Commit 65b2f7c4 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm: Inline drm_color_lut_extract() 



This thing can get called several thousand times per LUT
so seems like we want to inline it to:
- avoid the function call overhead
- allow constant folding

A quick synthetic test (w/o any hardware interaction) with
a ridiculously large LUT size shows about 50% reduction in
runtime on my HSW and BSW boxes. Slightly less with more
reasonable LUT size but still easily measurable in tens
of microseconds.

v2: Include drm_color_mgmt.h in the .rst (Daniel)

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191108135654.12907-1-ville.syrjala@linux.intel.com
parent 2c81bdc8

Documentation/gpu/drm-kms.rst

+3 −0
Original line number Diff line number Diff line
@@ -479,6 +479,9 @@ Color Management Properties 
.. kernel-doc:: drivers/gpu/drm/drm_color_mgmt.c

   :export:



.. kernel-doc:: include/drm/drm_color_mgmt.h

   :internal:



Tile Group Property

-------------------

drivers/gpu/drm/drm_color_mgmt.c

+0 −24
Original line number Diff line number Diff line
@@ -108,30 +108,6 @@ 
 * 	standard enum values supported by the DRM plane.

 */



/**

 * drm_color_lut_extract - clamp and round LUT entries

 * @user_input: input value

 * @bit_precision: number of bits the hw LUT supports

 *

 * Extract a degamma/gamma LUT value provided by user (in the form of

 * &drm_color_lut entries) and round it to the precision supported by the

 * hardware.

 */

uint32_t drm_color_lut_extract(uint32_t user_input, uint32_t bit_precision)

{

	uint32_t val = user_input;

	uint32_t max = 0xffff >> (16 - bit_precision);



	/* Round only if we're not using full precision. */

	if (bit_precision < 16) {

		val += 1UL << (16 - bit_precision - 1);

		val >>= 16 - bit_precision;

	}



	return clamp_val(val, 0, max);

}

EXPORT_SYMBOL(drm_color_lut_extract);



/**

 * drm_color_ctm_s31_32_to_qm_n

 *

include/drm/drm_color_mgmt.h

+23 −1
Original line number Diff line number Diff line
@@ -29,7 +29,29 @@ 
struct drm_crtc;

struct drm_plane;



uint32_t drm_color_lut_extract(uint32_t user_input, uint32_t bit_precision);

/**

 * drm_color_lut_extract - clamp and round LUT entries

 * @user_input: input value

 * @bit_precision: number of bits the hw LUT supports

 *

 * Extract a degamma/gamma LUT value provided by user (in the form of

 * &drm_color_lut entries) and round it to the precision supported by the

 * hardware.

 */

static inline u32 drm_color_lut_extract(u32 user_input, int bit_precision)

{

	u32 val = user_input;

	u32 max = 0xffff >> (16 - bit_precision);



	/* Round only if we're not using full precision. */

	if (bit_precision < 16) {

		val += 1UL << (16 - bit_precision - 1);

		val >>= 16 - bit_precision;

	}



	return clamp_val(val, 0, max);

}



u64 drm_color_ctm_s31_32_to_qm_n(u64 user_input, u32 m, u32 n);



void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,

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