error.h

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/*
 * Copyright (c) 2020 BayLibre, SAS
 *
 * SPDX-License-Identifier: Apache-2.0
 */

 
#ifndef ZEPHYR_INCLUDE_ARCH_RISCV_ERROR_H_
#define ZEPHYR_INCLUDE_ARCH_RISCV_ERROR_H_
 
#include <zephyr/arch/riscv/syscall.h>
#include <zephyr/arch/exception.h>
#include <stdbool.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifdef CONFIG_RISCV_S_MODE
/*
 * In S-mode, ecall (cause=9) is kept in M-mode for SBI so it never reaches
 * the S-mode exception handler.  Kernel-context panics use ebreak (cause=3,
 * breakpoint) which IS delegated to S-mode.  isr.S treats ebreak with
 * t0==RV_ECALL_RUNTIME_EXCEPT (0) as ARCH_EXCEPT and reads the reason from
 * saved a0 — mirroring exactly how M-mode handles ecall with RV_ECALL_RUNTIME_EXCEPT.
 */
#define ARCH_EXCEPT(reason_p)   do {                                    \
                if (k_is_user_context()) {                              \
                        arch_syscall_invoke1(reason_p,                  \
                                K_SYSCALL_USER_FAULT);                  \
                } else {                                                \
                        register unsigned long _r __asm__("a0") =       \
                                (unsigned long)(reason_p);              \
                        register unsigned long _t __asm__("t0") = 0;    \
                        __asm__ volatile("ebreak"                       \
                                         : : "r"(_r), "r"(_t)           \
                                         : "memory");                   \
                }                                                       \
                CODE_UNREACHABLE; /* LCOV_EXCL_LINE */                  \
        } while (false)
 
#elif defined(CONFIG_USERSPACE)
 
#define ARCH_EXCEPT(reason_p)   do {                    \
                if (k_is_user_context()) {              \
                        arch_syscall_invoke1(reason_p,  \
                                K_SYSCALL_USER_FAULT);  \
                } else {                                \
                        compiler_barrier();             \
                        arch_syscall_invoke1(reason_p,  \
                                RV_ECALL_RUNTIME_EXCEPT);\
                }                                       \
                CODE_UNREACHABLE; /* LCOV_EXCL_LINE */  \
        } while (false)
#else
#define ARCH_EXCEPT(reason_p) \
        arch_syscall_invoke1(reason_p, RV_ECALL_RUNTIME_EXCEPT)
#endif
 
__syscall void user_fault(unsigned int reason);
 
#include <zephyr/syscalls/error.h>
 
#ifdef __cplusplus
}
#endif
 
#endif /* ZEPHYR_INCLUDE_ARCH_RISCV_ERROR_H_ */