[Libva] [PATCH v3 intel-driver] Add support for new VA buffer export APIs.

[Gwenole Beauchesne]

Implement va{Acquire,Release}BufferHandle() hooks so that to allow
VA surface or VA image buffer sharing with thirdparty APIs like EGL,
OpenCL, etc.

v2: made sure to sync bo before export, improved VA buffer type check.
v3: tracked internal resources on acquire, disposed them on release.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne at intel.com>
---
 src/i965_drv_video.c |  129 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/i965_drv_video.h |    4 ++
 2 files changed, 133 insertions(+)

diff --git a/src/i965_drv_video.c b/src/i965_drv_video.c
index 32a7c72..92cbf9a 100755
--- a/src/i965_drv_video.c
+++ b/src/i965_drv_video.c
@@ -28,6 +28,7 @@
  */
 
 #include "sysdeps.h"
+#include <unistd.h>
 
 #ifdef HAVE_VA_X11
 # include "i965_output_dri.h"
@@ -5161,6 +5162,130 @@ i965_QuerySurfaceAttributes(VADriverContextP ctx,
     return vaStatus;
 }
 
+/* Acquires buffer handle for external API usage (internal implementation) */
+static VAStatus
+i965_acquire_buffer_handle(struct object_buffer *obj_buffer,
+    uint32_t mem_type, VABufferInfo *out_buf_info)
+{
+    struct buffer_store *buffer_store;
+
+    buffer_store = obj_buffer->buffer_store;
+    if (!buffer_store || !buffer_store->bo)
+        return VA_STATUS_ERROR_INVALID_BUFFER;
+
+    /* Synchronization point */
+    drm_intel_bo_wait_rendering(buffer_store->bo);
+
+    if (obj_buffer->export_refcount > 0) {
+        if (obj_buffer->export_state.mem_type != mem_type)
+            return VA_STATUS_ERROR_INVALID_PARAMETER;
+    }
+    else {
+        VABufferInfo * const buf_info = &obj_buffer->export_state;
+
+        switch (mem_type) {
+        case VA_SURFACE_ATTRIB_MEM_TYPE_KERNEL_DRM: {
+            uint32_t name;
+            if (drm_intel_bo_flink(buffer_store->bo, &name) != 0)
+                return VA_STATUS_ERROR_INVALID_BUFFER;
+            buf_info->handle = name;
+            break;
+        }
+        case VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME: {
+            int fd;
+            if (drm_intel_bo_gem_export_to_prime(buffer_store->bo, &fd) != 0)
+                return VA_STATUS_ERROR_INVALID_BUFFER;
+            buf_info->handle = (intptr_t)fd;
+            break;
+        }
+        }
+
+        buf_info->type = obj_buffer->type;
+        buf_info->mem_type = mem_type;
+        buf_info->mem_size =
+            obj_buffer->num_elements * obj_buffer->size_element;
+    }
+
+    obj_buffer->export_refcount++;
+    *out_buf_info = obj_buffer->export_state;
+    return VA_STATUS_SUCCESS;
+}
+
+/* Releases buffer handle after usage (internal implementation) */
+static VAStatus
+i965_release_buffer_handle(struct object_buffer *obj_buffer)
+{
+    if (obj_buffer->export_refcount == 0)
+        return VA_STATUS_ERROR_INVALID_BUFFER;
+
+    if (--obj_buffer->export_refcount == 0) {
+        VABufferInfo * const buf_info = &obj_buffer->export_state;
+
+        switch (buf_info->mem_type) {
+        case VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME: {
+            close((intptr_t)buf_info->handle);
+            break;
+        }
+        }
+        buf_info->mem_type = 0;
+    }
+    return VA_STATUS_SUCCESS;
+}
+
+/** Acquires buffer handle for external API usage */
+static VAStatus
+i965_AcquireBufferHandle(VADriverContextP ctx, VABufferID buf_id,
+    VABufferInfo *buf_info)
+{
+    struct i965_driver_data * const i965 = i965_driver_data(ctx);
+    struct object_buffer * const obj_buffer = BUFFER(buf_id);
+    uint32_t i, mem_type;
+
+    /* List of supported memory types, in preferred order */
+    static const uint32_t mem_types[] = {
+        VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME,
+        VA_SURFACE_ATTRIB_MEM_TYPE_KERNEL_DRM,
+        0
+    };
+
+    if (!obj_buffer)
+        return VA_STATUS_ERROR_INVALID_BUFFER;
+    /* XXX: only VA surface|image like buffers are supported for now */
+    if (obj_buffer->type != VAImageBufferType)
+        return VA_STATUS_ERROR_UNSUPPORTED_BUFFERTYPE;
+
+    if (!buf_info)
+        return VA_STATUS_ERROR_INVALID_PARAMETER;
+
+    if (!buf_info->mem_type)
+        mem_type = mem_types[0];
+    else {
+        mem_type = 0;
+        for (i = 0; mem_types[i] != 0; i++) {
+            if (buf_info->mem_type & mem_types[i]) {
+                mem_type = buf_info->mem_type;
+                break;
+            }
+        }
+        if (!mem_type)
+            return VA_STATUS_ERROR_UNSUPPORTED_MEMORY_TYPE;
+    }
+    return i965_acquire_buffer_handle(obj_buffer, mem_type, buf_info);
+}
+
+/** Releases buffer handle after usage from external API */
+static VAStatus
+i965_ReleaseBufferHandle(VADriverContextP ctx, VABufferID buf_id)
+{
+    struct i965_driver_data * const i965 = i965_driver_data(ctx);
+    struct object_buffer * const obj_buffer = BUFFER(buf_id);
+
+    if (!obj_buffer)
+        return VA_STATUS_ERROR_INVALID_BUFFER;
+
+    return i965_release_buffer_handle(obj_buffer);
+}
+
 static int
 i965_os_has_ring_support(VADriverContextP ctx,
                          int ring)
@@ -5690,6 +5815,10 @@ VA_DRIVER_INIT_FUNC(  VADriverContextP ctx )
     vtable->vaQuerySurfaceAttributes = i965_QuerySurfaceAttributes;
     vtable->vaCreateSurfaces2 = i965_CreateSurfaces2;
 
+    /* 0.36.0 */
+    vtable->vaAcquireBufferHandle = i965_AcquireBufferHandle;
+    vtable->vaReleaseBufferHandle = i965_ReleaseBufferHandle;
+
     vtable_vpp->vaQueryVideoProcFilters = i965_QueryVideoProcFilters;
     vtable_vpp->vaQueryVideoProcFilterCaps = i965_QueryVideoProcFilterCaps;
     vtable_vpp->vaQueryVideoProcPipelineCaps = i965_QueryVideoProcPipelineCaps;
diff --git a/src/i965_drv_video.h b/src/i965_drv_video.h
index ee4b163..145071f 100644
--- a/src/i965_drv_video.h
+++ b/src/i965_drv_video.h
@@ -287,6 +287,10 @@ struct object_buffer
     int num_elements;
     int size_element;
     VABufferType type;
+
+    /* Export state */
+    unsigned int export_refcount;
+    VABufferInfo export_state;
 };
 
 struct object_image 
-- 
1.7.9.5