kernel_samsung_a53x/arch/arm64/include/asm/lse.h
Sultan Alsawaf 15898055b7 arm64: lse: Always use LSE atomic instructions
Since we are compiling for a single chipset that is known to support LSE,
the system_uses_lse_atomics() static branch can be eliminated entirely.

Therefore, make system_uses_lse_atomics() always true to always use LSE
atomics, and update ARM64_LSE_ATOMIC_INSN() users to get rid of the extra
nops used for alternatives patching at runtime.

This reduces generated code size by removing LL/SC atomics, which improves
instruction cache footprint.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
2024-11-17 17:45:05 +01:00

44 lines
1.1 KiB
C
Executable file

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_LSE_H
#define __ASM_LSE_H
#include <asm/atomic_ll_sc.h>
#if defined(CONFIG_ARM64_LSE_ATOMICS) && !defined(BUILD_FIPS140_KO)
#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 <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;
/* Always use LSE atomics */
#define system_uses_lse_atomics() true
#define __lse_ll_sc_body(op, ...) \
({ \
system_uses_lse_atomics() ? \
__lse_##op(__VA_ARGS__) : \
__ll_sc_##op(__VA_ARGS__); \
})
/* Always use LSE atomics */
#define ARM64_LSE_ATOMIC_INSN(lse) __LSE_PREAMBLE lse
#else /* CONFIG_ARM64_LSE_ATOMICS */
static inline bool system_uses_lse_atomics(void) { return false; }
#define __lse_ll_sc_body(op, ...) __ll_sc_##op(__VA_ARGS__)
#define ARM64_LSE_ATOMIC_INSN(llsc, lse) llsc
#endif /* CONFIG_ARM64_LSE_ATOMICS */
#endif /* __ASM_LSE_H */