Release 4.11 drivers/char/hw_random/virtio-rng.c
/*
* Randomness driver for virtio
* Copyright (C) 2007, 2008 Rusty Russell IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/scatterlist.h>
#include <linux/spinlock.h>
#include <linux/virtio.h>
#include <linux/virtio_rng.h>
#include <linux/module.h>
static DEFINE_IDA(rng_index_ida);
struct virtrng_info {
struct hwrng hwrng;
struct virtqueue *vq;
struct completion have_data;
char name[25];
unsigned int data_avail;
int index;
bool busy;
bool hwrng_register_done;
bool hwrng_removed;
};
static void random_recv_done(struct virtqueue *vq)
{
struct virtrng_info *vi = vq->vdev->priv;
/* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
if (!virtqueue_get_buf(vi->vq, &vi->data_avail))
return;
complete(&vi->have_data);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Rusty Russell | 26 | 55.32% | 1 | 20.00% |
| Amos Kong | 17 | 36.17% | 1 | 20.00% |
| Christian Bornträger | 2 | 4.26% | 1 | 20.00% |
| Michael S. Tsirkin | 1 | 2.13% | 1 | 20.00% |
| Ian Molton | 1 | 2.13% | 1 | 20.00% |
| Total | 47 | 100.00% | 5 | 100.00% |
/* The host will fill any buffer we give it with sweet, sweet randomness. */
static void register_buffer(struct virtrng_info *vi, u8 *buf, size_t size)
{
struct scatterlist sg;
sg_init_one(&sg, buf, size);
/* There should always be room for one buffer. */
virtqueue_add_inbuf(vi->vq, &sg, 1, buf, GFP_KERNEL);
virtqueue_kick(vi->vq);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Rusty Russell | 37 | 66.07% | 3 | 50.00% |
| Ian Molton | 9 | 16.07% | 1 | 16.67% |
| Amos Kong | 9 | 16.07% | 1 | 16.67% |
| Michael S. Tsirkin | 1 | 1.79% | 1 | 16.67% |
| Total | 56 | 100.00% | 6 | 100.00% |
static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
{
int ret;
struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
if (vi->hwrng_removed)
return -ENODEV;
if (!vi->busy) {
vi->busy = true;
init_completion(&vi->have_data);
register_buffer(vi, buf, size);
}
if (!wait)
return 0;
ret = wait_for_completion_killable(&vi->have_data);
if (ret < 0)
return ret;
vi->busy = false;
return vi->data_avail;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amos Kong | 38 | 32.20% | 2 | 33.33% |
| Ian Molton | 33 | 27.97% | 1 | 16.67% |
| Rusty Russell | 32 | 27.12% | 2 | 33.33% |
| Amit Shah | 15 | 12.71% | 1 | 16.67% |
| Total | 118 | 100.00% | 6 | 100.00% |
static void virtio_cleanup(struct hwrng *rng)
{
struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
if (vi->busy)
wait_for_completion(&vi->have_data);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amos Kong | 18 | 46.15% | 1 | 33.33% |
| Rusty Russell | 17 | 43.59% | 1 | 33.33% |
| Ian Molton | 4 | 10.26% | 1 | 33.33% |
| Total | 39 | 100.00% | 3 | 100.00% |
static int probe_common(struct virtio_device *vdev)
{
int err, index;
struct virtrng_info *vi = NULL;
vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);
if (!vi)
return -ENOMEM;
vi->index = index = ida_simple_get(&rng_index_ida, 0, 0, GFP_KERNEL);
if (index < 0) {
err = index;
goto err_ida;
}
sprintf(vi->name, "virtio_rng.%d", index);
init_completion(&vi->have_data);
vi->hwrng = (struct hwrng) {
.read = virtio_read,
.cleanup = virtio_cleanup,
.priv = (unsigned long)vi,
.name = vi->name,
.quality = 1000,
};
vdev->priv = vi;
/* We expect a single virtqueue. */
vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");
if (IS_ERR(vi->vq)) {
err = PTR_ERR(vi->vq);
