspace: find "length" sized space in "map".
*
* => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is
* set in "flags" (in which case we insist on using "hint").
* => "result" is VA returned
* => uobj/uoffset are to be used to handle VAC alignment, if required
* => if "align" is non-zero, we attempt to align to that value.
* => caller must at least have read-locked map
* => returns NULL on failure, or pointer to prev. map entry if success
* => note this is a cross between the old vm_map_findspace and vm_map_find
*/
struct vm_map_entry *
uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length,
vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset,
vsize_t align, int flags)
{
struct vm_map_entry *entry;
struct vm_map_entry *child, *prev, *tmp;
vaddr_t orig_hint;
const int topdown = map->flags & VM_MAP_TOPDOWN;
UVMHIST_FUNC("uvm_map_findspace");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)",
map, hint, length, flags);
KASSERT((align & (align - 1)) == 0);
KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0);
uvm_map_check(map, "map_findspace entry");
/*
* remember the original hint. if we are aligning, then we
* may have to try again with no alignment constraint if
* we fail the first time.
*/
orig_hint = hint;
if (hint < vm_map_min(map)) { /* check ranges ... */
if (flags & UVM_FLAG_FIXED) {
UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0);
return (NULL);
}
hint = vm_map_min(map);
}
if (hint > vm_map_max(map)) {
UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]",
hint, vm_map_min(map), vm_map_max(map), 0);
return (NULL);
}
/*
* Look for the first possible address; if there's already
* something at this address, we have to start after it.
*/
/*
* @@@: there are four, no, eight cases to consider.
*
* 0: found, fixed, bottom up -> fail
* 1: found, fixed, top down -> fail
* 2: found, not fixed, bottom up -> start after entry->end,
* loop up
* 3: found, not fixed, top down -> start before entry->start,
* loop down
* 4: not found, fixed, bottom up -> check entry->next->start, fail
* 5: not found, fixed, top down -> check entry->next->start, fail
* 6: not found, not fixed, bottom up -> check entry->next->start,
* loop up
* 7: not found, not fixed, top down -> check entry->next->start,
* loop down
*
* as you can see, it reduces to roughly five cases, and that
* adding top down mapping only adds one unique case (without
* it, there would be four cases).
*/
if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) {
entry = map->first_free;
} else {
if (uvm_map_lookup_entry(map, hint, &entry)) {
/* "hint" address already in use ... */
if (flags & UVM_FLAG_FIXED) {
UVMHIST_LOG(maphist, "<- fixed & VA in use",
0, 0, 0, 0);
return (NULL);
}
if (topdown)
/* Start from lower gap. */
entry = entry->prev;
} else if (flags & UVM_FLAG_FIXED) {
if (entry->next->start >= hint + length &&
hint + length > hint)
goto found;
/* "hint" address is gap but too small */
UVMHIST_LOG(maphist, "<- fixed mapping failed",
0, 0, 0, 0);
return (NULL); /* only one shot at it ... */
} else {
/*
* See if given hint fits in this gap.
*/
switch (uvm_map_space_avail(&hint, length,
uoffset, align, topdown, entry)) {
case 1:
goto found;
case -1:
goto wraparound;
}
if (topdown) {
/*
* Still there is a chance to fit
* if hint > entry->end.
*/
} else {
/* Start from higher gap. */
entry = entry->next;
if (entry == &map->header)
goto notfound;
goto nextgap;
}
}
}
/*
* Note that all UVM_FLAGS_FIXED case is already handled.
*/
KDASSERT((flags & UVM_FLAG_FIXED) == 0);
/* Try to find the space in the red-black tree */
/* Check slot before any entry */
hint = topdown ? entry->next->start - length : entry->end;
switch (uvm_map_space_avail(&hint, length, uoffset, align,
topdown, entry)) {
case 1:
goto found;
case -1:
goto wraparound;
}
nextgap:
KDASSERT((flags & UVM_FLAG_FIXED) == 0);
/* If there is not enough space in the whole tree, we fail */
tmp = RB_ROOT(&map->rbhead);
if (tmp == NULL || tmp->space < length)
goto notfound;
prev = NULL; /* previous candidate */
/* Find an entry close to hint that has enough space */
for (; tmp;) {
KASSERT(tmp->next->start == tmp->end + tmp->ownspace);
if (topdown) {
if (tmp->next->start < hint + length &&
(prev == NULL || tmp->end > prev->end)) {
if (tmp->ownspace >= length)
prev = tmp;
else if ((child = RB_LEFT(tmp, rb_entry))
!= NULL && child->space >= length)
prev = tmp;
}
} else {
if (tmp->end >= hint &&
(prev == NULL || tmp->end < prev->end)) {
if (tmp->ownspace >= length)
prev = tmp;
else if ((child = RB_RIGHT(tmp, rb_entry))
!= NULL && child->space >= length)
prev = tmp;
}
}
if (tmp->next->start < hint + length)
child = RB_RIGHT(tmp, rb_entry);
else if (tmp->end > hint)
child = RB_LEFT(tmp, rb_entry);
else {
if (tmp->ownspace >= length)
break;
if (topdown)
child = RB_LEFT(tmp, rb_entry);
else
child = RB_RIGHT(tmp, rb_entry);
}
if (child == NULL || child->space < length)
break;
tmp = child;
}
if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) {
/*
* Check if the entry that we found satifies the
* space requirement
*/
if (topdown) {
if (hint > tmp->next->start - length)
hint = tmp->next->start - length;
} else {
if (hint < tmp->end)
hint = tmp->end;
}
switch (uvm_map_space_avail(&hint, length, uoffset, align,
topdown, tmp)) {
case 1:
entry = tmp;
goto found;
case -1:
goto wraparound;
}
if (tmp->ownspace >= length)
goto listsearch;
}
if (prev == NULL)
goto notfound;
if (topdown) {
KASSERT(orig_hint >= prev->next->start - length ||
prev->next->start - length > prev->next->start);
hint = prev->next->start - length;
} else {
KASSERT(orig_hint <= prev->end);
hint = prev->end;
}
switch (uvm_map_space_avail(&hint, length, uoffset, align,
topdown, prev)) {
case 1:
entry = prev;
goto found;
case -1:
goto wraparound;
}
if (prev->ownspace >= length)
goto listsearch;
if (topdown)
tmp = RB_LEFT(prev, rb_entry);
else
tmp = RB_RIGHT(prev, rb_entry);
for (;;) {
KASSERT(tmp && tmp->space >= length);
if (topdown)
child = RB_RIGHT(tmp, rb_entry);
else
child = RB_LEFT(tmp, rb_entry);
if (child && child->space >= length) {
tmp = child;
continue;
}
if (tmp->ownspace >= length)
break;
if (topdown)
tmp = RB_LEFT(tmp, rb_entry);
else
tmp = RB_RIGHT(tmp, rb_entry);
}
if (topdown) {
KASSERT(orig_hint >= tmp->next->start - length ||
tmp->next->start - length > tmp->next->start);
hint = tmp->next->start - length;
} else {
KASSERT(orig_hint <= tmp->end);
hint = tmp->end;
}
switch (uvm_map_space_avail(&hint, length, uoffset, align,
topdown, tmp)) {
case 1:
entry = tmp;
goto found;
case -1:
goto wraparound;
}
/*
* The tree fails to find an entry because of offset or alignment
* restrictions. Search the list instead.
*/
listsearch:
/*
* Look through the rest of the map, trying to fit a new region in
* the gap between existing regions, or after the very last region.
* note: entry->end = base VA of current gap,
* entry->next->start = VA of end of current gap
*/
for (;;) {
/* Update hint for current gap. */
hint = topdown ? entry->next->start - length : entry->end;
/* See if it fits. */
switch (uvm_map_space_avail(&hint, length, uoffset, align,
topdown, entry)) {
case 1:
goto found;
case -1:
goto wraparound;
}
/* Advance to next/previous gap */
if (topdown) {
if (entry == &map->header) {
UVMHIST_LOG(maphist, "<- failed (off start)",
0,0,0,0);
goto notfound;
}
entry = entry->prev;
} else {
entry = entry->next;
if (entry == &map->header) {
UVMHIST_LOG(maphist, "<- failed (off end)",
0,0,0,0);
goto notfound;
}
}
}
found:
SAVE_HINT(map, map->hint, entry);
*result = hint;
UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0);
KASSERT( topdown || hint >= orig_hint);
KASSERT(!topdown || hint <= orig_hint);
KASSERT(entry->end <= hint);
KASSERT(hint + length <= entry->next->start);
return (entry);
wraparound:
UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0);
return (NULL);
notfound:
UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0);
return (NULL);
}
/*
* U N M A P - m a i n h e l p e r f u n c t i o n s
*/
/*
* uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop")
*
* => caller must check alignment and size
* => map must be locked by caller
* => we return a list of map entries that we've remove from the map
* in "entry_list"
*/
void
uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end,
struct vm_map_entry **entry_list /* OUT */,
struct uvm_mapent_reservation *umr, int flags)
{
struct vm_map_entry *entry, *first_entry, *next;
vaddr_t len;
UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)",
map, start, end, 0);
VM_MAP_RANGE_CHECK(map, start, end);
uvm_map_check(map, "unmap_remove entry");
/*
* find first entry
*/
if (uvm_map_lookup_entry(map, start, &first_entry) == TRUE) {
/* clip and go... */
entry = first_entry;
UVM_MAP_CLIP_START(map, entry, start, umr);
/* critical! prevents stale hint */
SAVE_HINT(map, entry, entry->prev);
} else {
entry = first_entry->next;
}
/*
* Save the free space hint
*/
if (map->first_free != &map->header && map->first_free->start >= start)
map->first_free = entry->prev;
/*
* note: we now re-use first_entry for a different task. we remove
* a number of map entries from the map and save them in a linked
* list headed by "first_entry". once we remove them from the map
* the caller should unlock the map and drop the references to the
* backing objects [c.f. uvm_unmap_detach]. the object is to
* separate unmapping from reference dropping. why?
* [1] the map has to be locked for unmapping
* [2] the map need not be locked for reference dropping
* [3] dropping references may trigger pager I/O, and if we hit
* a pager that does synchronous I/O we may have to wait for it.
* [4] we would like all waiting for I/O to occur with maps unlocked
* so that we don't block other threads.
