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| author | Mark Rutland <mark.rutland@arm.com> | 2024-06-17 14:18:37 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-06-24 20:16:44 +0300 |
| commit | 118d777c4cb40f44e7b675955fd2da8b22f83913 (patch) | |
| tree | 8f1b01ee8e3062993a34ba1e694d75f8c647c832 | |
| parent | 83a7eefedc9b56fe7bfeff13b6c7356688ffa670 (diff) | |
| download | linux-118d777c4cb40f44e7b675955fd2da8b22f83913.tar.xz | |
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 <mark.rutland@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240617111841.2529370-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/wordpart.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/wordpart.h b/include/linux/wordpart.h index 4ca1ba66d2f0..5a7b97bb7c95 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) |