goto err_find;
}
return 0;
err_find:
ida_simple_remove(&rng_index_ida, index);
err_ida:
kfree(vi);
return err;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amos Kong | 69 | 33.82% | 1 | 10.00% |
| Sasha Levin | 64 | 31.37% | 2 | 20.00% |
| Rusty Russell | 35 | 17.16% | 2 | 20.00% |
| Michael S. Tsirkin | 23 | 11.27% | 2 | 20.00% |
| Amit Shah | 13 | 6.37% | 3 | 30.00% |
| Total | 204 | 100.00% | 10 | 100.00% |
static void remove_common(struct virtio_device *vdev)
{
struct virtrng_info *vi = vdev->priv;
vi->hwrng_removed = true;
vi->data_avail = 0;
complete(&vi->have_data);
vdev->config->reset(vdev);
vi->busy = false;
if (vi->hwrng_register_done)
hwrng_unregister(&vi->hwrng);
vdev->config->del_vqs(vdev);
ida_simple_remove(&rng_index_ida, vi->index);
kfree(vi);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amos Kong | 44 | 47.31% | 3 | 33.33% |
| Rusty Russell | 28 | 30.11% | 1 | 11.11% |
| Amit Shah | 14 | 15.05% | 3 | 33.33% |
| Sasha Levin | 5 | 5.38% | 1 | 11.11% |
| Michael S. Tsirkin | 2 | 2.15% | 1 | 11.11% |
| Total | 93 | 100.00% | 9 | 100.00% |
static int virtrng_probe(struct virtio_device *vdev)
{
return probe_common(vdev);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amit Shah | 17 | 100.00% | 1 | 100.00% |
| Total | 17 | 100.00% | 1 | 100.00% |
static void virtrng_remove(struct virtio_device *vdev)
{
remove_common(vdev);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amit Shah | 13 | 81.25% | 1 | 50.00% |
| Rusty Russell | 3 | 18.75% | 1 | 50.00% |
| Total | 16 | 100.00% | 2 | 100.00% |
static void virtrng_scan(struct virtio_device *vdev)
{
struct virtrng_info *vi = vdev->priv;
int err;
err = hwrng_register(&vi->hwrng);
if (!err)
vi->hwrng_register_done = true;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amit Shah | 44 | 100.00% | 1 | 100.00% |
| Total | 44 | 100.00% | 1 | 100.00% |
#ifdef CONFIG_PM_SLEEP
static int virtrng_freeze(struct virtio_device *vdev)
{
remove_common(vdev);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amit Shah | 19 | 100.00% | 1 | 100.00% |
| Total | 19 | 100.00% | 1 | 100.00% |
static int virtrng_restore(struct virtio_device *vdev)
{
return probe_common(vdev);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Amit Shah | 17 | 100.00% | 1 | 100.00% |
| Total | 17 | 100.00% | 1 | 100.00% |
#endif
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_RNG, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static struct virtio_driver virtio_rng_driver = {
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtrng_probe,
.remove = virtrng_remove,
.scan = virtrng_scan,
#ifdef CONFIG_PM_SLEEP
.freeze = virtrng_freeze,
.restore = virtrng_restore,
#endif
};
module_virtio_driver(virtio_rng_driver);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio random number driver");
MODULE_LICENSE("GPL");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Rusty Russell | 277 | 32.94% | 6 | 22.22% |
| Amos Kong | 210 | 24.97% | 3 | 11.11% |
| Amit Shah | 187 | 22.24% | 8 | 29.63% |
| Sasha Levin | 84 | 9.99% | 2 | 7.41% |
| Ian Molton | 48 | 5.71% | 1 | 3.70% |
| Michael S. Tsirkin | 27 | 3.21% | 3 | 11.11% |
| Paul Gortmaker | 3 | 0.36% | 1 | 3.70% |
| Christian Bornträger | 2 | 0.24% | 1 | 3.70% |
| Aaron Lu | 2 | 0.24% | 1 | 3.70% |
| Jeff Mahoney | 1 | 0.12% | 1 | 3.70% |
| Total | 841 | 100.00% | 27 | 100.00% |
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