Example #1
0
/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
    vm_offset_t offset, size_t tlen, struct uio *uio)
{
	vm_page_t	m;
	int		error;

	VM_OBJECT_LOCK(tobj);
	vm_object_pip_add(tobj, 1);
	m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
	    VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
	if (m->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
			error = vm_pager_get_pages(tobj, &m, 1, 0);
			if (error != 0) {
				printf("tmpfs get pages from pager error [read]\n");
				goto out;
			}
		} else
			vm_page_zero_invalid(m, TRUE);
	}
	VM_OBJECT_UNLOCK(tobj);
	error = uiomove_fromphys(&m, offset, tlen, uio);
	VM_OBJECT_LOCK(tobj);
out:
	vm_page_lock(m);
	vm_page_unwire(m, TRUE);
	vm_page_unlock(m);
	vm_page_wakeup(m);
	vm_object_pip_subtract(tobj, 1);
	VM_OBJECT_UNLOCK(tobj);

	return (error);
}
Example #2
0
int ttm_tt_swapin(struct ttm_tt *ttm)
{
	vm_object_t obj;
	vm_page_t from_page, to_page;
	int i, ret, rv;

	obj = ttm->swap_storage;

	VM_OBJECT_LOCK(obj);
	vm_object_pip_add(obj, 1);
	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL |
						 VM_ALLOC_RETRY);
		if (from_page->valid != VM_PAGE_BITS_ALL) {
			if (vm_pager_has_page(obj, i)) {
				rv = vm_pager_get_page(obj, &from_page, 1);
				if (rv != VM_PAGER_OK) {
					vm_page_free(from_page);
					ret = -EIO;
					goto err_ret;
				}
			} else {
				vm_page_zero_invalid(from_page, TRUE);
			}
		}
		to_page = ttm->pages[i];
		if (unlikely(to_page == NULL)) {
			ret = -ENOMEM;
			vm_page_wakeup(from_page);
			goto err_ret;
		}
		pmap_copy_page(VM_PAGE_TO_PHYS(from_page),
			       VM_PAGE_TO_PHYS(to_page));
		vm_page_wakeup(from_page);
	}
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);

	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
		vm_object_deallocate(obj);
	ttm->swap_storage = NULL;
	ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
	return (0);

err_ret:
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);
	return (ret);
}
Example #3
0
int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
{
	vm_object_t obj;
	vm_page_t from_page, to_page;
	int i;

	BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
	BUG_ON(ttm->caching_state != tt_cached);

	if (!persistent_swap_storage) {
		obj = swap_pager_alloc(NULL,
		    IDX_TO_OFF(ttm->num_pages), VM_PROT_DEFAULT, 0);
		if (obj == NULL) {
			pr_err("Failed allocating swap storage\n");
			return (-ENOMEM);
		}
	} else
		obj = persistent_swap_storage;

	VM_OBJECT_LOCK(obj);
	vm_object_pip_add(obj, 1);
	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = ttm->pages[i];
		if (unlikely(from_page == NULL))
			continue;
		to_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL |
					       VM_ALLOC_RETRY);
		pmap_copy_page(VM_PAGE_TO_PHYS(from_page),
					VM_PAGE_TO_PHYS(to_page));
		to_page->valid = VM_PAGE_BITS_ALL;
		vm_page_dirty(to_page);
		vm_page_wakeup(to_page);
	}
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);

	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
	ttm->swap_storage = obj;
	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
	if (persistent_swap_storage)
		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;

	return 0;
}
Example #4
0
int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
{
	vm_object_t obj;
	vm_page_t from_page, to_page;
	int i;

	MPASS(ttm->state == tt_unbound || ttm->state == tt_unpopulated);
	MPASS(ttm->caching_state == tt_cached);

	if (persistent_swap_storage == NULL) {
		obj = vm_pager_allocate(OBJT_SWAP, NULL,
		    IDX_TO_OFF(ttm->num_pages), VM_PROT_DEFAULT, 0,
		    curthread->td_ucred);
		if (obj == NULL) {
			printf("[TTM] Failed allocating swap storage\n");
			return (-ENOMEM);
		}
	} else
		obj = persistent_swap_storage;

	VM_OBJECT_WLOCK(obj);
	vm_object_pip_add(obj, 1);
	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = ttm->pages[i];
		if (unlikely(from_page == NULL))
			continue;
		to_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL);
		pmap_copy_page(from_page, to_page);
		to_page->valid = VM_PAGE_BITS_ALL;
		vm_page_dirty(to_page);
		vm_page_xunbusy(to_page);
	}
	vm_object_pip_wakeup(obj);
	VM_OBJECT_WUNLOCK(obj);

	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
	ttm->swap_storage = obj;
	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
	if (persistent_swap_storage != NULL)
		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;
	return (0);
}
Example #5
0
int
vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
    int fault_flags, vm_page_t *m_hold)
{
	vm_prot_t prot;
	long ahead, behind;
	int alloc_req, era, faultcount, nera, reqpage, result;
	boolean_t growstack, is_first_object_locked, wired;
	int map_generation;
	vm_object_t next_object;
	vm_page_t marray[VM_FAULT_READ_MAX];
	int hardfault;
	struct faultstate fs;
	struct vnode *vp;
	int locked, error;

	hardfault = 0;
	growstack = TRUE;
	PCPU_INC(cnt.v_vm_faults);
	fs.vp = NULL;
	faultcount = reqpage = 0;

RetryFault:;

	/*
	 * Find the backing store object and offset into it to begin the
	 * search.
	 */
	fs.map = map;
	result = vm_map_lookup(&fs.map, vaddr, fault_type, &fs.entry,
	    &fs.first_object, &fs.first_pindex, &prot, &wired);
	if (result != KERN_SUCCESS) {
		if (growstack && result == KERN_INVALID_ADDRESS &&
		    map != kernel_map) {
			result = vm_map_growstack(curproc, vaddr);
			if (result != KERN_SUCCESS)
				return (KERN_FAILURE);
			growstack = FALSE;
			goto RetryFault;
		}
		return (result);
	}

	map_generation = fs.map->timestamp;

	if (fs.entry->eflags & MAP_ENTRY_NOFAULT) {
		panic("vm_fault: fault on nofault entry, addr: %lx",
		    (u_long)vaddr);
	}

