/*
* amap_extend: extend the size of an amap (if needed)
*
* => called from uvm_map when we want to extend an amap to cover
* a new mapping (rather than allocate a new one)
* => amap should be unlocked (we will lock it)
* => to safely extend an amap it should have a reference count of
* one (thus it can't be shared)
*/
int
amap_extend(struct vm_map_entry *entry, vsize_t addsize, int flags)
{
struct vm_amap *amap = entry->aref.ar_amap;
int slotoff = entry->aref.ar_pageoff;
int slotmapped, slotadd, slotneed, slotadded, slotalloc;
int slotadj, slotspace;
int oldnslots;
#ifdef UVM_AMAP_PPREF
int *newppref, *oldppref;
#endif
int i, *newsl, *newbck, *oldsl, *oldbck;
struct vm_anon **newover, **oldover;
const km_flag_t kmflags =
(flags & AMAP_EXTEND_NOWAIT) ? KM_NOSLEEP : KM_SLEEP;
UVMHIST_FUNC("amap_extend"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, " (entry=0x%x, addsize=0x%x, flags=0x%x)",
entry, addsize, flags, 0);
/*
* first, determine how many slots we need in the amap. don't
* forget that ar_pageoff could be non-zero: this means that
* there are some unused slots before us in the amap.
*/
amap_lock(amap);
KASSERT(amap_refs(amap) == 1); /* amap can't be shared */
AMAP_B2SLOT(slotmapped, entry->end - entry->start); /* slots mapped */
AMAP_B2SLOT(slotadd, addsize); /* slots to add */
if (flags & AMAP_EXTEND_FORWARDS) {
slotneed = slotoff + slotmapped + slotadd;
slotadj = 0;
slotspace = 0;
}
else {
slotneed = slotadd + slotmapped;
slotadj = slotadd - slotoff;
slotspace = amap->am_maxslot - slotmapped;
}
/*
* case 1: we already have enough slots in the map and thus
* only need to bump the reference counts on the slots we are
* adding.
*/
if (flags & AMAP_EXTEND_FORWARDS) {
if (amap->am_nslot >= slotneed) {
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
amap_pp_adjref(amap, slotoff + slotmapped,
slotadd, 1);
}
#endif
amap_unlock(amap);
UVMHIST_LOG(maphist,
"<- done (case 1f), amap = 0x%x, sltneed=%d",
amap, slotneed, 0, 0);
return 0;
}
} else {
if (slotadj <= 0) {
slotoff -= slotadd;
entry->aref.ar_pageoff = slotoff;
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
amap_pp_adjref(amap, slotoff, slotadd, 1);
}
#endif
amap_unlock(amap);
UVMHIST_LOG(maphist,
"<- done (case 1b), amap = 0x%x, sltneed=%d",
amap, slotneed, 0, 0);
return 0;
}
}
/*
* case 2: we pre-allocated slots for use and we just need to
* bump nslot up to take account for these slots.
*/
if (amap->am_maxslot >= slotneed) {
if (flags & AMAP_EXTEND_FORWARDS) {
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
if ((slotoff + slotmapped) < amap->am_nslot)
amap_pp_adjref(amap,
slotoff + slotmapped,
(amap->am_nslot -
(slotoff + slotmapped)), 1);
pp_setreflen(amap->am_ppref, amap->am_nslot, 1,
slotneed - amap->am_nslot);
}
#endif
amap->am_nslot = slotneed;
amap_unlock(amap);
/*
* no need to zero am_anon since that was done at
* alloc time and we never shrink an allocation.
*/
UVMHIST_LOG(maphist,"<- done (case 2f), amap = 0x%x, "
"slotneed=%d", amap, slotneed, 0, 0);
return 0;
} else {
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
/*
* Slide up the ref counts on the pages that
* are actually in use.
*/
memmove(amap->am_ppref + slotspace,
amap->am_ppref + slotoff,
slotmapped * sizeof(int));
/*
* Mark the (adjusted) gap at the front as
* referenced/not referenced.
