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: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2] powerpc: slightly improve cache helpers
Date: Fri, 10 May 2019 09:24:48 +0000 (UTC) [thread overview]
Message-ID: <c6ff2faba7fbb56a7f5b5f08cd3453f89fc0aaf4.1557480165.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 'Z' constraint
and '%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..df8e4c407366 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" : : "Z"(*(u8 *)addr) : "memory");
}
static inline void dcbi(void *addr)
{
- __asm__ __volatile__ ("dcbi 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbi %y0" : : "Z"(*(u8 *)addr) : "memory");
}
static inline void dcbf(void *addr)
{
- __asm__ __volatile__ ("dcbf 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbf %y0" : : "Z"(*(u8 *)addr) : "memory");
}
static inline void dcbst(void *addr)
{
- __asm__ __volatile__ ("dcbst 0, %0" : : "r"(addr) : "memory");
+ __asm__ __volatile__ ("dcbst %y0" : : "Z"(*(u8 *)addr) : "memory");
}
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
--
2.13.3
next reply other threads:[~2019-05-10 9:25 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 9:24 Christophe Leroy [this message]
2019-07-08 1:19 ` [PATCH v2] powerpc: slightly improve cache helpers Michael Ellerman
2019-07-08 19:14 ` Nathan Chancellor
2019-07-09 5:04 ` Christophe Leroy
2019-07-09 6:49 ` Nathan Chancellor
2019-07-19 3:24 ` Nathan Chancellor
2019-07-19 15:23 ` Segher Boessenkool
2019-07-19 16:04 ` Nathan Chancellor
2019-07-21 7:58 ` Nathan Chancellor
2019-07-21 18:01 ` Segher Boessenkool
2019-07-22 2:41 ` Nathan Chancellor
2019-07-22 6:19 ` Segher Boessenkool
2019-07-22 17:21 ` Nick Desaulniers
2019-07-22 17:58 ` Segher Boessenkool
2019-07-25 21:30 ` Nick Desaulniers
2019-07-29 20:28 ` Nick Desaulniers
2019-07-22 10:15 ` Michael Ellerman
2019-07-22 15:18 ` Segher Boessenkool
2019-07-22 23:21 ` Michael Ellerman
2019-07-25 13:22 ` Segher Boessenkool
2019-07-22 0:53 ` [PATCH] powerpc: Test broken dcbz kbuild test robot
2019-07-09 13:35 ` [PATCH v2] powerpc: slightly improve cache helpers Segher Boessenkool
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