Le 14/09/2024 à 04:02, Michael Ellerman a écrit :
Mina Almasry <almasrym...@google.com> writes:
Building net-next with powerpc with GCC 14 compiler results in this
build error:
/home/sfr/next/tmp/ccuSzwiR.s: Assembler messages:
/home/sfr/next/tmp/ccuSzwiR.s:2579: Error: operand out of domain (39 is
not a multiple of 4)
make[5]: *** [/home/sfr/next/next/scripts/Makefile.build:229:
net/core/page_pool.o] Error 1
Root caused in this thread:
https://lore.kernel.org/netdev/913e2fbd-d318-4c9b-aed2-4d333a1d5...@cs-soprasteria.com/
Sorry I'm late to this, the original report wasn't Cc'ed to linuxppc-dev :D
I think this is a bug in the arch/powerpc inline asm constraints.
Can you try the patch below, it fixes the build error for me.
I'll run it through some boot tests and turn it into a proper patch over
the weekend.
cheers
diff --git a/arch/powerpc/include/asm/atomic.h
b/arch/powerpc/include/asm/atomic.h
index 5bf6a4d49268..0e41c1da82dd 100644
--- a/arch/powerpc/include/asm/atomic.h
+++ b/arch/powerpc/include/asm/atomic.h
@@ -23,6 +23,12 @@
#define __atomic_release_fence() \
__asm__ __volatile__(PPC_RELEASE_BARRIER "" : : : "memory")
+#ifdef CONFIG_CC_IS_CLANG
+#define DS_FORM_CONSTRAINT "Z<>"
+#else
+#define DS_FORM_CONSTRAINT "YZ<>"
+#endif
I see we have the same in uaccess.h, added by commit 2d43cc701b96
("powerpc/uaccess: Fix build errors seen with GCC 13/14")
Should that go in a common header, maybe ppc_asm.h ?
+
static __inline__ int arch_atomic_read(const atomic_t *v)
{
int t;
@@ -197,7 +203,7 @@ static __inline__ s64 arch_atomic64_read(const atomic64_t
*v)
if (IS_ENABLED(CONFIG_PPC_KERNEL_PREFIXED))
__asm__ __volatile__("ld %0,0(%1)" : "=r"(t) :
"b"(&v->counter));
else
- __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) :
"m<>"(v->counter));
+ __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) :
DS_FORM_CONSTRAINT (v->counter));
return t;
}
@@ -208,7 +214,7 @@ static __inline__ void arch_atomic64_set(atomic64_t *v, s64
i)
if (IS_ENABLED(CONFIG_PPC_KERNEL_PREFIXED))
__asm__ __volatile__("std %1,0(%2)" : "=m"(v->counter) : "r"(i),
"b"(&v->counter));
else
- __asm__ __volatile__("std%U0%X0 %1,%0" : "=m<>"(v->counter) :
"r"(i));
+ __asm__ __volatile__("std%U0%X0 %1,%0" : "=" DS_FORM_CONSTRAINT
(v->counter) : "r"(i));
}
#define ATOMIC64_OP(op, asm_op) \
