Re: [RFC AFBC 07/12] drm/arm/malidp: Define the constraints on each supported drm_fourcc format for the AFBC modifiers.

From: Ayan Halder <Ayan.Halder@arm.com>
To: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"corbet@lwn.net" <corbet@lwn.net>,
	"airlied@linux.ie" <airlied@linux.ie>,
	"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"nicolas.ferre@microchip.com" <nicolas.ferre@microchip.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"maxime.ripard@bootlin.com" <maxime.ripard@bootlin.com>,
	"malidp@foss.arm.com" <malidp@foss.arm.com>,
	"mchehab+samsung@kernel.org" <mchehab+samsung@kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	nd <nd@arm.com>, "sean@poorly.run" <sean@poorly.run>
Subject: Re: [RFC AFBC 07/12] drm/arm/malidp: Define the constraints on each supported drm_fourcc format for the AFBC modifiers.
Date: Fri, 14 Dec 2018 14:23:00 +0000	[thread overview]
Message-ID: <20181214142259.GD19564@arm.com> (raw)
In-Reply-To: <20181204174912.GO988@e110455-lin.cambridge.arm.com>

On Tue, Dec 04, 2018 at 05:49:12PM +0000, Liviu Dudau wrote:
> On Mon, Dec 03, 2018 at 11:32:01AM +0000, Ayan Halder wrote:
> > The constraints are as follows (for Mali-DP 500, 550, 650) :-
> > 
> > 1. AFBC is not supported for the formats defined in malidp_hw_format_is_linear_only()
> > 
> > 2. Some of the formats are supported only with AFBC modifiers. Thus we have
> > introduced a new function 'malidp_hw_format_is_afbc_only()' which verifies the same.
> > 
> > 3. AFBC_FORMAT_MOD_YTR needs to be provided for any RGB format.
> > 
> > 4. Formats <= 16bpp cannot support AFBC_FORMAT_MOD_SPLIT.
> > 
> > 5. CBR should not be set for non-subsampled formats.
> > 
> > 6. SMART layer does not support framebuffer with AFBC modifiers.
> > Return -EINVAL for such a scenario.
> > 
> > 7. AFBC_FORMAT_MOD_YTR is not supported for any YUV formats.
> > 
> > 8. Formats which are subsampled cannot support AFBC_FORMAT_MOD_SPLIT. However in
> > DP550, YUV_420_10BIT is supported with AFBC_FORMAT_MOD_SPLIT. This feature has
> > been identified with MALIDP_DEVICE_AFBC_YUV_420_10_SUPPORT_SPLIT.
> > 
> > 9. In DP550 and DP650, for YUYV, the hardware supports different format-ids to
> > be used with and without AFBC modifier. We have used the feature
> > 'MALIDP_DEVICE_AFBC_YUYV_USE_422_P2' to identify this characteristic.
> > 
> > Signed-off-by: Ayan Kumar halder <ayan.halder@arm.com>
> > ---
> >  drivers/gpu/drm/arm/malidp_drv.c    |  23 +------
> >  drivers/gpu/drm/arm/malidp_drv.h    |   6 ++
> >  drivers/gpu/drm/arm/malidp_hw.c     |  71 +++++++++++++++++++--
> >  drivers/gpu/drm/arm/malidp_hw.h     |   5 +-
> >  drivers/gpu/drm/arm/malidp_mw.c     |   2 +-
> >  drivers/gpu/drm/arm/malidp_planes.c | 124 +++++++++++++++++++++++++++++++++++-
> >  6 files changed, 199 insertions(+), 32 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
> > index b8db92f..2f0b553 100644
> > --- a/drivers/gpu/drm/arm/malidp_drv.c
> > +++ b/drivers/gpu/drm/arm/malidp_drv.c
> > @@ -264,29 +264,8 @@ static bool
> >  malidp_verify_afbc_framebuffer_caps(struct drm_device *dev,
> >  				    const struct drm_mode_fb_cmd2 *mode_cmd)
> >  {
> > -	const struct drm_format_info *info;
> > -
> > -	if ((mode_cmd->modifier[0] >> 56) != DRM_FORMAT_MOD_VENDOR_ARM) {
> > -		DRM_DEBUG_KMS("Unknown modifier (not Arm)\n");
> > +	if (malidp_format_mod_supported(dev, mode_cmd->pixel_format, mode_cmd->modifier[0]) == false)
> >  		return false;
> > -	}
> > -
> > -	if (mode_cmd->modifier[0] &
> > -	    ~DRM_FORMAT_MOD_ARM_AFBC(AFBC_MOD_VALID_BITS)) {
> > -		DRM_DEBUG_KMS("Unsupported modifiers\n");
> > -		return false;
> > -	}
> > -
> > -	info = drm_get_format_info(dev, mode_cmd);
