/************************************************************************************
* arch/z80/src/ez80/switch.h
* arch/z80/src/chip/switch.h
*
* Copyright (C) 2008-2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
#ifndef __EZ80_SWITCH_H
#define __EZ80_SWITCH_H
/************************************************************************************
* Included Files
************************************************************************************/
#ifndef __ASSEMBLY__
# include <nuttx/sched.h>
# include <nuttx/arch.h>
#endif
#include "common/up_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() 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() (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
* 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 *)current_regs; \
current_regs = (regs); \
} while (0)
/* The following macro is used when the system exits interrupt handling logic */
#define IRQ_LEAVE(irq) current_regs = savestate
/* The following macro is used to sample the interrupt state (as a opaque handle) */
#define IRQ_STATE() (current_regs)
/* Save the current IRQ context in the specified TCB */
#define SAVE_IRQCONTEXT(tcb) ez80_copystate((tcb)->xcp.regs, (FAR chipreg_t*)current_regs)
/* Set the current IRQ context to the state specified in the TCB */
#define SET_IRQCONTEXT(tcb) ez80_copystate((FAR chipreg_t*)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 Variables
************************************************************************************/
#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 *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_sigsetup.c */
void ez80_sigsetup(FAR struct tcb_s *tcb, sig_deliver_t sigdeliver, chipreg_t *regs);
/* Defined in ez80_registerdump.c */
void ez80_registerdump(void);
#ifdef __cplusplus
}
#endif
#endif
#endif /* __EZ80_SWITCH_H */
