From 118d777c4cb40f44e7b675955fd2da8b22f83913 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 17 Jun 2024 12:18:37 +0100 Subject: [PATCH] wordpart.h: Add REPEAT_BYTE_U32() In some cases it's necessary to replicate a byte across a u32 value, for which REPEAT_BYTE() would be helpful. Currently this requires explicit masking of the result to avoid sparse warnings, as e.g. (u32)REPEAT_BYTE(0xa0)) ... will result in a warning: cast truncates bits from constant value (a0a0a0a0a0a0a0a0 becomes a0a0a0a0) Add a new REPEAT_BYTE_U32() which does the necessary masking internally, so that we don't need to duplicate this for every usage. Signed-off-by: Mark Rutland Cc: Alexandru Elisei Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon Link: https://lore.kernel.org/r/20240617111841.2529370-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas Acked-by: Thomas Gleixner --- include/linux/wordpart.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/wordpart.h b/include/linux/wordpart.h index 4ca1ba66d2f07..5a7b97bb7c956 100644 --- a/include/linux/wordpart.h +++ b/include/linux/wordpart.h @@ -39,6 +39,14 @@ */ #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) +/** + * REPEAT_BYTE_U32 - repeat the value @x multiple times as a u32 value + * @x: value to repeat + * + * NOTE: @x is not checked for > 0xff; larger values produce odd results. + */ +#define REPEAT_BYTE_U32(x) lower_32_bits(REPEAT_BYTE(x)) + /* Set bits in the first 'n' bytes when loaded from memory */ #ifdef __LITTLE_ENDIAN # define aligned_byte_mask(n) ((1UL << 8*(n))-1) -- 2.49.0