Need to do a dcache invalidation when reading status from resource table

[iuliana-prodan]

For HiFi4 DSP, the resource table is added in SRAM which is cacheable region. When reading the status I need to do a dcache invalidation otherwise the status is never updated.

The issue was found while enabling the openamp_rsc_table from Zephyr. This app is running on HiFi4 DSP and on Cortex A we have Linux with rpmsg_client_sample.

cc: @carlocaione @arnopo

[iuliana-prodan]

Here's my proposed fix: https://github.com/OpenAMP/open-amp/pull/500

[iuliana-prodan]

Here's my proposed fix: #500

I would like to do this conditional, something like:

diff --git a/lib/remoteproc/remoteproc_virtio.c b/lib/remoteproc/remoteproc_virtio.c
index 169e5b5..4730116 100644
--- a/lib/remoteproc/remoteproc_virtio.c
+++ b/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;

But, how can I activate the OpenAMP macro (the VIRTIO_CACHED_RSC_TABLE ) from my platform or sample in Zephyr?

[carlocaione]

I'll leave to @arnopo the open-amp part of the question.

For this part:

But, how can I activate the OpenAMP macro (the VIRTIO_CACHED_RSC_TABLE ) from my platform or sample in Zephyr?

If you have a VIRTIO_CACHED_RSC_TABLE define in open-amp you have to add support for it in the options.cmake file in open-amp, for example: https://github.com/OpenAMP/open-amp/blob/7f906105a9ffef8e59287f0fca68fc8f8df7725c/cmake/options.cmake#L83-L91

and add support for that in Zephyr tweaking the CMakeLists.txt file for the open-amp module, for example: https://github.com/zephyrproject-rtos/open-amp/blob/c904a01d4a882bcbb39987e0e2ce5308f49ac7ad/CMakeLists.txt#L20-L23

[iuliana-prodan]

Fixed by #500