	/*
	 * Make a reference to this object to prevent its disposal while we
	 * are messing with it.  Once we have the reference, the map is free
	 * to be diddled.  Since objects reference their shadows (and copies),
	 * they will stay around as well.
	 *
	 * Bump the paging-in-progress count to prevent size changes (e.g. 
	 * truncation operations) during I/O.  This must be done after
	 * obtaining the vnode lock in order to avoid possible deadlocks.
	 */
	VM_OBJECT_WLOCK(fs.first_object);
	vm_object_reference_locked(fs.first_object);
	vm_object_pip_add(fs.first_object, 1);

	fs.lookup_still_valid = TRUE;

	if (wired)
		fault_type = prot | (fault_type & VM_PROT_COPY);

	fs.first_m = NULL;

	/*
	 * Search for the page at object/offset.
	 */
	fs.object = fs.first_object;
	fs.pindex = fs.first_pindex;
	while (TRUE) {
		/*
		 * If the object is dead, we stop here
		 */
		if (fs.object->flags & OBJ_DEAD) {
			unlock_and_deallocate(&fs);
			return (KERN_PROTECTION_FAILURE);
		}

		/*
		 * See if page is resident
		 */
		fs.m = vm_page_lookup(fs.object, fs.pindex);
		if (fs.m != NULL) {
			/* 
			 * check for page-based copy on write.
			 * We check fs.object == fs.first_object so
			 * as to ensure the legacy COW mechanism is
			 * used when the page in question is part of
			 * a shadow object.  Otherwise, vm_page_cowfault()
			 * removes the page from the backing object, 
			 * which is not what we want.
			 */
			vm_page_lock(fs.m);
			if ((fs.m->cow) && 
			    (fault_type & VM_PROT_WRITE) &&
			    (fs.object == fs.first_object)) {
				vm_page_cowfault(fs.m);
				unlock_and_deallocate(&fs);
				goto RetryFault;
			}

			/*
			 * Wait/Retry if the page is busy.  We have to do this
			 * if the page is busy via either VPO_BUSY or 
			 * vm_page_t->busy because the vm_pager may be using
			 * vm_page_t->busy for pageouts ( and even pageins if
			 * it is the vnode pager ), and we could end up trying
			 * to pagein and pageout the same page simultaneously.
			 *
			 * We can theoretically allow the busy case on a read
			 * fault if the page is marked valid, but since such
			 * pages are typically already pmap'd, putting that
			 * special case in might be more effort then it is 
			 * worth.  We cannot under any circumstances mess
			 * around with a vm_page_t->busy page except, perhaps,
			 * to pmap it.
			 */
			if ((fs.m->oflags & VPO_BUSY) || fs.m->busy) {
				/*
				 * Reference the page before unlocking and
				 * sleeping so that the page daemon is less
				 * likely to reclaim it. 
				 */
				vm_page_aflag_set(fs.m, PGA_REFERENCED);
				vm_page_unlock(fs.m);
				if (fs.object != fs.first_object) {
					if (!VM_OBJECT_TRYWLOCK(
					    fs.first_object)) {
						VM_OBJECT_WUNLOCK(fs.object);
						VM_OBJECT_WLOCK(fs.first_object);
						VM_OBJECT_WLOCK(fs.object);
					}
					vm_page_lock(fs.first_m);
					vm_page_free(fs.first_m);
					vm_page_unlock(fs.first_m);
					vm_object_pip_wakeup(fs.first_object);
					VM_OBJECT_WUNLOCK(fs.first_object);
					fs.first_m = NULL;
				}
				unlock_map(&fs);
				if (fs.m == vm_page_lookup(fs.object,
				    fs.pindex)) {
					vm_page_sleep_if_busy(fs.m, TRUE,
					    "vmpfw");
				}
				vm_object_pip_wakeup(fs.object);
				VM_OBJECT_WUNLOCK(fs.object);
				PCPU_INC(cnt.v_intrans);
				vm_object_deallocate(fs.first_object);
				goto RetryFault;
			}
			vm_page_remque(fs.m);
			vm_page_unlock(fs.m);

			/*
			 * Mark page busy for other processes, and the 
			 * pagedaemon.  If it still isn't completely valid
			 * (readable), jump to readrest, else break-out ( we
			 * found the page ).
			 */
			vm_page_busy(fs.m);
			if (fs.m->valid != VM_PAGE_BITS_ALL)
				goto readrest;
			break;
		}

		/*
		 * Page is not resident, If this is the search termination
		 * or the pager might contain the page, allocate a new page.
		 */
		if (TRYPAGER || fs.object == fs.first_object) {
			if (fs.pindex >= fs.object->size) {
				unlock_and_deallocate(&fs);
				return (KERN_PROTECTION_FAILURE);
			}

			/*
			 * Allocate a new page for this object/offset pair.
			 *
			 * Unlocked read of the p_flag is harmless. At
			 * worst, the P_KILLED might be not observed
			 * there, and allocation can fail, causing
			 * restart and new reading of the p_flag.
			 */
			fs.m = NULL;
			if (!vm_page_count_severe() || P_KILLED(curproc)) {
#if VM_NRESERVLEVEL > 0
				if ((fs.object->flags & OBJ_COLORED) == 0) {
					fs.object->flags |= OBJ_COLORED;
					fs.object->pg_color = atop(vaddr) -
					    fs.pindex;
				}
#endif
				alloc_req = P_KILLED(curproc) ?
				    VM_ALLOC_SYSTEM : VM_ALLOC_NORMAL;
				if (fs.object->type != OBJT_VNODE &&
				    fs.object->backing_object == NULL)
					alloc_req |= VM_ALLOC_ZERO;
				fs.m = vm_page_alloc(fs.object, fs.pindex,
				    alloc_req);
			}
			if (fs.m == NULL) {
				unlock_and_deallocate(&fs);
				VM_WAITPFAULT;
				goto RetryFault;
			} else if (fs.m->valid == VM_PAGE_BITS_ALL)
				break;
		}

readrest:
		/*
		 * We have found a valid page or we have allocated a new page.
		 * The page thus may not be valid or may not be entirely 
		 * valid.
		 *
		 * Attempt to fault-in the page if there is a chance that the
		 * pager has it, and potentially fault in additional pages
		 * at the same time.
		 */
		if (TRYPAGER) {
			int rv;
			u_char behavior = vm_map_entry_behavior(fs.entry);

