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>
diff --git a/drivers/virtio/virtio_blk.c b/drivers/virtio/virtio_blk.c
new file mode 100644
index 0000000..e793e34
--- /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,
+};