mirror of
https://github.com/AsahiLinux/u-boot
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03de305ec4
As part of bringing the master branch back in to next, we need to allow for all of these changes to exist here. Reported-by: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Tom Rini <trini@konsulko.com>
96 lines
1.9 KiB
C
96 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2019, Linaro Limited
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*/
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#include <dm.h>
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#include <log.h>
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#include <rng.h>
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#include <virtio_types.h>
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#include <virtio.h>
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#include <virtio_ring.h>
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#define BUFFER_SIZE 16UL
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struct virtio_rng_priv {
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struct virtqueue *rng_vq;
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};
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static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
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{
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int ret;
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unsigned int rsize = 1;
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unsigned char buf[BUFFER_SIZE] __aligned(4);
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unsigned char *ptr = data;
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struct virtio_sg sg;
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struct virtio_sg *sgs[1];
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struct virtio_rng_priv *priv = dev_get_priv(dev);
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while (len) {
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sg.addr = buf;
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/*
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* Work around implementations which always return 8 bytes
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* less than requested, down to 0 bytes, which would
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* cause an endless loop otherwise.
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*/
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sg.length = min(rsize ? len : len + 8, sizeof(buf));
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sgs[0] = &sg;
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ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);
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if (ret)
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return ret;
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virtqueue_kick(priv->rng_vq);
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while (!virtqueue_get_buf(priv->rng_vq, &rsize))
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;
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if (rsize > sg.length)
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return -EIO;
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memcpy(ptr, buf, rsize);
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len -= rsize;
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ptr += rsize;
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}
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return 0;
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}
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static int virtio_rng_bind(struct udevice *dev)
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{
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struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
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/* Indicate what driver features we support */
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virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
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return 0;
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}
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static int virtio_rng_probe(struct udevice *dev)
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{
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struct virtio_rng_priv *priv = dev_get_priv(dev);
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int ret;
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ret = virtio_find_vqs(dev, 1, &priv->rng_vq);
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if (ret < 0) {
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debug("%s: virtio_find_vqs failed\n", __func__);
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return ret;
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}
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return 0;
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}
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static const struct dm_rng_ops virtio_rng_ops = {
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.read = virtio_rng_read,
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};
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U_BOOT_DRIVER(virtio_rng) = {
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.name = VIRTIO_RNG_DRV_NAME,
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.id = UCLASS_RNG,
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.bind = virtio_rng_bind,
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.probe = virtio_rng_probe,
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.remove = virtio_reset,
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.ops = &virtio_rng_ops,
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.priv_auto = sizeof(struct virtio_rng_priv),
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.flags = DM_FLAG_ACTIVE_DMA,
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};
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