remoteproc: Add support for vringh (Host vrings)

Add functions for creating, deleting and kicking host-side virtio rings.

The host ring is not integrated with virtiqueues and cannot be managed
through virtio-config. Remoteproc must export functions for handling the
host-side virtio rings.

The functions rproc_virtio_get_vringh(), rproc_virtio_del_vringh(),
rproc_virtio_kick_vringh() are added to remoteproc_virtio.c. The
existing functions rproc_vq_interrupt() and rproc_virtio_find_vqs()
are updated to handle the new vhost rings.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
cc: Ohad Ben-Cohen <ohad@wizery.com>
cc: Rusty Russell <rusty@rustcorp.com.au>
cc: Ido Yariv <ido@wizery.com>
cc: Erwan Yvin <erwan.yvin@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 96ce101b906753c703cf88c1c76d6a7e9a33e826..c7d1d362a294665e94d40eff7a7c8d45f3cdbd3a 100644 (file)
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -7,6 +7,9 @@ config REMOTEPROC
        depends on HAS_DMA
        select FW_CONFIG
        select VIRTIO
+       select VHOST_RING
+
+source drivers/vhost/Kconfig
 
 config OMAP_REMOTEPROC
        tristate "OMAP remoteproc support"

diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index afed9b7731c456b43551e999d97f054e13b31032..750b21818e278ad36f3ae2f66b537fb4d532cff5 100644 (file)
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -23,6 +23,7 @@
 #include <linux/virtio_config.h>
 #include <linux/virtio_ids.h>
 #include <linux/virtio_ring.h>
+#include <linux/vringh.h>
 #include <linux/err.h>
 #include <linux/kref.h>
 #include <linux/slab.h>
@@ -60,10 +61,15 @@ irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
        dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);
 
        rvring = idr_find(&rproc->notifyids, notifyid);
-       if (!rvring || !rvring->vq)
+       if (!rvring)
                return IRQ_NONE;
 
-       return vring_interrupt(0, rvring->vq);
+       if (rvring->vringh && rvring->vringh_cb)
+               return rvring->vringh_cb(&rvring->rvdev->vdev, rvring->vringh);
+       else if (rvring->vq)
+               return vring_interrupt(0, rvring->vq);
+       else
+               return IRQ_NONE;
 }
 EXPORT_SYMBOL(rproc_vq_interrupt);
 
@@ -149,14 +155,21 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
                       const char *names[])
 {
        struct rproc *rproc = vdev_to_rproc(vdev);
-       int i, ret;
+       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+       int rng, id, ret, nrings = ARRAY_SIZE(rvdev->vring);
+
+       for (id = 0, rng = 0; rng < nrings; ++rng) {
+               struct rproc_vring *rvring = &rvdev->vring[rng];
+               /* Skip the host side rings */
+               if (rvring->vringh)
+                       continue;
 
-       for (i = 0; i < nvqs; ++i) {
-               vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
-               if (IS_ERR(vqs[i])) {
-                       ret = PTR_ERR(vqs[i]);
+               vqs[id] = rp_find_vq(vdev, rng, callbacks[id], names[id]);
+               if (IS_ERR(vqs[id])) {
+                       ret = PTR_ERR(vqs[id]);
                        goto error;
                }
+               ++id;
        }
 
        /* now that the vqs are all set, boot the remote processor */
@@ -173,6 +186,106 @@ error:
        return ret;
 }
 