			if (behavior == MAP_ENTRY_BEHAV_RANDOM ||
			    P_KILLED(curproc)) {
				behind = 0;
				ahead = 0;
			} else if (behavior == MAP_ENTRY_BEHAV_SEQUENTIAL) {
				behind = 0;
				ahead = atop(fs.entry->end - vaddr) - 1;
				if (ahead > VM_FAULT_READ_AHEAD_MAX)
					ahead = VM_FAULT_READ_AHEAD_MAX;
				if (fs.pindex == fs.entry->next_read)
					vm_fault_cache_behind(&fs,
					    VM_FAULT_READ_MAX);
			} else {
				/*
				 * If this is a sequential page fault, then
				 * arithmetically increase the number of pages
				 * in the read-ahead window.  Otherwise, reset
				 * the read-ahead window to its smallest size.
				 */
				behind = atop(vaddr - fs.entry->start);
				if (behind > VM_FAULT_READ_BEHIND)
					behind = VM_FAULT_READ_BEHIND;
				ahead = atop(fs.entry->end - vaddr) - 1;
				era = fs.entry->read_ahead;
				if (fs.pindex == fs.entry->next_read) {
					nera = era + behind;
					if (nera > VM_FAULT_READ_AHEAD_MAX)
						nera = VM_FAULT_READ_AHEAD_MAX;
					behind = 0;
					if (ahead > nera)
						ahead = nera;
					if (era == VM_FAULT_READ_AHEAD_MAX)
						vm_fault_cache_behind(&fs,
						    VM_FAULT_CACHE_BEHIND);
				} else if (ahead > VM_FAULT_READ_AHEAD_MIN)
					ahead = VM_FAULT_READ_AHEAD_MIN;
				if (era != ahead)
					fs.entry->read_ahead = ahead;
			}

			/*
			 * Call the pager to retrieve the data, if any, after
			 * releasing the lock on the map.  We hold a ref on
			 * fs.object and the pages are VPO_BUSY'd.
			 */
			unlock_map(&fs);

			if (fs.object->type == OBJT_VNODE) {
				vp = fs.object->handle;
				if (vp == fs.vp)
					goto vnode_locked;
				else if (fs.vp != NULL) {
					vput(fs.vp);
					fs.vp = NULL;
				}
				locked = VOP_ISLOCKED(vp);

				if (locked != LK_EXCLUSIVE)
					locked = LK_SHARED;
				/* Do not sleep for vnode lock while fs.m is busy */
				error = vget(vp, locked | LK_CANRECURSE |
				    LK_NOWAIT, curthread);
				if (error != 0) {
					vhold(vp);
					release_page(&fs);
					unlock_and_deallocate(&fs);
					error = vget(vp, locked | LK_RETRY |
					    LK_CANRECURSE, curthread);
					vdrop(vp);
					fs.vp = vp;
					KASSERT(error == 0,
					    ("vm_fault: vget failed"));
					goto RetryFault;
				}
				fs.vp = vp;
			}
vnode_locked:
			KASSERT(fs.vp == NULL || !fs.map->system_map,
			    ("vm_fault: vnode-backed object mapped by system map"));

			/*
			 * now we find out if any other pages should be paged
			 * in at this time this routine checks to see if the
			 * pages surrounding this fault reside in the same
			 * object as the page for this fault.  If they do,
			 * then they are faulted in also into the object.  The
			 * array "marray" returned contains an array of
			 * vm_page_t structs where one of them is the
			 * vm_page_t passed to the routine.  The reqpage
			 * return value is the index into the marray for the
			 * vm_page_t passed to the routine.
			 *
			 * fs.m plus the additional pages are VPO_BUSY'd.
			 */
			faultcount = vm_fault_additional_pages(
			    fs.m, behind, ahead, marray, &reqpage);

			rv = faultcount ?
			    vm_pager_get_pages(fs.object, marray, faultcount,
				reqpage) : VM_PAGER_FAIL;

			if (rv == VM_PAGER_OK) {
				/*
				 * Found the page. Leave it busy while we play
				 * with it.
				 */

				/*
				 * Relookup in case pager changed page. Pager
				 * is responsible for disposition of old page
				 * if moved.
				 */
				fs.m = vm_page_lookup(fs.object, fs.pindex);
				if (!fs.m) {
					unlock_and_deallocate(&fs);
					goto RetryFault;
				}

				hardfault++;
				break; /* break to PAGE HAS BEEN FOUND */
			}
			/*
			 * Remove the bogus page (which does not exist at this
			 * object/offset); before doing so, we must get back
			 * our object lock to preserve our invariant.
			 *
			 * Also wake up any other process that may want to bring
			 * in this page.
			 *
			 * If this is the top-level object, we must leave the
			 * busy page to prevent another process from rushing
			 * past us, and inserting the page in that object at
			 * the same time that we are.
			 */
			if (rv == VM_PAGER_ERROR)
				printf("vm_fault: pager read error, pid %d (%s)\n",
				    curproc->p_pid, curproc->p_comm);
			/*
			 * Data outside the range of the pager or an I/O error
			 */
			/*
			 * XXX - the check for kernel_map is a kludge to work
			 * around having the machine panic on a kernel space
			 * fault w/ I/O error.
			 */
			if (((fs.map != kernel_map) && (rv == VM_PAGER_ERROR)) ||
				(rv == VM_PAGER_BAD)) {
				vm_page_lock(fs.m);
				vm_page_free(fs.m);
				vm_page_unlock(fs.m);
				fs.m = NULL;
				unlock_and_deallocate(&fs);
				return ((rv == VM_PAGER_ERROR) ? KERN_FAILURE : KERN_PROTECTION_FAILURE);
			}
			if (fs.object != fs.first_object) {
				vm_page_lock(fs.m);
				vm_page_free(fs.m);
				vm_page_unlock(fs.m);
				fs.m = NULL;
				/*
				 * XXX - we cannot just fall out at this
				 * point, m has been freed and is invalid!
				 */
			}
		}

		/*
		 * We get here if the object has default pager (or unwiring) 
		 * or the pager doesn't have the page.
		 */
		if (fs.object == fs.first_object)
			fs.first_m = fs.m;

