drm/format-helper: Add generic conversion to 32-bit formats

Add drm_fb_xfrm_line_32to32() to implement conversion from 32-bit
pixels to 32-bit pixels. The pixel-conversion is specified by the
given callback parameter. Mark the helper as always_inline to avoid
overhead from function calls.

Then implement all existing line-conversion functions with the new
generic call and the respective pixel-conversion helper.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250328141709.217283-3-tzimmermann@suse.de

1 files changed, 19 insertions, 65 deletions

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 01d3ab307ac3..abd18c23cfbb 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -20,6 +20,8 @@
 #include <drm/drm_print.h>
 #include <drm/drm_rect.h>
 
+#include "drm_format_internal.h"
+
 /**
  * drm_format_conv_state_init - Initialize format-conversion state
  * @state: The state to initialize
@@ -244,6 +246,18 @@ static int drm_fb_xfrm(struct iosys_map *dst,
 				     xfrm_line);
 }
 
+static __always_inline void drm_fb_xfrm_line_32to32(void *dbuf, const void *sbuf,
+						    unsigned int pixels,
+						    u32 (*xfrm_pixel)(u32))
+{
+	__le32 *dbuf32 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	const __le32 *send32 = sbuf32 + pixels;
+
+	while (sbuf32 < send32)
+		*dbuf32++ = cpu_to_le32(xfrm_pixel(le32_to_cpup(sbuf32++)));
+}
+
 /**
  * drm_fb_memcpy - Copy clip buffer
  * @dst: Array of destination buffers
@@ -755,16 +769,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_bgr888);
 
 static void drm_fb_xrgb8888_to_argb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
-	__le32 *dbuf32 = dbuf;
-	const __le32 *sbuf32 = sbuf;
-	unsigned int x;
-	u32 pix;
-
-	for (x = 0; x < pixels; x++) {
-		pix = le32_to_cpu(sbuf32[x]);
-		pix |= GENMASK(31, 24); /* fill alpha bits */
-		dbuf32[x] = cpu_to_le32(pix);
-	}
+	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_argb8888);
 }
 
 /**
@@ -804,19 +809,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb8888);
 
 static void drm_fb_xrgb8888_to_abgr8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
-	__le32 *dbuf32 = dbuf;
-	const __le32 *sbuf32 = sbuf;
-	unsigned int x;
-	u32 pix;
-
-	for (x = 0; x < pixels; x++) {
-		pix = le32_to_cpu(sbuf32[x]);
-		pix = ((pix & 0x00ff0000) >> 16) <<  0 |
-		      ((pix & 0x0000ff00) >>  8) <<  8 |
-		      ((pix & 0x000000ff) >>  0) << 16 |
-		      GENMASK(31, 24); /* fill alpha bits */
-		*dbuf32++ = cpu_to_le32(pix);
-	}
+	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_abgr8888);
 }
 
 static void drm_fb_xrgb8888_to_abgr8888(struct iosys_map *dst, const unsigned int *dst_pitch,
@@ -835,19 +828,7 @@ static void drm_fb_xrgb8888_to_abgr8888(struct iosys_map *dst, const unsigned in
 
 static void drm_fb_xrgb8888_to_xbgr8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
-	__le32 *dbuf32 = dbuf;
-	const __le32 *sbuf32 = sbuf;
-	unsigned int x;
-	u32 pix;
-
-	for (x = 0; x < pixels; x++) {
-		pix = le32_to_cpu(sbuf32[x]);
-		pix = ((pix & 0x00ff0000) >> 16) <<  0 |
-		      ((pix & 0x0000ff00) >>  8) <<  8 |
-		      ((pix & 0x000000ff) >>  0) << 16 |
-		      ((pix & 0xff000000) >> 24) << 24;
-		*dbuf32++ = cpu_to_le32(pix);
-	}
+	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_xbgr8888);
 }
 
 static void drm_fb_xrgb8888_to_xbgr8888(struct iosys_map *dst, const unsigned int *dst_pitch,
@@ -866,20 +847,7 @@ static void drm_fb_xrgb8888_to_xbgr8888(struct iosys_map *dst, const unsigned in
 
 static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
-	__le32 *dbuf32 = dbuf;
-	const __le32 *sbuf32 = sbuf;
-	unsigned int x;
-	u32 val32;
-	u32 pix;
-
-	for (x = 0; x < pixels; x++) {
-		pix = le32_to_cpu(sbuf32[x]);
-		val32 = ((pix & 0x000000FF) << 2) |
-			((pix & 0x0000FF00) << 4) |
-			((pix & 0x00FF0000) << 6);
-		pix = val32 | ((val32 >> 8) & 0x00300C03);
-		*dbuf32++ = cpu_to_le32(pix);
-	}
+	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_xrgb2101010);
 }
 
 /**
@@ -920,21 +888,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
 
 static void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
-	__le32 *dbuf32 = dbuf;
-	const __le32 *sbuf32 = sbuf;
-	unsigned int x;
-	u32 val32;
-	u32 pix;
-
-	for (x = 0; x < pixels; x++) {
-		pix = le32_to_cpu(sbuf32[x]);
-		val32 = ((pix & 0x000000ff) << 2) |
-			((pix & 0x0000ff00) << 4) |
-			((pix & 0x00ff0000) << 6);
-		pix = GENMASK(31, 30) | /* set alpha bits */
-		      val32 | ((val32 >> 8) & 0x00300c03);
-		*dbuf32++ = cpu_to_le32(pix);
-	}
+	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_argb2101010);
 }
 
 /**