irq_arch.h

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/*
 * Copyright (C) 2017 Ken Rabold
 *               2020 Inria
 *               2020 Otto-von-Guericke-Universität Magdeburg
 *
 * This file is subject to the terms and conditions of the GNU Lesser General
 * Public License v2.1. See the file LICENSE in the top level directory for more
 * details.
 */
 
#ifndef IRQ_ARCH_H
#define IRQ_ARCH_H
 
#include <stdint.h>
 
#include "irq.h"
#include "vendor/riscv_csr.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define CPU_CSR_MCAUSE_CAUSE_MSK        (0x0fffu)
 
extern volatile int riscv_in_isr;
 
static inline __attribute__((always_inline)) unsigned int irq_enable(void)
{
    /* Enable all interrupts */
    unsigned state;
 
    __asm__ volatile (
        "csrrs %[dest], mstatus, %[mask]"
        :[dest]    "=r" (state)
        :[mask]    "i" (MSTATUS_MIE)
        : "memory"
        );
    return state;
}
 
static inline __attribute__((always_inline)) unsigned int irq_disable(void)
{
 
    unsigned int state;
 
    __asm__ volatile (
        "csrrc %[dest], mstatus, %[mask]"
        :[dest]    "=r" (state)
        :[mask]    "i" (MSTATUS_MIE)
        : "memory"
        );
 
    return state;
}
 
static inline __attribute__((always_inline)) void irq_restore(
    unsigned int state)
{
    /* Restore all interrupts to given state */
    __asm__ volatile (
        "csrw mstatus, %[state]"
        : /* no outputs */
        :[state]   "r" (state)
        : "memory"
        );
}
 
static inline __attribute__((always_inline)) bool irq_is_in(void)
{
    return riscv_in_isr;
}
 
static inline __attribute__((always_inline)) bool irq_is_enabled(void)
{
    unsigned state;
 
    __asm__ volatile (
        "csrr %[dest], mstatus"
        :[dest]    "=r" (state)
        : /* no inputs */
        : "memory"
        );
    return (state & MSTATUS_MIE);
}
 
#ifdef __cplusplus
}
#endif
 
#endif /* IRQ_ARCH_H */