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

[Chih-Wei Huang]

2017-10-25 7:40 GMT+08:00 Rob Herring <robh at kernel.org>:
> 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.
>
> Perhaps we should allow for multiple levels of subclassing by only defining
> the fields we care about here and not validating magic and the size.
>
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
> I'm not sure if there's a better way, but I can't find a way to remove
> the gralloc dependency. At least for EGL, only the fd is needed as it
> has the ANativeWindow and can get all the info from that.
>
>
>  Android.mk           |  1 -
>  gralloc_drm_handle.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 85 insertions(+), 1 deletion(-)
>  create mode 100644 gralloc_drm_handle.h
>
> diff --git a/Android.mk b/Android.mk
> index 611fcb75190b..ee5b8bfb44d0 100644
> --- a/Android.mk
> +++ b/Android.mk
> @@ -47,7 +47,6 @@ LOCAL_SHARED_LIBRARIES := \
>  LOCAL_STATIC_LIBRARIES := libdrmhwc_utils
>
>  LOCAL_C_INCLUDES := \
> -       external/gbm_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..aa89e46db619
> --- /dev/null
> +++ b/gralloc_drm_handle.h
> @@ -0,0 +1,85 @@
> +/*
> + * Copyright (C) 2010-2011 Chia-I Wu <olvaffe at gmail.com>
> + * Copyright (C) 2010-2011 LunarG Inc.
> + * Copyright (C) 2016 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 stride; /* the stride in bytes */
> +       uint64_t modifier; /* buffer modifiers */

As a fix [1] I sent to you before,
it's better to force align the 64-bit int to 8.

[1]: https://github.com/robherring/gbm_gralloc/commit/d8b95e3ed2f0b38949c9339b6f5c9ffb32ca1089

> +       int data_owner; /* owner of data (for validation) */
> +       union {
> +               void *data; /* private pointer for gralloc */
> +               uint64_t reserved;
> +       } __attribute__((aligned(8)));
> +};
> +#define GRALLOC_HANDLE_MAGIC 0x5f47424d
> +#define GRALLOC_HANDLE_NUM_FDS 1
> +#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_ */
> --




-- 
Chih-Wei
Android-x86 project
http://www.android-x86.org