zephyr/arch/riscv32/include/kernel_arch_func.h

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arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
/*
* Copyright (c) 2016 Jean-Paul Etienne <fractalclone@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
*/
/**
* @file
* @brief Private kernel definitions
*
* This file contains private kernel function/macro definitions and various
* other definitions for the RISCV32 processor architecture.
*/
#ifndef _kernel_arch_func__h_
#define _kernel_arch_func__h_
#include <soc.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _ASMLANGUAGE
void k_cpu_idle(void);
void k_cpu_atomic_idle(unsigned int key);
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
static ALWAYS_INLINE void kernel_arch_init(void)
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
{
_kernel.irq_stack =
K_THREAD_STACK_BUFFER(_interrupt_stack) + CONFIG_ISR_STACK_SIZE;
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
}
static ALWAYS_INLINE void
_set_thread_return_value(struct k_thread *thread, unsigned int value)
{
thread->arch.swap_return_value = value;
}
static inline void _IntLibInit(void)
{
#if defined(CONFIG_RISCV_SOC_INTERRUPT_INIT)
soc_interrupt_init();
#endif
}
FUNC_NORETURN void _NanoFatalErrorHandler(unsigned int reason,
const NANO_ESF *esf);
#define _is_in_isr() (_kernel.nested != 0)
#ifdef CONFIG_IRQ_OFFLOAD
int _irq_do_offload(void);
#endif
#endif /* _ASMLANGUAGE */
#ifdef __cplusplus
}
#endif
#endif /* _kernel_arch_func__h_ */