		/*
		 * Move on to the next object.  Lock the next object before
		 * unlocking the current one.
		 */
		fs.pindex += OFF_TO_IDX(fs.object->backing_object_offset);
		next_object = fs.object->backing_object;
		if (next_object == NULL) {
			/*
			 * If there's no object left, fill the page in the top
			 * object with zeros.
			 */
			if (fs.object != fs.first_object) {
				vm_object_pip_wakeup(fs.object);
				VM_OBJECT_WUNLOCK(fs.object);

				fs.object = fs.first_object;
				fs.pindex = fs.first_pindex;
				fs.m = fs.first_m;
				VM_OBJECT_WLOCK(fs.object);
			}
			fs.first_m = NULL;

			/*
			 * Zero the page if necessary and mark it valid.
			 */
			if ((fs.m->flags & PG_ZERO) == 0) {
				pmap_zero_page(fs.m);
			} else {
				PCPU_INC(cnt.v_ozfod);
			}
			PCPU_INC(cnt.v_zfod);
			fs.m->valid = VM_PAGE_BITS_ALL;
			break;	/* break to PAGE HAS BEEN FOUND */
		} else {
			KASSERT(fs.object != next_object,
			    ("object loop %p", next_object));
			VM_OBJECT_WLOCK(next_object);
			vm_object_pip_add(next_object, 1);
			if (fs.object != fs.first_object)
				vm_object_pip_wakeup(fs.object);
			VM_OBJECT_WUNLOCK(fs.object);
			fs.object = next_object;
		}
	}

	KASSERT((fs.m->oflags & VPO_BUSY) != 0,
	    ("vm_fault: not busy after main loop"));

	/*
	 * PAGE HAS BEEN FOUND. [Loop invariant still holds -- the object lock
	 * is held.]
	 */

	/*
	 * If the page is being written, but isn't already owned by the
	 * top-level object, we have to copy it into a new page owned by the
	 * top-level object.
	 */
	if (fs.object != fs.first_object) {
		/*
		 * We only really need to copy if we want to write it.
		 */
		if ((fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
			/*
			 * This allows pages to be virtually copied from a 
			 * backing_object into the first_object, where the 
			 * backing object has no other refs to it, and cannot
			 * gain any more refs.  Instead of a bcopy, we just 
			 * move the page from the backing object to the 
			 * first object.  Note that we must mark the page 
			 * dirty in the first object so that it will go out 
			 * to swap when needed.
			 */
			is_first_object_locked = FALSE;
			if (
				/*
				 * Only one shadow object
				 */
				(fs.object->shadow_count == 1) &&
				/*
				 * No COW refs, except us
				 */
				(fs.object->ref_count == 1) &&
				/*
				 * No one else can look this object up
				 */
				(fs.object->handle == NULL) &&
				/*
				 * No other ways to look the object up
				 */
				((fs.object->type == OBJT_DEFAULT) ||
				 (fs.object->type == OBJT_SWAP)) &&
			    (is_first_object_locked = VM_OBJECT_TRYWLOCK(fs.first_object)) &&
				/*
				 * We don't chase down the shadow chain
				 */
			    fs.object == fs.first_object->backing_object) {
				/*
				 * get rid of the unnecessary page
				 */
				vm_page_lock(fs.first_m);
				vm_page_free(fs.first_m);
				vm_page_unlock(fs.first_m);
				/*
				 * grab the page and put it into the 
				 * process'es object.  The page is 
				 * automatically made dirty.
				 */
				vm_page_lock(fs.m);
				vm_page_rename(fs.m, fs.first_object, fs.first_pindex);
				vm_page_unlock(fs.m);
				vm_page_busy(fs.m);
				fs.first_m = fs.m;
				fs.m = NULL;
				PCPU_INC(cnt.v_cow_optim);
			} else {
				/*
				 * Oh, well, lets copy it.
				 */
				pmap_copy_page(fs.m, fs.first_m);
				fs.first_m->valid = VM_PAGE_BITS_ALL;
				if (wired && (fault_flags &
				    VM_FAULT_CHANGE_WIRING) == 0) {
					vm_page_lock(fs.first_m);
					vm_page_wire(fs.first_m);
					vm_page_unlock(fs.first_m);
					
					vm_page_lock(fs.m);
					vm_page_unwire(fs.m, FALSE);
					vm_page_unlock(fs.m);
				}
				/*
				 * We no longer need the old page or object.
				 */
				release_page(&fs);
			}
			/*
			 * fs.object != fs.first_object due to above 
			 * conditional
			 */
			vm_object_pip_wakeup(fs.object);
			VM_OBJECT_WUNLOCK(fs.object);
			/*
			 * Only use the new page below...
			 */
			fs.object = fs.first_object;
			fs.pindex = fs.first_pindex;
			fs.m = fs.first_m;
			if (!is_first_object_locked)
				VM_OBJECT_WLOCK(fs.object);
			PCPU_INC(cnt.v_cow_faults);
			curthread->td_cow++;
		} else {
			prot &= ~VM_PROT_WRITE;
		}
	}

	/*
	 * We must verify that the maps have not changed since our last
	 * lookup.
	 */
	if (!fs.lookup_still_valid) {
		vm_object_t retry_object;
		vm_pindex_t retry_pindex;
		vm_prot_t retry_prot;

		if (!vm_map_trylock_read(fs.map)) {
			release_page(&fs);
			unlock_and_deallocate(&fs);
			goto RetryFault;
		}
		fs.lookup_still_valid = TRUE;
		if (fs.map->timestamp != map_generation) {
			result = vm_map_lookup_locked(&fs.map, vaddr, fault_type,
			    &fs.entry, &retry_object, &retry_pindex, &retry_prot, &wired);

			/*
			 * If we don't need the page any longer, put it on the inactive
			 * list (the easiest thing to do here).  If no one needs it,
			 * pageout will grab it eventually.
			 */
			if (result != KERN_SUCCESS) {
				release_page(&fs);
				unlock_and_deallocate(&fs);

				/*
				 * If retry of map lookup would have blocked then
				 * retry fault from start.
				 */
				if (result == KERN_FAILURE)
					goto RetryFault;
				return (result);
			}
			if ((retry_object != fs.first_object) ||
			    (retry_pindex != fs.first_pindex)) {
				release_page(&fs);
				unlock_and_deallocate(&fs);
				goto RetryFault;
			}