> > -	if (!info) {
> > -		DRM_DEBUG_KMS("Unable to get the format information\n");
> > -		return false;
> > -	}
> > -
> > -	if (info->num_planes != 1) {
> > -		DRM_DEBUG_KMS("AFBC buffers expect one plane\n");
> > -		return false;
> > -	}
> >  
> >  	if (mode_cmd->offsets[0] != 0) {
> >  		DRM_DEBUG_KMS("AFBC buffers' plane offset should be 0\n");
> > diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
> > index b76c86f..019a682 100644
> > --- a/drivers/gpu/drm/arm/malidp_drv.h
> > +++ b/drivers/gpu/drm/arm/malidp_drv.h
> > @@ -90,6 +90,12 @@ struct malidp_crtc_state {
> >  int malidp_de_planes_init(struct drm_device *drm);
> >  int malidp_crtc_init(struct drm_device *drm);
> >  
> > +bool malidp_hw_format_is_linear_only(u32 format);
> > +bool malidp_hw_format_is_afbc_only(u32 format);
> > +
> > +bool malidp_format_mod_supported(struct drm_device *drm,
> > +				 u32 format, u64 modifier);
> > +
> >  #ifdef CONFIG_DEBUG_FS
> >  void malidp_error(struct malidp_drm *malidp,
> >  		  struct malidp_error_stats *error_stats, u32 status,
> > diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
> > index 25ac5890..4a774be 100644
> > --- a/drivers/gpu/drm/arm/malidp_hw.c
> > +++ b/drivers/gpu/drm/arm/malidp_hw.c
> > @@ -60,6 +60,8 @@ static const struct malidp_format_id malidp500_de_formats[] = {
> >  #define MALIDP_ID(__group, __format) \
> >  	((((__group) & 0x7) << 3) | ((__format) & 0x7))
> >  
> > +#define AFBC_YUV_422_FORMAT_ID	MALIDP_ID(5, 1)
> > +
> >  #define MALIDP_COMMON_FORMATS \
> >  	/*    fourcc,   layers supporting the format,      internal id   */ \
> >  	{ DRM_FORMAT_ARGB2101010, DE_VIDEO1 | DE_GRAPHICS1 | DE_VIDEO2 | SE_MEMWRITE, MALIDP_ID(0, 0) }, \
> > @@ -887,7 +889,10 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
> >  			.se_base = MALIDP550_SE_BASE,
> >  			.dc_base = MALIDP550_DC_BASE,
> >  			.out_depth_base = MALIDP550_DE_OUTPUT_DEPTH,
> > -			.features = MALIDP_REGMAP_HAS_CLEARIRQ | MALIDP_DEVICE_AFBC_SUPPORT_SPLIT | AFBC_SUPPORT_SPLIT_WITH_YUV_420_10,
> > +			.features = MALIDP_REGMAP_HAS_CLEARIRQ |
> > +				    MALIDP_DEVICE_AFBC_SUPPORT_SPLIT |
> > +				    MALIDP_DEVICE_AFBC_YUV_420_10_SUPPORT_SPLIT |
> 
> Please roll some of these changes into patch 5/12.
> 
> > +				    MALIDP_DEVICE_AFBC_YUYV_USE_422_P2,
> >  			.n_layers = ARRAY_SIZE(malidp550_layers),
> >  			.layers = malidp550_layers,
> >  			.de_irq_map = {
> > @@ -933,7 +938,9 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
> >  			.se_base = MALIDP550_SE_BASE,
> >  			.dc_base = MALIDP550_DC_BASE,
> >  			.out_depth_base = MALIDP550_DE_OUTPUT_DEPTH,
> > -			.features = MALIDP_REGMAP_HAS_CLEARIRQ | MALIDP_DEVICE_AFBC_SUPPORT_SPLIT,
> > +			.features = MALIDP_REGMAP_HAS_CLEARIRQ |
> > +				    MALIDP_DEVICE_AFBC_SUPPORT_SPLIT |
> > +				    MALIDP_DEVICE_AFBC_YUYV_USE_422_P2,
> >  			.n_layers = ARRAY_SIZE(malidp650_layers),
> >  			.layers = malidp650_layers,
> >  			.de_irq_map = {
> > @@ -982,19 +989,73 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
> >  };
> >  
> >  u8 malidp_hw_get_format_id(const struct malidp_hw_regmap *map,
> > -			   u8 layer_id, u32 format)
> > +			   u8 layer_id, u32 format, bool has_modifier)
> >  {
> >  	unsigned int i;
> >  
> >  	for (i = 0; i < map->n_pixel_formats; i++) {
> >  		if (((map->pixel_formats[i].layer & layer_id) == layer_id) &&
> > -		    (map->pixel_formats[i].format == format))
> > -			return map->pixel_formats[i].id;
> > +		    (map->pixel_formats[i].format == format)) {
> > +
> > +			/*
> > +			 * In some DP550 and DP650, DRM_FORMAT_YUYV + AFBC modifier
> > +			 * is supported by a different h/w format id than
> > +			 * DRM_FORMAT_YUYV (only).