*/
first_entry = NULL;
*entry_list = NULL;
/*
* break up the area into map entry sized regions and unmap. note
* that all mappings have to be removed before we can even consider
* dropping references to amaps or VM objects (otherwise we could end
* up with a mapping to a page on the free list which would be very bad)
*/
while ((entry != &map->header) && (entry->start < end)) {
KASSERT((entry->flags & UVM_MAP_FIRST) == 0);
UVM_MAP_CLIP_END(map, entry, end, umr);
next = entry->next;
len = entry->end - entry->start;
/*
* unwire before removing addresses from the pmap; otherwise
* unwiring will put the entries back into the pmap (XXX).
*/
if (VM_MAPENT_ISWIRED(entry)) {
uvm_map_entry_unwire(map, entry);
}
if (flags & UVM_FLAG_VAONLY) {
/* nothing */
} else if ((map->flags & VM_MAP_PAGEABLE) == 0) {
/*
* if the map is non-pageable, any pages mapped there
* must be wired and entered with pmap_kenter_pa(),
* and we should free any such pages immediately.
* this is mostly used for kmem_map and mb_map.
*/
if ((entry->flags & UVM_MAP_KMAPENT) == 0) {
uvm_km_pgremove_intrsafe(entry->start,
entry->end);
pmap_kremove(entry->start, len);
}
} else if (UVM_ET_ISOBJ(entry) &&
UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) {
KASSERT(vm_map_pmap(map) == pmap_kernel());
/*
* note: kernel object mappings are currently used in
* two ways:
* [1] "normal" mappings of pages in the kernel object
* [2] uvm_km_valloc'd allocations in which we
* pmap_enter in some non-kernel-object page
* (e.g. vmapbuf).
*
* for case [1], we need to remove the mapping from
* the pmap and then remove the page from the kernel
* object (because, once pages in a kernel object are
* unmapped they are no longer needed, unlike, say,
* a vnode where you might want the data to persist
* until flushed out of a queue).
*
* for case [2], we need to remove the mapping from
* the pmap. there shouldn't be any pages at the
* specified offset in the kernel object [but it
* doesn't hurt to call uvm_km_pgremove just to be
* safe?]
*
* uvm_km_pgremove currently does the following:
* for pages in the kernel object in range:
* - drops the swap slot
* - uvm_pagefree the page
*/
/*
* remove mappings from pmap and drop the pages
* from the object. offsets are always relative
* to vm_map_min(kernel_map).
*/
pmap_remove(pmap_kernel(), entry->start,
entry->start + len);
uvm_km_pgremove(entry->start, entry->end);
/*
* null out kernel_object reference, we've just
* dropped it
*/
entry->etype &= ~UVM_ET_OBJ;
entry->object.uvm_obj = NULL;
} else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) {
/*
* remove mappings the standard way.
*/
pmap_remove(map->pmap, entry->start, entry->end);
}
#if defined(DEBUG)
if ((entry->flags & UVM_MAP_KMAPENT) == 0) {
/*
* check if there's remaining mapping,
* which is a bug in caller.
*/
vaddr_t va;
for (va = entry->start; va < entry->end;
va += PAGE_SIZE) {
if (pmap_extract(vm_map_pmap(map), va, NULL)) {
panic("uvm_unmap_remove: has mapping");
}
}
if (VM_MAP_IS_KERNEL(map)) {
uvm_km_check_empty(entry->start, entry->end,
(map->flags & VM_MAP_INTRSAFE) != 0);
}
}
#endif /* defined(DEBUG) */
/*
* remove entry from map and put it on our list of entries
* that we've nuked. then go to next entry.
*/
UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0);
/* critical! prevents stale hint */
SAVE_HINT(map, entry, entry->prev);
uvm_map_entry_unlink(map, entry);
KASSERT(map->size >= len);
map->size -= len;
entry->prev = NULL;
entry->next = first_entry;
first_entry = entry;
entry = next;
}
if ((map->flags & VM_MAP_DYING) == 0) {
pmap_update(vm_map_pmap(map));
}
uvm_map_check(map, "unmap_remove leave");
/*
* now we've cleaned up the map and are ready for the caller to drop
* references to the mapped objects.
*/
*entry_list = first_entry;
UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
simple_lock(&map->flags_lock);
if (map->flags & VM_MAP_WANTVA) {
map->flags &= ~VM_MAP_WANTVA;
wakeup(&map->header);
}
simple_unlock(&map->flags_lock);
}
/*
* uvm_unmap_detach: drop references in a chain of map entries
*
* => we will free the map entries as we traverse the list.
*/
void
uvm_unmap_detach(struct vm_map_entry *first_entry, int flags)
{
struct vm_map_entry *next_entry;
UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist);
while (first_entry) {
KASSERT(!VM_MAPENT_ISWIRED(first_entry));
UVMHIST_LOG(maphist,
" detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d",
first_entry, first_entry->aref.ar_amap,
first_entry->object.uvm_obj,
UVM_ET_ISSUBMAP(first_entry));
/*
* drop reference to amap, if we've got one
*/
if (first_entry->aref.ar_amap)
uvm_map_unreference_amap(first_entry, flags);
/*
* drop reference to our backing object, if we've got one
*/
KASSERT(!UVM_ET_ISSUBMAP(first_entry));
if (UVM_ET_ISOBJ(first_entry) &&
first_entry->object.uvm_obj->pgops->pgo_detach) {
(*first_entry->object.uvm_obj->pgops->pgo_detach)
(first_entry->object.uvm_obj);
}
next_entry = first_entry->next;
uvm_mapent_free(first_entry);
first_entry = next_entry;
}
UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
}
/*
* E X T R A C T I O N F U N C T I O N S
*/
/*
* uvm_map_reserve: reserve space in a vm_map for future use.
*
* => we reserve space in a map by putting a dummy map entry in the
* map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE)
* => map should be unlocked (we will write lock it)
* => we return true if we were able to reserve space
* => XXXCDC: should be inline?
*/
int
uvm_map_reserve(struct vm_map *map, vsize_t size,
vaddr_t offset /* hint for pmap_prefer */,
vsize_t align /* alignment hint */,
vaddr_t *raddr /* IN:hint, OUT: reserved VA */,
uvm_flag_t flags /* UVM_FLAG_FIXED or 0 */)
{
UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)",
map,size,offset,raddr);
size = round_page(size);
/*
* reserve some virtual space.
*/
if (uvm_map(map, raddr, size, NULL, offset, 0,
UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) {
UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
return (FALSE);
}
UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0);
return (TRUE);
}
/*
* uvm_map_replace: replace a reserved (blank) area of memory with
* real mappings.
*
* => caller must WRITE-LOCK the map
* => we return TRUE if replacement was a success
* => we expect the newents chain to have nnewents entrys on it and
* we expect newents->prev to point to the last entry on the list
* => note newents is allowed to be NULL
*/
int
uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end,
struct vm_map_entry *newents, int nnewents)
{
struct vm_map_entry *oldent, *last;
uvm_map_check(map, "map_replace entry");
/*
* first find the blank map entry at the specified address
*/
if (!uvm_map_lookup_entry(map, start, &oldent)) {
return (FALSE);
}
/*
* check to make sure we have a proper blank entry
*/
if (end < oldent->end && !VM_MAP_USE_KMAPENT(map)) {
UVM_MAP_CLIP_END(map, oldent, end, NULL);
}
if (oldent->start != start || oldent->end != end ||
oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) {
return (FALSE);
}
#ifdef DIAGNOSTIC
/*
* sanity check the newents chain
*/
{
struct vm_map_entry *tmpent = newents;
int nent = 0;
vaddr_t cur = start;
while (tmpent) {
nent++;
if (tmpent->start < cur)
panic("uvm_map_replace1");
if (tmpent->start > tmpent->end || tmpent->end > end) {
printf("tmpent->start=0x%lx, tmpent->end=0x%lx, end=0x%lx\n",
tmpent->start, tmpent->end, end);
panic("uvm_map_replace2");
}
cur = tmpent->end;
if (tmpent->next) {
if (tmpent->next->prev != tmpent)
panic("uvm_map_replace3");
} else {
if (newents->prev != tmpent)
panic("uvm_map_replace4");
}
tmpent = tmpent->next;
}
if (nent != nnewents)
panic("uvm_map_replace5");
}
#endif
/*
* map entry is a valid blank! replace it. (this does all the
* work of map entry link/unlink...).
*/
if (newents) {
last = newents->prev;
/* critical: flush stale hints out of map */
SAVE_HINT(map, map->hint, newents);
if (map->first_free == oldent)
map->first_free = last;
last->next = oldent->next;
last->next->prev = last;
/* Fix RB tree */
uvm_rb_remove(map, oldent);
newents->prev = oldent->prev;
newents->prev->next = newents;
map->nentries = map->nentries + (nnewents - 1);
/* Fixup the RB tree */
{
int i;
struct vm_map_entry *tmp;
tmp = newents;
for (i = 0; i < nnewents && tmp; i++) {
uvm_rb_insert(map, tmp);
tmp = tmp->next;
}
}
} else {
/* NULL list of new entries: just remove the old one */
clear_hints(map, oldent);
uvm_map_entry_unlink(map, oldent);
}
uvm_map_check(map, "map_replace leave");
/*
* now we can free the old blank entry and return.
*/
uvm_mapent_free(oldent);
return (TRUE);
}
/*
* uvm_map_extract: extract a mapping from a map and put it somewhere
* (maybe removing the old mapping)
*
* => maps should be unlocked (we will write lock them)
* => returns 0 on success, error code otherwise
* => start must be page aligned
* => len must be page sized
* => flags:
* UVM_EXTRACT_REMOVE: remove mappings from srcmap
* UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only)
* UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs
* UVM_EXTRACT_FIXPROT: set prot to maxprot as we go
* >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<<
* >>>NOTE: QREF's must be unmapped via the QREF path, thus should only
* be used from within the kernel in a kernel level map <<<
*/
int
uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len,
struct vm_map *dstmap, vaddr_t *dstaddrp, int flags)
{
vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge;
struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry,
*deadentry, *oldentry;
vsize_t elen;
int nchain, error, copy_ok;
UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start,
len,0);
UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0);
uvm_map_check(srcmap, "map_extract src enter");
uvm_map_check(dstmap, "map_extract dst enter");
/*
* step 0: sanity check: start must be on a page boundary, length
* must be page sized. can't ask for CONTIG/QREF if you asked for
* REMOVE.