			/*
			 * Check whether the protection has changed or the object has
			 * been copied while we left the map unlocked. Changing from
			 * read to write permission is OK - we leave the page
			 * write-protected, and catch the write fault. Changing from
			 * write to read permission means that we can't mark the page
			 * write-enabled after all.
			 */
			prot &= retry_prot;
		}
	}
	/*
	 * If the page was filled by a pager, update the map entry's
	 * last read offset.  Since the pager does not return the
	 * actual set of pages that it read, this update is based on
	 * the requested set.  Typically, the requested and actual
	 * sets are the same.
	 *
	 * XXX The following assignment modifies the map
	 * without holding a write lock on it.
	 */
	if (hardfault)
		fs.entry->next_read = fs.pindex + faultcount - reqpage;

	if ((prot & VM_PROT_WRITE) != 0 ||
	    (fault_flags & VM_FAULT_DIRTY) != 0) {
		vm_object_set_writeable_dirty(fs.object);

		/*
		 * If this is a NOSYNC mmap we do not want to set VPO_NOSYNC
		 * if the page is already dirty to prevent data written with
		 * the expectation of being synced from not being synced.
		 * Likewise if this entry does not request NOSYNC then make
		 * sure the page isn't marked NOSYNC.  Applications sharing
		 * data should use the same flags to avoid ping ponging.
		 */
		if (fs.entry->eflags & MAP_ENTRY_NOSYNC) {
			if (fs.m->dirty == 0)
				fs.m->oflags |= VPO_NOSYNC;
		} else {
			fs.m->oflags &= ~VPO_NOSYNC;
		}

		/*
		 * If the fault is a write, we know that this page is being
		 * written NOW so dirty it explicitly to save on 
		 * pmap_is_modified() calls later.
		 *
		 * Also tell the backing pager, if any, that it should remove
		 * any swap backing since the page is now dirty.
		 */
		if (((fault_type & VM_PROT_WRITE) != 0 &&
		    (fault_flags & VM_FAULT_CHANGE_WIRING) == 0) ||
		    (fault_flags & VM_FAULT_DIRTY) != 0) {
			vm_page_dirty(fs.m);
			vm_pager_page_unswapped(fs.m);
		}
	}

	/*
	 * Page had better still be busy
	 */
	KASSERT(fs.m->oflags & VPO_BUSY,
		("vm_fault: page %p not busy!", fs.m));
	/*
	 * Page must be completely valid or it is not fit to
	 * map into user space.  vm_pager_get_pages() ensures this.
	 */
	KASSERT(fs.m->valid == VM_PAGE_BITS_ALL,
	    ("vm_fault: page %p partially invalid", fs.m));
	VM_OBJECT_WUNLOCK(fs.object);

	/*
	 * Put this page into the physical map.  We had to do the unlock above
	 * because pmap_enter() may sleep.  We don't put the page
	 * back on the active queue until later so that the pageout daemon
	 * won't find it (yet).
	 */
	pmap_enter(fs.map->pmap, vaddr, fault_type, fs.m, prot, wired);
	if ((fault_flags & VM_FAULT_CHANGE_WIRING) == 0 && wired == 0)
		vm_fault_prefault(fs.map->pmap, vaddr, fs.entry);
	VM_OBJECT_WLOCK(fs.object);
	vm_page_lock(fs.m);

	/*
	 * If the page is not wired down, then put it where the pageout daemon
	 * can find it.
	 */
	if (fault_flags & VM_FAULT_CHANGE_WIRING) {
		if (wired)
			vm_page_wire(fs.m);
		else
			vm_page_unwire(fs.m, 1);
	} else
		vm_page_activate(fs.m);
	if (m_hold != NULL) {
		*m_hold = fs.m;
		vm_page_hold(fs.m);
	}
	vm_page_unlock(fs.m);
	vm_page_wakeup(fs.m);

	/*
	 * Unlock everything, and return
	 */
	unlock_and_deallocate(&fs);
	if (hardfault) {
		PCPU_INC(cnt.v_io_faults);
		curthread->td_ru.ru_majflt++;
	} else 
		curthread->td_ru.ru_minflt++;

	return (KERN_SUCCESS);
}
Example #6
0
/*
 * If blocks are contiguous on disk, use this to provide clustered
 * read ahead.  We will read as many blocks as possible sequentially
 * and then parcel them up into logical blocks in the buffer hash table.
 */
static struct buf *
cluster_rbuild(struct vnode *vp, u_quad_t filesize, daddr_t lbn,
    daddr_t blkno, long size, int run, int gbflags, struct buf *fbp)
{
	struct buf *bp, *tbp;
	daddr_t bn;
	off_t off;
	long tinc, tsize;
	int i, inc, j, k, toff;

	KASSERT(size == vp->v_mount->mnt_stat.f_iosize,
	    ("cluster_rbuild: size %ld != f_iosize %jd\n",
	    size, (intmax_t)vp->v_mount->mnt_stat.f_iosize));

	/*
	 * avoid a division
	 */
	while ((u_quad_t) size * (lbn + run) > filesize) {
		--run;
	}

	if (fbp) {
		tbp = fbp;
		tbp->b_iocmd = BIO_READ; 
	} else {
		tbp = getblk(vp, lbn, size, 0, 0, gbflags);
		if (tbp->b_flags & B_CACHE)
			return tbp;
		tbp->b_flags |= B_ASYNC | B_RAM;
		tbp->b_iocmd = BIO_READ;
	}
	tbp->b_blkno = blkno;
	if( (tbp->b_flags & B_MALLOC) ||
		((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
		return tbp;

	bp = trypbuf(&cluster_pbuf_freecnt);
	if (bp == NULL)
		return tbp;

	/*
	 * We are synthesizing a buffer out of vm_page_t's, but
	 * if the block size is not page aligned then the starting
	 * address may not be either.  Inherit the b_data offset
	 * from the original buffer.
	 */
	bp->b_flags = B_ASYNC | B_CLUSTER | B_VMIO;
	if ((gbflags & GB_UNMAPPED) != 0) {
		bp->b_data = unmapped_buf;
	} else {
		bp->b_data = (char *)((vm_offset_t)bp->b_data |
		    ((vm_offset_t)tbp->b_data & PAGE_MASK));
	}
	bp->b_iocmd = BIO_READ;
	bp->b_iodone = cluster_callback;
	bp->b_blkno = blkno;
	bp->b_lblkno = lbn;
	bp->b_offset = tbp->b_offset;
	KASSERT(bp->b_offset != NOOFFSET, ("cluster_rbuild: no buffer offset"));
	pbgetvp(vp, bp);

