nuttx/arch/z80/src/ez80/switch.h
2021-02-17 02:32:12 -08:00

152 lines
5.0 KiB
C

/************************************************************************************
* arch/z80/src/ez80/switch.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
************************************************************************************/
#ifndef __ARCH_Z80_SRC_EZ80_SWITCH_H
#define __ARCH_Z80_SRC_EZ80_SWITCH_H
/************************************************************************************
* Included Files
************************************************************************************/
#ifndef __ASSEMBLY__
# include <nuttx/sched.h>
# include <nuttx/arch.h>
#endif
#include "z80_internal.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Macros for portability ***********************************************************
*
* Common logic in arch/z80/src/common is customized for the z8 context switching
* logic via the following macros.
*/
/* Initialize the IRQ state */
#define INIT_IRQCONTEXT() g_current_regs = NULL
/* IN_INTERRUPT returns true if the system is currently operating in the interrupt
* context. IN_INTERRUPT is the inline equivalent of up_interrupt_context().
*/
#define IN_INTERRUPT() (g_current_regs != NULL)
/* The following macro is used when the system enters interrupt handling logic
*
* NOTE: Nested interrupts are not supported in this implementation. If you want
* to implement nested interrupts, you would have to change the way that
* g_current_regs is handled. The savestate variable would not work for
* that purpose as implemented here because only the outermost nested
* interrupt can result in a context switch (it can probably be deleted).
*/
#define DECL_SAVESTATE() \
FAR chipreg_t *savestate
#define IRQ_ENTER(irq, regs) \
do { \
savestate = (FAR chipreg_t *)g_current_regs; \
g_current_regs = (regs); \
} while (0)
/* The following macro is used when the system exits interrupt handling logic */
#define IRQ_LEAVE(irq) g_current_regs = savestate
/* The following macro is used to sample the interrupt state (as a opaque handle) */
#define IRQ_STATE() (g_current_regs)
/* Save the current IRQ context in the specified TCB */
#define SAVE_IRQCONTEXT(tcb) ez80_copystate((tcb)->xcp.regs, (FAR chipreg_t*)g_current_regs)
/* Set the current IRQ context to the state specified in the TCB */
#define SET_IRQCONTEXT(tcb) ez80_copystate((FAR chipreg_t*)g_current_regs, (tcb)->xcp.regs)
/* Save the user context in the specified TCB. User context saves can be simpler
* because only those registers normally saved in a C called need be stored.
*/
#define SAVE_USERCONTEXT(tcb) ez80_saveusercontext((tcb)->xcp.regs)
/* Restore the full context -- either a simple user state save or the full,
* IRQ state save.
*/
#define RESTORE_USERCONTEXT(tcb) ez80_restorecontext((tcb)->xcp.regs)
/* Dump the current machine registers */
#define _REGISTER_DUMP() ez80_registerdump()
/************************************************************************************
* Public Types
************************************************************************************/
/************************************************************************************
* Public Data
************************************************************************************/
#ifndef __ASSEMBLY__
/* This holds a references to the current interrupt level register storage structure.
* If is non-NULL only during interrupt processing.
*/
extern volatile chipreg_t *g_current_regs;
#endif
/************************************************************************************
* Public Function Prototypes
************************************************************************************/
#ifndef __ASSEMBLY__
#ifdef __cplusplus
extern "C"
{
#endif
/* Defined in ez80_copystate.c */
void ez80_copystate(FAR chipreg_t *dest, FAR const chipreg_t *src);
/* Defined in ez80_saveusercontext.asm */
int ez80_saveusercontext(FAR chipreg_t *regs);
/* Defined in ez80_restorecontext.asm */
void ez80_restorecontext(FAR chipreg_t *regs);
/* Defined in ez80_registerdump.c */
void ez80_registerdump(void);
#ifdef __cplusplus
}
#endif
#endif
#endif /* __ARCH_Z80_SRC_EZ80_SWITCH_H */