Thread (11 messages) flat view 11 messages, 3 authors, 2020-12-10
STALE2102d LANDED

Landed in mainline as 1f1676bb2dd5 on 2020-12-03.

[PATCH v14 5/9] powerpc/barrier: Use CONFIG_PPC64 for barrier selection

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2020-11-26 13:51:16
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

Currently we use ifdef __powerpc64__ in barrier.h to decide if we
should use lwsync or eieio for SMPWMB which is then used by
__smp_wmb().

That means when we are building the compat VDSO we will use eieio,
because it's 32-bit code, even though we're building a 64-bit kernel
for a 64-bit CPU.

Although eieio should work, it would be cleaner if we always used the
same barrier, even for the 32-bit VDSO.

So change the ifdef to CONFIG_PPC64, so that the selection is made
based on the bitness of the kernel we're building for, not the current
compilation unit.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/barrier.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

v14: new
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index f53c42380832..aecfde829d5d 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -40,7 +40,7 @@
 #define wmb()  __asm__ __volatile__ ("sync" : : : "memory")
 
 /* The sub-arch has lwsync */
-#if defined(__powerpc64__) || defined(CONFIG_PPC_E500MC)
+#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_E500MC)
 #    define SMPWMB      LWSYNC
 #else
 #    define SMPWMB      eieio
-- 
2.25.1
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