[1/6] drm/i915: Implement .get_format_info() hook for CCS

Commit Message

Ben Widawsky July 26, 2017, 6:07 p.m. UTC

From: Ville Syrjälä <[e-mail]>

SKL+ display engine can scan out certain kinds of compressed surfaces
produced by the render engine. This involved telling the display engine
the location of the color control surfae (CCS) which describes which
parts of the main surface are compressed and which are not. The location
of CCS is provided by userspace as just another plane with its own offset.

By providing our own format information for the CCS formats, we should
be able to make framebuffer_check() do the right thing for the CCS
surface as well.

Note that we'll return the same format info for both Y and Yf tiled
format as that's what happens with the non-CCS Y vs. Yf as well. If
desired, we could potentially return a unique pointer for each
pixel_format+tiling+ccs combination, in which case we immediately be
able to tell if any of that stuff changed by just comparing the
pointers. But that does sound a bit wasteful space wise.

v2: Drop the 'dev' argument from the hook
	v3: Include the description of the CCS surface layout
v4: Pretend CCS tiles are regular 128 byte wide Y tiles (Jason)

Cc: Daniel Vetter <[e-mail]>
Cc: Ben Widawsky <[e-mail]>
Cc: Jason Ekstrand <[e-mail]>
Reviewed-by: Ben Widawsky <[e-mail]> (v3)
Signed-off-by: Ville Syrjä <[e-mail]>
Signed-off-by: Ben Widawsky <[e-mail]>
---
 drivers/gpu/drm/drm_fourcc.c         |  2 +-
 drivers/gpu/drm/i915/intel_display.c | 37 ++++++++++++++++++++++++++++++++++++
 include/drm/drm_mode_config.h        |  3 ++-
 include/uapi/drm/drm_fourcc.h        |  3 +++
 4 files changed, 43 insertions(+), 2 deletions(-)

Comments

Daniel Stone July 31, 2017, 4:12 p.m. UTC | #1

Hi Ben,

On 26 July 2017 at 19:07, Ben Widawsky <[e-mail]> wrote:
> v2: Drop the 'dev' argument from the hook
>         v3: Include the description of the CCS surface layout

This went missing. Vidya's patch has it though.

> +static const struct drm_format_info ccs_formats[] = {
> +       { .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
> +       { .format = DRM_FORMAT_XBGR8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
> +       { .format = DRM_FORMAT_ARGB8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
> +       { .format = DRM_FORMAT_ABGR8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },

Mind you, this is backwards from Vidya's patch, in which CCS is
described as 8x16 subsampled rather than 16x8. I think yours is
correct though.

Cheers,
Daniel

Patch

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 9c0152df45ad..50da6180c495 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -222,7 +222,7 @@  drm_get_format_info(struct drm_device *dev,
 	const struct drm_format_info *info = NULL;
 
 	if (dev->mode_config.funcs->get_format_info)
-		info = dev->mode_config.funcs->get_format_info(mode_cmd);
+		info = dev->mode_config.funcs->get_format_info(dev, mode_cmd);
 
 	if (!info)
 		info = drm_format_info(mode_cmd->pixel_format);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f93d9a13b13a..0e71c7207258 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2428,6 +2428,42 @@  static unsigned int intel_fb_modifier_to_tiling(uint64_t fb_modifier)
 	}
 }
 
+static const struct drm_format_info ccs_formats[] = {
+	{ .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
+	{ .format = DRM_FORMAT_XBGR8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
+	{ .format = DRM_FORMAT_ARGB8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
+	{ .format = DRM_FORMAT_ABGR8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 16, .vsub = 8, },
+};
+
+static const struct drm_format_info *
+lookup_format_info(const struct drm_format_info formats[],
+		   int num_formats, u32 format)
+{
+	int i;
+
+	for (i = 0; i < num_formats; i++) {
+		if (formats[i].format == format)
+			return &formats[i];
+	}
+
+	return NULL;
+}
+
+static const struct drm_format_info *
+intel_get_format_info(struct drm_device *dev,
+		      const struct drm_mode_fb_cmd2 *cmd)
+{
+	switch (cmd->modifier[0]) {
+	case I915_FORMAT_MOD_Y_TILED_CCS:
+	case I915_FORMAT_MOD_Yf_TILED_CCS:
+		return lookup_format_info(ccs_formats,
+					  ARRAY_SIZE(ccs_formats),
+					  cmd->pixel_format);
+	default:
+		return NULL;
+	}
+}
+
 static int
 intel_fill_fb_info(struct drm_i915_private *dev_priv,
 		   struct drm_framebuffer *fb)
@@ -13675,6 +13711,7 @@  static void intel_atomic_state_free(struct drm_atomic_state *state)
 
 static const struct drm_mode_config_funcs intel_mode_funcs = {
 	.fb_create = intel_user_framebuffer_create,
+	.get_format_info = intel_get_format_info,
 	.output_poll_changed = intel_fbdev_output_poll_changed,
 	.atomic_check = intel_atomic_check,
 	.atomic_commit = intel_atomic_commit,
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 42981711189b..f0d3d3857ae2 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -81,7 +81,8 @@  struct drm_mode_config_funcs {
 	 * The format information specific to the given fb metadata, or
 	 * NULL if none is found.
 	 */
-	const struct drm_format_info *(*get_format_info)(const struct drm_mode_fb_cmd2 *mode_cmd);
+	const struct drm_format_info *(*get_format_info)(struct drm_device *dev,
+		const struct drm_mode_fb_cmd2 *mode_cmd);
 
 	/**
 	 * @output_poll_changed:
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 7586c46f68bf..ee5910944fac 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -252,6 +252,9 @@  extern "C" {
  */
 #define I915_FORMAT_MOD_Yf_TILED fourcc_mod_code(INTEL, 3)
 
+#define I915_FORMAT_MOD_Y_TILED_CCS	fourcc_mod_code(INTEL, 4)
+#define I915_FORMAT_MOD_Yf_TILED_CCS	fourcc_mod_code(INTEL, 5)
+
 /*
  * Tiled, NV12MT, grouped in 64 (pixels) x 32 (lines) -sized macroblocks
  *