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

[Robert Foss <robert.foss@collabora.com>]

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On Tue, 2017-10-31 at 17:44 +0100, Daniel Vetter wrote:
> 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@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@gmail.com>
> > + * Copyright (C) 2010-2011 LunarG Inc.
> > + * Copyright (C) 2016-2017 Linaro, Ltd., Rob Herring <robh@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

This seems like a good idea to me.
With this change feel free to add my r-b.

> 
> > +#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
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> 

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