Re: [Intel-gfx] [PATCH 2/3] drm: Create a format/modifier blob

[Ben Widawsky <ben@bwidawsk.net>]

On 17-05-03 17:08:27, Daniel Vetter wrote:
>On Tue, May 02, 2017 at 10:14:27PM -0700, Ben Widawsky wrote:
>> Updated blob layout (Rob, Daniel, Kristian, xerpi)
>>
>> Cc: Rob Clark <robdclark@gmail.com>
>> Cc: Daniel Stone <daniels@collabora.com>
>> Cc: Kristian H. Kristensen <hoegsberg@gmail.com>
>> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
>> ---
>>  drivers/gpu/drm/drm_mode_config.c |   7 +++
>>  drivers/gpu/drm/drm_plane.c       | 119 ++++++++++++++++++++++++++++++++++++++
>>  include/drm/drm_mode_config.h     |   6 ++
>>  include/uapi/drm/drm_mode.h       |  26 +++++++++
>>  4 files changed, 158 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
>> index d9862259a2a7..6bfbc3839df5 100644
>> --- a/drivers/gpu/drm/drm_mode_config.c
>> +++ b/drivers/gpu/drm/drm_mode_config.c
>> @@ -337,6 +337,13 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
>>  		return -ENOMEM;
>>  	dev->mode_config.gamma_lut_size_property = prop;
>>
>> +	prop = drm_property_create(dev,
>> +				   DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB,
>> +				   "IN_FORMATS", 0);
>> +	if (!prop)
>> +		return -ENOMEM;
>> +	dev->mode_config.modifiers = prop;
>> +
>>  	return 0;
>>  }
>>
>> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
>> index 286e183891e5..2e89e0e73435 100644
>> --- a/drivers/gpu/drm/drm_plane.c
>> +++ b/drivers/gpu/drm/drm_plane.c
>> @@ -62,6 +62,117 @@ static unsigned int drm_num_planes(struct drm_device *dev)
>>  	return num;
>>  }
>>
>> +struct drm_format_modifier_blob {
>> +#define FORMAT_BLOB_CURRENT 1
>> +	/* Version of this blob format */
>> +	u32 version;
>> +
>> +	/* Flags */
>> +	u32 flags;
>> +
>> +	/* Number of fourcc formats supported */
>> +	u32 count_formats;
>> +
>> +	/* Where in this blob the formats exist (in bytes) */
>> +	u32 formats_offset;
>> +
>> +	/* Number of drm_format_modifiers */
>> +	u32 count_modifiers;
>> +
>> +	/* Where in this blob the modifiers exist (in bytes) */
>> +	u32 modifiers_offset;
>> +
>> +	/* u32 formats[] */
>> +	/* struct drm_format_modifier modifiers[] */
>> +} __packed;
>
>The struct should be in the uapi header. Otherwise it won't show up in
>libdrm headers when following the proper process.
>-Daniel
>

I don't agree that blobs are ever really part of the API, but it doesn't hurt to
move it... in other words, done.

