Пример #1
0
static void
free_pagelist(PAGELIST_T *pagelist, int actual)
{
	vm_page_t *pages;
	unsigned int num_pages, i;

	vcos_log_trace("free_pagelist - %x, %d", (unsigned int)pagelist, actual);

	num_pages =
		 (pagelist->length + pagelist->offset + PAGE_SIZE - 1) / PAGE_SIZE;

	pages = (vm_page_t *)(pagelist->addrs + num_pages);

	/* Deal with any partial cache lines (fragments) */
	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
		FRAGMENTS_T *fragments =
			 g_fragments_base + (pagelist->type -
					PAGELIST_READ_WITH_FRAGMENTS);
		int head_bytes, tail_bytes;

		if (actual >= 0)
		{
			/* XXXBSD: might be inefficient */
			void *page_address = pmap_mapdev(VM_PAGE_TO_PHYS(pages[0]), PAGE_SIZE*num_pages);
			if ((head_bytes = (CACHE_LINE_SIZE - pagelist->offset) & (CACHE_LINE_SIZE - 1)) != 0) {
				if (head_bytes > actual)
					head_bytes = actual;

				memcpy((char *)page_address +
						 pagelist->offset, fragments->headbuf,
						 head_bytes);
			}
			if ((head_bytes < actual) &&
				(tail_bytes =
				(pagelist->offset + actual) & (CACHE_LINE_SIZE -
										1)) != 0) {
				memcpy((char *)page_address + PAGE_SIZE*(num_pages - 1) +
						 ((pagelist->offset + actual) & (PAGE_SIZE -
									1) & ~(CACHE_LINE_SIZE - 1)),
						 fragments->tailbuf, tail_bytes);
			}
			pmap_qremove((vm_offset_t)page_address, PAGE_SIZE*num_pages);
		}

		mtx_lock(&g_free_fragments_mutex);
		*(FRAGMENTS_T **) fragments = g_free_fragments;
		g_free_fragments = fragments;
		mtx_unlock(&g_free_fragments_mutex);
		sema_post(&g_free_fragments_sema);
	}

	for (i = 0; i < num_pages; i++) {
		if (pagelist->type != PAGELIST_WRITE)
			vm_page_dirty(pages[i]);
	}

	vm_page_unhold_pages(pages, num_pages);

	free(pagelist, M_VCPAGELIST);
}
Пример #2
0
/*
 * Copy a binary buffer from kernel space to user space.
 *
 * Returns 0 on success, EFAULT on failure.
 */
int
copyout(const void *kaddr, void *udaddr, size_t len)
{
	struct vmspace *vm = curproc->p_vmspace;
	struct lwbuf *lwb;
	struct lwbuf lwb_cache;
	vm_page_t m;
	int error;
	size_t n;

	error = 0;
	while (len) {
		m = vm_fault_page(&vm->vm_map, trunc_page((vm_offset_t)udaddr),
				  VM_PROT_READ|VM_PROT_WRITE,
				  VM_FAULT_NORMAL, &error);
		if (error)
			break;
		n = PAGE_SIZE - ((vm_offset_t)udaddr & PAGE_MASK);
		if (n > len)
			n = len;
		lwb = lwbuf_alloc(m, &lwb_cache);
		bcopy(kaddr, (char *)lwbuf_kva(lwb) +
			     ((vm_offset_t)udaddr & PAGE_MASK), n);
		len -= n;
		udaddr = (char *)udaddr + n;
		kaddr = (const char *)kaddr + n;
		vm_page_dirty(m);
		lwbuf_free(lwb);
		vm_page_unhold(m);
	}
	return (error);
}
Пример #3
0
/*
 * Identify the physical page mapped at the given kernel virtual
 * address.  Insert this physical page into the given address space at
 * the given virtual address, replacing the physical page, if any,
 * that already exists there.
 */
static int
vm_pgmoveco(vm_map_t mapa, vm_offset_t kaddr, vm_offset_t uaddr)
{
	vm_map_t map = mapa;
	vm_page_t kern_pg, user_pg;
	vm_object_t uobject;
	vm_map_entry_t entry;
	vm_pindex_t upindex;
	vm_prot_t prot;
	boolean_t wired;

	KASSERT((uaddr & PAGE_MASK) == 0,
	    ("vm_pgmoveco: uaddr is not page aligned"));

