remoteproc: do cache invalidation before reading rsc_table status

Do a cache invalidation before reading the resource table's status
since this ca be in a cacheable region.

Make this optional, based on VIRTIO_CACHED_RSC_TABLE.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>

cmake/options.cmake

@@ -90,6 +90,12 @@ if (WITH_DCACHE_BUFFERS)
  add_definitions(-DVIRTIO_CACHED_BUFFERS)
 endif (WITH_DCACHE_BUFFERS)
 
+option (WITH_DCACHE_RSC_TABLE "Build with resource table cache operations enabled" OFF)
+
+if (WITH_DCACHE_RSC_TABLE)
+ add_definitions(-DVIRTIO_CACHED_RSC_TABLE)
+endif (WITH_DCACHE_RSC_TABLE)
+
 # Set the complication flags
 set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra")
 

lib/remoteproc/remoteproc_virtio.c

@@ -15,6 +15,7 @@
 #include <metal/cpu.h>
 #include <metal/utilities.h>
 #include <metal/alloc.h>
+#include <metal/cache.h>
 
 static void rproc_virtio_virtqueue_notify(struct virtqueue *vq)
 {
@@ -40,6 +41,11 @@ static unsigned char rproc_virtio_get_status(struct virtio_device *vdev)
  rpvdev = metal_container_of(vdev, struct remoteproc_virtio, vdev);
  vdev_rsc = rpvdev->vdev_rsc;
  io = rpvdev->vdev_rsc_io;
+
+#ifdef VIRTIO_CACHED_RSC_TABLE
+ metal_cache_invalidate(vdev_rsc, sizeof(vdev_rsc));
+#endif /* VIRTIO_CACHED_RSC_TABLE */
+
  status = metal_io_read8(io,
  metal_io_virt_to_offset(io, &vdev_rsc->status));
  return status;