char/hw_random/virtio-rng.c

40 	struct virtrng_info *vi = vq->vdev->priv;
44 	if (!virtqueue_get_buf(vi->vq, &len))
47 	smp_store_release(&vi->data_avail, len);
48 	complete(&vi->have_data);
51 static void request_entropy(struct virtrng_info *vi)
55 	reinit_completion(&vi->have_data);
56 	vi->data_idx = 0;
58 	sg_init_one(&sg, vi->data, sizeof(vi->data));
61 	virtqueue_add_inbuf(vi->vq, &sg, 1, vi->data, GFP_KERNEL);
63 	virtqueue_kick(vi->vq);
66 static unsigned int copy_data(struct virtrng_info *vi, void *buf,
69 	size = min_t(unsigned int, size, vi->data_avail);
70 	memcpy(buf, vi->data + vi->data_idx, size);
71 	vi->data_idx += size;
72 	vi->data_avail -= size;
73 	if (vi->data_avail == 0)
74 		request_entropy(vi);
81 	struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
85 	if (vi->hwrng_removed)
91 	if (smp_load_acquire(&vi->data_avail)) {
92 		chunk = copy_data(vi, buf, size);
105 		ret = wait_for_completion_killable(&vi->have_data);
108 		/* if vi->data_avail is 0, we have been interrupted
111 		if (vi->data_avail == 0)
114 		chunk = copy_data(vi, buf + read, size);
124 	struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
126 	complete(&vi->have_data);
132 	struct virtrng_info *vi = NULL;
134 	vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);
135 	if (!vi)
138 	vi->index = index = ida_alloc(&rng_index_ida, GFP_KERNEL);
143 	sprintf(vi->name, "virtio_rng.%d", index);
144 	init_completion(&vi->have_data);
146 	vi->hwrng = (struct hwrng) {
149 		.priv = (unsigned long)vi,
150 		.name = vi->name,
152 	vdev->priv = vi;
155 	vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");
156 	if (IS_ERR(vi->vq)) {
157 		err = PTR_ERR(vi->vq);
164 	request_entropy(vi);
171 	kfree(vi);
177 	struct virtrng_info *vi = vdev->priv;
179 	vi->hwrng_removed = true;
180 	vi->data_avail = 0;
181 	vi->data_idx = 0;
182 	complete(&vi->have_data);
183 	if (vi->hwrng_register_done)
184 		hwrng_unregister(&vi->hwrng);
187 	ida_free(&rng_index_ida, vi->index);
188 	kfree(vi);
203 	struct virtrng_info *vi = vdev->priv;
206 	err = hwrng_register(&vi->hwrng);
208 		vi->hwrng_register_done = true;
223 		struct virtrng_info *vi = vdev->priv;
230 		vi->hwrng_removed = true;
231 		err = hwrng_register(&vi->hwrng);
233 			vi->hwrng_register_done = true;
234 			vi->hwrng_removed = false;