[PATCH v3 2/6] rpmsg: virtio_rpmsg_bus: fix sg_set_buf() when addr is not a valid kernel address

[Loic Pallardy]

To specify memory for remoteproc, we declare (dma_declare_coherent_memory())
an area which is ioremap'ed to the vmalloc area.  However, this address is
not a kernel address so virt_addr_valid(buf) fails.

Signed-off-by: Ludovic Barre <ludovic.ba...@st.com>
Signed-off-by: Loic Pallardy <loic.palla...@st.com>
Acked-by: Patrice Chotard <patrice.chot...@st.com>
Tested-by: Suman Anna <s-a...@ti.com>
---
Changes since V1:
- Remove extra line.

No change since v2.

---
 drivers/rpmsg/virtio_rpmsg_bus.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index d387589..c8d0d6d 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -195,6 +195,28 @@ static int virtio_rpmsg_trysend_offchannel(struct 
rpmsg_endpoint *ept, u32 src,
 };
 
 /**
+ * rpmsg_sg_init - initialize scatterlist according to cpu address location
+ * @sg: scatterlist to fill
+ * @cpu_addr: virtual address of the buffer
+ * @len: buffer length
+ *
+ * An internal function filling scatterlist according to virtual address
+ * location (in vmalloc or in kernel).
+ */
+static void
+rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
+{
+       if (is_vmalloc_addr(cpu_addr)) {
+               sg_init_table(sg, 1);
+               sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
+                           offset_in_page(cpu_addr));
+       } else {
+               WARN_ON(!virt_addr_valid(cpu_addr));
+               sg_init_one(sg, cpu_addr, len);
+       }
+}
+
+/**
  * __ept_release() - deallocate an rpmsg endpoint
  * @kref: the ept's reference count
  *
@@ -606,7 +628,7 @@ static int rpmsg_send_offchannel_raw(struct rpmsg_device 
*rpdev,
                         msg, sizeof(*msg) + msg->len, true);
 #endif
 
-       sg_init_one(&sg, msg, sizeof(*msg) + len);
+       rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
 
        mutex_lock(&vrp->tx_lock);
 
@@ -731,7 +753,7 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, 
struct device *dev,
                dev_warn(dev, "msg received with no recipient\n");
 
        /* publish the real size of the buffer */
-       sg_init_one(&sg, msg, vrp->buf_size);
+       rpmsg_sg_init(&sg, msg, vrp->buf_size);
 
        /* add the buffer back to the remote processor's virtqueue */
        err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
@@ -915,7 +937,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
                struct scatterlist sg;
                void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
 
-               sg_init_one(&sg, cpu_addr, vrp->buf_size);
+               rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
 
                err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
                                          GFP_KERNEL);
-- 
1.9.1