remoteproc: support virtio config space.

Support virtio configuration space and device status. The virtio
device can now access the resource table in shared memory.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Acked-by: Ido Yariv <ido@wizery.com>
[rebase and style changes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

3 files changed, 64 insertions, 22 deletions

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 617b825aa553..d0251fe9e119 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -345,9 +345,6 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
                         goto free_rvdev;
         }
 
-        /* remember the device features */
-        rvdev->dfeatures = rsc->dfeatures;
-
         /* remember the resource offset*/
         rvdev->rsc_offset = offset;
 
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index afed9b7731c4..b09c75c21b60 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -173,25 +173,35 @@ error:
         return ret;
 }
 
-/*
- * We don't support yet real virtio status semantics.
- *
- * The plan is to provide this via the VDEV resource entry
- * which is part of the firmware: this way the remote processor
- * will be able to access the status values as set by us.
- */
 static u8 rproc_virtio_get_status(struct virtio_device *vdev)
 {
-        return 0;
+        struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
+
+        return rsc->status;
 }
 
 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
 {
+        struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
+
+        rsc->status = status;
         dev_dbg(&vdev->dev, "status: %d\n", status);
 }
 
 static void rproc_virtio_reset(struct virtio_device *vdev)
 {
+        struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
+
+        rsc->status = 0;
         dev_dbg(&vdev->dev, "reset !\n");
 }
 
@@ -199,13 +209,19 @@ static void rproc_virtio_reset(struct virtio_device *vdev)
 static u32 rproc_virtio_get_features(struct virtio_device *vdev)
 {
         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 
-        return rvdev->dfeatures;
+        return rsc->dfeatures;
 }
 
 static void rproc_virtio_finalize_features(struct virtio_device *vdev)
 {
         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
 
         /* Give virtio_ring a chance to accept features */
         vring_transport_features(vdev);
@@ -213,13 +229,44 @@ static void rproc_virtio_finalize_features(struct virtio_device *vdev)
         /*
          * Remember the finalized features of our vdev, and provide it
          * to the remote processor once it is powered on.
-         *
-         * Similarly to the status field, we don't expose yet the negotiated
-         * features to the remote processors at this point. This will be
-         * fixed as part of a small resource table overhaul and then an
-         * extension of the virtio resource entries.
          */
-        rvdev->gfeatures = vdev->features[0];
+        rsc->gfeatures = vdev->features[0];
+}
+
+static void rproc_virtio_get(struct virtio_device *vdev, unsigned offset,
+                                                        void *buf, unsigned len)
+{
+        struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+        void *cfg;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
+        cfg = &rsc->vring[rsc->num_of_vrings];
+
+        if (offset + len > rsc->config_len || offset + len < len) {
+                dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
+                return;
+        }
+
+        memcpy(buf, cfg + offset, len);
+}
+
+static void rproc_virtio_set(struct virtio_device *vdev, unsigned offset,
+                      const void *buf, unsigned len)
+{
+        struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+        struct fw_rsc_vdev *rsc;
+        void *cfg;
+
+        rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
+        cfg = &rsc->vring[rsc->num_of_vrings];
+
+        if (offset + len > rsc->config_len || offset + len < len) {
+                dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
+                return;
+        }
+
+        memcpy(cfg + offset, buf, len);
 }
 
 static const struct virtio_config_ops rproc_virtio_config_ops = {
@@ -230,6 +277,8 @@ static const struct virtio_config_ops rproc_virtio_config_ops = {
         .reset          = rproc_virtio_reset,
         .set_status     = rproc_virtio_set_status,
         .get_status     = rproc_virtio_get_status,
+        .get            = rproc_virtio_get,
+        .set            = rproc_virtio_set,
 };
 
 /*
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index b4cef16460f8..9e7e745dac55 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -469,8 +469,6 @@ struct rproc_vring {
  * @rproc: the rproc handle
  * @vdev: the virio device
  * @vring: the vrings for this vdev
- * @dfeatures: virtio device features
- * @gfeatures: virtio guest features
  * @rsc_offset: offset of the vdev's resource entry
  */
 struct rproc_vdev {
@@ -478,8 +476,6 @@ struct rproc_vdev {
         struct rproc *rproc;
         struct virtio_device vdev;
         struct rproc_vring vring[RVDEV_NUM_VRINGS];
-        unsigned long dfeatures;
-        unsigned long gfeatures;
         u32 rsc_offset;
 };