diff options
Diffstat (limited to 'nuttx/arch/z80/src/z180/switch.h')
| -rw-r--r-- | nuttx/arch/z80/src/z180/switch.h | 103 |
1 files changed, 86 insertions, 17 deletions
diff --git a/nuttx/arch/z80/src/z180/switch.h b/nuttx/arch/z80/src/z180/switch.h index 38054e4b8..aa33bd1e1 100644 --- a/nuttx/arch/z80/src/z180/switch.h +++ b/nuttx/arch/z80/src/z180/switch.h @@ -44,6 +44,7 @@ #include <nuttx/sched.h> #include <nuttx/arch.h> +#include "z180_iomap.h" #include "up_internal.h" /************************************************************************************ @@ -58,56 +59,116 @@ /* Initialize the IRQ state */ -#define INIT_IRQCONTEXT() current_regs = NULL +#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) +#define IN_INTERRUPT() \ + (current_regs != NULL) -/* The following macro is used when the system enters interrupt handling logic */ +/* The following macro declares the variables need by IRQ_ENTER and IRQ_LEAVE. + * These variables are used to support nested interrupts. + * + * - savestate holds the previous value of current_state. + * - savecpr holds the previous value of current_cpr. + * + * TODO: I think this logic is bad... I do not thing that this will really + * handle nested interrupts correctly. What if we are nested and then a + * context switch occurs? current_regs will not be updated correctly! + */ #define DECL_SAVESTATE() \ - FAR chipreg_t *savestate + FAR chipreg_t *savestate; \ + uint8_t savecbr; -#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 enters interrupt handling logic. + * The entry values of current_regs and current_cbr and stored in local variables. + * Then current_regs and current_cbr are set to the values of the interrupted + * task. + */ -/* The following macro is used when the system exits interrupt handling logic */ +#define IRQ_ENTER(irq, regs) \ + do \ + { \ + savestate = (FAR chipreg_t *)current_regs; \ + savecbr = current_cbr; \ + current_regs = (regs); \ + current_cbr = inp(Z180_MMU_CBR); \ + } \ + while (0) + +/* The following macro is used when the system exits interrupt handling logic. + * The value of current_regs is restored. If we are not processing a nested + * interrupt (meaning that we going to return to the user task), then also + * set the MMU's CBR register. + */ -#define IRQ_LEAVE(irq) current_regs = savestate +#define IRQ_LEAVE(irq) \ + do \ + { \ + current_regs = savestate; \ + if (current_regs) \ + { \ + current_cbr = savecbr; \ + } \ + else \ + { \ + outp(Z180_MMU_CBR, savecbr); \ + } \ + } /* The following macro is used to sample the interrupt state (as a opaque handle) */ -#define IRQ_STATE() (current_regs) +#define IRQ_STATE() \ + (current_regs) /* Save the current IRQ context in the specified TCB */ -#define SAVE_IRQCONTEXT(tcb) z180_copystate((tcb)->xcp.regs, (FAR chipreg_t*)current_regs) +#define SAVE_IRQCONTEXT(tcb) \ + z180_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) z180_copystate((FAR chipreg_t*)current_regs, (tcb)->xcp.regs) +#define SET_IRQCONTEXT(tcb) \ + do \ + { \ + if ((tcb)->xcp.cbr.cbr) \ + { \ + current_cbr = (tcb)->xcp.cbr->cbr); \ + } \ + z180_copystate((FAR chipreg_t*)current_regs, (tcb)->xcp.regs); \ + } \ + while (0) /* 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) z180_saveusercontext((tcb)->xcp.regs) +#define SAVE_USERCONTEXT(tcb) \ + z180_saveusercontext((tcb)->xcp.regs) /* Restore the full context -- either a simple user state save or the full, * IRQ state save. */ -#define RESTORE_USERCONTEXT(tcb) z180_restoreusercontext((tcb)->xcp.regs) +#define RESTORE_USERCONTEXT(tcb) \ + do \ + { \ + if ((tcb)->xcp.cbr.cbr) \ + { \ + outp(Z180_MMU_CBR, (tcb)->xcp.cbr->cbr); \ + } \ + z180_restoreusercontext((tcb)->xcp.regs); \ + } \ + while (0) /* Dump the current machine registers */ -#define _REGISTER_DUMP() z180_registerdump() +#define _REGISTER_DUMP() \ + z180_registerdump() /************************************************************************************ * Public Types @@ -123,6 +184,14 @@ */ extern volatile chipreg_t *current_regs; + +/* This holds the value of the MMU's CBR register. This value is set to the + * interrupted tasks's CBR on interrupt entry, changed to the new task's CBR if + * an interrrupt level context switch occurs, and restored on interrupt exit. In + * this way, the CBR is always correct on interrupt exit. + */ + +extern uint8_t current_cbr; #endif /************************************************************************************ |