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author | Arnd Bergmann <arnd@arndb.de> | 2024-06-04 22:59:57 +0200 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2024-06-05 13:30:58 +0100 |
commit | 5c40e428aea644c9d924e491b1bc22fa9f272bcc (patch) | |
tree | 51d3db96223a9db4f1e2e957e8c209b2b89ba53d /arch/arm64/include/asm | |
parent | 14951beaec93696b092a906baa0f29322cf34004 (diff) | |
download | linux-stable-5c40e428aea644c9d924e491b1bc22fa9f272bcc.tar.gz linux-stable-5c40e428aea644c9d924e491b1bc22fa9f272bcc.tar.bz2 linux-stable-5c40e428aea644c9d924e491b1bc22fa9f272bcc.zip |
arm64/io: add constant-argument check
In some configurations __const_iowrite32_copy() does not get inlined
and gcc runs into the BUILD_BUG():
In file included from <command-line>:
In function '__const_memcpy_toio_aligned32',
inlined from '__const_iowrite32_copy' at arch/arm64/include/asm/io.h:203:3,
inlined from '__const_iowrite32_copy' at arch/arm64/include/asm/io.h:199:20:
include/linux/compiler_types.h:487:45: error: call to '__compiletime_assert_538' declared with attribute error: BUILD_BUG failed
487 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
include/linux/compiler_types.h:468:25: note: in definition of macro '__compiletime_assert'
468 | prefix ## suffix(); \
| ^~~~~~
include/linux/compiler_types.h:487:9: note: in expansion of macro '_compiletime_assert'
487 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^~~~~~~~~~~~~~~~~~
include/linux/build_bug.h:59:21: note: in expansion of macro 'BUILD_BUG_ON_MSG'
59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
| ^~~~~~~~~~~~~~~~
arch/arm64/include/asm/io.h:193:17: note: in expansion of macro 'BUILD_BUG'
193 | BUILD_BUG();
| ^~~~~~~~~
Move the check for constant arguments into the inline function to ensure
it is still constant if the compiler decides against inlining it, and
mark them as __always_inline to override the logic that sometimes leads
to the compiler not producing the simplified output.
Note that either the __always_inline annotation or the check for a
constant value are sufficient here, but combining the two looks cleaner
as it also avoids the macro. With clang-8 and older, the macro was still
needed, but all versions of gcc and clang can reliably perform constant
folding here.
Fixes: ead79118dae6 ("arm64/io: Provide a WC friendly __iowriteXX_copy()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240604210006.668912-1-arnd@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm')
-rw-r--r-- | arch/arm64/include/asm/io.h | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h index 4ff0ae3f6d66..41fd90895dfc 100644 --- a/arch/arm64/include/asm/io.h +++ b/arch/arm64/include/asm/io.h @@ -153,8 +153,9 @@ extern void __memset_io(volatile void __iomem *, int, size_t); * emit the large TLP from the CPU. */ -static inline void __const_memcpy_toio_aligned32(volatile u32 __iomem *to, - const u32 *from, size_t count) +static __always_inline void +__const_memcpy_toio_aligned32(volatile u32 __iomem *to, const u32 *from, + size_t count) { switch (count) { case 8: @@ -196,24 +197,22 @@ static inline void __const_memcpy_toio_aligned32(volatile u32 __iomem *to, void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count); -static inline void __const_iowrite32_copy(void __iomem *to, const void *from, - size_t count) +static __always_inline void +__iowrite32_copy(void __iomem *to, const void *from, size_t count) { - if (count == 8 || count == 4 || count == 2 || count == 1) { + if (__builtin_constant_p(count) && + (count == 8 || count == 4 || count == 2 || count == 1)) { __const_memcpy_toio_aligned32(to, from, count); dgh(); } else { __iowrite32_copy_full(to, from, count); } } +#define __iowrite32_copy __iowrite32_copy -#define __iowrite32_copy(to, from, count) \ - (__builtin_constant_p(count) ? \ - __const_iowrite32_copy(to, from, count) : \ - __iowrite32_copy_full(to, from, count)) - -static inline void __const_memcpy_toio_aligned64(volatile u64 __iomem *to, - const u64 *from, size_t count) +static __always_inline void +__const_memcpy_toio_aligned64(volatile u64 __iomem *to, const u64 *from, + size_t count) { switch (count) { case 8: @@ -255,21 +254,18 @@ static inline void __const_memcpy_toio_aligned64(volatile u64 __iomem *to, void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count); -static inline void __const_iowrite64_copy(void __iomem *to, const void *from, - size_t count) +static __always_inline void +__iowrite64_copy(void __iomem *to, const void *from, size_t count) { - if (count == 8 || count == 4 || count == 2 || count == 1) { + if (__builtin_constant_p(count) && + (count == 8 || count == 4 || count == 2 || count == 1)) { __const_memcpy_toio_aligned64(to, from, count); dgh(); } else { __iowrite64_copy_full(to, from, count); } } - -#define __iowrite64_copy(to, from, count) \ - (__builtin_constant_p(count) ? \ - __const_iowrite64_copy(to, from, count) : \ - __iowrite64_copy_full(to, from, count)) +#define __iowrite64_copy __iowrite64_copy /* * I/O memory mapping functions. |