rpmsg: virtio: add endianness conversions

According to the VirtIO 1.0 spec data, sent over virtual queues must
be in little-endian format. Update the RPMsg VirtIO implementation
to enforce that but let legacy configurations continue use native
endianness.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Link: https://lore.kernel.org/r/20200721085638.GA3815@ubuntu
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 07d4f33740985bc3295829b0fd3ae005e78b25e6..9006fc7f73d09156b46558ff331efe78596c3d88 100644 (file)
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/virtio.h>
+#include <linux/virtio_byteorder.h>
 #include <linux/virtio_ids.h>
 #include <linux/virtio_config.h>
 #include <linux/wait.h>
@@ -84,11 +85,11 @@ struct virtproc_info {
  * Every message sent(/received) on the rpmsg bus begins with this header.
  */
 struct rpmsg_hdr {
-       u32 src;
-       u32 dst;
-       u32 reserved;
-       u16 len;
-       u16 flags;
+       __virtio32 src;
+       __virtio32 dst;
+       __virtio32 reserved;
+       __virtio16 len;
+       __virtio16 flags;
        u8 data[];
 } __packed;
 
@@ -106,8 +107,8 @@ struct rpmsg_hdr {
  */
 struct rpmsg_ns_msg {
        char name[RPMSG_NAME_SIZE];
-       u32 addr;
-       u32 flags;
+       __virtio32 addr;
+       __virtio32 flags;
 } __packed;
 
 /**
@@ -335,8 +336,8 @@ static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev)
                struct rpmsg_ns_msg nsm;
 
                strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
-               nsm.addr = rpdev->ept->addr;
-               nsm.flags = RPMSG_NS_CREATE;
+               nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
+               nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_CREATE);
 
                err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
                if (err)
@@ -359,8 +360,8 @@ static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev)
                struct rpmsg_ns_msg nsm;
 
                strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE);
-               nsm.addr = rpdev->ept->addr;
-               nsm.flags = RPMSG_NS_DESTROY;
+               nsm.addr = cpu_to_virtio32(vrp->vdev, rpdev->ept->addr);
+               nsm.flags = cpu_to_virtio32(vrp->vdev, RPMSG_NS_DESTROY);
 
                err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR);
                if (err)
@@ -612,18 +613,18 @@ static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
                }
        }
 
-       msg->len = len;
+       msg->len = cpu_to_virtio16(vrp->vdev, len);
        msg->flags = 0;
-       msg->src = src;
-       msg->dst = dst;
+       msg->src = cpu_to_virtio32(vrp->vdev, src);
+       msg->dst = cpu_to_virtio32(vrp->vdev, dst);
        msg->reserved = 0;
        memcpy(msg->data, data, len);
 
        dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n",
-               msg->src, msg->dst, msg->len, msg->flags, msg->reserved);
+               src, dst, len, msg->flags, msg->reserved);
 #if defined(CONFIG_DYNAMIC_DEBUG)
        dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1,
-                        msg, sizeof(*msg) + msg->len, true);
+                        msg, sizeof(*msg) + len, true);
 #endif
 
        rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
@@ -704,13 +705,17 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
 {
        struct rpmsg_endpoint *ept;
        struct scatterlist sg;
+       unsigned int msg_len = virtio16_to_cpu(vrp->vdev, msg->len);
        int err;
 
        dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n",
-               msg->src, msg->dst, msg->len, msg->flags, msg->reserved);
+               virtio32_to_cpu(vrp->vdev, msg->src),
+               virtio32_to_cpu(vrp->vdev, msg->dst), msg_len,
+               virtio16_to_cpu(vrp->vdev, msg->flags),
+               virtio32_to_cpu(vrp->vdev, msg->reserved));
 #if defined(CONFIG_DYNAMIC_DEBUG)
        dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1,
-                        msg, sizeof(*msg) + msg->len, true);
+                        msg, sizeof(*msg) + msg_len, true);
 #endif
 
        /*
@@ -718,15 +723,15 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
         * the reported payload length.
         */
        if (len > vrp->buf_size ||
-           msg->len > (len - sizeof(struct rpmsg_hdr))) {
-               dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg->len);
+           msg_len > (len - sizeof(struct rpmsg_hdr))) {
+               dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len);
                return -EINVAL;
        }
 
        /* use the dst addr to fetch the callback of the appropriate user */
        mutex_lock(&vrp->endpoints_lock);
 
-       ept = idr_find(&vrp->endpoints, msg->dst);
+       ept = idr_find(&vrp->endpoints, virtio32_to_cpu(vrp->vdev, msg->dst));
 
        /* let's make sure no one deallocates ept while we use it */
        if (ept)
@@ -739,8 +744,8 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
                mutex_lock(&ept->cb_lock);
 
                if (ept->cb)
-                       ept->cb(ept->rpdev, msg->data, msg->len, ept->priv,
-                               msg->src);
+                       ept->cb(ept->rpdev, msg->data, msg_len, ept->priv,
+                               virtio32_to_cpu(vrp->vdev, msg->src));
 
                mutex_unlock(&ept->cb_lock);
 
@@ -846,15 +851,15 @@ static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
        /* don't trust the remote processor for null terminating the name */
        msg->name[RPMSG_NAME_SIZE - 1] = '\0';
 
-       dev_info(dev, "%sing channel %s addr 0x%x\n",
-                msg->flags & RPMSG_NS_DESTROY ? "destroy" : "creat",
-                msg->name, msg->addr);
-
        strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
        chinfo.src = RPMSG_ADDR_ANY;
-       chinfo.dst = msg->addr;
+       chinfo.dst = virtio32_to_cpu(vrp->vdev, msg->addr);
+
+       dev_info(dev, "%sing channel %s addr 0x%x\n",
+                virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY ?
+                "destroy" : "creat", msg->name, chinfo.dst);
 
-       if (msg->flags & RPMSG_NS_DESTROY) {
+       if (virtio32_to_cpu(vrp->vdev, msg->flags) & RPMSG_NS_DESTROY) {
                ret = rpmsg_unregister_device(&vrp->vdev->dev, &chinfo);
                if (ret)
                        dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);