fbcon: Move fbcon callbacks into struct fbcon_bitops

Depending on rotation settings, fbcon sets different callback
functions in struct fbcon_par from within fbcon_set_bitops(). Declare
the callback functions in the new type struct fbcon_bitops. Then
only replace the single bitops pointer in struct fbcon_par.

Keeping callbacks in constant instances of struct fbcon_bitops
makes it harder to exploit the callbacks. Also makes the code slightly
easier to maintain.

For tile-based consoles, there's a separate instance of the bitops
structure.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20250909124616.143365-5-tzimmermann@suse.de

1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c
index ebadc9619699..7a68372f0444 100644
--- a/drivers/video/fbdev/core/bitblit.c
+++ b/drivers/video/fbdev/core/bitblit.c
@@ -384,15 +384,18 @@ static int bit_update_start(struct fb_info *info)
 	return err;
 }
 
+static const struct fbcon_bitops bit_fbcon_bitops = {
+	.bmove = bit_bmove,
+	.clear = bit_clear,
+	.putcs = bit_putcs,
+	.clear_margins = bit_clear_margins,
+	.cursor = bit_cursor,
+	.update_start = bit_update_start,
+};
+
 void fbcon_set_bitops(struct fbcon_par *par)
 {
-	par->bmove = bit_bmove;
-	par->clear = bit_clear;
-	par->putcs = bit_putcs;
-	par->clear_margins = bit_clear_margins;
-	par->cursor = bit_cursor;
-	par->update_start = bit_update_start;
-	par->rotate_font = NULL;
+	par->bitops = &bit_fbcon_bitops;
 
 	if (par->rotate)
 		fbcon_set_rotate(par);