*/
KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0);
KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 ||
(flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0);
/*
* step 1: reserve space in the target map for the extracted area
*/
if ((flags & UVM_EXTRACT_RESERVED) == 0) {
dstaddr = vm_map_min(dstmap);
if (!uvm_map_reserve(dstmap, len, start, 0, &dstaddr, 0))
return (ENOMEM);
*dstaddrp = dstaddr; /* pass address back to caller */
UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0);
} else {
dstaddr = *dstaddrp;
}
/*
* step 2: setup for the extraction process loop by init'ing the
* map entry chain, locking src map, and looking up the first useful
* entry in the map.
*/
end = start + len;
newend = dstaddr + len;
chain = endchain = NULL;
nchain = 0;
vm_map_lock(srcmap);
if (uvm_map_lookup_entry(srcmap, start, &entry)) {
/* "start" is within an entry */
if (flags & UVM_EXTRACT_QREF) {
/*
* for quick references we don't clip the entry, so
* the entry may map space "before" the starting
* virtual address... this is the "fudge" factor
* (which can be non-zero only the first time
* through the "while" loop in step 3).
*/
fudge = start - entry->start;
} else {
/*
* normal reference: we clip the map to fit (thus
* fudge is zero)
*/
UVM_MAP_CLIP_START(srcmap, entry, start, NULL);
SAVE_HINT(srcmap, srcmap->hint, entry->prev);
fudge = 0;
}
} else {
/* "start" is not within an entry ... skip to next entry */
if (flags & UVM_EXTRACT_CONTIG) {
error = EINVAL;
goto bad; /* definite hole here ... */
}
entry = entry->next;
fudge = 0;
}
/* save values from srcmap for step 6 */
orig_entry = entry;
orig_fudge = fudge;
/*
* step 3: now start looping through the map entries, extracting
* as we go.
*/
while (entry->start < end && entry != &srcmap->header) {
/* if we are not doing a quick reference, clip it */
if ((flags & UVM_EXTRACT_QREF) == 0)
UVM_MAP_CLIP_END(srcmap, entry, end, NULL);
/* clear needs_copy (allow chunking) */
if (UVM_ET_ISNEEDSCOPY(entry)) {
amap_copy(srcmap, entry,
AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end);
if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */
error = ENOMEM;
goto bad;
}
/* amap_copy could clip (during chunk)! update fudge */
if (fudge) {
fudge = start - entry->start;
orig_fudge = fudge;
}
}
/* calculate the offset of this from "start" */
oldoffset = (entry->start + fudge) - start;
/* allocate a new map entry */
newentry = uvm_mapent_alloc(dstmap, 0);
if (newentry == NULL) {
error = ENOMEM;
goto bad;
}
/* set up new map entry */
newentry->next = NULL;
newentry->prev = endchain;
newentry->start = dstaddr + oldoffset;
newentry->end =
newentry->start + (entry->end - (entry->start + fudge));
if (newentry->end > newend || newentry->end < newentry->start)
newentry->end = newend;
newentry->object.uvm_obj = entry->object.uvm_obj;
if (newentry->object.uvm_obj) {
if (newentry->object.uvm_obj->pgops->pgo_reference)
newentry->object.uvm_obj->pgops->
pgo_reference(newentry->object.uvm_obj);
newentry->offset = entry->offset + fudge;
} else {
newentry->offset = 0;
}
newentry->etype = entry->etype;
newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ?
entry->max_protection : entry->protection;
newentry->max_protection = entry->max_protection;
newentry->inheritance = entry->inheritance;
newentry->wired_count = 0;
newentry->aref.ar_amap = entry->aref.ar_amap;
if (newentry->aref.ar_amap) {
newentry->aref.ar_pageoff =
entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT);
uvm_map_reference_amap(newentry, AMAP_SHARED |
((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0));
} else {
newentry->aref.ar_pageoff = 0;
}
newentry->advice = entry->advice;
/* now link it on the chain */
nchain++;
if (endchain == NULL) {
chain = endchain = newentry;
} else {
endchain->next = newentry;
endchain = newentry;
}
/* end of 'while' loop! */
if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end &&
(entry->next == &srcmap->header ||
entry->next->start != entry->end)) {
error = EINVAL;
goto bad;
}
entry = entry->next;
fudge = 0;
}
/*
* step 4: close off chain (in format expected by uvm_map_replace)
*/
if (chain)
chain->prev = endchain;
/*
* step 5: attempt to lock the dest map so we can pmap_copy.
* note usage of copy_ok:
* 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5)
* 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7
*/
if (srcmap == dstmap || vm_map_lock_try(dstmap) == TRUE) {
copy_ok = 1;
if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
nchain)) {
if (srcmap != dstmap)
vm_map_unlock(dstmap);
error = EIO;
goto bad;
}
} else {
copy_ok = 0;
/* replace defered until step 7 */
}
/*
* step 6: traverse the srcmap a second time to do the following:
* - if we got a lock on the dstmap do pmap_copy
* - if UVM_EXTRACT_REMOVE remove the entries
* we make use of orig_entry and orig_fudge (saved in step 2)
*/
if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) {
/* purge possible stale hints from srcmap */
if (flags & UVM_EXTRACT_REMOVE) {
SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev);
if (srcmap->first_free != &srcmap->header &&
srcmap->first_free->start >= start)
srcmap->first_free = orig_entry->prev;
}
entry = orig_entry;
fudge = orig_fudge;
deadentry = NULL; /* for UVM_EXTRACT_REMOVE */
while (entry->start < end && entry != &srcmap->header) {
if (copy_ok) {
oldoffset = (entry->start + fudge) - start;
elen = MIN(end, entry->end) -
(entry->start + fudge);
pmap_copy(dstmap->pmap, srcmap->pmap,
dstaddr + oldoffset, elen,
entry->start + fudge);
}
/* we advance "entry" in the following if statement */
if (flags & UVM_EXTRACT_REMOVE) {
pmap_remove(srcmap->pmap, entry->start,
entry->end);
oldentry = entry; /* save entry */
entry = entry->next; /* advance */
uvm_map_entry_unlink(srcmap, oldentry);
/* add to dead list */
oldentry->next = deadentry;
deadentry = oldentry;
} else {
entry = entry->next; /* advance */
}
/* end of 'while' loop */
fudge = 0;
}
pmap_update(srcmap->pmap);
/*
* unlock dstmap. we will dispose of deadentry in
* step 7 if needed
*/
if (copy_ok && srcmap != dstmap)
vm_map_unlock(dstmap);
} else {
deadentry = NULL;
}
/*
* step 7: we are done with the source map, unlock. if copy_ok
* is 0 then we have not replaced the dummy mapping in dstmap yet
* and we need to do so now.
*/
vm_map_unlock(srcmap);
if ((flags & UVM_EXTRACT_REMOVE) && deadentry)
uvm_unmap_detach(deadentry, 0); /* dispose of old entries */
/* now do the replacement if we didn't do it in step 5 */
if (copy_ok == 0) {
vm_map_lock(dstmap);
error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
nchain);
vm_map_unlock(dstmap);
if (error == FALSE) {
error = EIO;
goto bad2;
}
}
uvm_map_check(srcmap, "map_extract src leave");
uvm_map_check(dstmap, "map_extract dst leave");
return (0);
/*
* bad: failure recovery
*/
bad:
vm_map_unlock(srcmap);
bad2: /* src already unlocked */
if (chain)
uvm_unmap_detach(chain,
(flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0);
uvm_map_check(srcmap, "map_extract src err leave");
uvm_map_check(dstmap, "map_extract dst err leave");
if ((flags & UVM_EXTRACT_RESERVED) == 0) {
uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */
}
return (error);
}
/* end of extraction functions */
/*
* uvm_map_submap: punch down part of a map into a submap
*
* => only the kernel_map is allowed to be submapped
* => the purpose of submapping is to break up the locking granularity
* of a larger map
* => the range specified must have been mapped previously with a uvm_map()
* call [with uobj==NULL] to create a blank map entry in the main map.
* [And it had better still be blank!]
* => maps which contain submaps should never be copied or forked.
* => to remove a submap, use uvm_unmap() on the main map
* and then uvm_map_deallocate() the submap.
* => main map must be unlocked.
* => submap must have been init'd and have a zero reference count.
* [need not be locked as we don't actually reference it]
*/
int
uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end,
struct vm_map *submap)
{
struct vm_map_entry *entry;
struct uvm_mapent_reservation umr;
int error;
uvm_mapent_reserve(map, &umr, 2, 0);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &entry)) {
UVM_MAP_CLIP_START(map, entry, start, &umr);
UVM_MAP_CLIP_END(map, entry, end, &umr); /* to be safe */
} else {
entry = NULL;
}
if (entry != NULL &&
entry->start == start && entry->end == end &&
entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL &&
!UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) {
entry->etype |= UVM_ET_SUBMAP;
entry->object.sub_map = submap;
entry->offset = 0;
uvm_map_reference(submap);
error = 0;
} else {
error = EINVAL;
}
vm_map_unlock(map);
uvm_mapent_unreserve(map, &umr);
return error;
}
/*
* uvm_map_setup_kernel: init in-kernel map
*
* => map must not be in service yet.
*/
void
uvm_map_setup_kernel(struct vm_map_kernel *map,
vaddr_t vmin, vaddr_t vmax, int flags)
{
uvm_map_setup(&map->vmk_map, vmin, vmax, flags);
callback_head_init(&map->vmk_reclaim_callback);
LIST_INIT(&map->vmk_kentry_free);
map->vmk_merged_entries = NULL;
}
/*
* uvm_map_protect: change map protection
*
* => set_max means set max_protection.
* => map must be unlocked.
*/
#define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \
~VM_PROT_WRITE : VM_PROT_ALL)
int
uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end,
vm_prot_t new_prot, boolean_t set_max)
{
struct vm_map_entry *current, *entry;
int error = 0;
UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)",
map, start, end, new_prot);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &entry)) {
UVM_MAP_CLIP_START(map, entry, start, NULL);
} else {
entry = entry->next;
}
/*
* make a first pass to check for protection violations.
*/
current = entry;
while ((current != &map->header) && (current->start < end)) {
if (UVM_ET_ISSUBMAP(current)) {
error = EINVAL;
goto out;
}
if ((new_prot & current->max_protection) != new_prot) {
error = EACCES;
goto out;
}
/*
* Don't allow VM_PROT_EXECUTE to be set on entries that
* point to vnodes that are associated with a NOEXEC file
* system.