>> +
>> +static inline u32 *
>> +formats_ptr(struct drm_format_modifier_blob *blob)
>> +{
>> +	return (u32 *)(((char *)blob) + blob->formats_offset);
>> +}
>> +
>> +static inline struct drm_format_modifier *
>> +modifiers_ptr(struct drm_format_modifier_blob *blob)
>> +{
>> +	return (struct drm_format_modifier *)(((char *)blob) + blob->modifiers_offset);
>> +}
>> +
>> +static int create_in_format_blob(struct drm_device *dev, struct drm_plane *plane,
>> +				 const struct drm_plane_funcs *funcs,
>> +				 const uint32_t *formats, unsigned int format_count,
>> +				 const uint64_t *format_modifiers)
>> +{
>> +	const struct drm_mode_config *config = &dev->mode_config;
>> +	const uint64_t *temp_modifiers = format_modifiers;
>> +	unsigned int format_modifier_count = 0;
>> +	struct drm_property_blob *blob = NULL;
>> +	struct drm_format_modifier *mod;
>> +	size_t blob_size = 0, formats_size, modifiers_size;
>> +	struct drm_format_modifier_blob *blob_data;
>> +	int i, j, ret = 0;
>> +
>> +	if (format_modifiers)
>> +		while (*temp_modifiers++ != DRM_FORMAT_MOD_INVALID)
>> +			format_modifier_count++;
>> +
>> +	formats_size = sizeof(__u32) * format_count;
>> +	if (WARN_ON(!formats_size)) {
>> +		/* 0 formats are never expected */
>> +		return 0;
>> +	}
>> +
>> +	modifiers_size =
>> +		sizeof(struct drm_format_modifier) * format_modifier_count;
>> +
>> +	blob_size = ALIGN(sizeof(struct drm_format_modifier_blob), 8);
>> +	blob_size += ALIGN(formats_size, 8);
>> +	blob_size += modifiers_size;
>> +
>> +	blob = drm_property_create_blob(dev, blob_size, NULL);
>> +	if (IS_ERR(blob))
>> +		return -1;
>> +
>> +	blob_data = (struct drm_format_modifier_blob *)blob->data;
>> +	blob_data->version = FORMAT_BLOB_CURRENT;
>> +	blob_data->count_formats = format_count;
>> +	blob_data->formats_offset = sizeof(struct drm_format_modifier_blob);
>> +	blob_data->count_modifiers = format_modifier_count;
>> +
>> +	/* Modifiers offset is a pointer to a struct with a 64 bit field so it
>> +	 * should be naturally aligned to 8B.
>> +	 */
>> +	blob_data->modifiers_offset =
>> +		ALIGN(blob_data->formats_offset + formats_size, 8);
>> +
>> +	memcpy(formats_ptr(blob_data), formats, formats_size);
>> +
>> +	/* If we can't determine support, just bail */
>> +	if (!funcs->format_mod_supported)
>> +		goto done;
>> +
>> +	mod = modifiers_ptr(blob_data);
>> +	for (i = 0; i < format_modifier_count; i++) {
>> +		for (j = 0; j < format_count; j++) {
>> +			if (funcs->format_mod_supported(plane, formats[j],
>> +							format_modifiers[i])) {
>> +				mod->formats |= 1 << j;
>> +			}
>> +		}
>> +
>> +		mod->modifier = format_modifiers[i];
>> +		mod->offset = 0;
>> +		mod->pad = 0;
>> +		mod++;
>> +	}
>> +
>> +done:
>> +	drm_object_attach_property(&plane->base, config->modifiers,
>> +				   blob->base.id);
>> +
>> +	return ret;
>> +}
>> +
>>  /**
>>   * drm_universal_plane_init - Initialize a new universal plane object
>>   * @dev: DRM device
>> @@ -130,6 +241,10 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
>>  		return -ENOMEM;
>>  	}
>>
>> +	/* First driver to need more than 64 formats needs to fix this */
>> +	if (WARN_ON(format_count > 64))
>> +		return -EINVAL;
>> +
>>  	if (name) {
>>  		va_list ap;
>>
>> @@ -177,6 +292,10 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
>>  		drm_object_attach_property(&plane->base, config->prop_src_h, 0);
>>  	}
>>
>> +	if (config->allow_fb_modifiers)
>> +		create_in_format_blob(dev, plane, funcs, formats, format_count,
>> +				      format_modifiers);
>> +
>>  	return 0;
>>  }
>>  EXPORT_SYMBOL(drm_universal_plane_init);
>> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
>> index 42981711189b..03776e659811 100644
>> --- a/include/drm/drm_mode_config.h
>> +++ b/include/drm/drm_mode_config.h
>> @@ -757,6 +757,12 @@ struct drm_mode_config {
>>  	 */
>>  	bool allow_fb_modifiers;
>>
>> +	/**
>> +	 * @modifiers: Plane property to list support modifier/format
>> +	 * combination.
>> +	 */
>> +	struct drm_property *modifiers;
>> +
>>  	/* cursor size */
>>  	uint32_t cursor_width, cursor_height;
>>
>> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
>> index 8c67fc03d53d..dcdd04c55792 100644
>> --- a/include/uapi/drm/drm_mode.h
>> +++ b/include/uapi/drm/drm_mode.h
>> @@ -665,6 +665,32 @@ struct drm_mode_atomic {
>>  	__u64 user_data;
>>  };
>>
>> +struct drm_format_modifier {
>> +       /* Bitmask of formats in get_plane format list this info applies to. The
>> +	* offset allows a sliding window of which 64 formats (bits).
>> +	*
>> +	* Some examples:
>> +	* In today's world with < 65 formats, and formats 0, and 2 are
>> +	* supported
>> +	* 0x0000000000000005
>> +	*		  ^-offset = 0, formats = 5
>> +	*
>> +	* If the number formats grew to 128, and formats 98-102 are
>> +	* supported with the modifier:
>> +	*
>> +	* 0x0000003c00000000 0000000000000000
>> +	*		  ^
>> +	*		  |__offset = 64, formats = 0x3c00000000
>> +	*
>> +	*/
>> +       uint64_t formats;
>> +       uint32_t offset;
>> +       uint32_t pad;
>> +
>> +       /* This modifier can be used with the format for this plane. */
>> +       uint64_t modifier;
>> +} __packed;
>> +
>>  /**
>>   * Create a new 'blob' data property, copying length bytes from data pointer,
>>   * and returning new blob ID.
>> --
>> 2.12.2
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
>-- 
>Daniel Vetter
>Software Engineer, Intel Corporation
>http://blog.ffwll.ch
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