	/*
	 * Herein the physical page is validated and dirtied.  It is
	 * unwired in sf_buf_mext().
	 */
	kern_pg = PHYS_TO_VM_PAGE(vtophys(kaddr));
	kern_pg->valid = VM_PAGE_BITS_ALL;
	KASSERT(kern_pg->queue == PQ_NONE && kern_pg->wire_count == 1,
	    ("vm_pgmoveco: kern_pg is not correctly wired"));

	if ((vm_map_lookup(&map, uaddr,
			   VM_PROT_WRITE, &entry, &uobject,
			   &upindex, &prot, &wired)) != KERN_SUCCESS) {
		return(EFAULT);
	}
	VM_OBJECT_LOCK(uobject);
retry:
	if ((user_pg = vm_page_lookup(uobject, upindex)) != NULL) {
		if (vm_page_sleep_if_busy(user_pg, TRUE, "vm_pgmoveco"))
			goto retry;
		vm_page_lock_queues();
		pmap_remove_all(user_pg);
		vm_page_free(user_pg);
	} else {
		/*
		 * Even if a physical page does not exist in the
		 * object chain's first object, a physical page from a
		 * backing object may be mapped read only.
		 */
		if (uobject->backing_object != NULL)
			pmap_remove(map->pmap, uaddr, uaddr + PAGE_SIZE);
		vm_page_lock_queues();
	}
	vm_page_insert(kern_pg, uobject, upindex);
	vm_page_dirty(kern_pg);
	vm_page_unlock_queues();
	VM_OBJECT_UNLOCK(uobject);
	vm_map_lookup_done(map, entry);
	return(KERN_SUCCESS);
}
Пример #4
0
/*
 * Cleanup an XIO so it can be destroyed.  The pages associated with the
 * XIO are released.
 */
void
xio_release(xio_t xio)
{
    int i;
    vm_page_t m;

    for (i = 0; i < xio->xio_npages; ++i) {
	m = xio->xio_pages[i];
	if (xio->xio_flags & XIOF_WRITE)
		vm_page_dirty(m);
	vm_page_unhold(m);
    }
    xio->xio_offset = 0;
    xio->xio_npages = 0;
    xio->xio_bytes = 0;
    xio->xio_error = ENOBUFS;
}
void
i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj)
{
	int page_count = obj->base.size >> PAGE_SHIFT;
	int i;

	if (obj->bit_17 == NULL)
		return;

	for (i = 0; i < page_count; i++) {
		char new_bit_17 = VM_PAGE_TO_PHYS(obj->pages[i]) >> 17;
		if ((new_bit_17 & 0x1) !=
		    (test_bit(i, obj->bit_17) != 0)) {
			i915_gem_swizzle_page(obj->pages[i]);
			vm_page_dirty(obj->pages[i]);
		}
	}
}
Пример #6
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;
}
Пример #7
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);
}
Пример #8
0
/*
 * Cleanup an XIO so it can be destroyed.  The pages associated with the
 * XIO are released.
 */
void
xio_release(xio_t xio)
{
    int i;
    vm_page_t m;

    lwkt_gettoken(&vm_token);
    crit_enter();
    for (i = 0; i < xio->xio_npages; ++i) {
	m = xio->xio_pages[i];
	if (xio->xio_flags & XIOF_WRITE)
		vm_page_dirty(m);
	vm_page_unhold(m);
    }
    crit_exit();
    lwkt_reltoken(&vm_token);
    xio->xio_offset = 0;
    xio->xio_npages = 0;
    xio->xio_bytes = 0;
    xio->xio_error = ENOBUFS;
}
Пример #9
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);
}
Пример #10
0
/*
 * Hold each of the physical pages that are mapped by the specified range of
 * virtual addresses, ["addr", "addr" + "len"), if those mappings are valid
 * and allow the specified types of access, "prot".  If all of the implied
 * pages are successfully held, then the number of held pages is returned
 * together with pointers to those pages in the array "ma".  However, if any
 * of the pages cannot be held, -1 is returned.
 */
int
vm_fault_quick_hold_pages(vm_map_t map, vm_offset_t addr, vm_size_t len,
    vm_prot_t prot, vm_page_t *ma, int max_count)
{
	vm_offset_t end, va;
	vm_page_t *mp;
	int count;
	boolean_t pmap_failed;

	if (len == 0)
		return (0);
	end = round_page(addr + len);	
	addr = trunc_page(addr);

	/*
	 * Check for illegal addresses.
	 */
	if (addr < vm_map_min(map) || addr > end || end > vm_map_max(map))
		return (-1);

	count = howmany(end - addr, PAGE_SIZE);
	if (count > max_count)
		panic("vm_fault_quick_hold_pages: count > max_count");

