[RFC PATCH v2 12/15] xen/arm64: port Linux's arm64 lse.h to Xen

[Ash Wilding <ash.j.wilding@xxxxxxxxx>]

From: Ash Wilding <ash.j.wilding@xxxxxxxxx>

This just involves making system_uses_lse_atomics() call cpus_have_cap()
instead of directly looking up in cpu_hwcap_keys.

Not 100% sure whether this is a valid transformation until I do a run
test.

Signed-off-by: Ash Wilding <ash.j.wilding@xxxxxxxxx>
---
 xen/include/asm-arm/arm64/lse.h | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/xen/include/asm-arm/arm64/lse.h b/xen/include/asm-arm/arm64/lse.h
index 704be3e4e4..847727f219 100644
--- a/xen/include/asm-arm/arm64/lse.h
+++ b/xen/include/asm-arm/arm64/lse.h
@@ -1,28 +1,28 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ASM_LSE_H
-#define __ASM_LSE_H
+/*
+ * Taken from Linux 5.10-rc2 (last commit 3cea11cd5)
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#ifndef __ASM_ARM_ARM64_LSE_H
+#define __ASM_ARM_ARM64_LSE_H
 
-#include <asm/atomic_ll_sc.h>
+#include "atomic_ll_sc.h"
 
 #ifdef CONFIG_ARM64_LSE_ATOMICS
 
 #define __LSE_PREAMBLE ".arch_extension lse\n"
 
-#include <linux/compiler_types.h>
-#include <linux/export.h>
-#include <linux/jump_label.h>
-#include <linux/stringify.h>
+#include <xen/compiler.h>
+#include <xen/stringify.h>
+#include <xen/types.h>
+
 #include <asm/alternative.h>
-#include <asm/atomic_lse.h>
-#include <asm/cpucaps.h>
 
-extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
-extern struct static_key_false arm64_const_caps_ready;
+#include "atomic_lse.h"
 
 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]);
+       return cpus_have_cap(ARM64_HAS_LSE_ATOMICS);
 }
 
 #define __lse_ll_sc_body(op, ...)                                      \
@@ -45,4 +45,4 @@ static inline bool system_uses_lse_atomics(void) { return 
false; }
 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)       llsc
 
 #endif /* CONFIG_ARM64_LSE_ATOMICS */
-#endif /* __ASM_LSE_H */
\ No newline at end of file
+#endif /* __ASM_ARM_ARM64_LSE_H */
\ No newline at end of file
-- 
2.24.3 (Apple Git-128)