+/**
+ * rproc_virtio_new_vringh() - create a reversed virtio ring.
+ * @vdev: the virtio device
+ * @index: the virtio ring index
+ * @cb: callback for the reversed virtio ring
+ *
+ * This function should be called by the virtio-driver
+ * before calling find_vqs(). It returns a struct vringh for
+ * accessing the virtio ring.
+ *
+ * Return: struct vhost, or NULL upon error.
+ */
+struct vringh *
+rproc_virtio_new_vringh(struct virtio_device *vdev, unsigned index,
+                       irqreturn_t (*cb)(struct virtio_device *vdev,
+                                         struct vringh *vring))
+{
+       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+       struct rproc_vring *rvring;
+       struct vringh *vrh;
+       int err;
+
+       if (index > ARRAY_SIZE(rvdev->vring)) {
+               dev_err(&rvdev->vdev.dev, "bad vring index: %d\n", index);
+               return NULL;
+       }
+
+       vrh = kzalloc(sizeof(*vrh), GFP_KERNEL);
+       if (!vrh)
+               return NULL;
+
+       err = rproc_alloc_vring(rvdev, index);
+       if (err)
+               goto free_vring;
+
+
+       rvring = &rvdev->vring[index];
+       /* zero vring */
+       memset(rvring->va, 0, vring_size(rvring->len, rvring->align));
+       vring_init(&vrh->vring, rvring->len, rvring->va, rvring->align);
+
+       rvring->vringh_cb = cb;
+       rvring->vringh = vrh;
+
+       err = vringh_init_kern(vrh,
+                              rvdev->dfeatures,
+                              rvring->len,
+                              false,
+                              vrh->vring.desc,
+                              vrh->vring.avail,
+                              vrh->vring.used);
+       if (!err)
+               return vrh;
+
+       dev_err(&vdev->dev, "failed to create vhost: %d\n", err);
+       rproc_free_vring(rvring);
+free_vring:
+       kfree(vrh);
+       return NULL;
+}
+EXPORT_SYMBOL(rproc_virtio_new_vringh);
+
+/**
+ * rproc_virtio_del_vringh() - release a reversed virtio ring.
+ * @vdev: the virtio device
+ * @index: the virtio ring index
+ *
+ * This function release the reversed virtio ring.
+ */
+void rproc_virtio_del_vringh(struct virtio_device *vdev, unsigned index)
+{
+       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+       struct rproc_vring *rvring = &rvdev->vring[index];
+       kfree(rvring->vringh);
+       rproc_free_vring(rvring);
+       rvring->vringh_cb = NULL;
+       rvring->vringh = NULL;
+}
+EXPORT_SYMBOL(rproc_virtio_del_vringh);
+
+/**
+ * rproc_virtio_kick_vringh() - kick the remote processor.
+ * @vdev: the virtio device
+ * @index: the virtio ring index
+ *
+ * kick the remote processor, and let it know which vring to poke at
+ */
+void rproc_virtio_kick_vringh(struct virtio_device *vdev, unsigned index)
+{
+       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
+       struct rproc_vring *rvring = &rvdev->vring[index];
+       struct rproc *rproc = rvring->rvdev->rproc;
+       int notifyid = rvring->notifyid;
+
+       dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
+
+       rproc->ops->kick(rproc, notifyid);
+}
+EXPORT_SYMBOL(rproc_virtio_kick_vringh);
+
 /*
  * We don't support yet real virtio status semantics.
  *

diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index faf33324c78f9613526a66474670303ae5661aab..414a1fda828bcb40947bfdc83ab9adf6b42d50b8 100644 (file)
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -39,7 +39,9 @@
 #include <linux/klist.h>
 #include <linux/mutex.h>
 #include <linux/virtio.h>
+#include <linux/vringh.h>
 #include <linux/completion.h>
+#include <linux/interrupt.h>
 #include <linux/idr.h>
 
 /**
@@ -444,6 +446,8 @@ struct rproc {
  * @notifyid: rproc-specific unique vring index
  * @rvdev: remote vdev
  * @vq: the virtqueue of this vring
+ * @vringh_cb: callback used when device has kicked
+ * @vringh: the reversed host-side vring
  */
 struct rproc_vring {
        void *va;
@@ -454,6 +458,9 @@ struct rproc_vring {
        int notifyid;
        struct rproc_vdev *rvdev;
        struct virtqueue *vq;
+       irqreturn_t (*vringh_cb)(struct virtio_device *vdev,
+                                struct vringh *vring);
+       struct vringh *vringh;
 };
 
 /**
@@ -485,6 +492,13 @@ int rproc_boot(struct rproc *rproc);
 void rproc_shutdown(struct rproc *rproc);
 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
 
+struct vringh *
+rproc_virtio_new_vringh(struct virtio_device *vdev, unsigned index,
+                       irqreturn_t (*cb)(struct virtio_device *vdev,
+                                         struct vringh *vring));
+void rproc_virtio_del_vringh(struct virtio_device *vdev, unsigned index);
+void rproc_virtio_kick_vringh(struct virtio_device *vdev, unsigned index);
+
 static inline struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
 {
        return container_of(vdev, struct rproc_vdev, vdev);