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Diffstat (limited to 'arch/arm64/include/asm/lse.h')
-rw-r--r--arch/arm64/include/asm/lse.h34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
new file mode 100644
index 000000000000..d516624a461e
--- /dev/null
+++ b/arch/arm64/include/asm/lse.h
@@ -0,0 +1,34 @@
+#ifndef __ASM_LSE_H
+#define __ASM_LSE_H
+
+#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
+
+#include <linux/stringify.h>
+
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
+
+__asm__(".arch_extension lse");
+
+/* Move the ll/sc atomics out-of-line */
+#define __LL_SC_INLINE
+#define __LL_SC_PREFIX(x) __ll_sc_##x
+#define __LL_SC_EXPORT(x) EXPORT_SYMBOL(__LL_SC_PREFIX(x))
+
+/* Macro for constructing calls to out-of-line ll/sc atomics */
+#define __LL_SC_CALL(op) "bl\t" __stringify(__LL_SC_PREFIX(op)) "\n"
+
+/* In-line patching at runtime */
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse) \
+ ALTERNATIVE(llsc, lse, ARM64_CPU_FEAT_LSE_ATOMICS)
+
+#else
+
+#define __LL_SC_INLINE static inline
+#define __LL_SC_PREFIX(x) x
+#define __LL_SC_EXPORT(x)
+
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse) llsc
+
+#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
+#endif /* __ASM_LSE_H */