Changeset 341df5f in mainline for uspace/lib/virtio/virtio-pci.c

Timestamp:

2018-05-22T19:06:50Z (6 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2d4faf7

Parents:

cbcb34c

git-author:

Jakub Jermar <jakub@…> (2018-05-05 20:07:00)

git-committer:

Jakub Jermar <jakub@…> (2018-05-22 19:06:50)

Message:

Factor our generic virtio device initialization

File:

• uspace/lib/virtio/virtio-pci.c (modified) (1 diff)

uspace/lib/virtio/virtio-pci.c

@@ -272 +272 @@
 }
 
+/**
+ * Perform device initialization as described in section 3.1.1 of the
+ * specification, steps 1 - 6.
+ */
+errno_t virtio_device_setup_start(virtio_dev_t *vdev, uint32_t features)
+{
+        virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
+
+        /* 1. Reset the device */
+        uint8_t status = VIRTIO_DEV_STATUS_RESET;
+        pio_write_8(&cfg->device_status, status);
+
+        /* 2. Acknowledge we found the device */
+        status |= VIRTIO_DEV_STATUS_ACKNOWLEDGE;
+        pio_write_8(&cfg->device_status, status);
+
+        /* 3. We know how to drive the device */
+        status |= VIRTIO_DEV_STATUS_DRIVER;
+        pio_write_8(&cfg->device_status, status);
+
+        /* 4. Read the offered feature flags */
+        pio_write_32(&cfg->device_feature_select, VIRTIO_FEATURES_0_31);
+        uint32_t device_features = pio_read_32(&cfg->device_feature);
+
+        ddf_msg(LVL_NOTE, "offered features %x", device_features);
+        features &= device_features;
+
+        if (!features)
+                return ENOTSUP;
+
+        /* 4. Write the accepted feature flags */
+        pio_write_32(&cfg->driver_feature_select, VIRTIO_FEATURES_0_31);
+        pio_write_32(&cfg->driver_feature, features);
+
+        ddf_msg(LVL_NOTE, "accepted features %x", features);
+
+        /* 5. Set FEATURES_OK */
+        status |= VIRTIO_DEV_STATUS_FEATURES_OK;
+        pio_write_8(&cfg->device_status, status);
+
+        /* 6. Test if the device supports our feature subset */ 
+        status = pio_read_8(&cfg->device_status);
+        if (!(status & VIRTIO_DEV_STATUS_FEATURES_OK))
+                return ENOTSUP;
+
+        return EOK;
+}
+
+/**
+ * Perform device initialization as described in section 3.1.1 of the
+ * specification, step 8 (go live).
+ */
+void virtio_device_setup_finalize(virtio_dev_t *vdev)
+{
+        virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
+
+        /* 8. Go live */
+        uint8_t status = pio_read_8(&cfg->device_status);
+        pio_write_8(&cfg->device_status, status | VIRTIO_DEV_STATUS_DRIVER_OK);
+}
+
+void virtio_device_setup_fail(virtio_dev_t *vdev)
+{
+        virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
+
+        uint8_t status = pio_read_8(&cfg->device_status);
+        pio_write_8(&cfg->device_status, status | VIRTIO_DEV_STATUS_FAILED);
+}
+
 errno_t virtio_pci_dev_initialize(ddf_dev_t *dev, virtio_dev_t *vdev)
 {