> > +			 */
> > +			if (format == DRM_FORMAT_YUYV &&
> > +			    (has_modifier) &&
> > +			    (map->features & MALIDP_DEVICE_AFBC_YUYV_USE_422_P2))
> > +				return AFBC_YUV_422_FORMAT_ID;
> > +			else
> > +				return map->pixel_formats[i].id;
> > +		}
> >  	}
> >  
> >  	return MALIDP_INVALID_FORMAT_ID;
> >  }
> >  
> > +bool malidp_hw_format_is_linear_only(u32 format)
> > +{
> > +	switch (format) {
> > +	case DRM_FORMAT_ARGB2101010:
> > +	case DRM_FORMAT_RGBA1010102:
> > +	case DRM_FORMAT_BGRA1010102:
> > +	case DRM_FORMAT_ARGB8888:
> > +	case DRM_FORMAT_RGBA8888:
> > +	case DRM_FORMAT_BGRA8888:
> > +	case DRM_FORMAT_XBGR8888:
> > +	case DRM_FORMAT_XRGB8888:
> > +	case DRM_FORMAT_RGBX8888:
> > +	case DRM_FORMAT_BGRX8888:
> > +	case DRM_FORMAT_RGB888:
> > +	case DRM_FORMAT_RGB565:
> > +	case DRM_FORMAT_ARGB1555:
> > +	case DRM_FORMAT_RGBA5551:
> > +	case DRM_FORMAT_BGRA5551:
> > +	case DRM_FORMAT_UYVY:
> > +	case DRM_FORMAT_XYUV8888:
> > +	case DRM_FORMAT_XVYU2101010:
> > +	case DRM_FORMAT_X0L2:
> > +	case DRM_FORMAT_X0L0:
> > +		return true;
> > +	default:
> > +		return false;
> > +	}
> > +}
> > +
> > +bool malidp_hw_format_is_afbc_only(u32 format)
> > +{
> > +	switch (format) {
> > +	case DRM_FORMAT_VUY888:
> > +	case DRM_FORMAT_VUY101010:
> > +	case DRM_FORMAT_YUV420_8BIT:
> > +	case DRM_FORMAT_YUV420_10BIT:
> > +		return true;
> > +	default:
> > +		return false;
> > +	}
> > +}
> > +
> >  static void malidp_hw_clear_irq(struct malidp_hw_device *hwdev, u8 block, u32 irq)
> >  {
> >  	u32 base = malidp_get_block_base(hwdev, block);
> > diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
> > index 27b907f..52188f0 100644
> > --- a/drivers/gpu/drm/arm/malidp_hw.h
> > +++ b/drivers/gpu/drm/arm/malidp_hw.h
> > @@ -97,7 +97,8 @@ struct malidp_se_config {
> >  /* regmap features */
> >  #define MALIDP_REGMAP_HAS_CLEARIRQ				BIT(0)
> >  #define MALIDP_DEVICE_AFBC_SUPPORT_SPLIT			BIT(1)
> > -#define AFBC_SUPPORT_SPLIT_WITH_YUV_420_10			BIT(2)
> > +#define MALIDP_DEVICE_AFBC_YUV_420_10_SUPPORT_SPLIT		BIT(2)
> > +#define MALIDP_DEVICE_AFBC_YUYV_USE_422_P2			BIT(3)
> >  
> >  struct malidp_hw_regmap {
> >  	/* address offset of the DE register bank */
> > @@ -323,7 +324,7 @@ int malidp_se_irq_init(struct drm_device *drm, int irq);
> >  void malidp_se_irq_fini(struct malidp_hw_device *hwdev);
> >  
> >  u8 malidp_hw_get_format_id(const struct malidp_hw_regmap *map,
> > -			   u8 layer_id, u32 format);
> > +			   u8 layer_id, u32 format, bool has_modifier);
> >  
> >  static inline u8 malidp_hw_get_pitch_align(struct malidp_hw_device *hwdev, bool rotated)
> >  {
> > diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
> > index 91472e5..0484744 100644
> > --- a/drivers/gpu/drm/arm/malidp_mw.c
> > +++ b/drivers/gpu/drm/arm/malidp_mw.c
> > @@ -143,7 +143,7 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
> >  
> >  	mw_state->format =
> >  		malidp_hw_get_format_id(&malidp->dev->hw->map, SE_MEMWRITE,
> > -					fb->format->format);
> > +					fb->format->format, !!fb->modifier);
> >  	if (mw_state->format == MALIDP_INVALID_FORMAT_ID) {
> >  		struct drm_format_name_buf format_name;
> >  
> > diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c
> > index cd60f73..0765cee 100644
> > --- a/drivers/gpu/drm/arm/malidp_planes.c
> > +++ b/drivers/gpu/drm/arm/malidp_planes.c
> > @@ -52,6 +52,8 @@
> >  #define MALIDP550_LS_ENABLE		0x01c
> >  #define MALIDP550_LS_R1_IN_SIZE		0x020
> >  
> > +#define MODIFIERS_COUNT_MAX		15
> > +
> >  /*
> >   * This 4-entry look-up-table is used to determine the full 8-bit alpha value
> >   * for formats with 1- or 2-bit alpha channels.
