[RFC PATCH net-next 1/4] arm64: barrier: add DGH macros to control memory accesses merging
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STALE1902d
From: Guangbin Huang <hidden>
Date: 2021-07-23 06:19:54
Also in:
linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Revision rfc of 5 in this series.
Revisions (5)
From: Xiongfeng Wang <redacted> DGH prohibits merging memory accesses with Normal-NC or Device-GRE attributes before the hint instruction with any memory accesses appearing after the hint instruction. Provide macros to expose it to the arch code. Signed-off-by: Xiongfeng Wang <redacted> Signed-off-by: Cheng Jian <redacted> Signed-off-by: Yufeng Mo <redacted> --- arch/arm64/include/asm/assembler.h | 7 +++++++ arch/arm64/include/asm/barrier.h | 1 + 2 files changed, 8 insertions(+)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 89faca0e740d..5a3348b5e9f3 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h@@ -90,6 +90,13 @@ .endm /* + * Data gathering hint + */ + .macro dgh + hint #6 + .endm + +/* * RAS Error Synchronization barrier */ .macro esb
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 451e11e5fd23..02e1735706d2 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h@@ -22,6 +22,7 @@ #define dmb(opt) asm volatile("dmb " #opt : : : "memory") #define dsb(opt) asm volatile("dsb " #opt : : : "memory") +#define dgh() asm volatile("hint #6" : : : "memory") #define psb_csync() asm volatile("hint #17" : : : "memory") #define tsb_csync() asm volatile("hint #18" : : : "memory") #define csdb() asm volatile("hint #20" : : : "memory")
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2.8.1