*/
if (UVM_ET_ISOBJ(current) &&
UVM_OBJ_IS_VNODE(current->object.uvm_obj)) {
struct vnode *vp =
(struct vnode *) current->object.uvm_obj;
if ((new_prot & VM_PROT_EXECUTE) != 0 &&
(vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) {
error = EACCES;
goto out;
}
}
current = current->next;
}
/* go back and fix up protections (no need to clip this time). */
current = entry;
while ((current != &map->header) && (current->start < end)) {
vm_prot_t old_prot;
UVM_MAP_CLIP_END(map, current, end, NULL);
old_prot = current->protection;
if (set_max)
current->protection =
(current->max_protection = new_prot) & old_prot;
else
current->protection = new_prot;
/*
* update physical map if necessary. worry about copy-on-write
* here -- CHECK THIS XXX
*/
if (current->protection != old_prot) {
/* update pmap! */
pmap_protect(map->pmap, current->start, current->end,
current->protection & MASK(entry));
/*
* If this entry points at a vnode, and the
* protection includes VM_PROT_EXECUTE, mark
* the vnode as VEXECMAP.
*/
if (UVM_ET_ISOBJ(current)) {
struct uvm_object *uobj =
current->object.uvm_obj;
if (UVM_OBJ_IS_VNODE(uobj) &&
(current->protection & VM_PROT_EXECUTE))
vn_markexec((struct vnode *) uobj);
}
}
/*
* If the map is configured to lock any future mappings,
* wire this entry now if the old protection was VM_PROT_NONE
* and the new protection is not VM_PROT_NONE.
*/
if ((map->flags & VM_MAP_WIREFUTURE) != 0 &&
VM_MAPENT_ISWIRED(entry) == 0 &&
old_prot == VM_PROT_NONE &&
new_prot != VM_PROT_NONE) {
if (uvm_map_pageable(map, entry->start,
entry->end, FALSE,
UVM_LK_ENTER|UVM_LK_EXIT) != 0) {
/*
* If locking the entry fails, remember the
* error if it's the first one. Note we
* still continue setting the protection in
* the map, but will return the error
* condition regardless.
*
* XXX Ignore what the actual error is,
* XXX just call it a resource shortage
* XXX so that it doesn't get confused
* XXX what uvm_map_protect() itself would
* XXX normally return.
*/
error = ENOMEM;
}
}
current = current->next;
}
pmap_update(map->pmap);
out:
vm_map_unlock(map);
UVMHIST_LOG(maphist, "<- done, error=%d",error,0,0,0);
return error;
}
#undef MASK
/*
* uvm_map_inherit: set inheritance code for range of addrs in map.
*
* => map must be unlocked
* => note that the inherit code is used during a "fork". see fork
* code for details.
*/
int
uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end,
vm_inherit_t new_inheritance)
{
struct vm_map_entry *entry, *temp_entry;
UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)",
map, start, end, new_inheritance);
switch (new_inheritance) {
case MAP_INHERIT_NONE:
case MAP_INHERIT_COPY:
case MAP_INHERIT_SHARE:
break;
default:
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
return EINVAL;
}
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &temp_entry)) {
entry = temp_entry;
UVM_MAP_CLIP_START(map, entry, start, NULL);
} else {
entry = temp_entry->next;
}
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end, NULL);
entry->inheritance = new_inheritance;
entry = entry->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
return 0;
}
/*
* uvm_map_advice: set advice code for range of addrs in map.
*
* => map must be unlocked
*/
int
uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice)
{
struct vm_map_entry *entry, *temp_entry;
UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)",
map, start, end, new_advice);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &temp_entry)) {
entry = temp_entry;
UVM_MAP_CLIP_START(map, entry, start, NULL);
} else {
entry = temp_entry->next;
}
/*
* XXXJRT: disallow holes?
*/
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end, NULL);
switch (new_advice) {
case MADV_NORMAL:
case MADV_RANDOM:
case MADV_SEQUENTIAL:
/* nothing special here */
break;
default:
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
return EINVAL;
}
entry->advice = new_advice;
entry = entry->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
return 0;
}
/*
* uvm_map_pageable: sets the pageability of a range in a map.
*
* => wires map entries. should not be used for transient page locking.
* for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()).
* => regions specified as not pageable require lock-down (wired) memory
* and page tables.
* => map must never be read-locked
* => if islocked is TRUE, map is already write-locked
* => we always unlock the map, since we must downgrade to a read-lock
* to call uvm_fault_wire()
* => XXXCDC: check this and try and clean it up.
*/
int
uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end,
boolean_t new_pageable, int lockflags)
{
struct vm_map_entry *entry, *start_entry, *failed_entry;
int rv;
#ifdef DIAGNOSTIC
u_int timestamp_save;
#endif
UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)",
map, start, end, new_pageable);
KASSERT(map->flags & VM_MAP_PAGEABLE);
if ((lockflags & UVM_LK_ENTER) == 0)
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
/*
* only one pageability change may take place at one time, since
* uvm_fault_wire assumes it will be called only once for each
* wiring/unwiring. therefore, we have to make sure we're actually
* changing the pageability for the entire region. we do so before
* making any changes.
*/
if (uvm_map_lookup_entry(map, start, &start_entry) == FALSE) {
if ((lockflags & UVM_LK_EXIT) == 0)
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0);
return EFAULT;
}
entry = start_entry;
/*
* handle wiring and unwiring separately.
*/
if (new_pageable) { /* unwire */
UVM_MAP_CLIP_START(map, entry, start, NULL);
/*
* unwiring. first ensure that the range to be unwired is
* really wired down and that there are no holes.
*/
while ((entry != &map->header) && (entry->start < end)) {
if (entry->wired_count == 0 ||
(entry->end < end &&
(entry->next == &map->header ||
entry->next->start > entry->end))) {
if ((lockflags & UVM_LK_EXIT) == 0)
vm_map_unlock(map);
UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0);
return EINVAL;
}
entry = entry->next;
}
/*
* POSIX 1003.1b - a single munlock call unlocks a region,
* regardless of the number of mlock calls made on that
* region.
*/
entry = start_entry;
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end, NULL);
if (VM_MAPENT_ISWIRED(entry))
uvm_map_entry_unwire(map, entry);
entry = entry->next;
}
if ((lockflags & UVM_LK_EXIT) == 0)
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
return 0;
}
/*
* wire case: in two passes [XXXCDC: ugly block of code here]
*
* 1: holding the write lock, we create any anonymous maps that need
* to be created. then we clip each map entry to the region to
* be wired and increment its wiring count.
*
* 2: we downgrade to a read lock, and call uvm_fault_wire to fault
* in the pages for any newly wired area (wired_count == 1).
*
* downgrading to a read lock for uvm_fault_wire avoids a possible
* deadlock with another thread that may have faulted on one of
* the pages to be wired (it would mark the page busy, blocking
* us, then in turn block on the map lock that we hold). because
* of problems in the recursive lock package, we cannot upgrade
* to a write lock in vm_map_lookup. thus, any actions that
* require the write lock must be done beforehand. because we
* keep the read lock on the map, the copy-on-write status of the
* entries we modify here cannot change.
*/
while ((entry != &map->header) && (entry->start < end)) {
if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
/*
* perform actions of vm_map_lookup that need the
* write lock on the map: create an anonymous map
* for a copy-on-write region, or an anonymous map
* for a zero-fill region. (XXXCDC: submap case
* ok?)
*/
if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
if (UVM_ET_ISNEEDSCOPY(entry) &&
((entry->max_protection & VM_PROT_WRITE) ||
(entry->object.uvm_obj == NULL))) {
amap_copy(map, entry, 0, start, end);
/* XXXCDC: wait OK? */
}
}
}
UVM_MAP_CLIP_START(map, entry, start, NULL);
UVM_MAP_CLIP_END(map, entry, end, NULL);
entry->wired_count++;
/*
* Check for holes
*/
if (entry->protection == VM_PROT_NONE ||
(entry->end < end &&
(entry->next == &map->header ||
entry->next->start > entry->end))) {
/*
* found one. amap creation actions do not need to
* be undone, but the wired counts need to be restored.
*/
while (entry != &map->header && entry->end > start) {
entry->wired_count--;
entry = entry->prev;
}
if ((lockflags & UVM_LK_EXIT) == 0)
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0);
return EINVAL;
}
entry = entry->next;
}
/*
* Pass 2.
*/
#ifdef DIAGNOSTIC
timestamp_save = map->timestamp;
#endif
vm_map_busy(map);
vm_map_downgrade(map);
rv = 0;
entry = start_entry;
while (entry != &map->header && entry->start < end) {
if (entry->wired_count == 1) {
rv = uvm_fault_wire(map, entry->start, entry->end,
entry->max_protection, 1);
if (rv) {
/*
* wiring failed. break out of the loop.
* we'll clean up the map below, once we
* have a write lock again.
*/
break;
}
}
entry = entry->next;
}
if (rv) { /* failed? */
/*
* Get back to an exclusive (write) lock.
*/
vm_map_upgrade(map);
vm_map_unbusy(map);
#ifdef DIAGNOSTIC
if (timestamp_save != map->timestamp)
panic("uvm_map_pageable: stale map");
#endif
/*
* first drop the wiring count on all the entries
* which haven't actually been wired yet.
*/
failed_entry = entry;
while (entry != &map->header && entry->start < end) {
entry->wired_count--;
entry = entry->next;
}
/*
* now, unwire all the entries that were successfully
* wired above.
*/
entry = start_entry;
while (entry != failed_entry) {
entry->wired_count--;
if (VM_MAPENT_ISWIRED(entry) == 0)
uvm_map_entry_unwire(map, entry);
entry = entry->next;
}
if ((lockflags & UVM_LK_EXIT) == 0)
vm_map_unlock(map);
UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0);
return (rv);
}
/* We are holding a read lock here. */
if ((lockflags & UVM_LK_EXIT) == 0) {
vm_map_unbusy(map);
vm_map_unlock_read(map);
} else {
/*
* Get back to an exclusive (write) lock.
*/
vm_map_upgrade(map);
vm_map_unbusy(map);
}
UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
return 0;
}
/*
* uvm_map_pageable_all: special case of uvm_map_pageable - affects
* all mapped regions.
*
* => map must not be locked.
