mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 07:34:57 +07:00
52e7c52d2d
GCC allows users to hint to the register allocation that a variable should be placed in a register by using a syntax along the lines of function(...) { register long in_REG __asm__("REG"); } We've abused this a bit throughout the RISC-V port to access fixed registers directly as C variables. In practice it's never going to blow up because GCC isn't going to allocate these registers, but it's not a well defined syntax so we really shouldn't be relying upon this. Luckily there is a very similar but well defined syntax that allows us to still access these registers directly as C variables, which is to simply declare the register variables globally. For fixed variables this doesn't change the ABI. LLVM disallows this ambiguous syntax, so this isn't just strictly a formatting change. Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
39 lines
940 B
C
39 lines
940 B
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Based on arm/arm64/include/asm/current.h
|
|
*
|
|
* Copyright (C) 2016 ARM
|
|
* Copyright (C) 2017 SiFive
|
|
*/
|
|
|
|
|
|
#ifndef _ASM_RISCV_CURRENT_H
|
|
#define _ASM_RISCV_CURRENT_H
|
|
|
|
#include <linux/bug.h>
|
|
#include <linux/compiler.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
struct task_struct;
|
|
|
|
register struct task_struct *riscv_current_is_tp __asm__("tp");
|
|
|
|
/*
|
|
* This only works because "struct thread_info" is at offset 0 from "struct
|
|
* task_struct". This constraint seems to be necessary on other architectures
|
|
* as well, but __switch_to enforces it. We can't check TASK_TI here because
|
|
* <asm/asm-offsets.h> includes this, and I can't get the definition of "struct
|
|
* task_struct" here due to some header ordering problems.
|
|
*/
|
|
static __always_inline struct task_struct *get_current(void)
|
|
{
|
|
return riscv_current_is_tp;
|
|
}
|
|
|
|
#define current get_current()
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif /* _ASM_RISCV_CURRENT_H */
|