virtio: Add a Sandbox transport driver

This driver provides support for Sandbox implementation of virtio
transport driver which is used for testing purpose only.

Two drivers are provided. The 2nd one is a driver that lacks the
'notify' op.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 242 insertions, 0 deletions

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 753912f0f9..a9d5fd07b7 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -37,6 +37,14 @@ config VIRTIO_PCI
           This driver provides support for virtio based paravirtual device
           drivers over PCI.
 
+config VIRTIO_SANDBOX
+        bool "Sandbox driver for virtio devices"
+        depends on SANDBOX
+        select VIRTIO
+        help
+          This driver provides support for Sandbox implementation of virtio
+          transport driver which is used for testing purpose only.
+
 config VIRTIO_NET
         bool "virtio net driver"
         depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 072fb563b3..4579044ae3 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -6,5 +6,6 @@
 obj-y += virtio-uclass.o virtio_ring.o
 obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o
+obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o
 obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
 obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
diff --git a/drivers/virtio/virtio_sandbox.c b/drivers/virtio/virtio_sandbox.c
new file mode 100644
index 0000000000..2addb1ebc5
--- /dev/null
+++ b/drivers/virtio/virtio_sandbox.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * VirtIO Sandbox transport driver, for testing purpose only
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <virtio_types.h>
+#include <virtio.h>
+#include <virtio_ring.h>
+#include <linux/compat.h>
+#include <linux/io.h>
+
+struct virtio_sandbox_priv {
+        u8 id;
+        u8 status;
+        u64 device_features;
+        u64 driver_features;
+        ulong queue_desc;
+        ulong queue_available;
+        ulong queue_used;
+};
+
+static int virtio_sandbox_get_config(struct udevice *udev, unsigned int offset,
+                                     void *buf, unsigned int len)
+{
+        return 0;
+}
+
+static int virtio_sandbox_set_config(struct udevice *udev, unsigned int offset,
+                                     const void *buf, unsigned int len)
+{
+        return 0;
+}
+
+static int virtio_sandbox_get_status(struct udevice *udev, u8 *status)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+
+        *status = priv->status;
+
+        return 0;
+}
+
+static int virtio_sandbox_set_status(struct udevice *udev, u8 status)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+
+        /* We should never be setting status to 0 */
+        WARN_ON(status == 0);
+
+        priv->status = status;
+
+        return 0;
+}
+
+static int virtio_sandbox_reset(struct udevice *udev)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+
+        /* 0 status means a reset */
+        priv->status = 0;
+
+        return 0;
+}
+
+static int virtio_sandbox_get_features(struct udevice *udev, u64 *features)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+
+        *features = priv->device_features;
+
+        return 0;
+}
+
+static int virtio_sandbox_set_features(struct udevice *udev)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
+
+        priv->driver_features = uc_priv->features;
+
+        return 0;
+}
+
+static struct virtqueue *virtio_sandbox_setup_vq(struct udevice *udev,
+                                                 unsigned int index)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+        struct virtqueue *vq;
+        ulong addr;
+        int err;
+
+        /* Create the vring */
+        vq = vring_create_virtqueue(index, 4, 4096, udev);
+        if (!vq) {
+                err = -ENOMEM;
+                goto error_new_virtqueue;
+        }
+
+        addr = virtqueue_get_desc_addr(vq);
+        priv->queue_desc = addr;
+
+        addr = virtqueue_get_avail_addr(vq);
