Change in coreboot[master]: libpayload: cbgfx: Clear screen by memcpy

[Hung-Te Lin (Code Review)]

Hung-Te Lin has submitted this change. ( https://review.coreboot.org/c/coreboot/+/58128 )

Change subject: libpayload: cbgfx: Clear screen by memcpy
......................................................................

libpayload: cbgfx: Clear screen by memcpy

Instead of setting each pixel in the framebuffer, use memcpy() to clear
screen faster. As this method should be fast enough, remove the fast
path using memset().

The speed of clear_screen() on brya (x_resolution = 1920,
bytes_per_line = 7680):

- Using memset(): 15ms
- Setting each pixel: 25ms
- Using memcpy(): 14ms

Also remove set_pixel_raw() since it's now used in only one place.

BUG=none
TEST=emerge-brya libpayload
TEST=Saw developer screen on brya
BRANCH=none

Change-Id: I5f08fb50faab48d3db6b61ae022af3226914f72b
Signed-off-by: Yu-Ping Wu 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58128
Tested-by: build bot (Jenkins) 
Reviewed-by: Paul Menzel 
Reviewed-by: Tim Wawrzynczak 
Reviewed-by: Julius Werner 
Reviewed-by: Hung-Te Lin 
---
M payloads/libpayload/drivers/video/graphics.c
1 file changed, 18 insertions(+), 20 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Paul Menzel: Looks good to me, but someone else must approve
  Julius Werner: Looks good to me, approved
  Hung-Te Lin: Looks good to me, approved
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/payloads/libpayload/drivers/video/graphics.c b/payloads/libpayload/drivers/video/graphics.c
index 53de302..7f08d40 100644
--- a/payloads/libpayload/drivers/video/graphics.c
+++ b/payloads/libpayload/drivers/video/graphics.c
@@ -274,19 +274,12 @@
  * Plot a pixel in a framebuffer. This is called from tight loops. Keep it slim
  * and do the validation at callers' site.
  */
-static inline void set_pixel_raw(struct vector *rcoord, uint32_t color)
+static inline void set_pixel(struct vector *coord, uint32_t color)
 {
    const int bpp = fbinfo->bits_per_pixel;
    const int bpl = fbinfo->bytes_per_line;
-	int i;
-	uint8_t * const pixel = FB + rcoord->y * bpl + rcoord->x * bpp / 8;
-	for (i = 0; i < bpp / 8; i++)
-		pixel[i] = (color >> (i * 8));
-}
-
-static inline void set_pixel(struct vector *coord, uint32_t color)
-{
    struct vector rcoord;
+	int i;

switch (fbinfo->orientation) {
    case CB_FB_ORIENTATION_NORMAL:
@@ -308,7 +301,9 @@
    	break;
    }

-	set_pixel_raw(&rcoord, color);
+	uint8_t * const pixel = FB + rcoord.y * bpl + rcoord.x * bpp / 8;
+	for (i = 0; i < bpp / 8; i++)
+		pixel[i] = (color >> (i * 8));
 }

/*
@@ -625,22 +620,25 @@
    if (cbgfx_init())
    	return CBGFX_ERROR_INIT;

-	struct vector p;
+	int x, y, i;
    uint32_t color = calculate_color(rgb, 0);
    const int bpp = fbinfo->bits_per_pixel;
    const int bpl = fbinfo->bytes_per_line;
+	uint8_t *line = malloc(bpl);

-	/* If all significant bytes in color are equal, fastpath through memset.
-	 * We assume that for 32bpp the high byte gets ignored anyway. */
-	if ((((color >> 8) & 0xff) == (color & 0xff)) && (bpp == 16 ||
-	    (((color >> 16) & 0xff) == (color & 0xff)))) {
-		memset(FB, color & 0xff, fbinfo->y_resolution * bpl);
-	} else {
-		for (p.y = 0; p.y < fbinfo->y_resolution; p.y++)
-			for (p.x = 0; p.x < fbinfo->x_resolution; p.x++)
-				set_pixel_raw(&p, color);
+	if (!line) {
+		LOG("Failed to allocate line buffer (%u bytes)\n", bpl);
+		return CBGFX_ERROR_UNKNOWN;
    }

+	/* Set line buffer pixels, then memcpy to framebuffer */
+	for (x = 0; x < fbinfo->x_resolution; x++)
+		for (i = 0; i < bpp / 8; i++)
+			line[x * bpp / 8 + i] = (color >> (i * 8));
+	for (y = 0; y < fbinfo->y_resolution; y++)
+		memcpy(FB + y * bpl, line, bpl);
+
+	free(line);
    return CBGFX_SUCCESS;
 }