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[v2,1/2] tools: Add riscv barrier implementation

Message ID 20240806-optimize_ring_buffer_read_riscv-v2-1-ca7e193ae198@rivosinc.com (mailing list archive)
State New
Headers show
Series tools: Add barrier implementations for riscv | expand

Checks

Context Check Description
conchuod/vmtest-for-next-PR success PR summary
conchuod/patch-1-test-1 success .github/scripts/patches/tests/build_rv32_defconfig.sh
conchuod/patch-1-test-2 success .github/scripts/patches/tests/build_rv64_clang_allmodconfig.sh
conchuod/patch-1-test-3 success .github/scripts/patches/tests/build_rv64_gcc_allmodconfig.sh
conchuod/patch-1-test-4 success .github/scripts/patches/tests/build_rv64_nommu_k210_defconfig.sh
conchuod/patch-1-test-5 success .github/scripts/patches/tests/build_rv64_nommu_virt_defconfig.sh
conchuod/patch-1-test-6 warning .github/scripts/patches/tests/checkpatch.sh
conchuod/patch-1-test-7 success .github/scripts/patches/tests/dtb_warn_rv64.sh
conchuod/patch-1-test-8 success .github/scripts/patches/tests/header_inline.sh
conchuod/patch-1-test-9 success .github/scripts/patches/tests/kdoc.sh
conchuod/patch-1-test-10 success .github/scripts/patches/tests/module_param.sh
conchuod/patch-1-test-11 success .github/scripts/patches/tests/verify_fixes.sh
conchuod/patch-1-test-12 success .github/scripts/patches/tests/verify_signedoff.sh

Commit Message

Charlie Jenkins Aug. 6, 2024, 10:01 p.m. UTC 
Many of the other architectures use their custom barrier implementations.
Use the barrier code from the kernel sources to optimize barriers in
tools.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
---
 tools/arch/riscv/include/asm/barrier.h | 39 ++++++++++++++++++++++++++++++++++
 tools/arch/riscv/include/asm/fence.h   | 13 ++++++++++++
 tools/include/asm/barrier.h            |  2 ++
 3 files changed, 54 insertions(+)
diff mbox series

Patch

diff --git a/tools/arch/riscv/include/asm/barrier.h b/tools/arch/riscv/include/asm/barrier.h
new file mode 100644
index 000000000000..6997f197086d
--- /dev/null
+++ b/tools/arch/riscv/include/asm/barrier.h
@@ -0,0 +1,39 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copied from the kernel sources to tools/arch/riscv:
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2013 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#ifndef _TOOLS_LINUX_ASM_RISCV_BARRIER_H
+#define _TOOLS_LINUX_ASM_RISCV_BARRIER_H
+
+#include <asm/fence.h>
+#include <linux/compiler.h>
+
+/* These barriers need to enforce ordering on both devices and memory. */
+#define mb()		RISCV_FENCE(iorw, iorw)
+#define rmb()		RISCV_FENCE(ir, ir)
+#define wmb()		RISCV_FENCE(ow, ow)
+
+/* These barriers do not need to enforce ordering on devices, just memory. */
+#define smp_mb()	RISCV_FENCE(rw, rw)
+#define smp_rmb()	RISCV_FENCE(r, r)
+#define smp_wmb()	RISCV_FENCE(w, w)
+
+#define smp_store_release(p, v)						\
+do {									\
+	RISCV_FENCE(rw, w);						\
+	WRITE_ONCE(*p, v);						\
+} while (0)
+
+#define smp_load_acquire(p)						\
+({									\
+	typeof(*p) ___p1 = READ_ONCE(*p);				\
+	RISCV_FENCE(r, rw);						\
+	___p1;								\
+})
+
+#endif /* _TOOLS_LINUX_ASM_RISCV_BARRIER_H */
diff --git a/tools/arch/riscv/include/asm/fence.h b/tools/arch/riscv/include/asm/fence.h
new file mode 100644
index 000000000000..37860e86771d
--- /dev/null
+++ b/tools/arch/riscv/include/asm/fence.h
@@ -0,0 +1,13 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copied from the kernel sources to tools/arch/riscv:
+ */
+
+#ifndef _ASM_RISCV_FENCE_H
+#define _ASM_RISCV_FENCE_H
+
+#define RISCV_FENCE_ASM(p, s)		"\tfence " #p "," #s "\n"
+#define RISCV_FENCE(p, s) \
+	({ __asm__ __volatile__ (RISCV_FENCE_ASM(p, s) : : : "memory"); })
+
+#endif	/* _ASM_RISCV_FENCE_H */
diff --git a/tools/include/asm/barrier.h b/tools/include/asm/barrier.h
index 8d378c57cb01..0c21678ac5e6 100644
--- a/tools/include/asm/barrier.h
+++ b/tools/include/asm/barrier.h
@@ -8,6 +8,8 @@ 
 #include "../../arch/arm64/include/asm/barrier.h"
 #elif defined(__powerpc__)
 #include "../../arch/powerpc/include/asm/barrier.h"
+#elif defined(__riscv)
+#include "../../arch/riscv/include/asm/barrier.h"
 #elif defined(__s390__)
 #include "../../arch/s390/include/asm/barrier.h"
 #elif defined(__sh__)