*/
pp_setreflen(amap->am_ppref,
0, 0, slotspace - slotadd);
pp_setreflen(amap->am_ppref,
slotspace - slotadd, 1, slotadd);
}
#endif
/*
* Slide the anon pointers up and clear out
* the space we just made.
*/
memmove(amap->am_anon + slotspace,
amap->am_anon + slotoff,
slotmapped * sizeof(struct vm_anon*));
memset(amap->am_anon + slotoff, 0,
(slotspace - slotoff) * sizeof(struct vm_anon *));
/*
* Slide the backpointers up, but don't bother
* wiping out the old slots.
*/
memmove(amap->am_bckptr + slotspace,
amap->am_bckptr + slotoff,
slotmapped * sizeof(int));
/*
* Adjust all the useful active slot numbers.
*/
for (i = 0; i < amap->am_nused; i++)
amap->am_slots[i] += (slotspace - slotoff);
/*
* We just filled all the empty space in the
* front of the amap by activating a few new
* slots.
*/
amap->am_nslot = amap->am_maxslot;
entry->aref.ar_pageoff = slotspace - slotadd;
amap_unlock(amap);
UVMHIST_LOG(maphist,"<- done (case 2b), amap = 0x%x, "
"slotneed=%d", amap, slotneed, 0, 0);
return 0;
}
}
/*
* case 3: we need to malloc a new amap and copy all the amap
* data over from old amap to the new one.
*
* note that the use of a kernel realloc() probably would not
* help here, since we wish to abort cleanly if one of the
* three (or four) mallocs fails.
*/
amap_unlock(amap); /* unlock in case we sleep in malloc */
if (slotneed >= UVM_AMAP_LARGE) {
return E2BIG;
}
slotalloc = amap_roundup_slots(slotneed);
#ifdef UVM_AMAP_PPREF
newppref = NULL;
if (amap->am_ppref && amap->am_ppref != PPREF_NONE)
newppref = kmem_alloc(slotalloc * sizeof(*newppref), kmflags);
#endif
newsl = kmem_alloc(slotalloc * sizeof(*newsl), kmflags);
newbck = kmem_alloc(slotalloc * sizeof(*newbck), kmflags);
newover = kmem_alloc(slotalloc * sizeof(*newover), kmflags);
if (newsl == NULL || newbck == NULL || newover == NULL) {
#ifdef UVM_AMAP_PPREF
if (newppref != NULL) {
kmem_free(newppref, slotalloc * sizeof(*newppref));
}
#endif
if (newsl != NULL) {
kmem_free(newsl, slotalloc * sizeof(*newsl));
}
if (newbck != NULL) {
kmem_free(newbck, slotalloc * sizeof(*newbck));
}
if (newover != NULL) {
kmem_free(newover, slotalloc * sizeof(*newover));
}
return ENOMEM;
}
amap_lock(amap);
KASSERT(amap->am_maxslot < slotneed);
/*
* now copy everything over to new malloc'd areas...
