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authorWill Deacon <will@kernel.org>2019-08-30 12:55:39 +0100
committerWill Deacon <will@kernel.org>2019-08-30 12:55:39 +0100
commit61b7cddfe861f239bf39ab19a065e29b58153a80 (patch)
treee4930ac4950b72203cfebfc3b6565b346747b33f /arch/arm64/include/asm/lse.h
parentac12cf85d682a2c1948210c65f7fb21ef01dd9f6 (diff)
parent03adcbd996be7ce81cac793b1511406a7a4df117 (diff)
Merge branch 'for-next/atomics' into for-next/core
* for-next/atomics: (10 commits) Rework LSE instruction selection to use static keys instead of alternatives
Diffstat (limited to 'arch/arm64/include/asm/lse.h')
-rw-r--r--arch/arm64/include/asm/lse.h49
1 files changed, 20 insertions, 29 deletions
diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
index 8262325e2fc6..80b388278149 100644
--- a/arch/arm64/include/asm/lse.h
+++ b/arch/arm64/include/asm/lse.h
@@ -2,56 +2,47 @@
#ifndef __ASM_LSE_H
#define __ASM_LSE_H
+#include <asm/atomic_ll_sc.h>
+
#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
#include <linux/compiler_types.h>
#include <linux/export.h>
+#include <linux/jump_label.h>
#include <linux/stringify.h>
#include <asm/alternative.h>
+#include <asm/atomic_lse.h>
#include <asm/cpucaps.h>
-#ifdef __ASSEMBLER__
-
-.arch_extension lse
-
-.macro alt_lse, llsc, lse
- alternative_insn "\llsc", "\lse", ARM64_HAS_LSE_ATOMICS
-.endm
-
-#else /* __ASSEMBLER__ */
-
__asm__(".arch_extension lse");
-/* Move the ll/sc atomics out-of-line */
-#define __LL_SC_INLINE notrace
-#define __LL_SC_PREFIX(x) __ll_sc_##x
-#define __LL_SC_EXPORT(x) EXPORT_SYMBOL(__LL_SC_PREFIX(x))
+extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
+extern struct static_key_false arm64_const_caps_ready;
+
+static inline bool system_uses_lse_atomics(void)
+{
+ return (static_branch_likely(&arm64_const_caps_ready)) &&
+ static_branch_likely(&cpu_hwcap_keys[ARM64_HAS_LSE_ATOMICS]);
+}
-/* Macro for constructing calls to out-of-line ll/sc atomics */
-#define __LL_SC_CALL(op) "bl\t" __stringify(__LL_SC_PREFIX(op)) "\n"
-#define __LL_SC_CLOBBERS "x16", "x17", "x30"
+#define __lse_ll_sc_body(op, ...) \
+({ \
+ system_uses_lse_atomics() ? \
+ __lse_##op(__VA_ARGS__) : \
+ __ll_sc_##op(__VA_ARGS__); \
+})
/* In-line patching at runtime */
#define ARM64_LSE_ATOMIC_INSN(llsc, lse) \
ALTERNATIVE(llsc, lse, ARM64_HAS_LSE_ATOMICS)
-#endif /* __ASSEMBLER__ */
#else /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
-#ifdef __ASSEMBLER__
-
-.macro alt_lse, llsc, lse
- \llsc
-.endm
-
-#else /* __ASSEMBLER__ */
+static inline bool system_uses_lse_atomics(void) { return false; }
-#define __LL_SC_INLINE static inline
-#define __LL_SC_PREFIX(x) x
-#define __LL_SC_EXPORT(x)
+#define __lse_ll_sc_body(op, ...) __ll_sc_##op(__VA_ARGS__)
#define ARM64_LSE_ATOMIC_INSN(llsc, lse) llsc
-#endif /* __ASSEMBLER__ */
#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
#endif /* __ASM_LSE_H */