From: Arvind Sankar <nivedita@xxxxxxxxxxxx> Use the __ffs/__fls macros to calculate the position and size of the mask. Correct type of mask to u32 instead of unsigned long. Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200320020028.1936003-9-nivedita@xxxxxxxxxxxx Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- drivers/firmware/efi/libstub/gop.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c index 7b0baf9a912f..8bf424f35759 100644 --- a/drivers/firmware/efi/libstub/gop.c +++ b/drivers/firmware/efi/libstub/gop.c @@ -5,6 +5,7 @@ * * ----------------------------------------------------------------------- */ +#include <linux/bitops.h> #include <linux/efi.h> #include <linux/screen_info.h> #include <asm/efi.h> @@ -12,27 +13,16 @@ #include "efistub.h" -static void find_bits(unsigned long mask, u8 *pos, u8 *size) +static void find_bits(u32 mask, u8 *pos, u8 *size) { - u8 first, len; - - first = 0; - len = 0; - - if (mask) { - while (!(mask & 0x1)) { - mask = mask >> 1; - first++; - } - - while (mask & 0x1) { - mask = mask >> 1; - len++; - } + if (!mask) { + *pos = *size = 0; + return; } - *pos = first; - *size = len; + /* UEFI spec guarantees that the set bits are contiguous */ + *pos = __ffs(mask); + *size = __fls(mask) - *pos + 1; } static void -- 2.17.1
