efi/gop: Remove unreachable code from setup_pixel_info

pixel_format must be one of
	PIXEL_RGB_RESERVED_8BIT_PER_COLOR
	PIXEL_BGR_RESERVED_8BIT_PER_COLOR
	PIXEL_BIT_MASK
since we skip PIXEL_BLT_ONLY when finding a gop.

Remove the redundant code and add another check in find_gop to skip any
pixel formats that we don't know about, in case a later version of the
UEFI spec adds one.

Reformat the code a little.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200320020028.1936003-10-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 8bf424f35759fcd1819e6660165341f7b49cd3dd..2d91699e3061a11dab4d58ae911f813973ccd0f7 100644 (file)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -29,49 +29,34 @@ static void
 setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
                 efi_pixel_bitmask_t pixel_info, int pixel_format)
 {
-       if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
-               si->lfb_depth = 32;
-               si->lfb_linelength = pixels_per_scan_line * 4;
-               si->red_size = 8;
-               si->red_pos = 0;
-               si->green_size = 8;
-               si->green_pos = 8;
-               si->blue_size = 8;
-               si->blue_pos = 16;
-               si->rsvd_size = 8;
-               si->rsvd_pos = 24;
-       } else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
-               si->lfb_depth = 32;
-               si->lfb_linelength = pixels_per_scan_line * 4;
-               si->red_size = 8;
-               si->red_pos = 16;
-               si->green_size = 8;
-               si->green_pos = 8;
-               si->blue_size = 8;
-               si->blue_pos = 0;
-               si->rsvd_size = 8;
-               si->rsvd_pos = 24;
-       } else if (pixel_format == PIXEL_BIT_MASK) {
-               find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
-               find_bits(pixel_info.green_mask, &si->green_pos,
-                         &si->green_size);
-               find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
-               find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
-                         &si->rsvd_size);
+       if (pixel_format == PIXEL_BIT_MASK) {
+               find_bits(pixel_info.red_mask,
+                         &si->red_pos, &si->red_size);
+               find_bits(pixel_info.green_mask,
+                         &si->green_pos, &si->green_size);
+               find_bits(pixel_info.blue_mask,
+                         &si->blue_pos, &si->blue_size);
+               find_bits(pixel_info.reserved_mask,
+                         &si->rsvd_pos, &si->rsvd_size);
                si->lfb_depth = si->red_size + si->green_size +
                        si->blue_size + si->rsvd_size;
                si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
        } else {
-               si->lfb_depth = 4;
-               si->lfb_linelength = si->lfb_width / 2;
-               si->red_size = 0;
-               si->red_pos = 0;
-               si->green_size = 0;
-               si->green_pos = 0;
-               si->blue_size = 0;
-               si->blue_pos = 0;
-               si->rsvd_size = 0;
-               si->rsvd_pos = 0;
+               if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
+                       si->red_pos   = 0;
+                       si->blue_pos  = 16;
+               } else /* PIXEL_BGR_RESERVED_8BIT_PER_COLOR */ {
+                       si->blue_pos  = 0;
+                       si->red_pos   = 16;
+               }
+
+               si->green_pos = 8;
+               si->rsvd_pos  = 24;
+               si->red_size = si->green_size =
+                       si->blue_size = si->rsvd_size = 8;
+
+               si->lfb_depth = 32;
+               si->lfb_linelength = pixels_per_scan_line * 4;
        }
 }
 
@@ -100,7 +85,8 @@ find_gop(efi_guid_t *proto, unsigned long size, void **handles)
 
                mode = efi_table_attr(gop, mode);
                info = efi_table_attr(mode, info);
-               if (info->pixel_format == PIXEL_BLT_ONLY)
+               if (info->pixel_format == PIXEL_BLT_ONLY ||
+                   info->pixel_format >= PIXEL_FORMAT_MAX)
                        continue;
 
                /*