* => if no flags are specified, all regions are unwired.
* => XXXJRT: has some of the same problems as uvm_map_pageable() above.
*/
int
uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit)
{
struct vm_map_entry *entry, *failed_entry;
vsize_t size;
int rv;
#ifdef DIAGNOSTIC
u_int timestamp_save;
#endif
UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0);
KASSERT(map->flags & VM_MAP_PAGEABLE);
vm_map_lock(map);
/*
* handle wiring and unwiring separately.
*/
if (flags == 0) { /* unwire */
/*
* POSIX 1003.1b -- munlockall unlocks all regions,
* regardless of how many times mlockall has been called.
*/
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
if (VM_MAPENT_ISWIRED(entry))
uvm_map_entry_unwire(map, entry);
}
vm_map_modflags(map, 0, VM_MAP_WIREFUTURE);
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
return 0;
}
if (flags & MCL_FUTURE) {
/*
* must wire all future mappings; remember this.
*/
vm_map_modflags(map, VM_MAP_WIREFUTURE, 0);
}
if ((flags & MCL_CURRENT) == 0) {
/*
* no more work to do!
*/
UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0);
vm_map_unlock(map);
return 0;
}
/*
* wire case: in three passes [XXXCDC: ugly block of code here]
*
* 1: holding the write lock, count all pages mapped by non-wired
* entries. if this would cause us to go over our limit, we fail.
*
* 2: still holding the write lock, we create any anonymous maps that
* need to be created. then we increment its wiring count.
*
* 3: we downgrade to a read lock, and call uvm_fault_wire to fault
* in the pages for any newly wired area (wired_count == 1).
*
* downgrading to a read lock for uvm_fault_wire avoids a possible
* deadlock with another thread that may have faulted on one of
* the pages to be wired (it would mark the page busy, blocking
* us, then in turn block on the map lock that we hold). because
* of problems in the recursive lock package, we cannot upgrade
* to a write lock in vm_map_lookup. thus, any actions that
* require the write lock must be done beforehand. because we
* keep the read lock on the map, the copy-on-write status of the
* entries we modify here cannot change.
*/
for (size = 0, entry = map->header.next; entry != &map->header;
entry = entry->next) {
if (entry->protection != VM_PROT_NONE &&
VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
size += entry->end - entry->start;
}
}
if (atop(size) + uvmexp.wired > uvmexp.wiredmax) {
vm_map_unlock(map);
return ENOMEM;
}
if (limit != 0 &&
(size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) {
vm_map_unlock(map);
return ENOMEM;
}
/*
* Pass 2.
*/
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
if (entry->protection == VM_PROT_NONE)
continue;
if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
/*
* perform actions of vm_map_lookup that need the
* write lock on the map: create an anonymous map
* for a copy-on-write region, or an anonymous map
* for a zero-fill region. (XXXCDC: submap case
* ok?)
*/
if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
if (UVM_ET_ISNEEDSCOPY(entry) &&
((entry->max_protection & VM_PROT_WRITE) ||
(entry->object.uvm_obj == NULL))) {
amap_copy(map, entry, 0, entry->start,
entry->end);
/* XXXCDC: wait OK? */
}
}
}
entry->wired_count++;
}
/*
* Pass 3.
*/
#ifdef DIAGNOSTIC
timestamp_save = map->timestamp;
#endif
vm_map_busy(map);
vm_map_downgrade(map);
rv = 0;
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
if (entry->wired_count == 1) {
rv = uvm_fault_wire(map, entry->start, entry->end,
entry->max_protection, 1);
if (rv) {
/*
* wiring failed. break out of the loop.
* we'll clean up the map below, once we
* have a write lock again.
*/
break;
}
}
}
if (rv) {
/*
* Get back an exclusive (write) lock.
*/
vm_map_upgrade(map);
vm_map_unbusy(map);
#ifdef DIAGNOSTIC
if (timestamp_save != map->timestamp)
panic("uvm_map_pageable_all: stale map");
#endif
/*
* first drop the wiring count on all the entries
* which haven't actually been wired yet.
*
* Skip VM_PROT_NONE entries like we did above.
*/
failed_entry = entry;
for (/* nothing */; entry != &map->header;
entry = entry->next) {
if (entry->protection == VM_PROT_NONE)
continue;
entry->wired_count--;
}
/*
* now, unwire all the entries that were successfully
* wired above.
*
* Skip VM_PROT_NONE entries like we did above.
*/
for (entry = map->header.next; entry != failed_entry;
entry = entry->next) {
if (entry->protection == VM_PROT_NONE)
continue;
entry->wired_count--;
if (VM_MAPENT_ISWIRED(entry))
uvm_map_entry_unwire(map, entry);
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0);
return (rv);
}
/* We are holding a read lock here. */
vm_map_unbusy(map);
vm_map_unlock_read(map);
UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
return 0;
}
/*
* uvm_map_clean: clean out a map range
*
* => valid flags:
* if (flags & PGO_CLEANIT): dirty pages are cleaned first
* if (flags & PGO_SYNCIO): dirty pages are written synchronously
* if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean
* if (flags & PGO_FREE): any cached pages are freed after clean
* => returns an error if any part of the specified range isn't mapped
* => never a need to flush amap layer since the anonymous memory has
* no permanent home, but may deactivate pages there
* => called from sys_msync() and sys_madvise()
* => caller must not write-lock map (read OK).
* => we may sleep while cleaning if SYNCIO [with map read-locked]
*/
int
uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
{
struct vm_map_entry *current, *entry;
struct uvm_object *uobj;
struct vm_amap *amap;
struct vm_anon *anon;
struct vm_page *pg;
vaddr_t offset;
vsize_t size;
voff_t uoff;
int error, refs;
UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)",
map, start, end, flags);
KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) !=
(PGO_FREE|PGO_DEACTIVATE));
vm_map_lock_read(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &entry) == FALSE) {
vm_map_unlock_read(map);
return EFAULT;
}
/*
* Make a first pass to check for holes and wiring problems.
*/
for (current = entry; current->start < end; current = current->next) {
if (UVM_ET_ISSUBMAP(current)) {
vm_map_unlock_read(map);
return EINVAL;
}
if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) {
vm_map_unlock_read(map);
return EBUSY;
}
if (end <= current->end) {
break;
}
if (current->end != current->next->start) {
vm_map_unlock_read(map);
return EFAULT;
}
}
error = 0;
for (current = entry; start < end; current = current->next) {
amap = current->aref.ar_amap; /* top layer */
uobj = current->object.uvm_obj; /* bottom layer */
KASSERT(start >= current->start);
/*
* No amap cleaning necessary if:
*
* (1) There's no amap.
*
* (2) We're not deactivating or freeing pages.
*/
if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0)
goto flush_object;
amap_lock(amap);
offset = start - current->start;
size = MIN(end, current->end) - start;
for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) {
anon = amap_lookup(&current->aref, offset);
if (anon == NULL)
continue;
simple_lock(&anon->an_lock);
pg = anon->an_page;
if (pg == NULL) {
simple_unlock(&anon->an_lock);
continue;
}
switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
/*
* In these first 3 cases, we just deactivate the page.
*/
case PGO_CLEANIT|PGO_FREE:
case PGO_CLEANIT|PGO_DEACTIVATE:
case PGO_DEACTIVATE:
deactivate_it:
/*
* skip the page if it's loaned or wired,
* since it shouldn't be on a paging queue
* at all in these cases.
*/
uvm_lock_pageq();
if (pg->loan_count != 0 ||
pg->wire_count != 0) {
uvm_unlock_pageq();
simple_unlock(&anon->an_lock);
continue;
}
KASSERT(pg->uanon == anon);
pmap_clear_reference(pg);
uvm_pagedeactivate(pg);
uvm_unlock_pageq();
simple_unlock(&anon->an_lock);
continue;
case PGO_FREE:
/*
* If there are multiple references to
* the amap, just deactivate the page.
*/
if (amap_refs(amap) > 1)
goto deactivate_it;
/* skip the page if it's wired */
if (pg->wire_count != 0) {
simple_unlock(&anon->an_lock);
continue;
}
amap_unadd(&current->aref, offset);
refs = --anon->an_ref;
simple_unlock(&anon->an_lock);
if (refs == 0)
uvm_anfree(anon);
continue;
}
}
amap_unlock(amap);
flush_object:
/*
* flush pages if we've got a valid backing object.
* note that we must always clean object pages before
* freeing them since otherwise we could reveal stale
* data from files.
*/
uoff = current->offset + (start - current->start);
size = MIN(end, current->end) - start;
if (uobj != NULL) {
simple_lock(&uobj->vmobjlock);
if (uobj->pgops->pgo_put != NULL)
error = (uobj->pgops->pgo_put)(uobj, uoff,
uoff + size, flags | PGO_CLEANIT);
else
error = 0;
}
start += size;
}
vm_map_unlock_read(map);
return (error);
}
/*
* uvm_map_checkprot: check protection in map
*
* => must allow specified protection in a fully allocated region.
* => map must be read or write locked by caller.
*/
boolean_t
uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end,
vm_prot_t protection)
{
struct vm_map_entry *entry;
struct vm_map_entry *tmp_entry;
if (!uvm_map_lookup_entry(map, start, &tmp_entry)) {
return (FALSE);
}
entry = tmp_entry;
while (start < end) {
if (entry == &map->header) {
return (FALSE);
}
/*
* no holes allowed
*/
if (start < entry->start) {
return (FALSE);
}
/*
* check protection associated with entry
*/
if ((entry->protection & protection) != protection) {
return (FALSE);
}
start = entry->end;
entry = entry->next;
}
return (TRUE);
}
/*
* uvmspace_alloc: allocate a vmspace structure.
*
* - structure includes vm_map and pmap
* - XXX: no locking on this structure
* - refcnt set to 1, rest must be init'd by caller
*/
struct vmspace *
uvmspace_alloc(vaddr_t vmin, vaddr_t vmax)
{
struct vmspace *vm;
UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist);
vm = pool_get(&uvm_vmspace_pool, PR_WAITOK);
uvmspace_init(vm, NULL, vmin, vmax);
UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0);
return (vm);
}
/*
* uvmspace_init: initialize a vmspace structure.
