[PATCH v2 1/3] bits: split the definition of the asm and non-asm GENMASK*()

From: Vincent Mailhol via B4 Relay
Date: Sun Jun 08 2025 - 22:46:38 EST


From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>

In an upcoming change, the non-asm GENMASK*() will all be unified to
depend on GENMASK_TYPE() which indirectly depend on sizeof(), something
not available in asm.

Instead of adding further complexity to GENMASK_TYPE() to make it work
for both asm and non asm, just split the definition of the two variants.

Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
---
Changelog:

v1 -> v2:

- No changes

This patch previously belonged to this series:

bits: Fixed-type GENMASK_U*() and BIT_U*()
Link: https://lore.kernel.org/r/20250308-fixed-type-genmasks-v6-0-f59315e73c29@xxxxxxxxxx

Below changelog contains the history from the previous series.

Changelog:

v6 (previous series) -> v1 (new series):

- Do not rephrase the comment saying that BUILD_BUG_ON() is not
available in asm code. Leave it as it is.

- Add Lucas reviewed-by tag.

v5 -> v6:

- Restore the comment saying that BUILD_BUG_ON() is not available in asm
code.

v4 -> v5:

- Use tab indentations instead of single space to separate the
macro name from its body.

v3 -> v4:

- New patch in the series
---
include/linux/bits.h | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/linux/bits.h b/include/linux/bits.h
index 7ad0562191153471dac729b0020cdb1c9d3049fc..13dbc8adc70ee0a624b509cb6cb9f807459e0899 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -35,6 +35,11 @@

#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h)))

+#define GENMASK(h, l) \
+ (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
+#define GENMASK_ULL(h, l) \
+ (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
+
/*
* Generate a mask for the specified type @t. Additional checks are made to
* guarantee the value returned fits in that type, relying on
@@ -79,15 +84,11 @@
* BUILD_BUG_ON_ZERO is not available in h files included from asm files,
* disable the input check if that is the case.
*/
-#define GENMASK_INPUT_CHECK(h, l) 0
+#define GENMASK(h, l) __GENMASK(h, l)
+#define GENMASK_ULL(h, l) __GENMASK_ULL(h, l)

#endif /* !defined(__ASSEMBLY__) */

-#define GENMASK(h, l) \
- (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
-#define GENMASK_ULL(h, l) \
- (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
-
#if !defined(__ASSEMBLY__)
/*
* Missing asm support

--
2.49.0