70 	struct virtio_balloon *vb;  in balloon_ack()  local
73 	vb = vq->vq_ops->get_buf(vq, &len);  in balloon_ack()
74 	if (vb)  in balloon_ack()
75 		complete(&vb->acked);  in balloon_ack()
78 static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)  in tell_host()  argument
82 	sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns);  in tell_host()
84 	init_completion(&vb->acked);  in tell_host()
87 	if (vq->vq_ops->add_buf(vq, &sg, 1, 0, vb) != 0)  in tell_host()
92 	wait_for_completion(&vb->acked);  in tell_host()
95 static void fill_balloon(struct virtio_balloon *vb, size_t num)  in fill_balloon()  argument
98 	num = min(num, ARRAY_SIZE(vb->pfns));  in fill_balloon()
100 	for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {  in fill_balloon()
104 				dev_printk(KERN_INFO, &vb->vdev->dev,  in fill_balloon()
111 		vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);  in fill_balloon()
113 		vb->num_pages++;  in fill_balloon()
114 		list_add(&page->lru, &vb->pages);  in fill_balloon()
118 	if (vb->num_pfns == 0)  in fill_balloon()
121 	tell_host(vb, vb->inflate_vq);  in fill_balloon()
134 static void leak_balloon(struct virtio_balloon *vb, size_t num)  in leak_balloon()  argument
139 	num = min(num, ARRAY_SIZE(vb->pfns));  in leak_balloon()
141 	for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {  in leak_balloon()
142 		page = list_first_entry(&vb->pages, struct page, lru);  in leak_balloon()
144 		vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);  in leak_balloon()
145 		vb->num_pages--;  in leak_balloon()
148 	if (vb->tell_host_first) {  in leak_balloon()
149 		tell_host(vb, vb->deflate_vq);  in leak_balloon()
150 		release_pages_by_pfn(vb->pfns, vb->num_pfns);  in leak_balloon()
152 		release_pages_by_pfn(vb->pfns, vb->num_pfns);  in leak_balloon()
153 		tell_host(vb, vb->deflate_vq);  in leak_balloon()
159 	struct virtio_balloon *vb = vdev->priv;  in virtballoon_changed()  local
161 	wake_up(&vb->config_change);  in virtballoon_changed()
164 static inline s64 towards_target(struct virtio_balloon *vb)  in towards_target()  argument
167 	vb->vdev->config->get(vb->vdev,  in towards_target()
170 	return (s64)v - vb->num_pages;  in towards_target()
173 static void update_balloon_size(struct virtio_balloon *vb)  in update_balloon_size()  argument
175 	__le32 actual = cpu_to_le32(vb->num_pages);  in update_balloon_size()
177 	vb->vdev->config->set(vb->vdev,  in update_balloon_size()
184 	struct virtio_balloon *vb = _vballoon;  in balloon()  local
191 		wait_event_interruptible(vb->config_change,  in balloon()
192 					 (diff = towards_target(vb)) != 0  in balloon()
195 			fill_balloon(vb, diff);  in balloon()
197 			leak_balloon(vb, -diff);  in balloon()
198 		update_balloon_size(vb);  in balloon()
205 	struct virtio_balloon *vb;  in virtballoon_probe()  local
208 	vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);  in virtballoon_probe()
209 	if (!vb) {  in virtballoon_probe()
214 	INIT_LIST_HEAD(&vb->pages);  in virtballoon_probe()
215 	vb->num_pages = 0;  in virtballoon_probe()
216 	init_waitqueue_head(&vb->config_change);  in virtballoon_probe()
217 	vb->vdev = vdev;  in virtballoon_probe()
220 	vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack);  in virtballoon_probe()
221 	if (IS_ERR(vb->inflate_vq)) {  in virtballoon_probe()
222 		err = PTR_ERR(vb->inflate_vq);  in virtballoon_probe()
226 	vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack);  in virtballoon_probe()
227 	if (IS_ERR(vb->deflate_vq)) {  in virtballoon_probe()
228 		err = PTR_ERR(vb->deflate_vq);  in virtballoon_probe()
232 	vb->thread = kthread_run(balloon, vb, "vballoon");  in virtballoon_probe()
233 	if (IS_ERR(vb->thread)) {  in virtballoon_probe()
234 		err = PTR_ERR(vb->thread);  in virtballoon_probe()
238 	vb->tell_host_first  in virtballoon_probe()
244 	vdev->config->del_vq(vb->deflate_vq);  in virtballoon_probe()
246 	vdev->config->del_vq(vb->inflate_vq);  in virtballoon_probe()
248 	kfree(vb);  in virtballoon_probe()
255 	struct virtio_balloon *vb = vdev->priv;  in virtballoon_remove()  local
257 	kthread_stop(vb->thread);  in virtballoon_remove()
260 	while (vb->num_pages)  in virtballoon_remove()
261 		leak_balloon(vb, vb->num_pages);  in virtballoon_remove()
266 	vdev->config->del_vq(vb->deflate_vq);  in virtballoon_remove()
267 	vdev->config->del_vq(vb->inflate_vq);  in virtballoon_remove()
268 	kfree(vb);  in virtballoon_remove()