*
* - XXX: no locking on this structure
* - refcnt set to 1, rest must be init'd by caller
*/
void
uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax)
{
UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist);
memset(vm, 0, sizeof(*vm));
uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE
#ifdef __USING_TOPDOWN_VM
| VM_MAP_TOPDOWN
#endif
);
if (pmap)
pmap_reference(pmap);
else
pmap = pmap_create();
vm->vm_map.pmap = pmap;
vm->vm_refcnt = 1;
UVMHIST_LOG(maphist,"<- done",0,0,0,0);
}
/*
* uvmspace_share: share a vmspace between two processes
*
* - used for vfork, threads(?)
*/
void
uvmspace_share(struct proc *p1, struct proc *p2)
{
uvmspace_addref(p1->p_vmspace);
p2->p_vmspace = p1->p_vmspace;
}
/*
* uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace
*
* - XXX: no locking on vmspace
*/
void
uvmspace_unshare(struct lwp *l)
{
struct proc *p = l->l_proc;
struct vmspace *nvm, *ovm = p->p_vmspace;
if (ovm->vm_refcnt == 1)
/* nothing to do: vmspace isn't shared in the first place */
return;
/* make a new vmspace, still holding old one */
nvm = uvmspace_fork(ovm);
pmap_deactivate(l); /* unbind old vmspace */
p->p_vmspace = nvm;
pmap_activate(l); /* switch to new vmspace */
uvmspace_free(ovm); /* drop reference to old vmspace */
}
/*
* uvmspace_exec: the process wants to exec a new program
*/
void
uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end)
{
struct proc *p = l->l_proc;
struct vmspace *nvm, *ovm = p->p_vmspace;
struct vm_map *map = &ovm->vm_map;
#ifdef __sparc__
/* XXX cgd 960926: the sparc #ifdef should be a MD hook */
kill_user_windows(l); /* before stack addresses go away */
#endif
/*
* see if more than one process is using this vmspace...
*/
if (ovm->vm_refcnt == 1) {
/*
* if p is the only process using its vmspace then we can safely
* recycle that vmspace for the program that is being exec'd.
*/
#ifdef SYSVSHM
/*
* SYSV SHM semantics require us to kill all segments on an exec
*/
if (ovm->vm_shm)
shmexit(ovm);
#endif
/*
* POSIX 1003.1b -- "lock future mappings" is revoked
* when a process execs another program image.
*/
vm_map_modflags(map, 0, VM_MAP_WIREFUTURE);
/*
* now unmap the old program
*/
pmap_remove_all(map->pmap);
uvm_unmap(map, vm_map_min(map), vm_map_max(map));
KASSERT(map->header.prev == &map->header);
KASSERT(map->nentries == 0);
/*
* resize the map
*/
vm_map_setmin(map, start);
vm_map_setmax(map, end);
} else {
/*
* p's vmspace is being shared, so we can't reuse it for p since
* it is still being used for others. allocate a new vmspace
* for p
*/
nvm = uvmspace_alloc(start, end);
/*
* install new vmspace and drop our ref to the old one.
*/
pmap_deactivate(l);
p->p_vmspace = nvm;
pmap_activate(l);
uvmspace_free(ovm);
}
}
/*
* uvmspace_addref: add a referece to a vmspace.
*/
void
uvmspace_addref(struct vmspace *vm)
{
struct vm_map *map = &vm->vm_map;
KASSERT((map->flags & VM_MAP_DYING) == 0);
simple_lock(&map->ref_lock);
KASSERT(vm->vm_refcnt > 0);
vm->vm_refcnt++;
simple_unlock(&map->ref_lock);
}
/*
* uvmspace_free: free a vmspace data structure
*/
void
uvmspace_free(struct vmspace *vm)
{
struct vm_map_entry *dead_entries;
struct vm_map *map = &vm->vm_map;
int n;
UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0);
simple_lock(&map->ref_lock);
n = --vm->vm_refcnt;
simple_unlock(&map->ref_lock);
if (n > 0)
return;
/*
* at this point, there should be no other references to the map.
* delete all of the mappings, then destroy the pmap.
*/
map->flags |= VM_MAP_DYING;
pmap_remove_all(map->pmap);
#ifdef SYSVSHM
/* Get rid of any SYSV shared memory segments. */
if (vm->vm_shm != NULL)
shmexit(vm);
#endif
if (map->nentries) {
uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map),
&dead_entries, NULL, 0);
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
}
KASSERT(map->nentries == 0);
KASSERT(map->size == 0);
pmap_destroy(map->pmap);
pool_put(&uvm_vmspace_pool, vm);
}
/*
* F O R K - m a i n e n t r y p o i n t
*/
/*
* uvmspace_fork: fork a process' main map
*
* => create a new vmspace for child process from parent.
* => parent's map must not be locked.
*/
struct vmspace *
uvmspace_fork(struct vmspace *vm1)
{
struct vmspace *vm2;
struct vm_map *old_map = &vm1->vm_map;
struct vm_map *new_map;
struct vm_map_entry *old_entry;
struct vm_map_entry *new_entry;
UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist);
vm_map_lock(old_map);
vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map));
memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy,
(caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy);
new_map = &vm2->vm_map; /* XXX */
old_entry = old_map->header.next;
new_map->size = old_map->size;
/*
* go entry-by-entry
*/
while (old_entry != &old_map->header) {
/*
* first, some sanity checks on the old entry
*/
KASSERT(!UVM_ET_ISSUBMAP(old_entry));
KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) ||
!UVM_ET_ISNEEDSCOPY(old_entry));
switch (old_entry->inheritance) {
case MAP_INHERIT_NONE:
/*
* drop the mapping, modify size
*/
new_map->size -= old_entry->end - old_entry->start;
break;
case MAP_INHERIT_SHARE:
/*
* share the mapping: this means we want the old and
* new entries to share amaps and backing objects.
*/
/*
* if the old_entry needs a new amap (due to prev fork)
* then we need to allocate it now so that we have
* something we own to share with the new_entry. [in
* other words, we need to clear needs_copy]
*/
if (UVM_ET_ISNEEDSCOPY(old_entry)) {
/* get our own amap, clears needs_copy */
amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK,
0, 0);
/* XXXCDC: WAITOK??? */
}
new_entry = uvm_mapent_alloc(new_map, 0);
/* old_entry -> new_entry */
uvm_mapent_copy(old_entry, new_entry);
/* new pmap has nothing wired in it */
new_entry->wired_count = 0;
/*
* gain reference to object backing the map (can't
* be a submap, already checked this case).
*/
if (new_entry->aref.ar_amap)
uvm_map_reference_amap(new_entry, AMAP_SHARED);
if (new_entry->object.uvm_obj &&
new_entry->object.uvm_obj->pgops->pgo_reference)
new_entry->object.uvm_obj->
pgops->pgo_reference(
new_entry->object.uvm_obj);
/* insert entry at end of new_map's entry list */
uvm_map_entry_link(new_map, new_map->header.prev,
new_entry);
break;
case MAP_INHERIT_COPY:
/*
* copy-on-write the mapping (using mmap's
* MAP_PRIVATE semantics)
*
* allocate new_entry, adjust reference counts.
* (note that new references are read-only).
*/
new_entry = uvm_mapent_alloc(new_map, 0);
/* old_entry -> new_entry */
uvm_mapent_copy(old_entry, new_entry);
if (new_entry->aref.ar_amap)
uvm_map_reference_amap(new_entry, 0);
if (new_entry->object.uvm_obj &&
new_entry->object.uvm_obj->pgops->pgo_reference)
new_entry->object.uvm_obj->pgops->pgo_reference
(new_entry->object.uvm_obj);
/* new pmap has nothing wired in it */
new_entry->wired_count = 0;
new_entry->etype |=
(UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
uvm_map_entry_link(new_map, new_map->header.prev,
new_entry);
/*
* the new entry will need an amap. it will either
* need to be copied from the old entry or created
* from scratch (if the old entry does not have an
* amap). can we defer this process until later
* (by setting "needs_copy") or do we need to copy
* the amap now?
*
* we must copy the amap now if any of the following
* conditions hold:
* 1. the old entry has an amap and that amap is
* being shared. this means that the old (parent)
* process is sharing the amap with another
* process. if we do not clear needs_copy here
* we will end up in a situation where both the
* parent and child process are refering to the
* same amap with "needs_copy" set. if the
* parent write-faults, the fault routine will
* clear "needs_copy" in the parent by allocating
* a new amap. this is wrong because the
* parent is supposed to be sharing the old amap
* and the new amap will break that.
*
* 2. if the old entry has an amap and a non-zero
* wire count then we are going to have to call
* amap_cow_now to avoid page faults in the
* parent process. since amap_cow_now requires
* "needs_copy" to be clear we might as well
* clear it here as well.
*
*/
if (old_entry->aref.ar_amap != NULL) {
if ((amap_flags(old_entry->aref.ar_amap) &
AMAP_SHARED) != 0 ||
VM_MAPENT_ISWIRED(old_entry)) {
amap_copy(new_map, new_entry,
AMAP_COPY_NOCHUNK, 0, 0);
/* XXXCDC: M_WAITOK ... ok? */
}
}
/*
* if the parent's entry is wired down, then the
* parent process does not want page faults on
* access to that memory. this means that we
* cannot do copy-on-write because we can't write
* protect the old entry. in this case we
* resolve all copy-on-write faults now, using
* amap_cow_now. note that we have already
* allocated any needed amap (above).
*/
if (VM_MAPENT_ISWIRED(old_entry)) {
/*
* resolve all copy-on-write faults now
* (note that there is nothing to do if
* the old mapping does not have an amap).
*/
if (old_entry->aref.ar_amap)
amap_cow_now(new_map, new_entry);
} else {
/*
* setup mappings to trigger copy-on-write faults
* we must write-protect the parent if it has
* an amap and it is not already "needs_copy"...
* if it is already "needs_copy" then the parent
* has already been write-protected by a previous
* fork operation.
*/
if (old_entry->aref.ar_amap &&
!UVM_ET_ISNEEDSCOPY(old_entry)) {
if (old_entry->max_protection & VM_PROT_WRITE) {
pmap_protect(old_map->pmap,
old_entry->start,
old_entry->end,
old_entry->protection &
~VM_PROT_WRITE);
pmap_update(old_map->pmap);
}
old_entry->etype |= UVM_ET_NEEDSCOPY;
}
}
break;
} /* end of switch statement */
old_entry = old_entry->next;
}
vm_map_unlock(old_map);
#ifdef SYSVSHM
if (vm1->vm_shm)
shmfork(vm1, vm2);
#endif
#ifdef PMAP_FORK
pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap);
#endif
UVMHIST_LOG(maphist,"<- done",0,0,0,0);
return (vm2);
}
/*
* in-kernel map entry allocation.