	TAILQ_INIT(&bp->b_cluster.cluster_head);

	bp->b_bcount = 0;
	bp->b_bufsize = 0;
	bp->b_npages = 0;

	inc = btodb(size);
	for (bn = blkno, i = 0; i < run; ++i, bn += inc) {
		if (i == 0) {
			VM_OBJECT_WLOCK(tbp->b_bufobj->bo_object);
			vfs_drain_busy_pages(tbp);
			vm_object_pip_add(tbp->b_bufobj->bo_object,
			    tbp->b_npages);
			for (k = 0; k < tbp->b_npages; k++)
				vm_page_sbusy(tbp->b_pages[k]);
			VM_OBJECT_WUNLOCK(tbp->b_bufobj->bo_object);
		} else {
			if ((bp->b_npages * PAGE_SIZE) +
			    round_page(size) > vp->v_mount->mnt_iosize_max) {
				break;
			}

			tbp = getblk(vp, lbn + i, size, 0, 0, GB_LOCK_NOWAIT |
			    (gbflags & GB_UNMAPPED));

			/* Don't wait around for locked bufs. */
			if (tbp == NULL)
				break;

			/*
			 * Stop scanning if the buffer is fully valid
			 * (marked B_CACHE), or locked (may be doing a
			 * background write), or if the buffer is not
			 * VMIO backed.  The clustering code can only deal
			 * with VMIO-backed buffers.  The bo lock is not
			 * required for the BKGRDINPROG check since it
			 * can not be set without the buf lock.
			 */
			if ((tbp->b_vflags & BV_BKGRDINPROG) ||
			    (tbp->b_flags & B_CACHE) ||
			    (tbp->b_flags & B_VMIO) == 0) {
				bqrelse(tbp);
				break;
			}

			/*
			 * The buffer must be completely invalid in order to
			 * take part in the cluster.  If it is partially valid
			 * then we stop.
			 */
			off = tbp->b_offset;
			tsize = size;
			VM_OBJECT_WLOCK(tbp->b_bufobj->bo_object);
			for (j = 0; tsize > 0; j++) {
				toff = off & PAGE_MASK;
				tinc = tsize;
				if (toff + tinc > PAGE_SIZE)
					tinc = PAGE_SIZE - toff;
				VM_OBJECT_ASSERT_WLOCKED(tbp->b_pages[j]->object);
				if ((tbp->b_pages[j]->valid &
				    vm_page_bits(toff, tinc)) != 0)
					break;
				if (vm_page_xbusied(tbp->b_pages[j]))
					break;
				vm_object_pip_add(tbp->b_bufobj->bo_object, 1);
				vm_page_sbusy(tbp->b_pages[j]);
				off += tinc;
				tsize -= tinc;
			}
			if (tsize > 0) {
clean_sbusy:
				vm_object_pip_add(tbp->b_bufobj->bo_object, -j);
				for (k = 0; k < j; k++)
					vm_page_sunbusy(tbp->b_pages[k]);
				VM_OBJECT_WUNLOCK(tbp->b_bufobj->bo_object);
				bqrelse(tbp);
				break;
			}
			VM_OBJECT_WUNLOCK(tbp->b_bufobj->bo_object);

			/*
			 * Set a read-ahead mark as appropriate
			 */
			if ((fbp && (i == 1)) || (i == (run - 1)))
				tbp->b_flags |= B_RAM;

			/*
			 * Set the buffer up for an async read (XXX should
			 * we do this only if we do not wind up brelse()ing?).
			 * Set the block number if it isn't set, otherwise
			 * if it is make sure it matches the block number we
			 * expect.
			 */
			tbp->b_flags |= B_ASYNC;
			tbp->b_iocmd = BIO_READ;
			if (tbp->b_blkno == tbp->b_lblkno) {
				tbp->b_blkno = bn;
			} else if (tbp->b_blkno != bn) {
				VM_OBJECT_WLOCK(tbp->b_bufobj->bo_object);
				goto clean_sbusy;
			}
		}
		/*
		 * XXX fbp from caller may not be B_ASYNC, but we are going
		 * to biodone() it in cluster_callback() anyway
		 */
		BUF_KERNPROC(tbp);
		TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
			tbp, b_cluster.cluster_entry);
		VM_OBJECT_WLOCK(tbp->b_bufobj->bo_object);
		for (j = 0; j < tbp->b_npages; j += 1) {
			vm_page_t m;
			m = tbp->b_pages[j];
			if ((bp->b_npages == 0) ||
			    (bp->b_pages[bp->b_npages-1] != m)) {
				bp->b_pages[bp->b_npages] = m;
				bp->b_npages++;
			}
			if (m->valid == VM_PAGE_BITS_ALL)
				tbp->b_pages[j] = bogus_page;
		}
		VM_OBJECT_WUNLOCK(tbp->b_bufobj->bo_object);
		/*
		 * Don't inherit tbp->b_bufsize as it may be larger due to
		 * a non-page-aligned size.  Instead just aggregate using
		 * 'size'.
		 */
		if (tbp->b_bcount != size)
			printf("warning: tbp->b_bcount wrong %ld vs %ld\n", tbp->b_bcount, size);
		if (tbp->b_bufsize != size)
			printf("warning: tbp->b_bufsize wrong %ld vs %ld\n", tbp->b_bufsize, size);
		bp->b_bcount += size;
		bp->b_bufsize += size;
	}

