[PATCH v3 6/7] arm64/asm: introduce lsui.h
From: Yeoreum Yun <hidden>
Date: 2025-06-17 18:36:51
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
This patch introduces lsui.h header file for applying runtime patch to use load/store unprevileged instructions when cpu supports FEAT_LSUI otherwise uses method implemented via ll/sc way with clearing PSTATE.PAN bit Signed-off-by: Yeoreum Yun <redacted> --- arch/arm64/include/asm/lsui.h | 37 +++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 arch/arm64/include/asm/lsui.h
diff --git a/arch/arm64/include/asm/lsui.h b/arch/arm64/include/asm/lsui.h
new file mode 100644
index 000000000000..39bf232f3eb7
--- /dev/null
+++ b/arch/arm64/include/asm/lsui.h@@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2025 Arm Ltd. + */ +#ifndef __ASM_LSUI_H +#define __ASM_LSUI_H + +#define LL_SC_MAX_LOOPS 128 /* What's the largest number you can think of? */ + +#include <asm/futex_ll_sc_u.h> + +#ifdef CONFIG_AS_HAS_LSUI + +#define __LSUI_PREAMBLE ".arch_extension lsui\n" + +#include <linux/compiler_types.h> +#include <linux/export.h> +#include <linux/stringify.h> +#include <asm/alternative.h> +#include <asm/alternative-macros.h> +#include <asm/cpucaps.h> + +#include <asm/futex_lsui.h> + +#define __lsui_ll_sc_u_body(op, ...) \ +({ \ + alternative_has_cap_likely(ARM64_HAS_LSUI) ? \ + __lsui_##op(__VA_ARGS__) : \ + __ll_sc_u_##op(__VA_ARGS__); \ +}) + +#else /* CONFIG_AS_HAS_LSUI */ + +#define __lsui_ll_sc_u_body(op, ...) __ll_sc_u_##op(__VA_ARGS__) + +#endif /* CONFIG_AS_HAS_LSUI */ +#endif /* __ASM_LSUI_H */
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}