On Fri, 27 Dec 2019 at 12:42, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 12/26/19 6:25 PM, Sughosh Ganu wrote:
Add a driver for the virtio-rng device on the qemu platform. The device uses pci as a transport medium. The driver can be enabled with the following configs
CONFIG_VIRTIO CONFIG_DM_RNG CONFIG_VIRTIO_PCI CONFIG_VIRTIO_RNG
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org
Changes since V4:
Return number of bytes read on a successful read, and a -ve value on error.
drivers/virtio/Kconfig | 6 +++ drivers/virtio/Makefile | 1 + drivers/virtio/virtio-uclass.c | 1 + drivers/virtio/virtio_rng.c | 85
++++++++++++++++++++++++++++++++++++++++++
include/virtio.h | 4 +- 5 files changed, 96 insertions(+), 1 deletion(-) create mode 100644 drivers/virtio/virtio_rng.c
<snip>
diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c new file mode 100644 index 0000000..fda8d04 --- /dev/null +++ b/drivers/virtio/virtio_rng.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Copyright (c) 2019, Linaro Limited
- */
+#include <common.h> +#include <dm.h> +#include <rng.h> +#include <virtio_types.h> +#include <virtio.h> +#include <virtio_ring.h>
+struct virtio_rng_priv {
struct virtqueue *rng_vq;+};
+static int virtio_rng_read(struct udevice *dev, void *data, size_t len) +{
int ret;unsigned int rsize = 0;struct virtio_sg sg;struct virtio_sg *sgs[1];struct virtio_rng_priv *priv = dev_get_priv(dev);/** Only INT_MAX number of bytes can be returned. If more* bytes need to be read, the caller must do it in a loop.*/if (len > INT_MAX)len = INT_MAX;sg.addr = data;sg.length = len;sgs[0] = &sg;ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);if (ret)return ret;virtqueue_kick(priv->rng_vq);while (!virtqueue_get_buf(priv->rng_vq, &rsize))This code assumes that data is 4 byte aligned and may lead to a crash due to missing alignment on ARM in function le32_to_cpu().
Are you referring to the virtqueue_get_buf function. Not sure I understand. In any case, I will be sending an updated version which moves the loop into the driver, as you had commented on my other patch.
-sughosh