	/*
	 * Most likely, the physical pages are resident in the pmap, so it is
	 * faster to try pmap_extract_and_hold() first.
	 */
	pmap_failed = FALSE;
	for (mp = ma, va = addr; va < end; mp++, va += PAGE_SIZE) {
		*mp = pmap_extract_and_hold(map->pmap, va, prot);
		if (*mp == NULL)
			pmap_failed = TRUE;
		else if ((prot & VM_PROT_WRITE) != 0 &&
		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
			/*
			 * Explicitly dirty the physical page.  Otherwise, the
			 * caller's changes may go unnoticed because they are
			 * performed through an unmanaged mapping or by a DMA
			 * operation.
			 *
			 * The object lock is not held here.
			 * See vm_page_clear_dirty_mask().
			 */
			vm_page_dirty(*mp);
		}
	}
	if (pmap_failed) {
		/*
		 * One or more pages could not be held by the pmap.  Either no
		 * page was mapped at the specified virtual address or that
		 * mapping had insufficient permissions.  Attempt to fault in
		 * and hold these pages.
		 */
		for (mp = ma, va = addr; va < end; mp++, va += PAGE_SIZE)
			if (*mp == NULL && vm_fault_hold(map, va, prot,
			    VM_FAULT_NORMAL, mp) != KERN_SUCCESS)
				goto error;
	}
	return (count);
error:	
	for (mp = ma; mp < ma + count; mp++)
		if (*mp != NULL) {
			vm_page_lock(*mp);
			vm_page_unhold(*mp);
			vm_page_unlock(*mp);
		}
	return (-1);
}
Пример #11
0
/*
 * This routine takes a user's map, array of pages, number of pages, and flags
 * and then does the following:
 *  - validate that the user has access to those pages (flags indicates read
 *	or write) - if not fail
 *  - validate that count is enough to hold range number of pages - if not fail
 *  - fault in any non-resident pages
 *  - if the user is doing a read force a write fault for any COWed pages
 *  - if the user is doing a read mark all pages as dirty
 *  - hold all pages
 */
int
vm_fault_hold_user_pages(vm_map_t map, vm_offset_t addr, vm_page_t *mp,
    int count, vm_prot_t prot)
{
	vm_offset_t end, va;
	int faults, rv;
	pmap_t pmap;
	vm_page_t m, *pages;
	
	pmap = vm_map_pmap(map);
	pages = mp;
	addr &= ~PAGE_MASK;
	/*
	 * Check that virtual address range is legal
	 * This check is somewhat bogus as on some architectures kernel
	 * and user do not share VA - however, it appears that all FreeBSD
	 * architectures define it
	 */
	end = addr + (count * PAGE_SIZE);
	if (end > VM_MAXUSER_ADDRESS) {
		log(LOG_WARNING, "bad address passed to vm_fault_hold_user_pages");
		return (EFAULT);
	}

	/*
	 * First optimistically assume that all pages are resident 
	 * (and R/W if for write) if so just mark pages as held (and 
	 * dirty if for write) and return
	 */
	vm_page_lock_queues();
	for (pages = mp, faults = 0, va = addr; va < end;
	     va += PAGE_SIZE, pages++) {
		/*
		 * page queue mutex is recursable so this is OK
		 * it would be really nice if we had an unlocked
		 * version of this so we were only acquiring the 
		 * pmap lock 1 time as opposed to potentially
		 * many dozens of times
		 */
		*pages = m = pmap_extract_and_hold(pmap, va, prot);
		if (m == NULL) {
			faults++;
			continue;
		}
		/*
		 * Preemptively mark dirty - the pages
		 * will never have the modified bit set if
		 * they are only changed via DMA
		 */
		if (prot & VM_PROT_WRITE)
			vm_page_dirty(m);
		
	}
	vm_page_unlock_queues();
	
	if (faults == 0)
		return (0);
	
	/*
	 * Pages either have insufficient permissions or are not present
	 * trigger a fault where neccessary
	 * 
	 */
	rv = 0;
	for (pages = mp, va = addr; va < end; va += PAGE_SIZE, pages++) {
		/*
		 * Account for a very narrow race where the page may be
		 * taken away from us before it is held
		 */
		while (*pages == NULL) {
			rv = vm_fault(map, va, prot,
			    (prot & VM_PROT_WRITE) ? VM_FAULT_DIRTY : VM_FAULT_NORMAL);
			if (rv) 
				goto error;
			*pages = pmap_extract_and_hold(pmap, va, prot);
		}
	}
	return (0);
error:	
	log(LOG_WARNING,
	    "vm_fault bad return rv=%d va=0x%zx\n", rv, va);
	vm_page_lock_queues();
	for (pages = mp, va = addr; va < end; va += PAGE_SIZE, pages++)
		if (*pages) {
			vm_page_unhold(*pages);
			*pages = NULL;
		}
	vm_page_unlock_queues();
	return (EFAULT);
}
Пример #12
0
static int
shm_dotruncate(struct shmfd *shmfd, off_t length)
{
	vm_object_t object;
	vm_page_t m, ma[1];
	vm_pindex_t idx, nobjsize;
	vm_ooffset_t delta;
	int base, rv;

