From: Arnd Bergmann <[email protected]>
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.
Fixes: ead79118dae6 ("arm64/io: Provide a WC friendly __iowriteXX_copy()")
Signed-off-by: Arnd Bergmann <[email protected]>
---
v2:
- fix both 32-bit and 64-bit copies
- remove now-redundant macros
---
arch/arm64/include/asm/io.h | 24 +++++++++---------------
1 file changed, 9 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 4ff0ae3f6d66..902026f81b97 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -196,21 +196,18 @@ 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 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(to, from, count) \
- (__builtin_constant_p(count) ? \
- __const_iowrite32_copy(to, from, count) : \
- __iowrite32_copy_full(to, from, count))
+#define __iowrite32_copy(to, from, count) __iowrite32_copy(to, from, count)
static inline void __const_memcpy_toio_aligned64(volatile u64 __iomem *to,
const u64 *from, size_t count)
@@ -255,21 +252,18 @@ 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,
+static 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(to, from, count) __iowrite64_copy(to, from, count)
/*
* I/O memory mapping functions.
--
2.39.2
On Tue, May 28, 2024 at 05:37:11PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> 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.
>
> Fixes: ead79118dae6 ("arm64/io: Provide a WC friendly __iowriteXX_copy()")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> v2:
> - fix both 32-bit and 64-bit copies
> - remove now-redundant macros
> ---
> arch/arm64/include/asm/io.h | 24 +++++++++---------------
> 1 file changed, 9 insertions(+), 15 deletions(-)
I think this is superseded by Mark's diff in reply to v1, right?
https://lore.kernel.org/r/ZlcODqVXTDh6n0h-@J2N7QTR9R3
If so, Mark, please can you post that as a proper patch so that we can
get this fixed?
Cheers,
Will
On Tue, Jun 04, 2024 at 04:55:37PM +0100, Will Deacon wrote:
> On Tue, May 28, 2024 at 05:37:11PM +0200, Arnd Bergmann wrote:
> > From: Arnd Bergmann <[email protected]>
> >
> > 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.
> >
> > Fixes: ead79118dae6 ("arm64/io: Provide a WC friendly __iowriteXX_copy()")
> > Signed-off-by: Arnd Bergmann <[email protected]>
> > ---
> > v2:
> > - fix both 32-bit and 64-bit copies
> > - remove now-redundant macros
> > ---
> > arch/arm64/include/asm/io.h | 24 +++++++++---------------
> > 1 file changed, 9 insertions(+), 15 deletions(-)
>
> I think this is superseded by Mark's diff in reply to v1, right?
>
> https://lore.kernel.org/r/ZlcODqVXTDh6n0h-@J2N7QTR9R3
>
> If so, Mark, please can you post that as a proper patch so that we can
> get this fixed?
I wouldn't say superseded, but I agree with Mark that we should have
the __always_inline added to the __iowrite64_copy() and
__const_memcpy_toio_aligned64() in addition to the stuff here.
When I originally wrote this I copied the fairly common pattern of
having the builtin_constant_p test inside a macro, but I see now it is
quite common to put that into an inline. Putting it in the inline is
definately much better, so I like Arnd's patch.
Arnd can you just make that addition and repost this?
Thanks,
Jason
On Tue, Jun 4, 2024, at 22:12, Jason Gunthorpe wrote:
> On Tue, Jun 04, 2024 at 04:55:37PM +0100, Will Deacon wrote:
>> On Tue, May 28, 2024 at 05:37:11PM +0200, Arnd Bergmann wrote:
>>
>> I think this is superseded by Mark's diff in reply to v1, right?
>>
>> https://lore.kernel.org/r/ZlcODqVXTDh6n0h-@J2N7QTR9R3
>>
>> If so, Mark, please can you post that as a proper patch so that we can
>> get this fixed?
>
> I wouldn't say superseded, but I agree with Mark that we should have
> the __always_inline added to the __iowrite64_copy() and
> __const_memcpy_toio_aligned64() in addition to the stuff here.
>
> When I originally wrote this I copied the fairly common pattern of
> having the builtin_constant_p test inside a macro, but I see now it is
> quite common to put that into an inline. Putting it in the inline is
> definately much better, so I like Arnd's patch.
>
> Arnd can you just make that addition and repost this?
>
Yes, sorry for failing to follow up earlier. I'm doing a little
more build testing now, will send soon.
Arnd