	/*
	 * Fully valid pages in the cluster are already good and do not need
	 * to be re-read from disk.  Replace the page with bogus_page
	 */
	VM_OBJECT_WLOCK(bp->b_bufobj->bo_object);
	for (j = 0; j < bp->b_npages; j++) {
		VM_OBJECT_ASSERT_WLOCKED(bp->b_pages[j]->object);
		if (bp->b_pages[j]->valid == VM_PAGE_BITS_ALL)
			bp->b_pages[j] = bogus_page;
	}
	VM_OBJECT_WUNLOCK(bp->b_bufobj->bo_object);
	if (bp->b_bufsize > bp->b_kvasize)
		panic("cluster_rbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
		    bp->b_bufsize, bp->b_kvasize);

	if (buf_mapped(bp)) {
		pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
		    (vm_page_t *)bp->b_pages, bp->b_npages);
	}
	return (bp);
}
Example #7
0
static int
ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
    int prot, vm_page_t *mres)
{

	struct ttm_buffer_object *bo = vm_obj->handle;
	struct ttm_bo_device *bdev = bo->bdev;
	struct ttm_tt *ttm = NULL;
	vm_page_t m, m1, oldm;
	int ret;
	int retval = VM_PAGER_OK;
	struct ttm_mem_type_manager *man =
		&bdev->man[bo->mem.mem_type];

	vm_object_pip_add(vm_obj, 1);
	oldm = *mres;
	if (oldm != NULL) {
		vm_page_lock(oldm);
		vm_page_remove(oldm);
		vm_page_unlock(oldm);
		*mres = NULL;
	} else
		oldm = NULL;
retry:
	VM_OBJECT_WUNLOCK(vm_obj);
	m = NULL;

reserve:
	ret = ttm_bo_reserve(bo, false, false, false, 0);
	if (unlikely(ret != 0)) {
		if (ret == -EBUSY) {
			kern_yield(0);
			goto reserve;
		}
	}

	if (bdev->driver->fault_reserve_notify) {
		ret = bdev->driver->fault_reserve_notify(bo);
		switch (ret) {
		case 0:
			break;
		case -EBUSY:
		case -ERESTART:
		case -EINTR:
			kern_yield(0);
			goto reserve;
		default:
			retval = VM_PAGER_ERROR;
			goto out_unlock;
		}
	}

	/*
	 * Wait for buffer data in transit, due to a pipelined
	 * move.
	 */

	mtx_lock(&bdev->fence_lock);
	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
		/*
		 * Here, the behavior differs between Linux and FreeBSD.
		 *
		 * On Linux, the wait is interruptible (3rd argument to
		 * ttm_bo_wait). There must be some mechanism to resume
		 * page fault handling, once the signal is processed.
		 *
		 * On FreeBSD, the wait is uninteruptible. This is not a
		 * problem as we can't end up with an unkillable process
		 * here, because the wait will eventually time out.
		 *
		 * An example of this situation is the Xorg process
		 * which uses SIGALRM internally. The signal could
		 * interrupt the wait, causing the page fault to fail
		 * and the process to receive SIGSEGV.
		 */
		ret = ttm_bo_wait(bo, false, false, false);
		mtx_unlock(&bdev->fence_lock);
		if (unlikely(ret != 0)) {
			retval = VM_PAGER_ERROR;
			goto out_unlock;
		}
	} else
		mtx_unlock(&bdev->fence_lock);

	ret = ttm_mem_io_lock(man, true);
	if (unlikely(ret != 0)) {
		retval = VM_PAGER_ERROR;
		goto out_unlock;
	}
	ret = ttm_mem_io_reserve_vm(bo);
	if (unlikely(ret != 0)) {
		retval = VM_PAGER_ERROR;
		goto out_io_unlock;
	}

	/*
	 * Strictly, we're not allowed to modify vma->vm_page_prot here,
	 * since the mmap_sem is only held in read mode. However, we
	 * modify only the caching bits of vma->vm_page_prot and
	 * consider those bits protected by
	 * the bo->mutex, as we should be the only writers.
	 * There shouldn't really be any readers of these bits except
	 * within vm_insert_mixed()? fork?
	 *
	 * TODO: Add a list of vmas to the bo, and change the
	 * vma->vm_page_prot when the object changes caching policy, with
	 * the correct locks held.
	 */
	if (!bo->mem.bus.is_iomem) {
		/* Allocate all page at once, most common usage */
		ttm = bo->ttm;
		if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
			retval = VM_PAGER_ERROR;
			goto out_io_unlock;
		}
	}

	if (bo->mem.bus.is_iomem) {
		m = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset +
		    offset);
		KASSERT((m->flags & PG_FICTITIOUS) != 0,
		    ("physical address %#jx not fictitious",
		    (uintmax_t)(bo->mem.bus.base + bo->mem.bus.offset
		    + offset)));
		pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
	} else {
		ttm = bo->ttm;
		m = ttm->pages[OFF_TO_IDX(offset)];
		if (unlikely(!m)) {
			retval = VM_PAGER_ERROR;
			goto out_io_unlock;
		}
		pmap_page_set_memattr(m,
		    (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
		    VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
	}

	VM_OBJECT_WLOCK(vm_obj);
	if (vm_page_busied(m)) {
		vm_page_lock(m);
		VM_OBJECT_WUNLOCK(vm_obj);
		vm_page_busy_sleep(m, "ttmpbs");
		VM_OBJECT_WLOCK(vm_obj);
		ttm_mem_io_unlock(man);
		ttm_bo_unreserve(bo);
		goto retry;
	}
	m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
	if (m1 == NULL) {
		if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
			VM_OBJECT_WUNLOCK(vm_obj);
			VM_WAIT;
			VM_OBJECT_WLOCK(vm_obj);
			ttm_mem_io_unlock(man);
			ttm_bo_unreserve(bo);
			goto retry;
		}
	} else {
		KASSERT(m == m1,
		    ("inconsistent insert bo %p m %p m1 %p offset %jx",
		    bo, m, m1, (uintmax_t)offset));
	}
	m->valid = VM_PAGE_BITS_ALL;
	*mres = m;
	vm_page_xbusy(m);

	if (oldm != NULL) {
		vm_page_lock(oldm);
		vm_page_free(oldm);
		vm_page_unlock(oldm);
	}

out_io_unlock1:
	ttm_mem_io_unlock(man);
out_unlock1:
	ttm_bo_unreserve(bo);
	vm_object_pip_wakeup(vm_obj);
	return (retval);

out_io_unlock:
	VM_OBJECT_WLOCK(vm_obj);
	goto out_io_unlock1;

out_unlock:
	VM_OBJECT_WLOCK(vm_obj);
	goto out_unlock1;
}
Example #8
0
static int
tmpfs_mappedwrite(vm_object_t vobj, vm_object_t tobj, size_t len, struct uio *uio)
{
	vm_pindex_t	idx;
	vm_page_t	vpg, tpg;
	vm_offset_t	offset;
	off_t		addr;
	size_t		tlen;
	int		error;

	error = 0;
	
	addr = uio->uio_offset;
	idx = OFF_TO_IDX(addr);
	offset = addr & PAGE_MASK;
	tlen = MIN(PAGE_SIZE - offset, len);

	if ((vobj == NULL) ||
	    (vobj->resident_page_count == 0 && vobj->cache == NULL)) {
		vpg = NULL;
		goto nocache;
	}