*/
slotadded = slotalloc - amap->am_nslot;
if (!(flags & AMAP_EXTEND_FORWARDS))
slotspace = slotalloc - slotmapped;
/* do am_slots */
oldsl = amap->am_slots;
if (flags & AMAP_EXTEND_FORWARDS)
memcpy(newsl, oldsl, sizeof(int) * amap->am_nused);
else
for (i = 0; i < amap->am_nused; i++)
newsl[i] = oldsl[i] + slotspace - slotoff;
amap->am_slots = newsl;
/* do am_anon */
oldover = amap->am_anon;
if (flags & AMAP_EXTEND_FORWARDS) {
memcpy(newover, oldover,
sizeof(struct vm_anon *) * amap->am_nslot);
memset(newover + amap->am_nslot, 0,
sizeof(struct vm_anon *) * slotadded);
} else {
memcpy(newover + slotspace, oldover + slotoff,
sizeof(struct vm_anon *) * slotmapped);
memset(newover, 0,
sizeof(struct vm_anon *) * slotspace);
}
amap->am_anon = newover;
/* do am_bckptr */
oldbck = amap->am_bckptr;
if (flags & AMAP_EXTEND_FORWARDS)
memcpy(newbck, oldbck, sizeof(int) * amap->am_nslot);
else
memcpy(newbck + slotspace, oldbck + slotoff,
sizeof(int) * slotmapped);
amap->am_bckptr = newbck;
#ifdef UVM_AMAP_PPREF
/* do ppref */
oldppref = amap->am_ppref;
if (newppref) {
if (flags & AMAP_EXTEND_FORWARDS) {
memcpy(newppref, oldppref,
sizeof(int) * amap->am_nslot);
memset(newppref + amap->am_nslot, 0,
sizeof(int) * slotadded);
} else {
memcpy(newppref + slotspace, oldppref + slotoff,
sizeof(int) * slotmapped);
}
amap->am_ppref = newppref;
if ((flags & AMAP_EXTEND_FORWARDS) &&
(slotoff + slotmapped) < amap->am_nslot)
amap_pp_adjref(amap, slotoff + slotmapped,
(amap->am_nslot - (slotoff + slotmapped)), 1);
if (flags & AMAP_EXTEND_FORWARDS)
pp_setreflen(newppref, amap->am_nslot, 1,
slotneed - amap->am_nslot);
else {
pp_setreflen(newppref, 0, 0,
slotalloc - slotneed);
pp_setreflen(newppref, slotalloc - slotneed, 1,
slotneed - slotmapped);
}
} else {
if (amap->am_ppref)
amap->am_ppref = PPREF_NONE;
}
#endif
/* update master values */
if (flags & AMAP_EXTEND_FORWARDS)
amap->am_nslot = slotneed;
else {
entry->aref.ar_pageoff = slotspace - slotadd;
amap->am_nslot = slotalloc;
}
oldnslots = amap->am_maxslot;
amap->am_maxslot = slotalloc;
amap_unlock(amap);
kmem_free(oldsl, oldnslots * sizeof(*oldsl));
kmem_free(oldbck, oldnslots * sizeof(*oldbck));
kmem_free(oldover, oldnslots * sizeof(*oldover));
#ifdef UVM_AMAP_PPREF
if (oldppref && oldppref != PPREF_NONE)
kmem_free(oldppref, oldnslots * sizeof(*oldppref));
#endif
UVMHIST_LOG(maphist,"<- done (case 3), amap = 0x%x, slotneed=%d",
amap, slotneed, 0, 0);
return 0;
}
/*
* amap_extend: extend the size of an amap (if needed)
*
* => called from uvm_map when we want to extend an amap to cover
* a new mapping (rather than allocate a new one)
* => to safely extend an amap it should have a reference count of
* one (thus it can't be shared)
* => XXXCDC: support padding at this level?
*/
int
amap_extend(struct vm_map_entry *entry, vsize_t addsize)
{
struct vm_amap *amap = entry->aref.ar_amap;
int slotoff = entry->aref.ar_pageoff;
int slotmapped, slotadd, slotneed, slotalloc;
#ifdef UVM_AMAP_PPREF
int *newppref, *oldppref;
#endif
u_int *newsl, *newbck, *oldsl, *oldbck;
struct vm_anon **newover, **oldover;
int slotadded;
/*
* first, determine how many slots we need in the amap. don't
* forget that ar_pageoff could be non-zero: this means that
* there are some unused slots before us in the amap.
*/
AMAP_B2SLOT(slotmapped, entry->end - entry->start); /* slots mapped */
AMAP_B2SLOT(slotadd, addsize); /* slots to add */
slotneed = slotoff + slotmapped + slotadd;
/*
* case 1: we already have enough slots in the map and thus
* only need to bump the reference counts on the slots we are
* adding.
