linux-stable/arch/riscv/include/uapi/asm/unistd.h
Evan Green ea3de9ce8a
RISC-V: Add a syscall for HW probing
We don't have enough space for these all in ELF_HWCAP{,2} and there's no
system call that quite does this, so let's just provide an arch-specific
one to probe for hardware capabilities.  This currently just provides
m{arch,imp,vendor}id, but with the key-value pairs we can pass more in
the future.

Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Link: https://lore.kernel.org/r/20230407231103.2622178-3-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18 15:48:14 -07:00

54 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* Copyright (C) 2018 David Abdurachmanov <david.abdurachmanov@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
#define __ARCH_WANT_NEW_STAT
#define __ARCH_WANT_SET_GET_RLIMIT
#endif /* __LP64__ */
#define __ARCH_WANT_SYS_CLONE3
#define __ARCH_WANT_MEMFD_SECRET
#include <asm-generic/unistd.h>
/*
* Allows the instruction cache to be flushed from userspace. Despite RISC-V
* having a direct 'fence.i' instruction available to userspace (which we
* can't trap!), that's not actually viable when running on Linux because the
* kernel might schedule a process on another hart. There is no way for
* userspace to handle this without invoking the kernel (as it doesn't know the
* thread->hart mappings), so we've defined a RISC-V specific system call to
* flush the instruction cache.
*
* __NR_riscv_flush_icache is defined to flush the instruction cache over an
* address range, with the flush applying to either all threads or just the
* caller. We don't currently do anything with the address range, that's just
* in there for forwards compatibility.
*/
#ifndef __NR_riscv_flush_icache
#define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
#endif
__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
/*
* Allows userspace to query the kernel for CPU architecture and
* microarchitecture details across a given set of CPUs.
*/
#ifndef __NR_riscv_hwprobe
#define __NR_riscv_hwprobe (__NR_arch_specific_syscall + 14)
#endif
__SYSCALL(__NR_riscv_hwprobe, sys_riscv_hwprobe)