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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2021 Keith Packard <keithp@keithp.com>
* Copyright (c) 2021 Google, LLC <ardb@kernel.org>
*/
#ifndef _ASM_ARM_CURRENT_H
#define _ASM_ARM_CURRENT_H
#ifndef __ASSEMBLY__
struct task_struct;
static inline void set_current(struct task_struct *cur)
{
if (!IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO))
return;
/* Set TPIDRURO */
asm("mcr p15, 0, %0, c13, c0, 3" :: "r"(cur) : "memory");
}
#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
static inline struct task_struct *get_current(void)
{
struct task_struct *cur;
#if __has_builtin(__builtin_thread_pointer) && \
!(defined(CONFIG_THUMB2_KERNEL) && \
defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 130001)
/*
* Use the __builtin helper when available - this results in better
* code, especially when using GCC in combination with the per-task
* stack protector, as the compiler will recognize that it needs to
* load the TLS register only once in every function.
*
* Clang < 13.0.1 gets this wrong for Thumb2 builds:
* https://github.com/ClangBuiltLinux/linux/issues/1485
*/
cur = __builtin_thread_pointer();
#else
asm("mrc p15, 0, %0, c13, c0, 3" : "=r"(cur));
#endif
return cur;
}
#define current get_current()
#else
#include <asm-generic/current.h>
#endif /* CONFIG_CURRENT_POINTER_IN_TPIDRURO */
#endif /* __ASSEMBLY__ */
#endif /* _ASM_ARM_CURRENT_H */
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