Display the boot logo at a smaller size for low-power CPUs

smol-penguins.diff

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 8268bbee8..708c1846e 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -45,6 +45,8 @@
 
 #define FBPIXMAPSIZE	(1024 * 8)
 
+#define RESIZE_RATIO 75
+
 static DEFINE_MUTEX(registration_lock);
 
 struct fb_info *registered_fb[FB_MAX] __read_mostly;
@@ -416,6 +418,36 @@ static void fb_rotate_logo(struct fb_info *info, u8 *dst,
 	image->data = dst;
 }
 
+#ifdef CONFIG_LOGO_SMALL
+static char* fb_resize_logo(struct fb_image *target, const struct fb_image *source) {
+	char* resized_data;
+
+	target->dx = 0;
+	target->dy = 0;
+	target->width = source->width * RESIZE_RATIO / 100;
+	target->height = source->height * RESIZE_RATIO / 100;
+	target->fg_color = source->fg_color;
+	target->bg_color = source->bg_color;
+	resized_data = kmalloc_array(target->width, target->height, GFP_KERNEL);
+	target->data = resized_data;
+	target->cmap = source->cmap;
+
+	if (resized_data) {
+		int x, y;
+
+		for (x = 0 ; x < target->width ; x++) {
+			for (y = 0 ; y < target->height ; y++) {
+				int target_x = x * 100 / RESIZE_RATIO;
+				int target_y = y * 100 / RESIZE_RATIO;
+				resized_data[x + y * target->width] = source->data[target_x + target_y * source->width];
+			}
+		}
+	}
+
+	return resized_data;
+}
+#endif
+
 static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 			    int rotate, unsigned int num)
 {
@@ -457,11 +489,16 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 
 static int fb_show_logo_line(struct fb_info *info, int rotate,
 			     const struct linux_logo *logo, int y,
-			     unsigned int n)
+			     unsigned int n, unsigned int n_small
+)
 {
 	u32 *palette = NULL, *saved_pseudo_palette = NULL;
 	unsigned char *logo_new = NULL, *logo_rotate = NULL;
 	struct fb_image image;
+	#ifdef CONFIG_LOGO_SMALL
+	struct fb_image small_image;
+	unsigned char *small_logo_data = NULL, *small_logo_rotate = NULL;
+	#endif
 
 	/* Return if the frame buffer is not mapped or suspended */
 	if (logo == NULL || info->state != FBINFO_STATE_RUNNING ||
@@ -502,6 +539,13 @@ static int fb_show_logo_line(struct fb_info *info, int rotate,
 		fb_set_logo(info, logo, logo_new, fb_logo.depth);
 	}
 
+	image.width = logo->width;
+	image.height = logo->height;
+
+	#ifdef CONFIG_LOGO_SMALL
+	small_logo_data = fb_resize_logo(&small_image, &image);
+	#endif
+
 	if (fb_center_logo) {
 		int xres = info->var.xres;
 		int yres = info->var.yres;
@@ -513,30 +557,59 @@ static int fb_show_logo_line(struct fb_info *info, int rotate,
 
 		while (n && (n * (logo->width + 8) - 8 > xres))
 			--n;
-		image.dx = (xres - n * (logo->width + 8) - 8) / 2;
+
+		// Remaining empty space around the logo
+		xres = xres - n * (logo->width + 8) - 8;
+
+		#ifdef CONFIG_LOGO_SMALL
+		while (n_small && (n_small * (small_image.width + 8) - 8 > xres))
+			--n_small;
+
+		xres = xres - n_small * (small_image.width + 8) - 8;
+		#endif
+
+		image.dx = xres / 2;
 		image.dy = y ?: (yres - logo->height) / 2;
 	} else {
 		image.dx = 0;
 		image.dy = y;
 	}
 
-	image.width = logo->width;
-	image.height = logo->height;
+	#ifdef CONFIG_LOGO_SMALL
+	small_image.dx = image.dx + n * (logo->width + 8);
+	small_image.dy = image.dy + (logo->height - small_image.height);
+	#endif
 
 	if (rotate) {
 		logo_rotate = kmalloc_array(logo->width, logo->height,
 					    GFP_KERNEL);
-		if (logo_rotate)
+		if (logo_rotate) {
 			fb_rotate_logo(info, logo_rotate, &image, rotate);
+		}
+
+		#ifdef CONFIG_LOGO_SMALL
+		small_logo_rotate = kmalloc_array(small_image.width, small_image.height,
+					    GFP_KERNEL);
+		if (small_logo_rotate) {
+			fb_rotate_logo(info, small_logo_rotate, &small_image, rotate);
+		}
+		#endif
 	}
 
 	fb_do_show_logo(info, &image, rotate, n);
+	#ifdef CONFIG_LOGO_SMALL
+	fb_do_show_logo(info, &small_image, rotate, n_small);
+	#endif
 
 	kfree(palette);
 	if (saved_pseudo_palette != NULL)
 		info->pseudo_palette = saved_pseudo_palette;
 	kfree(logo_new);
 	kfree(logo_rotate);
+	#ifdef CONFIG_LOGO_SMALL
+	kfree(small_logo_data);
+	kfree(small_logo_rotate);
+	#endif
 	return image.dy + logo->height;
 }
 
@@ -590,7 +663,8 @@ static int fb_show_extra_logos(struct fb_info *info, int y, int rotate)
 
 	for (i = 0; i < fb_logo_ex_num; i++)
 		y = fb_show_logo_line(info, rotate,
-				      fb_logo_ex[i].logo, y, fb_logo_ex[i].n);
+				      fb_logo_ex[i].logo, y, fb_logo_ex[i].n,
+				      0);
 
 	return y;
 }
@@ -694,7 +768,11 @@ int fb_show_logo(struct fb_info *info, int rotate)
 		return 0;
 
 	count = fb_logo_count < 0 ? num_online_cpus() : fb_logo_count;
-	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0, count);
+	#ifdef CONFIG_LOGO_SMALL
+	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0, count - (count / 2), count / 2);
+	#else
+	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0, count, 0);
+	#endif
 	y = fb_show_extra_logos(info, y, rotate);
 
 	return y;
diff --git a/drivers/video/logo/Kconfig b/drivers/video/logo/Kconfig
index 6d6f8c087..d6d7349f9 100644
--- a/drivers/video/logo/Kconfig
+++ b/drivers/video/logo/Kconfig
@@ -16,6 +16,12 @@ config FB_LOGO_EXTRA
 	depends on FB=y
 	default y if SPU_BASE
 
+config LOGO_SMALL
+	bool "Use a smaller logo for low-power CPUs"
+	help
+	  Instead of displaying the normal logo for each CPU in the system,
+	  use a small version of the logo for system CPUs that are low-power.
+
 config LOGO_LINUX_MONO
 	bool "Standard black and white Linux logo"
 	default y