syscall.h

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/*
 * Copyright (c) 2020 BayLibre, SAS
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_ARCH_RISCV_SYSCALL_H_
#define ZEPHYR_INCLUDE_ARCH_RISCV_SYSCALL_H_
 
/*
 * Privileged mode system calls
 */
#define RV_ECALL_RUNTIME_EXCEPT 0
#define RV_ECALL_IRQ_OFFLOAD 1
#define RV_ECALL_SCHEDULE 2
 
#ifndef _ASMLANGUAGE
 
#include <zephyr/types.h>
#include <stdbool.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
/*
 * Syscall invocation macros. riscv-specific machine constraints used to ensure
 * args land in the proper registers.
 */
static inline uintptr_t arch_syscall_invoke6(uintptr_t arg1, uintptr_t arg2,
 uintptr_t arg3, uintptr_t arg4,
 uintptr_t arg5, uintptr_t arg6,
 uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long a1 __asm__ ("a1") = arg2;
 register unsigned long a2 __asm__ ("a2") = arg3;
 register unsigned long a3 __asm__ ("a3") = arg4;
 register unsigned long a4 __asm__ ("a4") = arg5;
 register unsigned long a5 __asm__ ("a5") = arg6;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (a1), "r" (a2), "r" (a3), "r" (a4), "r" (a5),
 "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke5(uintptr_t arg1, uintptr_t arg2,
 uintptr_t arg3, uintptr_t arg4,
 uintptr_t arg5,
 uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long a1 __asm__ ("a1") = arg2;
 register unsigned long a2 __asm__ ("a2") = arg3;
 register unsigned long a3 __asm__ ("a3") = arg4;
 register unsigned long a4 __asm__ ("a4") = arg5;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (a1), "r" (a2), "r" (a3), "r" (a4), "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke4(uintptr_t arg1, uintptr_t arg2,
 uintptr_t arg3, uintptr_t arg4,
 uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long a1 __asm__ ("a1") = arg2;
 register unsigned long a2 __asm__ ("a2") = arg3;
 register unsigned long a3 __asm__ ("a3") = arg4;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (a1), "r" (a2), "r" (a3), "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke3(uintptr_t arg1, uintptr_t arg2,
 uintptr_t arg3,
 uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long a1 __asm__ ("a1") = arg2;
 register unsigned long a2 __asm__ ("a2") = arg3;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (a1), "r" (a2), "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke2(uintptr_t arg1, uintptr_t arg2,
 uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long a1 __asm__ ("a1") = arg2;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (a1), "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke1(uintptr_t arg1, uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0") = arg1;
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "+r" (a0)
 : "r" (t0)
 : "memory");
 return a0;
}
 
static inline uintptr_t arch_syscall_invoke0(uintptr_t call_id)
{
 register unsigned long a0 __asm__ ("a0");
 register unsigned long t0 __asm__ ("t0") = call_id;
 
 __asm__ volatile ("ecall"
 : "=r" (a0)
 : "r" (t0)
 : "memory");
 return a0;
}
 
#ifdef CONFIG_USERSPACE
register unsigned long riscv_tp_reg __asm__ ("tp");
 
static inline bool arch_is_user_context(void)
{
 /* don't try accessing TLS variables if tp is not initialized */
 if (riscv_tp_reg == 0) {
 return false;
 }
 
 /* Defined in arch/riscv/core/thread.c */
 extern __thread uint8_t is_user_mode;
 
 return is_user_mode != 0;
}
#endif
 
#ifdef __cplusplus
}
#endif
 
#endif /* _ASMLANGUAGE */
#endif /* ZEPHYR_INCLUDE_ARCH_RISCV_SYSCALL_H_ */