From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Segher Boessenkool <segher@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc: slightly improve cache helpers
Date: Tue, 7 May 2019 13:31:39 +0000 (UTC) [thread overview]
Message-ID: <0b460a85319fb89dab2c5d1200ac69a3e1b7c1ef.1557235807.git.christophe.leroy@c-s.fr> (raw)
Cache instructions (dcbz, dcbi, dcbf and dcbst) take two registers
that are summed to obtain the target address. Using '%y0' argument
gives GCC the opportunity to use both registers instead of only one
with the second being forced to 0.
Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/cache.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/cache.h b/arch/powerpc/include/asm/cache.h
index 40ea5b3781c6..5a22a869a20b 100644
--- a/arch/powerpc/include/asm/cache.h
+++ b/arch/powerpc/include/asm/cache.h
@@ -85,22 +85,22 @@ extern void _set_L3CR(unsigned long);
static inline void dcbz(void *addr)
{
- __asm__ __volatile__ ("dcbz 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbz %y0" : : "m"(*(u8 *)addr) : "memory");
}
static inline void dcbi(void *addr)
{
- __asm__ __volatile__ ("dcbi 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbi %y0" : : "m"(*(u8 *)addr) : "memory");
}
static inline void dcbf(void *addr)
{
- __asm__ __volatile__ ("dcbf 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbf %y0" : : "m"(*(u8 *)addr) : "memory");
}
static inline void dcbst(void *addr)
{
- __asm__ __volatile__ ("dcbst 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbst %y0" : : "m"(*(u8 *)addr) : "memory");
}
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
--
2.13.3
next reply other threads:[~2019-05-07 13:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-07 13:31 Christophe Leroy [this message]
2019-05-07 15:10 ` [PATCH] powerpc: slightly improve cache helpers Segher Boessenkool
2019-05-07 16:53 ` Christophe Leroy
2019-05-08 14:40 ` Segher Boessenkool
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