	object = shmfd->shm_object;
	VM_OBJECT_LOCK(object);
	if (length == shmfd->shm_size) {
		VM_OBJECT_UNLOCK(object);
		return (0);
	}
	nobjsize = OFF_TO_IDX(length + PAGE_MASK);

	/* Are we shrinking?  If so, trim the end. */
	if (length < shmfd->shm_size) {
		/*
		 * Disallow any requests to shrink the size if this
		 * object is mapped into the kernel.
		 */
		if (shmfd->shm_kmappings > 0) {
			VM_OBJECT_UNLOCK(object);
			return (EBUSY);
		}

		/*
		 * Zero the truncated part of the last page.
		 */
		base = length & PAGE_MASK;
		if (base != 0) {
			idx = OFF_TO_IDX(length);
retry:
			m = vm_page_lookup(object, idx);
			if (m != NULL) {
				if ((m->oflags & VPO_BUSY) != 0 ||
				    m->busy != 0) {
					vm_page_sleep(m, "shmtrc");
					goto retry;
				}
			} else if (vm_pager_has_page(object, idx, NULL, NULL)) {
				m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL);
				if (m == NULL) {
					VM_OBJECT_UNLOCK(object);
					VM_WAIT;
					VM_OBJECT_LOCK(object);
					goto retry;
				} else if (m->valid != VM_PAGE_BITS_ALL) {
					ma[0] = m;
					rv = vm_pager_get_pages(object, ma, 1,
					    0);
					m = vm_page_lookup(object, idx);
				} else
					/* A cached page was reactivated. */
					rv = VM_PAGER_OK;
				vm_page_lock(m);
				if (rv == VM_PAGER_OK) {
					vm_page_deactivate(m);
					vm_page_unlock(m);
					vm_page_wakeup(m);
				} else {
					vm_page_free(m);
					vm_page_unlock(m);
					VM_OBJECT_UNLOCK(object);
					return (EIO);
				}
			}
			if (m != NULL) {
				pmap_zero_page_area(m, base, PAGE_SIZE - base);
				KASSERT(m->valid == VM_PAGE_BITS_ALL,
				    ("shm_dotruncate: page %p is invalid", m));
				vm_page_dirty(m);
				vm_pager_page_unswapped(m);
			}
		}
		delta = ptoa(object->size - nobjsize);

		/* Toss in memory pages. */
		if (nobjsize < object->size)
			vm_object_page_remove(object, nobjsize, object->size,
			    0);

		/* Toss pages from swap. */
		if (object->type == OBJT_SWAP)
			swap_pager_freespace(object, nobjsize, delta);

		/* Free the swap accounted for shm */
		swap_release_by_cred(delta, object->cred);
		object->charge -= delta;
	} else {
		/* Attempt to reserve the swap */
		delta = ptoa(nobjsize - object->size);
		if (!swap_reserve_by_cred(delta, object->cred)) {
			VM_OBJECT_UNLOCK(object);
			return (ENOMEM);
		}
		object->charge += delta;
	}
	shmfd->shm_size = length;
	mtx_lock(&shm_timestamp_lock);
	vfs_timestamp(&shmfd->shm_ctime);
	shmfd->shm_mtime = shmfd->shm_ctime;
	mtx_unlock(&shm_timestamp_lock);
	object->size = nobjsize;
	VM_OBJECT_UNLOCK(object);
	return (0);
}
Пример #13
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, rv;

	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);
	tpg = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
	    VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
	if (tpg->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
			rv = vm_pager_get_pages(tobj, &tpg, 1, 0);
			if (rv != VM_PAGER_OK) {
				vm_page_lock(tpg);
				vm_page_free(tpg);
				vm_page_unlock(tpg);
				error = EIO;
				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);
	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);
out:
	VM_OBJECT_UNLOCK(tobj);
	if (vpg != NULL) {
		VM_OBJECT_LOCK(vobj);
		vm_page_wakeup(vpg);
		VM_OBJECT_UNLOCK(vobj);
	}

	return	(error);
}
Пример #14
0
static int
uiomove_object_page(vm_object_t obj, size_t len, struct uio *uio)
{
	vm_page_t m;
	vm_pindex_t idx;
	size_t tlen;
	int error, offset, rv;

