[PATCH v2 hwc] drm_hwcomposer: provide a common gralloc handle definition

[Daniel Vetter]

On Tue, Oct 31, 2017 at 09:59:20AM -0500, Rob Herring wrote:
> EGL, gralloc, and HWC must all have a common definition of fd's and int's
> in native_handle_t to share the fd and width, height, format, etc. of a
> dmabuf.
> 
> Move the definition into HWC so we aren't dependent on a specific gralloc
> implementation and so we don't have to create an importer just for
> different native_handle_t layouts. This will allow supporting multiple
> gralloc implementations that conform to this layout.
> 
> For now, this is aligned with gbm_gralloc's struct. Once we change
> gbm_gralloc and mesa to point to this copy, we can make modifications to
> the struct.
> 
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
>  Android.mk           |  1 -
>  gralloc_drm_handle.h | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 87 insertions(+), 1 deletion(-)
>  create mode 100644 gralloc_drm_handle.h
> 
> diff --git a/Android.mk b/Android.mk
> index 8b11e375adde..ee5b8bfb44d0 100644
> --- a/Android.mk
> +++ b/Android.mk
> @@ -47,7 +47,6 @@ LOCAL_SHARED_LIBRARIES := \
>  LOCAL_STATIC_LIBRARIES := libdrmhwc_utils
>  
>  LOCAL_C_INCLUDES := \
> -	external/drm_gralloc \
>  	system/core/libsync
>  
>  LOCAL_SRC_FILES := \
> diff --git a/gralloc_drm_handle.h b/gralloc_drm_handle.h
> new file mode 100644
> index 000000000000..e2f35dda539b
> --- /dev/null
> +++ b/gralloc_drm_handle.h
> @@ -0,0 +1,87 @@
> +/*
> + * Copyright (C) 2010-2011 Chia-I Wu <olvaffe at gmail.com>
> + * Copyright (C) 2010-2011 LunarG Inc.
> + * Copyright (C) 2016-2017 Linaro, Ltd., Rob Herring <robh at kernel.org>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included
> + * in all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef _GRALLOC_DRM_HANDLE_H_
> +#define _GRALLOC_DRM_HANDLE_H_
> +
> +#include <cutils/native_handle.h>
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +struct gralloc_drm_handle_t {
> +	native_handle_t base;
> +
> +	/* file descriptors */
> +	int prime_fd;
> +
> +	/* integers */
> +	int magic;
> +
> +	int width;
> +	int height;
> +	int format;
> +	int usage;
> +
> +	int name;   /* the name of the bo */
> +	int stride; /* the stride in bytes */
> +	int data_owner; /* owner of data (for validation) */
> +
> +	uint64_t modifier __attribute__((aligned(8))); /* buffer modifiers */
> +	union {
> +		void *data; /* private pointer for gralloc */
> +		uint64_t reserved;
> +	} __attribute__((aligned(8)));
> +};
> +#define GRALLOC_HANDLE_MAGIC 0x5f47424d

Maybe add a

#define GRALLOC_HANDLE_VERSION 1
#define GRALLOC_HANDLE_MAGIC (0x5f47424d + GRALLOC_HANDLE_VERSION)

and a comment that the version needs to be incremented for every change,
to catch mismatching mesa/hwc versions? Given the layout there's no way to
add more fds in a backwards-compatible way, so we need full versioning I
think, and treat any change as a breaking one.
-Daniel

> +#define GRALLOC_HANDLE_NUM_INTS (						\
> +	((sizeof(struct gralloc_drm_handle_t) - sizeof(native_handle_t))/sizeof(int))	\
> +	 - GRALLOC_HANDLE_NUM_FDS)
> +
> +static inline struct gralloc_drm_handle_t *gralloc_drm_handle(buffer_handle_t _handle)
> +{
> +	struct gralloc_drm_handle_t *handle =
> +		(struct gralloc_drm_handle_t *) _handle;
> +
> +	if (handle && (handle->base.version != sizeof(handle->base) ||
> +	               handle->base.numInts != GRALLOC_HANDLE_NUM_INTS ||
> +	               handle->base.numFds != GRALLOC_HANDLE_NUM_FDS ||
> +	               handle->magic != GRALLOC_HANDLE_MAGIC))
> +		return NULL;
> +
> +	return handle;
> +}
> +
> +static inline int gralloc_drm_get_prime_fd(buffer_handle_t _handle)
> +{
> +	struct gralloc_drm_handle_t *handle = gralloc_drm_handle(_handle);
> +	return (handle) ? handle->prime_fd : -1;
> +}
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +#endif /* _GRALLOC_DRM_HANDLE_H_ */
> -- 
> 2.14.1
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch