asm_inline_gcc.h

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/* ARM AArch32 GCC specific public inline assembler functions and macros */
 
/*
 * Copyright (c) 2015, Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
/* Either public functions or macros or invoked by public functions */
 
#ifndef ZEPHYR_INCLUDE_ARCH_ARM_AARCH32_ASM_INLINE_GCC_H_
#define ZEPHYR_INCLUDE_ARCH_ARM_AARCH32_ASM_INLINE_GCC_H_
 
/*
 * The file must not be included directly
 * Include arch/cpu.h instead
 */
 
#ifndef _ASMLANGUAGE
 
#include <zephyr/types.h>
#include <arch/arm/aarch32/exc.h>
#include <irq.h>
 
#if defined(CONFIG_CPU_CORTEX_R)
#include <arch/arm/aarch32/cortex_a_r/cpu.h>
#endif
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* On ARMv7-M and ARMv8-M Mainline CPUs, this function prevents regular
 * exceptions (i.e. with interrupt priority lower than or equal to
 * _EXC_IRQ_DEFAULT_PRIO) from interrupting the CPU. NMI, Faults, SVC,
 * and Zero Latency IRQs (if supported) may still interrupt the CPU.
 *
 * On ARMv6-M and ARMv8-M Baseline CPUs, this function reads the value of
 * PRIMASK which shows if interrupts are enabled, then disables all interrupts
 * except NMI.
 */
 
static ALWAYS_INLINE unsigned int arch_irq_lock(void)
{
        unsigned int key;
 
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
        __asm__ volatile("mrs %0, PRIMASK;"
                "cpsid i"
                : "=r" (key)
                :
                : "memory");
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
        unsigned int tmp;
 
        __asm__ volatile(
                "mov %1, %2;"
                "mrs %0, BASEPRI;"
                "msr BASEPRI_MAX, %1;"
                "isb;"
                : "=r"(key), "=r"(tmp)
                : "i"(_EXC_IRQ_DEFAULT_PRIO)
                : "memory");
#elif defined(CONFIG_ARMV7_R)
        __asm__ volatile(
                "mrs %0, cpsr;"
                "and %0, #" TOSTR(I_BIT) ";"
                "cpsid i;"
                : "=r" (key)
                :
                : "memory", "cc");
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
 
        return key;
}
 
 
/* On Cortex-M0/M0+, this enables all interrupts if they were not
 * previously disabled.
 */
 
static ALWAYS_INLINE void arch_irq_unlock(unsigned int key)
{
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
        if (key != 0U) {
                return;
        }
        __asm__ volatile(
                "cpsie i;"
                "isb"
                : : : "memory");
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
        __asm__ volatile(
                "msr BASEPRI, %0;"
                "isb;"
                :  : "r"(key) : "memory");
#elif defined(CONFIG_ARMV7_R)
        if (key != 0U) {
                return;
        }
        __asm__ volatile(
                "cpsie i;"
                : : : "memory", "cc");
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
}
 
static ALWAYS_INLINE bool arch_irq_unlocked(unsigned int key)
{
        /* This convention works for both PRIMASK and BASEPRI */
        return key == 0U;
}
 
#ifdef __cplusplus
}
#endif
 
#endif /* _ASMLANGUAGE */
 
#endif /* ZEPHYR_INCLUDE_ARCH_ARM_AARCH32_ASM_INLINE_GCC_H_ */