*/
if (amap->am_nslot >= slotneed) {
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
amap_pp_adjref(amap, slotoff + slotmapped, slotadd, 1);
}
#endif
return (0);
}
/*
* case 2: we pre-allocated slots for use and we just need to
* bump nslot up to take account for these slots.
*/
if (amap->am_maxslot >= slotneed) {
#ifdef UVM_AMAP_PPREF
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
if ((slotoff + slotmapped) < amap->am_nslot)
amap_pp_adjref(amap, slotoff + slotmapped,
(amap->am_nslot - (slotoff + slotmapped)),
1);
pp_setreflen(amap->am_ppref, amap->am_nslot, 1,
slotneed - amap->am_nslot);
}
#endif
amap->am_nslot = slotneed;
/*
* no need to zero am_anon since that was done at
* alloc time and we never shrink an allocation.
*/
return (0);
}
/*
* case 3: we need to malloc a new amap and copy all the amap
* data over from old amap to the new one.
*
* XXXCDC: could we take advantage of a kernel realloc()?
*/
if (slotneed >= UVM_AMAP_LARGE)
return E2BIG;
slotalloc = malloc_roundup(slotneed * MALLOC_SLOT_UNIT) /
MALLOC_SLOT_UNIT;
#ifdef UVM_AMAP_PPREF
newppref = NULL;
if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
newppref = mallocarray(slotalloc, sizeof(int), M_UVMAMAP,
M_WAITOK | M_CANFAIL);
if (newppref == NULL) {
/* give up if malloc fails */
free(amap->am_ppref, M_UVMAMAP, 0);
amap->am_ppref = PPREF_NONE;
}
}
#endif
newsl = malloc(slotalloc * MALLOC_SLOT_UNIT, M_UVMAMAP,
M_WAITOK | M_CANFAIL);
if (newsl == NULL) {
#ifdef UVM_AMAP_PPREF
if (newppref != NULL) {
free(newppref, M_UVMAMAP, 0);
}
#endif
return (ENOMEM);
}
newbck = (int *)(((char *)newsl) + slotalloc * sizeof(int));
newover = (struct vm_anon **)(((char *)newbck) + slotalloc *
sizeof(int));
KASSERT(amap->am_maxslot < slotneed);
/* now copy everything over to new malloc'd areas... */
slotadded = slotalloc - amap->am_nslot;
/* do am_slots */
oldsl = amap->am_slots;
memcpy(newsl, oldsl, sizeof(int) * amap->am_nused);
amap->am_slots = newsl;
/* do am_anon */
oldover = amap->am_anon;
memcpy(newover, oldover, sizeof(struct vm_anon *) * amap->am_nslot);
memset(newover + amap->am_nslot, 0, sizeof(struct vm_anon *) *
slotadded);
amap->am_anon = newover;
/* do am_bckptr */
oldbck = amap->am_bckptr;
memcpy(newbck, oldbck, sizeof(int) * amap->am_nslot);
memset(newbck + amap->am_nslot, 0, sizeof(int) * slotadded); /* XXX: needed? */
amap->am_bckptr = newbck;
#ifdef UVM_AMAP_PPREF
/* do ppref */
oldppref = amap->am_ppref;
if (newppref) {
memcpy(newppref, oldppref, sizeof(int) * amap->am_nslot);
memset(newppref + amap->am_nslot, 0, sizeof(int) * slotadded);
amap->am_ppref = newppref;
if ((slotoff + slotmapped) < amap->am_nslot)
amap_pp_adjref(amap, slotoff + slotmapped,
(amap->am_nslot - (slotoff + slotmapped)), 1);
pp_setreflen(newppref, amap->am_nslot, 1,
slotneed - amap->am_nslot);
}
#endif
/* update master values */
amap->am_nslot = slotneed;
amap->am_maxslot = slotalloc;
/* and free */
free(oldsl, M_UVMAMAP, 0);
#ifdef UVM_AMAP_PPREF
if (oldppref && oldppref != PPREF_NONE)
free(oldppref, M_UVMAMAP, 0);
#endif
return (0);
}
