[PATCH] bits: introduce fixed-type genmasks

From: Yury Norov
Date: Wed Jun 21 2023 - 18:27:29 EST


Generalize __GENMASK() to support different types, and implement
fixed-types versions of GENMASK() based on it.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
include/linux/bitops.h | 1 -
include/linux/bits.h | 22 ++++++++++++----------
2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 2ba557e067fe..1db50c69cfdb 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -15,7 +15,6 @@
# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
#endif

-#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
diff --git a/include/linux/bits.h b/include/linux/bits.h
index 7c0cf5031abe..cb94128171b2 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -6,6 +6,8 @@
#include <vdso/bits.h>
#include <asm/bitsperlong.h>

+#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
+
#define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG))
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
#define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG))
@@ -30,16 +32,16 @@
#define GENMASK_INPUT_CHECK(h, l) 0
#endif

-#define __GENMASK(h, l) \
- (((~UL(0)) - (UL(1) << (l)) + 1) & \
- (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
-#define GENMASK(h, l) \
- (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
+#define __GENMASK(t, h, l) \
+ (GENMASK_INPUT_CHECK(h, l) + \
+ (((t)~0ULL - ((t)(1) << (l)) + 1) & \
+ ((t)~0ULL >> (BITS_PER_TYPE(t) - 1 - (h)))))

-#define __GENMASK_ULL(h, l) \
- (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
- (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
-#define GENMASK_ULL(h, l) \
- (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
+#define GENMASK(h, l) __GENMASK(unsigned long, h, l)
+#define GENMASK_ULL(h, l) __GENMASK(unsigned long long, h, l)
+#define GENMASK_U8(h, l) __GENMASK(u8, h, l)
+#define GENMASK_U16(h, l) __GENMASK(u16, h, l)
+#define GENMASK_U32(h, l) __GENMASK(u32, h, l)
+#define GENMASK_U64(h, l) __GENMASK(u64, h, l)

#endif /* __LINUX_BITS_H */
--
2.39.2