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

	VM_OBJECT_WLOCK(obj);

	/*
	 * Parallel reads of the page content from disk are prevented
	 * by exclusive busy.
	 *
	 * Although the tmpfs vnode lock is held here, it is
	 * nonetheless safe to sleep waiting for a free page.  The
	 * pageout daemon does not need to acquire the tmpfs vnode
	 * lock to page out tobj's pages because tobj is a OBJT_SWAP
	 * type object.
	 */
	m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL);
	if (m->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(obj, idx, NULL, NULL)) {
			rv = vm_pager_get_pages(obj, &m, 1, 0);
			m = vm_page_lookup(obj, idx);
			if (m == NULL) {
				printf(
		    "uiomove_object: vm_obj %p idx %jd null lookup rv %d\n",
				    obj, idx, rv);
				VM_OBJECT_WUNLOCK(obj);
				return (EIO);
			}
			if (rv != VM_PAGER_OK) {
				printf(
	    "uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n",
				    obj, idx, m->valid, rv);
				vm_page_lock(m);
				vm_page_free(m);
				vm_page_unlock(m);
				VM_OBJECT_WUNLOCK(obj);
				return (EIO);
			}
		} else
			vm_page_zero_invalid(m, TRUE);
	}
	vm_page_xunbusy(m);
	vm_page_lock(m);
	vm_page_hold(m);
	vm_page_unlock(m);
	VM_OBJECT_WUNLOCK(obj);
	error = uiomove_fromphys(&m, offset, tlen, uio);
	if (uio->uio_rw == UIO_WRITE && error == 0) {
		VM_OBJECT_WLOCK(obj);
		vm_page_dirty(m);
		VM_OBJECT_WUNLOCK(obj);
	}
	vm_page_lock(m);
	vm_page_unhold(m);
	if (m->queue == PQ_NONE) {
		vm_page_deactivate(m);
	} else {
		/* Requeue to maintain LRU ordering. */
		vm_page_requeue(m);
	}
	vm_page_unlock(m);

	return (error);
}
Пример #15
0
static void
free_pagelist(BULKINFO_T *bi, int actual)
{
    vm_page_t*pages;
    unsigned int num_pages, i;
    void *page_address;
    PAGELIST_T *pagelist;

    pagelist = bi->pagelist;

    vchiq_log_trace(vchiq_arm_log_level,
                    "free_pagelist - %x, %d", (unsigned int)pagelist, actual);

    num_pages =
        (pagelist->length + pagelist->offset + PAGE_SIZE - 1) /
        PAGE_SIZE;

    pages = (vm_page_t*)(pagelist->addrs + num_pages);

    /* Deal with any partial cache lines (fragments) */
    if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
        FRAGMENTS_T *fragments = g_fragments_base +
                                 (pagelist->type - PAGELIST_READ_WITH_FRAGMENTS);
        int head_bytes, tail_bytes;
        head_bytes = (CACHE_LINE_SIZE - pagelist->offset) &
                     (CACHE_LINE_SIZE - 1);
        tail_bytes = (pagelist->offset + actual) &
                     (CACHE_LINE_SIZE - 1);

        if ((actual >= 0) && (head_bytes != 0)) {
            if (head_bytes > actual)
                head_bytes = actual;

            memcpy((char *)bi->buf,
                   fragments->headbuf,
                   head_bytes);
        }

        if ((actual >= 0) && (head_bytes < actual) &&
                (tail_bytes != 0)) {
            memcpy((char *)bi->buf + actual - tail_bytes,
                   fragments->tailbuf, tail_bytes);
        }

        down(&g_free_fragments_mutex);
        *(FRAGMENTS_T **) fragments = g_free_fragments;
        g_free_fragments = fragments;
        up(&g_free_fragments_mutex);
        up(&g_free_fragments_sema);
    }

    for (i = 0; i < num_pages; i++) {
        if (pagelist->type != PAGELIST_WRITE)
            vm_page_dirty(pages[i]);
    }

    vm_page_unhold_pages(pages, num_pages);

    bus_dmamap_unload(bi->pagelist_dma_tag, bi->pagelist_dma_map);
    bus_dmamem_free(bi->pagelist_dma_tag, bi->pagelist, bi->pagelist_dma_map);
    bus_dmamap_destroy(bi->pagelist_dma_tag, bi->pagelist_dma_map);
    bus_dma_tag_destroy(bi->pagelist_dma_tag);

    free(bi, M_VCPAGELIST);
}