> > @@ -145,6 +147,117 @@ static void malidp_plane_atomic_print_state(struct drm_printer *p,
> >  	drm_printf(p, "\tmmu_prefetch_pgsize=%d\n", ms->mmu_prefetch_pgsize);
> >  }
> >  
> > +bool malidp_format_mod_supported(struct drm_device *drm,
> > +				 u32 format, u64 modifier)
> > +{
> > +	const struct drm_format_info *info;
> > +	const u64 *modifiers;
> > +	struct malidp_drm *malidp = drm->dev_private;
> > +	const struct malidp_hw_regmap *map = &malidp->dev->hw->map;
> > +
> > +	if (WARN_ON(modifier == DRM_FORMAT_MOD_INVALID))
> > +		return false;
> > +
> > +	/* Some pixel formats are supported without any modifier */
> > +	if (modifier == DRM_FORMAT_MOD_LINEAR) {
> > +		/* However these pixel formats need to be supported with
> 
> Nitpick: multi-line comment style is to start with a line that contains
> only the marker for the start of the comment.
Agreed
> 
> > +		 * modifiers only
> > +		 */
> > +		return !malidp_hw_format_is_afbc_only(format);
> > +	}
> > +
> > +	if ((modifier >> 56) != DRM_FORMAT_MOD_VENDOR_ARM) {
> > +		DRM_ERROR("Unknown modifier (not Arm)\n");
> > +		return false;
> > +	}
> > +
> > +	if (modifier &
> > +	    ~DRM_FORMAT_MOD_ARM_AFBC(AFBC_MOD_VALID_BITS)) {
> > +		DRM_DEBUG_KMS("Unsupported modifiers\n");
> > +		return false;
> > +	}
> > +
> > +	modifiers = malidp_format_modifiers;
> 
> Actually, looking again at patch 5/12 it looks to me like you could roll
> it into this patch completely.
>
Agreed, I will merge patch 5/12 "Defining a common list of AFBC
modifiers" with the current patch ("adding constraints for each format
and modifier").

> > +	while (*modifiers != DRM_FORMAT_MOD_INVALID) {
> > +		if (*modifiers == modifier) {
> > +			/* SPLIT buffers must use SPARSE layout */
> > +			if (WARN_ON_ONCE((modifier & AFBC_SPLIT) && !(modifier & AFBC_SPARSE)))
> > +				return false;
> > +
> > +			/* CBR only applies to YUV formats, where YTR should be always 0 */
> > +			if (WARN_ON_ONCE((modifier & AFBC_CBR) && (modifier & AFBC_YTR)))
> > +				return false;
> 
> You can take these checks outside the while() loop as they test if the
> modifier passed as a parameter is valid, which you should check before
> running through the array. If you do that, then the loop through the
> malidp_format_modifiers is a simple "if found, break out of loop" and
> then the next check will return false if you iterated over the entire
> list.