*/
struct uvm_kmapent_hdr {
LIST_ENTRY(uvm_kmapent_hdr) ukh_listq;
int ukh_nused;
struct vm_map_entry *ukh_freelist;
struct vm_map *ukh_map;
struct vm_map_entry ukh_entries[0];
};
#define UVM_KMAPENT_CHUNK \
((PAGE_SIZE - sizeof(struct uvm_kmapent_hdr)) \
/ sizeof(struct vm_map_entry))
#define UVM_KHDR_FIND(entry) \
((struct uvm_kmapent_hdr *)(((vaddr_t)entry) & ~PAGE_MASK))
#ifdef DIAGNOSTIC
static struct vm_map *
uvm_kmapent_map(struct vm_map_entry *entry)
{
const struct uvm_kmapent_hdr *ukh;
ukh = UVM_KHDR_FIND(entry);
return ukh->ukh_map;
}
#endif
static inline struct vm_map_entry *
uvm_kmapent_get(struct uvm_kmapent_hdr *ukh)
{
struct vm_map_entry *entry;
KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
KASSERT(ukh->ukh_nused >= 0);
entry = ukh->ukh_freelist;
if (entry) {
KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT))
== UVM_MAP_KERNEL);
ukh->ukh_freelist = entry->next;
ukh->ukh_nused++;
KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
} else {
KASSERT(ukh->ukh_nused == UVM_KMAPENT_CHUNK);
}
return entry;
}
static inline void
uvm_kmapent_put(struct uvm_kmapent_hdr *ukh, struct vm_map_entry *entry)
{
KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT))
== UVM_MAP_KERNEL);
KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
KASSERT(ukh->ukh_nused > 0);
KASSERT(ukh->ukh_freelist != NULL ||
ukh->ukh_nused == UVM_KMAPENT_CHUNK);
KASSERT(ukh->ukh_freelist == NULL ||
ukh->ukh_nused < UVM_KMAPENT_CHUNK);
ukh->ukh_nused--;
entry->next = ukh->ukh_freelist;
ukh->ukh_freelist = entry;
}
/*
* uvm_kmapent_alloc: allocate a map entry for in-kernel map
*/
static struct vm_map_entry *
uvm_kmapent_alloc(struct vm_map *map, int flags)
{
struct vm_page *pg;
struct uvm_map_args args;
struct uvm_kmapent_hdr *ukh;
struct vm_map_entry *entry;
uvm_flag_t mapflags = UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL,
UVM_INH_NONE, UVM_ADV_RANDOM, flags | UVM_FLAG_NOMERGE);
vaddr_t va;
int error;
int i;
int s;
KDASSERT(UVM_KMAPENT_CHUNK > 2);
KDASSERT(kernel_map != NULL);
KASSERT(vm_map_pmap(map) == pmap_kernel());
UVMMAP_EVCNT_INCR(uke_alloc);
entry = NULL;
again:
/*
* try to grab an entry from freelist.
*/
s = splvm();
simple_lock(&uvm.kentry_lock);
ukh = LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free);
if (ukh) {
entry = uvm_kmapent_get(ukh);
if (ukh->ukh_nused == UVM_KMAPENT_CHUNK)
LIST_REMOVE(ukh, ukh_listq);
}
simple_unlock(&uvm.kentry_lock);
splx(s);
if (entry)
return entry;
/*
* there's no free entry for this vm_map.
* now we need to allocate some vm_map_entry.
* for simplicity, always allocate one page chunk of them at once.
*/
pg = uvm_pagealloc(NULL, 0, NULL, 0);
if (__predict_false(pg == NULL)) {
if (flags & UVM_FLAG_NOWAIT)
return NULL;
uvm_wait("kme_alloc");
goto again;
}
error = uvm_map_prepare(map, 0, PAGE_SIZE, NULL, 0, 0, mapflags, &args);
if (error) {
uvm_pagefree(pg);
return NULL;
}
va = args.uma_start;
pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE);
pmap_update(vm_map_pmap(map));
ukh = (void *)va;
/*
* use the first entry for ukh itsself.
*/
entry = &ukh->ukh_entries[0];
entry->flags = UVM_MAP_KERNEL | UVM_MAP_KMAPENT;
error = uvm_map_enter(map, &args, entry);
KASSERT(error == 0);
ukh->ukh_nused = UVM_KMAPENT_CHUNK;
ukh->ukh_map = map;
ukh->ukh_freelist = NULL;
for (i = UVM_KMAPENT_CHUNK - 1; i >= 2; i--) {
struct vm_map_entry *xentry = &ukh->ukh_entries[i];
xentry->flags = UVM_MAP_KERNEL;
uvm_kmapent_put(ukh, xentry);
}
KASSERT(ukh->ukh_nused == 2);
s = splvm();
simple_lock(&uvm.kentry_lock);
LIST_INSERT_HEAD(&vm_map_to_kernel(map)->vmk_kentry_free,
ukh, ukh_listq);
simple_unlock(&uvm.kentry_lock);
splx(s);
/*
* return second entry.
*/
entry = &ukh->ukh_entries[1];
entry->flags = UVM_MAP_KERNEL;
UVMMAP_EVCNT_INCR(ukh_alloc);
return entry;
}
/*
* uvm_mapent_free: free map entry for in-kernel map
*/
static void
uvm_kmapent_free(struct vm_map_entry *entry)
{
struct uvm_kmapent_hdr *ukh;
struct vm_page *pg;
struct vm_map *map;
struct pmap *pmap;
vaddr_t va;
paddr_t pa;
struct vm_map_entry *deadentry;
int s;
UVMMAP_EVCNT_INCR(uke_free);
ukh = UVM_KHDR_FIND(entry);
map = ukh->ukh_map;
s = splvm();
simple_lock(&uvm.kentry_lock);
uvm_kmapent_put(ukh, entry);
if (ukh->ukh_nused > 1) {
if (ukh->ukh_nused == UVM_KMAPENT_CHUNK - 1)
LIST_INSERT_HEAD(
&vm_map_to_kernel(map)->vmk_kentry_free,
ukh, ukh_listq);
simple_unlock(&uvm.kentry_lock);
splx(s);
return;
}
/*
* now we can free this ukh.
*
* however, keep an empty ukh to avoid ping-pong.
*/
if (LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free) == ukh &&
LIST_NEXT(ukh, ukh_listq) == NULL) {
simple_unlock(&uvm.kentry_lock);
splx(s);
return;
}
LIST_REMOVE(ukh, ukh_listq);
simple_unlock(&uvm.kentry_lock);
splx(s);
KASSERT(ukh->ukh_nused == 1);
/*
* remove map entry for ukh itsself.
*/
va = (vaddr_t)ukh;
KASSERT((va & PAGE_MASK) == 0);
vm_map_lock(map);
uvm_unmap_remove(map, va, va + PAGE_SIZE, &deadentry, NULL, 0);
KASSERT(deadentry->flags & UVM_MAP_KERNEL);
KASSERT(deadentry->flags & UVM_MAP_KMAPENT);
KASSERT(deadentry->next == NULL);
KASSERT(deadentry == &ukh->ukh_entries[0]);
/*
* unmap the page from pmap and free it.
*/
pmap = vm_map_pmap(map);
KASSERT(pmap == pmap_kernel());
if (!pmap_extract(pmap, va, &pa))
panic("%s: no mapping", __func__);
pmap_kremove(va, PAGE_SIZE);
vm_map_unlock(map);
pg = PHYS_TO_VM_PAGE(pa);
uvm_pagefree(pg);
UVMMAP_EVCNT_INCR(ukh_free);
}
static vsize_t
uvm_kmapent_overhead(vsize_t size)
{
/*
* - the max number of unmerged entries is howmany(size, PAGE_SIZE)
* as the min allocation unit is PAGE_SIZE.
* - UVM_KMAPENT_CHUNK "kmapent"s are allocated from a page.
* one of them are used to map the page itself.
*/
return howmany(howmany(size, PAGE_SIZE), (UVM_KMAPENT_CHUNK - 1)) *
PAGE_SIZE;
}
/*
* map entry reservation
*/
/*
* uvm_mapent_reserve: reserve map entries for clipping before locking map.
*
* => needed when unmapping entries allocated without UVM_FLAG_QUANTUM.
* => caller shouldn't hold map locked.
*/
int
uvm_mapent_reserve(struct vm_map *map, struct uvm_mapent_reservation *umr,
int nentries, int flags)
{
umr->umr_nentries = 0;
if ((flags & UVM_FLAG_QUANTUM) != 0)
return 0;
if (!VM_MAP_USE_KMAPENT(map))
return 0;
while (nentries--) {
struct vm_map_entry *ent;
ent = uvm_kmapent_alloc(map, flags);
if (!ent) {
uvm_mapent_unreserve(map, umr);
return ENOMEM;
}
UMR_PUTENTRY(umr, ent);
}
return 0;
}
/*
* uvm_mapent_unreserve:
*
* => caller shouldn't hold map locked.
* => never fail or sleep.
*/
void
uvm_mapent_unreserve(struct vm_map *map, struct uvm_mapent_reservation *umr)
{
while (!UMR_EMPTY(umr))
uvm_kmapent_free(UMR_GETENTRY(umr));
}
/*
* uvm_mapent_trymerge: try to merge an entry with its neighbors.
*
* => called with map locked.
* => return non zero if successfully merged.