+        priv->queue_available = addr;
+
+        addr = virtqueue_get_used_addr(vq);
+        priv->queue_used = addr;
+
+        return vq;
+
+error_new_virtqueue:
+        return ERR_PTR(err);
+}
+
+static void virtio_sandbox_del_vq(struct virtqueue *vq)
+{
+        vring_del_virtqueue(vq);
+}
+
+static int virtio_sandbox_del_vqs(struct udevice *udev)
+{
+        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
+        struct virtqueue *vq, *n;
+
+        list_for_each_entry_safe(vq, n, &uc_priv->vqs, list)
+                virtio_sandbox_del_vq(vq);
+
+        return 0;
+}
+
+static int virtio_sandbox_find_vqs(struct udevice *udev, unsigned int nvqs,
+                                   struct virtqueue *vqs[])
+{
+        int i;
+
+        for (i = 0; i < nvqs; ++i) {
+                vqs[i] = virtio_sandbox_setup_vq(udev, i);
+                if (IS_ERR(vqs[i])) {
+                        virtio_sandbox_del_vqs(udev);
+                        return PTR_ERR(vqs[i]);
+                }
+        }
+
+        return 0;
+}
+
+static int virtio_sandbox_notify(struct udevice *udev, struct virtqueue *vq)
+{
+        return 0;
+}
+
+static int virtio_sandbox_probe(struct udevice *udev)
+{
+        struct virtio_sandbox_priv *priv = dev_get_priv(udev);
+        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
+
+        /* fake some information for testing */
+        priv->device_features = VIRTIO_F_VERSION_1;
+        uc_priv->device = VIRTIO_ID_BLOCK;
+        uc_priv->vendor = ('u' << 24) | ('b' << 16) | ('o' << 8) | 't';
+
+        return 0;
+}
+
+/* check virtio device driver's remove routine was called to reset the device */
+static int virtio_sandbox_child_post_remove(struct udevice *vdev)
+{
+        u8 status;
+
+        virtio_get_status(vdev, &status);
+        if (status)
+                panic("virtio device was not reset\n");
+
+        return 0;
+}
+
+static const struct dm_virtio_ops virtio_sandbox1_ops = {
+        .get_config     = virtio_sandbox_get_config,
+        .set_config     = virtio_sandbox_set_config,
+        .get_status     = virtio_sandbox_get_status,
+        .set_status     = virtio_sandbox_set_status,
+        .reset          = virtio_sandbox_reset,
+        .get_features   = virtio_sandbox_get_features,
+        .set_features   = virtio_sandbox_set_features,
+        .find_vqs       = virtio_sandbox_find_vqs,
+        .del_vqs        = virtio_sandbox_del_vqs,
+        .notify         = virtio_sandbox_notify,
+};
+
+static const struct udevice_id virtio_sandbox1_ids[] = {
+        { .compatible = "sandbox,virtio1" },
+        { }
+};
+
+U_BOOT_DRIVER(virtio_sandbox1) = {
+        .name   = "virtio-sandbox1",
+        .id     = UCLASS_VIRTIO,
+        .of_match = virtio_sandbox1_ids,
+        .ops    = &virtio_sandbox1_ops,
+        .probe  = virtio_sandbox_probe,
+        .child_post_remove = virtio_sandbox_child_post_remove,
+        .priv_auto_alloc_size = sizeof(struct virtio_sandbox_priv),
+};
+
+/* this one without notify op */
+static const struct dm_virtio_ops virtio_sandbox2_ops = {
+        .get_config     = virtio_sandbox_get_config,
+        .set_config     = virtio_sandbox_set_config,
+        .get_status     = virtio_sandbox_get_status,
+        .set_status     = virtio_sandbox_set_status,
+        .reset          = virtio_sandbox_reset,
+        .get_features   = virtio_sandbox_get_features,
+        .set_features   = virtio_sandbox_set_features,
+        .find_vqs       = virtio_sandbox_find_vqs,
+        .del_vqs        = virtio_sandbox_del_vqs,
+};
+
+static const struct udevice_id virtio_sandbox2_ids[] = {
+        { .compatible = "sandbox,virtio2" },
+        { }
+};
+
+U_BOOT_DRIVER(virtio_sandbox2) = {
+        .name   = "virtio-sandbox2",
+        .id     = UCLASS_VIRTIO,
+        .of_match = virtio_sandbox2_ids,
+        .ops    = &virtio_sandbox2_ops,
+        .probe  = virtio_sandbox_probe,
+        .priv_auto_alloc_size = sizeof(struct virtio_sandbox_priv),
+};