> 
Agreed
> > +
> > +			break;
> > +		}
> > +
> > +		modifiers++;
> > +	}
> > +
> > +	/* return false, if the modifier was not found */
> > +	if (*modifiers == DRM_FORMAT_MOD_INVALID) {
> > +		DRM_DEBUG_KMS("Unsupported modifier\n");
> > +		return false;
> > +	}
> > +
> > +	info = drm_format_info(format);
> > +
> > +	if (info->num_planes != 1) {
> > +		DRM_DEBUG_KMS("AFBC buffers expect one plane\n");
> > +		return false;
> > +	}
> > +
> > +	if (malidp_hw_format_is_linear_only(format) == true) {
> > +		DRM_DEBUG_KMS("Given format (0x%x) is supported is linear mode only\n", format);
> > +		return false;
> > +	}
> > +
> > +	/*
> > +	 * RGB formats need to provide YTR modifier and YUV formats should not
> > +	 * provide YTR modifier.
> > +	 */
> > +	if (!(info->is_yuv) != !!(modifier & AFBC_FORMAT_MOD_YTR)) {
> > +		DRM_DEBUG_KMS("AFBC_FORMAT_MOD_YTR is %s for %s formats\n",
> > +			      info->is_yuv ? "disallowed" : "mandatory",
> > +			      info->is_yuv ? "YUV" : "RGB");
> > +		return false;
> > +	}
> > +
> > +	if (modifier & AFBC_SPLIT) {
> > +		if (!info->is_yuv) {
> > +			if (drm_format_plane_cpp(format, 0) <= 2) {
> > +				DRM_DEBUG_KMS("RGB formats <= 16bpp are not supported with SPLIT\n");
> > +				return false;
> > +			}
> > +		}
> > +
> > +		if ((drm_format_horz_chroma_subsampling(format) != 1) ||
> > +		    (drm_format_vert_chroma_subsampling(format) != 1)) {
> > +			if (!(format == DRM_FORMAT_YUV420_10BIT &&
> > +			     (map->features & MALIDP_DEVICE_AFBC_YUV_420_10_SUPPORT_SPLIT))) {
> > +				DRM_DEBUG_KMS("Formats which are sub-sampled should never be split\n");
> > +				return false;
> > +			}
> > +		}
> > +	}
> > +
> > +	if (modifier & AFBC_CBR) {
> > +		if ((drm_format_horz_chroma_subsampling(format) == 1) ||
> > +		    (drm_format_vert_chroma_subsampling(format) == 1)) {
> > +			DRM_DEBUG_KMS("Formats which are not sub-sampled should not have CBR set\n");
> > +			return false;
> > +		}
> > +	}
> > +
> > +	return true;
> > +}
> > +
> > +static bool malidp_format_mod_supported_per_plane(struct drm_plane *plane,
> > +						  u32 format, u64 modifier)
> > +{
> > +	return malidp_format_mod_supported(plane->dev, format, modifier);
> > +}
> > +
> >  static const struct drm_plane_funcs malidp_de_plane_funcs = {
> >  	.update_plane = drm_atomic_helper_update_plane,
> >  	.disable_plane = drm_atomic_helper_disable_plane,
> > @@ -153,6 +266,7 @@ static const struct drm_plane_funcs malidp_de_plane_funcs = {
> >  	.atomic_duplicate_state = malidp_duplicate_plane_state,
> >  	.atomic_destroy_state = malidp_destroy_plane_state,
> >  	.atomic_print_state = malidp_plane_atomic_print_state,
> > +	.format_mod_supported = malidp_format_mod_supported_per_plane,
> >  };
> >  
> >  static int malidp_se_check_scaling(struct malidp_plane *mp,
> > @@ -406,8 +520,8 @@ static int malidp_de_plane_check(struct drm_plane *plane,
> >  	fb = state->fb;
> >  
> >  	ms->format = malidp_hw_get_format_id(&mp->hwdev->hw->map,
> > -					     mp->layer->id,
> > -					     fb->format->format);
> > +					     mp->layer->id, fb->format->format,
> > +					     !!fb->modifier);
> >  	if (ms->format == MALIDP_INVALID_FORMAT_ID)
> >  		return -EINVAL;
> >  
> > @@ -469,6 +583,12 @@ static int malidp_de_plane_check(struct drm_plane *plane,
> >  			return -EINVAL;
> >  	}
> >  
> > +	/* SMART layer does not support AFBC */
> > +	if (mp->layer->id == DE_SMART && fb->modifier) {
> > +		DRM_ERROR("AFBC framebuffer not supported in SMART layer");
> > +		return -EINVAL;
> > +	}
> > +
> >  	ms->rotmem_size = 0;
> >  	if (state->rotation & MALIDP_ROTATED_MASK) {
> >  		int val;
> > -- 
> > 2.7.4
> > 
> 
> Best regards,
> Liviu
> 
> 
> -- 
> ====================
> | I would like to |
> | fix the world,  |
> | but they're not |
> | giving me the   |
>  \ source code!  /
>   ---------------
>     ??\_(???)_/??
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