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SubjectRe: [PATCH 00/12] treewide: Fix GENMASK misuses
Date
Trimming CC-list.

> It'd can't be done as it's used in declarations
> and included in asm files and it uses the UL()
> macro.

Can the BUILD_BUG_ON_ZERO() macro be used instead? It works in
declarations. I don't know if it works in asm-files, but the below
changes builds an x86-64 allyesconfig without problems (after the rest
of this series have been applied.

/Rikard

---
include/linux/bits.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/linux/bits.h b/include/linux/bits.h
index 669d69441a62..52e747d27f87 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -2,6 +2,7 @@
#ifndef __LINUX_BITS_H
#define __LINUX_BITS_H

+#include <linux/build_bug.h>
#include <linux/const.h>
#include <asm/bitsperlong.h>

@@ -19,11 +20,15 @@
* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
*/
#define GENMASK(h, l) \
+ (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
+ __is_constexpr(h) && __is_constexpr(l), (l) > (h), 0)) + \
(((~UL(0)) - (UL(1) << (l)) + 1) & \
- (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
+ (~UL(0) >> (BITS_PER_LONG - 1 - (h)))))

#define GENMASK_ULL(h, l) \
+ (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
+ __is_constexpr(h) && __is_constexpr(l), (l) > (h), 0)) + \
(((~ULL(0)) - (ULL(1) << (l)) + 1) & \
- (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
+ (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h)))))

#endif /* __LINUX_BITS_H */
--
2.22.0
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