[PATCH v2 04/36] MIPS: barrier: Clean up rmb() & wmb() definitions

From: Paul Burton
Date: Tue Oct 01 2019 - 17:53:24 EST


Simplify our definitions of rmb() & wmb() using the new __SYNC()
infrastructure.

The fast_rmb() & fast_wmb() macros are removed, since they only provided
a level of indirection that made the code less readable & weren't
directly used anywhere in the kernel tree.

The Octeon #ifdef'ery is removed, since the "syncw" instruction
previously used is merely an alias for "sync 4" which __SYNC() will emit
for the wmb sync type when the kernel is configured for an Octeon CPU.
Similarly __SYNC() will emit nothing for the rmb sync type in Octeon
configurations.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
---

Changes in v2: None

arch/mips/include/asm/barrier.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
index 5ad39bfd3b6d..f36cab87cfde 100644
--- a/arch/mips/include/asm/barrier.h
+++ b/arch/mips/include/asm/barrier.h
@@ -26,6 +26,18 @@
#define __sync() do { } while(0)
#endif

+static inline void rmb(void)
+{
+ asm volatile(__SYNC(rmb, always) ::: "memory");
+}
+#define rmb rmb
+
+static inline void wmb(void)
+{
+ asm volatile(__SYNC(wmb, always) ::: "memory");
+}
+#define wmb wmb
+
#define __fast_iob() \
__asm__ __volatile__( \
".set push\n\t" \
@@ -37,16 +49,9 @@
: "m" (*(int *)CKSEG1) \
: "memory")
#ifdef CONFIG_CPU_CAVIUM_OCTEON
-# define OCTEON_SYNCW_STR ".set push\n.set arch=octeon\nsyncw\nsyncw\n.set pop\n"
-# define __syncw() __asm__ __volatile__(OCTEON_SYNCW_STR : : : "memory")
-
-# define fast_wmb() __syncw()
-# define fast_rmb() barrier()
# define fast_mb() __sync()
# define fast_iob() do { } while (0)
#else /* ! CONFIG_CPU_CAVIUM_OCTEON */
-# define fast_wmb() __sync()
-# define fast_rmb() __sync()
# define fast_mb() __sync()
# ifdef CONFIG_SGI_IP28
# define fast_iob() \
@@ -83,19 +88,14 @@

#endif /* !CONFIG_CPU_HAS_WB */

-#define wmb() fast_wmb()
-#define rmb() fast_rmb()
-
#if defined(CONFIG_WEAK_ORDERING)
# ifdef CONFIG_CPU_CAVIUM_OCTEON
# define __smp_mb() __sync()
-# define __smp_rmb() barrier()
-# define __smp_wmb() __syncw()
# else
# define __smp_mb() __asm__ __volatile__("sync" : : :"memory")
-# define __smp_rmb() __asm__ __volatile__("sync" : : :"memory")
-# define __smp_wmb() __asm__ __volatile__("sync" : : :"memory")
# endif
+# define __smp_rmb() rmb()
+# define __smp_wmb() wmb()
#else
#define __smp_mb() barrier()
#define __smp_rmb() barrier()
--
2.23.0