[v7,5/7] powerpc/pmem: Update ppc64 to use the new barrier instruction.
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Message ID 20200701072235.223558-6-aneesh.kumar@linux.ibm.com
State New
Headers show
Series
  • Support new pmem flush and sync instructions for POWER
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Commit Message

Aneesh Kumar K.V July 1, 2020, 7:22 a.m. UTC
pmem on POWER10 can now use phwsync instead of hwsync to ensure
all previous writes are architecturally visible for the platform
buffer flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/barrier.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Patch
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diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index 123adcefd40f..35c1b8f3aa68 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -7,6 +7,10 @@ 
 
 #include <asm/asm-const.h>
 
+#ifndef __ASSEMBLY__
+#include <asm/ppc-opcode.h>
+#endif
+
 /*
  * Memory barrier.
  * The sync instruction guarantees that all memory accesses initiated
@@ -97,6 +101,15 @@  do {									\
 #define barrier_nospec()
 #endif /* CONFIG_PPC_BARRIER_NOSPEC */
 
+/*
+ * pmem_wmb() ensures that all stores for which the modification
+ * are written to persistent storage by preceding dcbfps/dcbstps
+ * instructions have updated persistent storage before any data
+ * access or data transfer caused by subsequent instructions is
+ * initiated.
+ */
+#define pmem_wmb() __asm__ __volatile__(PPC_PHWSYNC ::: "memory")
+
 #include <asm-generic/barrier.h>
 
 #endif /* _ASM_POWERPC_BARRIER_H */