	VM_OBJECT_LOCK(vobj);
lookupvpg:
	if (((vpg = vm_page_lookup(vobj, idx)) != NULL) &&
	    vm_page_is_valid(vpg, offset, tlen)) {
		if ((vpg->oflags & VPO_BUSY) != 0) {
			/*
			 * Reference the page before unlocking and sleeping so
			 * that the page daemon is less likely to reclaim it.  
			 */
			vm_page_reference(vpg);
			vm_page_sleep(vpg, "tmfsmw");
			goto lookupvpg;
		}
		vm_page_busy(vpg);
		vm_page_undirty(vpg);
		VM_OBJECT_UNLOCK(vobj);
		error = uiomove_fromphys(&vpg, offset, tlen, uio);
	} else {
		if (__predict_false(vobj->cache != NULL))
			vm_page_cache_free(vobj, idx, idx + 1);
		VM_OBJECT_UNLOCK(vobj);
		vpg = NULL;
	}
nocache:
	VM_OBJECT_LOCK(tobj);
	vm_object_pip_add(tobj, 1);
	tpg = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
	    VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
	if (tpg->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
			error = vm_pager_get_pages(tobj, &tpg, 1, 0);
			if (error != 0) {
				printf("tmpfs get pages from pager error [write]\n");
				goto out;
			}
		} else
			vm_page_zero_invalid(tpg, TRUE);
	}
	VM_OBJECT_UNLOCK(tobj);
	if (vpg == NULL)
		error = uiomove_fromphys(&tpg, offset, tlen, uio);
	else {
		KASSERT(vpg->valid == VM_PAGE_BITS_ALL, ("parts of vpg invalid"));
		pmap_copy_page(vpg, tpg);
	}
	VM_OBJECT_LOCK(tobj);
out:
	if (vobj != NULL)
		VM_OBJECT_LOCK(vobj);
	if (error == 0) {
		KASSERT(tpg->valid == VM_PAGE_BITS_ALL,
		    ("parts of tpg invalid"));
		vm_page_dirty(tpg);
	}
	vm_page_lock(tpg);
	vm_page_unwire(tpg, TRUE);
	vm_page_unlock(tpg);
	vm_page_wakeup(tpg);
	if (vpg != NULL)
		vm_page_wakeup(vpg);
	if (vobj != NULL)
		VM_OBJECT_UNLOCK(vobj);
	vm_object_pip_subtract(tobj, 1);
	VM_OBJECT_UNLOCK(tobj);

	return	(error);
}
Example #9
0
static int
pscnv_gem_pager_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
    vm_page_t *mres)
{
	struct drm_gem_object *gem_obj = vm_obj->handle;
	struct pscnv_bo *bo = gem_obj->driver_private;
	struct drm_device *dev = gem_obj->dev;
	struct drm_nouveau_private *dev_priv = dev->dev_private;
	vm_page_t m = NULL;
	vm_page_t oldm;
	vm_memattr_t mattr;
	vm_paddr_t paddr;
	const char *what;

	if (bo->chan) {
		paddr = dev_priv->fb_phys + offset +
			nvc0_fifo_ctrl_offs(dev, bo->chan->cid);
		mattr = VM_MEMATTR_UNCACHEABLE;
		what = "fifo";
	} else switch (bo->flags & PSCNV_GEM_MEMTYPE_MASK) {
	case PSCNV_GEM_VRAM_SMALL:
	case PSCNV_GEM_VRAM_LARGE:
		paddr = dev_priv->fb_phys + bo->map1->start + offset;
		mattr = VM_MEMATTR_WRITE_COMBINING;
		what = "vram";
		break;
	case PSCNV_GEM_SYSRAM_SNOOP:
	case PSCNV_GEM_SYSRAM_NOSNOOP:
		paddr = bo->dmapages[OFF_TO_IDX(offset)];
		mattr = VM_MEMATTR_WRITE_BACK;
		what = "sysram";
		break;
	default: return (EINVAL);
	}

	if (offset >= bo->size) {
		if (pscnv_mem_debug > 0)
			NV_WARN(dev, "Reading %p + %08llx (%s) is past max size %08llx\n",
				bo, offset, what, bo->size);
		return (VM_PAGER_ERROR);
	}
	DRM_LOCK(dev);
	if (pscnv_mem_debug > 0)
		NV_WARN(dev, "Connecting %p+%08llx (%s) at phys %010llx\n",
			bo, offset, what, paddr);
	vm_object_pip_add(vm_obj, 1);

	if (*mres != NULL) {
		oldm = *mres;
		vm_page_lock(oldm);
		vm_page_remove(oldm);
		vm_page_unlock(oldm);
		*mres = NULL;
	} else
		oldm = NULL;
	//VM_OBJECT_LOCK(vm_obj);
	m = vm_phys_fictitious_to_vm_page(paddr);
	if (m == NULL) {
		DRM_UNLOCK(dev);
		return -EFAULT;
	}
	KASSERT((m->flags & PG_FICTITIOUS) != 0,
	    ("not fictitious %p", m));
	KASSERT(m->wire_count == 1, ("wire_count not 1 %p", m));

	if ((m->flags & VPO_BUSY) != 0) {
		DRM_UNLOCK(dev);
		return -EFAULT;
	}
	pmap_page_set_memattr(m, mattr);
	m->valid = VM_PAGE_BITS_ALL;
	*mres = m;
	vm_page_lock(m);
	vm_page_insert(m, vm_obj, OFF_TO_IDX(offset));
	vm_page_unlock(m);
	vm_page_busy(m);

	printf("fault %p %jx %x phys %x", gem_obj, offset, prot,
	    m->phys_addr);
	DRM_UNLOCK(dev);
	if (oldm != NULL) {
		vm_page_lock(oldm);
		vm_page_free(oldm);
		vm_page_unlock(oldm);
	}
	vm_object_pip_wakeup(vm_obj);
	return (VM_PAGER_OK);
}