*/
int
uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags)
{
struct uvm_object *uobj;
struct vm_map_entry *next;
struct vm_map_entry *prev;
vsize_t size;
int merged = 0;
boolean_t copying;
int newetype;
if (VM_MAP_USE_KMAPENT(map)) {
return 0;
}
if (entry->aref.ar_amap != NULL) {
return 0;
}
if ((entry->flags & UVM_MAP_NOMERGE) != 0) {
return 0;
}
uobj = entry->object.uvm_obj;
size = entry->end - entry->start;
copying = (flags & UVM_MERGE_COPYING) != 0;
newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype;
next = entry->next;
if (next != &map->header &&
next->start == entry->end &&
((copying && next->aref.ar_amap != NULL &&
amap_refs(next->aref.ar_amap) == 1) ||
(!copying && next->aref.ar_amap == NULL)) &&
UVM_ET_ISCOMPATIBLE(next, newetype,
uobj, entry->flags, entry->protection,
entry->max_protection, entry->inheritance, entry->advice,
entry->wired_count) &&
(uobj == NULL || entry->offset + size == next->offset)) {
int error;
if (copying) {
error = amap_extend(next, size,
AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS);
} else {
error = 0;
}
if (error == 0) {
if (uobj) {
if (uobj->pgops->pgo_detach) {
uobj->pgops->pgo_detach(uobj);
}
}
entry->end = next->end;
clear_hints(map, next);
uvm_map_entry_unlink(map, next);
if (copying) {
entry->aref = next->aref;
entry->etype &= ~UVM_ET_NEEDSCOPY;
}
uvm_map_check(map, "trymerge forwardmerge");
uvm_mapent_free_merged(map, next);
merged++;
}
}
prev = entry->prev;
if (prev != &map->header &&
prev->end == entry->start &&
((copying && !merged && prev->aref.ar_amap != NULL &&
amap_refs(prev->aref.ar_amap) == 1) ||
(!copying && prev->aref.ar_amap == NULL)) &&
UVM_ET_ISCOMPATIBLE(prev, newetype,
uobj, entry->flags, entry->protection,
entry->max_protection, entry->inheritance, entry->advice,
entry->wired_count) &&
(uobj == NULL ||
prev->offset + prev->end - prev->start == entry->offset)) {
int error;
if (copying) {
error = amap_extend(prev, size,
AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS);
} else {
error = 0;
}
if (error == 0) {
if (uobj) {
if (uobj->pgops->pgo_detach) {
uobj->pgops->pgo_detach(uobj);
}
entry->offset = prev->offset;
}
entry->start = prev->start;
clear_hints(map, prev);
uvm_map_entry_unlink(map, prev);
if (copying) {
entry->aref = prev->aref;
entry->etype &= ~UVM_ET_NEEDSCOPY;
}
uvm_map_check(map, "trymerge backmerge");
uvm_mapent_free_merged(map, prev);
merged++;
}
}
return merged;
}
#if defined(DDB)
/*
* DDB hooks
*/
/*
* uvm_map_printit: actually prints the map
*/
void
uvm_map_printit(struct vm_map *map, boolean_t full,
void (*pr)(const char *, ...))
{
struct vm_map_entry *entry;
(*pr)("MAP %p: [0x%lx->0x%lx]\n", map, vm_map_min(map),
vm_map_max(map));
(*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n",
map->nentries, map->size, map->ref_count, map->timestamp,
map->flags);
(*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap,
pmap_resident_count(map->pmap), pmap_wired_count(map->pmap));
if (!full)
return;
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
(*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%llx, amap=%p/%d\n",
entry, entry->start, entry->end, entry->object.uvm_obj,
(long long)entry->offset, entry->aref.ar_amap,
entry->aref.ar_pageoff);
(*pr)(
"\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, "
"wc=%d, adv=%d\n",
(entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F',
(entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F',
(entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F',
entry->protection, entry->max_protection,
entry->inheritance, entry->wired_count, entry->advice);
}
}
/*
* uvm_object_printit: actually prints the object
*/
void
uvm_object_printit(struct uvm_object *uobj, boolean_t full,
void (*pr)(const char *, ...))
{
struct vm_page *pg;
int cnt = 0;
(*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ",
uobj, uobj->vmobjlock.lock_data, uobj->pgops, uobj->uo_npages);
if (UVM_OBJ_IS_KERN_OBJECT(uobj))
(*pr)("refs=<SYSTEM>\n");
else
(*pr)("refs=%d\n", uobj->uo_refs);
if (!full) {
return;
}
(*pr)(" PAGES <pg,offset>:\n ");
TAILQ_FOREACH(pg, &uobj->memq, listq) {
cnt++;
(*pr)("<%p,0x%llx> ", pg, (long long)pg->offset);
if ((cnt % 3) == 0) {
(*pr)("\n ");
}
}
if ((cnt % 3) != 0) {
(*pr)("\n");
}
}
/*
* uvm_page_printit: actually print the page
*/
static const char page_flagbits[] =
"\20\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY"
"\11ZERO\15PAGER1";
static const char page_pqflagbits[] =
"\20\1FREE\2INACTIVE\3ACTIVE\5ANON\6AOBJ";
void
uvm_page_printit(struct vm_page *pg, boolean_t full,
void (*pr)(const char *, ...))
{
struct vm_page *tpg;
struct uvm_object *uobj;
struct pglist *pgl;
char pgbuf[128];
char pqbuf[128];
(*pr)("PAGE %p:\n", pg);
bitmask_snprintf(pg->flags, page_flagbits, pgbuf, sizeof(pgbuf));
bitmask_snprintf(pg->pqflags, page_pqflagbits, pqbuf, sizeof(pqbuf));
(*pr)(" flags=%s, pqflags=%s, wire_count=%d, pa=0x%lx\n",
pgbuf, pqbuf, pg->wire_count, (long)VM_PAGE_TO_PHYS(pg));
(*pr)(" uobject=%p, uanon=%p, offset=0x%llx loan_count=%d\n",
pg->uobject, pg->uanon, (long long)pg->offset, pg->loan_count);
#if defined(UVM_PAGE_TRKOWN)
if (pg->flags & PG_BUSY)
(*pr)(" owning process = %d, tag=%s\n",
pg->owner, pg->owner_tag);
else
(*pr)(" page not busy, no owner\n");
#else
(*pr)(" [page ownership tracking disabled]\n");
#endif
if (!full)
return;
/* cross-verify object/anon */
if ((pg->pqflags & PQ_FREE) == 0) {
if (pg->pqflags & PQ_ANON) {
if (pg->uanon == NULL || pg->uanon->an_page != pg)
(*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n",
(pg->uanon) ? pg->uanon->an_page : NULL);
else
(*pr)(" anon backpointer is OK\n");
} else {
uobj = pg->uobject;
if (uobj) {
(*pr)(" checking object list\n");
TAILQ_FOREACH(tpg, &uobj->memq, listq) {
if (tpg == pg) {
break;
}
}
if (tpg)
(*pr)(" page found on object list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n");
}
}
}
/* cross-verify page queue */
if (pg->pqflags & PQ_FREE) {
int fl = uvm_page_lookup_freelist(pg);
int color = VM_PGCOLOR_BUCKET(pg);
pgl = &uvm.page_free[fl].pgfl_buckets[color].pgfl_queues[
((pg)->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN];
} else if (pg->pqflags & PQ_INACTIVE) {
pgl = &uvm.page_inactive;
} else if (pg->pqflags & PQ_ACTIVE) {
pgl = &uvm.page_active;
} else {
pgl = NULL;
}
if (pgl) {
(*pr)(" checking pageq list\n");
TAILQ_FOREACH(tpg, pgl, pageq) {
if (tpg == pg) {
break;
}
}
if (tpg)
(*pr)(" page found on pageq list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n");
}
}
/*
* uvm_pages_printthem - print a summary of all managed pages
*/
void
uvm_page_printall(void (*pr)(const char *, ...))
{
unsigned i;
struct vm_page *pg;
(*pr)("%18s %4s %2s %18s %18s"
#ifdef UVM_PAGE_TRKOWN
" OWNER"
#endif
"\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON");
for (i = 0; i < vm_nphysseg; i++) {
for (pg = vm_physmem[i].pgs; pg <= vm_physmem[i].lastpg; pg++) {
(*pr)("%18p %04x %02x %18p %18p",
pg, pg->flags, pg->pqflags, pg->uobject,
pg->uanon);
#ifdef UVM_PAGE_TRKOWN
if (pg->flags & PG_BUSY)
(*pr)(" %d [%s]", pg->owner, pg->owner_tag);
#endif
(*pr)("\n");
}
}
}
#endif
/*
* uvm_map_create: create map
*/
struct vm_map *
uvm_map_create(pmap_t pmap, vaddr_t vmin, vaddr_t vmax, int flags)
{
struct vm_map *result;
MALLOC(result, struct vm_map *, sizeof(struct vm_map),
M_VMMAP, M_WAITOK);
uvm_map_setup(result, vmin, vmax, flags);
result->pmap = pmap;
return(result);
}
/*
* uvm_map_setup: init map
*
* => map must not be in service yet.
*/
void
uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags)
{
RB_INIT(&map->rbhead);
map->header.next = map->header.prev = &map->header;
map->nentries = 0;
map->size = 0;
map->ref_count = 1;
vm_map_setmin(map, vmin);
vm_map_setmax(map, vmax);
map->flags = flags;
map->first_free = &map->header;
map->hint = &map->header;
map->timestamp = 0;
lockinit(&map->lock, PVM, "vmmaplk", 0, 0);
simple_lock_init(&map->ref_lock);
simple_lock_init(&map->hint_lock);
simple_lock_init(&map->flags_lock);
}
/*
* U N M A P - m a i n e n t r y p o i n t
*/
/*
* uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop")
*
* => caller must check alignment and size
* => map must be unlocked (we will lock it)
* => flags is UVM_FLAG_QUANTUM or 0.
*/
void
uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
{
struct vm_map_entry *dead_entries;
struct uvm_mapent_reservation umr;
UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, " (map=0x%x, start=0x%x, end=0x%x)",
map, start, end, 0);
/*
* work now done by helper functions. wipe the pmap's and then
* detach from the dead entries...
*/
uvm_mapent_reserve(map, &umr, 2, flags);
vm_map_lock(map);
uvm_unmap_remove(map, start, end, &dead_entries, &umr, flags);
vm_map_unlock(map);
uvm_mapent_unreserve(map, &umr);
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
}
/*
* uvm_map_reference: add reference to a map
*
* => map need not be locked (we use ref_lock).
*/
void
uvm_map_reference(struct vm_map *map)
{
simple_lock(&map->ref_lock);
map->ref_count++;
simple_unlock(&map->ref_lock);
}
struct vm_map_kernel *
vm_map_to_kernel(struct vm_map *map)
{
KASSERT(VM_MAP_IS_KERNEL(map));
return (struct vm_map_kernel *)map;
}
boolean_t
vm_map_starved_p(struct vm_map *map)
{
if ((map->flags & VM_MAP_WANTVA) != 0) {
return TRUE;
}
/* XXX */
if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) {
return TRUE;
}
return FALSE;
}