From 7db91e57a0acde126a162ababfb1e0ab190130cb Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 10 Jul 2017 18:04:30 -0700 Subject: RISC-V: Task implementation This patch contains the implementation of tasks on RISC-V, most of which is involved in task switching. Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/current.h | 45 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 arch/riscv/include/asm/current.h (limited to 'arch/riscv/include/asm/current.h') diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h new file mode 100644 index 000000000000..2cf6336ef600 --- /dev/null +++ b/arch/riscv/include/asm/current.h @@ -0,0 +1,45 @@ +/* + * Based on arm/arm64/include/asm/current.h + * + * Copyright (C) 2016 ARM + * Copyright (C) 2017 SiFive + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + + +#ifndef __ASM_CURRENT_H +#define __ASM_CURRENT_H + +#include +#include + +#ifndef __ASSEMBLY__ + +struct task_struct; + +/* + * 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 + * 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) +{ + register struct task_struct *tp __asm__("tp"); + return tp; +} + +#define current get_current() + +#endif /* __ASSEMBLY__ */ + +#endif /* __ASM_CURRENT_H */ -- cgit v1.2.3