zephyr/include/arch/arm/asm_inline_gcc.h

168 lines
4.4 KiB
C

/* ARM Cortex-M 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_CORTEX_M_ASM_INLINE_GCC_H_
#define ZEPHYR_INCLUDE_ARCH_ARM_CORTEX_M_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/exc.h>
#include <irq.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
*
* @brief Disable all interrupts on the CPU
*
* This routine disables interrupts. It can be called from either interrupt or
* thread level. This routine returns an architecture-dependent
* lock-out key representing the "interrupt disable state" prior to the call;
* this key can be passed to irq_unlock() to re-enable interrupts.
*
* The lock-out key should only be used as the argument to the irq_unlock()
* API. It should never be used to manually re-enable interrupts or to inspect
* or manipulate the contents of the source register.
*
* This function can be called recursively: it will return a key to return the
* state of interrupt locking to the previous level.
*
* WARNINGS
* Invoking a kernel routine with interrupts locked may result in
* interrupts being re-enabled for an unspecified period of time. If the
* called routine blocks, interrupts will be re-enabled while another
* thread executes, or while the system is idle.
*
* The "interrupt disable state" is an attribute of a thread. Thus, if a
* thread disables interrupts and subsequently invokes a kernel
* routine that causes the calling thread to block, the interrupt
* disable state will be restored when the thread is later rescheduled
* for execution.
*
* @return An architecture-dependent lock-out key representing the
* "interrupt disable state" prior to the call.
*
* @internal
*
* 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 z_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, %1;"
"isb;"
: "=r"(key), "=r"(tmp)
: "i"(_EXC_IRQ_DEFAULT_PRIO)
: "memory");
#elif defined(CONFIG_ARMV7_R)
__asm__ volatile("mrs %0, cpsr;"
"cpsid i"
: "=r" (key)
:
: "memory", "cc");
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
return key;
}
/**
*
* @brief Enable all interrupts on the CPU (inline)
*
* This routine re-enables interrupts on the CPU. The @a key parameter is an
* architecture-dependent lock-out key that is returned by a previous
* invocation of irq_lock().
*
* This routine can be called from either interrupt or thread level.
*
* @param key architecture-dependent lock-out key
*
* @return N/A
*
* On Cortex-M0/M0+, this enables all interrupts if they were not
* previously disabled.
*
*/
static ALWAYS_INLINE void z_arch_irq_unlock(unsigned int key)
{
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
if (key) {
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)
__asm__ volatile("msr cpsr_c, %0"
:
: "r" (key)
: "memory", "cc");
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
}
/**
* Returns true if interrupts were unlocked prior to the
* z_arch_irq_lock() call that produced the key argument.
*/
static ALWAYS_INLINE bool z_arch_irq_unlocked(unsigned int key)
{
/* This convention works for both PRIMASK and BASEPRI */
return key == 0;
}
#ifdef __cplusplus
}
#endif
#endif /* _ASMLANGUAGE */
#endif /* ZEPHYR_INCLUDE_ARCH_ARM_CORTEX_M_ASM_INLINE_GCC_H_ */