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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-19 21:00:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-19 21:00:30 +0000
commite54def4ad8144ab15f826416e2e0f290ef1901b4 (patch)
tree583f8d4bd95cd67c44ff37b878a7eddfca9ab97a /tools/arch/riscv/include/asm/vdso/processor.h
parentAdding upstream version 6.8.12. (diff)
downloadlinux-e54def4ad8144ab15f826416e2e0f290ef1901b4.tar.xz
linux-e54def4ad8144ab15f826416e2e0f290ef1901b4.zip
Adding upstream version 6.9.2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/arch/riscv/include/asm/vdso/processor.h')
-rw-r--r--tools/arch/riscv/include/asm/vdso/processor.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/tools/arch/riscv/include/asm/vdso/processor.h b/tools/arch/riscv/include/asm/vdso/processor.h
new file mode 100644
index 0000000000..662aca0398
--- /dev/null
+++ b/tools/arch/riscv/include/asm/vdso/processor.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_VDSO_PROCESSOR_H
+#define __ASM_VDSO_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm-generic/barrier.h>
+
+static inline void cpu_relax(void)
+{
+#ifdef __riscv_muldiv
+ int dummy;
+ /* In lieu of a halt instruction, induce a long-latency stall. */
+ __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
+#endif
+
+#ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE
+ /*
+ * Reduce instruction retirement.
+ * This assumes the PC changes.
+ */
+ __asm__ __volatile__ ("pause");
+#else
+ /* Encoding of the pause instruction */
+ __asm__ __volatile__ (".4byte 0x100000F");
+#endif
+ barrier();
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_PROCESSOR_H */