virtio: Add block driver support

This adds virtio block device driver support.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/virtio/virtio_blk.c b/drivers/virtio/virtio_blk.c
new file mode 100644
index 0000000000..e793e34e83
--- /dev/null
+++ b/drivers/virtio/virtio_blk.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <blk.h>
+#include <dm.h>
+#include <virtio_types.h>
+#include <virtio.h>
+#include <virtio_ring.h>
+#include "virtio_blk.h"
+
+struct virtio_blk_priv {
+	struct virtqueue *vq;
+};
+
+static ulong virtio_blk_do_req(struct udevice *dev, u64 sector,
+			       lbaint_t blkcnt, void *buffer, u32 type)
+{
+	struct virtio_blk_priv *priv = dev_get_priv(dev);
+	unsigned int num_out = 0, num_in = 0;
+	struct virtio_sg *sgs[3];
+	u8 status;
+	int ret;
+
+	struct virtio_blk_outhdr out_hdr = {
+		.type = cpu_to_virtio32(dev, type),
+		.sector = cpu_to_virtio64(dev, sector),
+	};
+	struct virtio_sg hdr_sg = { &out_hdr, sizeof(out_hdr) };
+	struct virtio_sg data_sg = { buffer, blkcnt * 512 };
+	struct virtio_sg status_sg = { &status, sizeof(status) };
+
+	sgs[num_out++] = &hdr_sg;
+
+	if (type & VIRTIO_BLK_T_OUT)
+		sgs[num_out++] = &data_sg;
+	else
+		sgs[num_out + num_in++] = &data_sg;
+
+	sgs[num_out + num_in++] = &status_sg;
+
+	ret = virtqueue_add(priv->vq, sgs, num_out, num_in);
+	if (ret)
+		return ret;
+
+	virtqueue_kick(priv->vq);
+
+	while (!virtqueue_get_buf(priv->vq, NULL))
+		;
+
+	return status == VIRTIO_BLK_S_OK ? blkcnt : -EIO;
+}
+
+static ulong virtio_blk_read(struct udevice *dev, lbaint_t start,
+			     lbaint_t blkcnt, void *buffer)
+{
+	return virtio_blk_do_req(dev, start, blkcnt, buffer,
+				 VIRTIO_BLK_T_IN);
+}
+
+static ulong virtio_blk_write(struct udevice *dev, lbaint_t start,
+			      lbaint_t blkcnt, const void *buffer)
+{
+	return virtio_blk_do_req(dev, start, blkcnt, (void *)buffer,
+				 VIRTIO_BLK_T_OUT);
+}
+
+static int virtio_blk_bind(struct udevice *dev)
+{
+	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
+	struct blk_desc *desc = dev_get_uclass_platdata(dev);
+	int devnum;
+
+	desc->if_type = IF_TYPE_VIRTIO;
+	/*
+	 * Initialize the devnum to -ENODEV. This is to make sure that
+	 * blk_next_free_devnum() works as expected, since the default
+	 * value 0 is a valid devnum.
+	 */
+	desc->devnum = -ENODEV;
+	devnum = blk_next_free_devnum(IF_TYPE_VIRTIO);
+	if (devnum < 0)
+		return devnum;
+	desc->devnum = devnum;
+	desc->part_type = PART_TYPE_UNKNOWN;
+	/*
+	 * virtio mmio transport supplies string identification for us,
+	 * while pci trnasport uses a 2-byte subvendor value.
+	 */
+	if (uc_priv->vendor >> 16)
+		sprintf(desc->vendor, "%s", (char *)&uc_priv->vendor);
+	else
+		sprintf(desc->vendor, "%04x", uc_priv->vendor);
+	desc->bdev = dev;
+
+	/* Indicate what driver features we support */
+	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
+
+	return 0;
+}
+
+static int virtio_blk_probe(struct udevice *dev)
+{
+	struct virtio_blk_priv *priv = dev_get_priv(dev);
+	struct blk_desc *desc = dev_get_uclass_platdata(dev);
+	u64 cap;
+	int ret;
+
+	ret = virtio_find_vqs(dev, 1, &priv->vq);
+	if (ret)
+		return ret;
+
+	desc->blksz = 512;
+	virtio_cread(dev, struct virtio_blk_config, capacity, &cap);
+	desc->lba = cap;
+
+	return 0;
+}
+
+static const struct blk_ops virtio_blk_ops = {
+	.read	= virtio_blk_read,
+	.write	= virtio_blk_write,
+};
+
+U_BOOT_DRIVER(virtio_blk) = {
+	.name	= VIRTIO_BLK_DRV_NAME,
+	.id	= UCLASS_BLK,
+	.ops	= &virtio_blk_ops,
+	.bind	= virtio_blk_bind,
+	.probe	= virtio_blk_probe,
+	.remove	= virtio_reset,
+	.priv_auto_alloc_size = sizeof(struct virtio_blk_priv),
+	.flags	= DM_FLAG_ACTIVE_DMA,
+};