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add plic.c

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Robert Morris 2019-06-06 05:19:59 -04:00
parent b05bcce939
commit 31ef85f552
1 changed files with 63 additions and 0 deletions
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#include "types.h"
#include "param.h"
#include "memlayout.h"
#include "riscv.h"
#include "defs.h"
//
// the riscv Platform Level Interrupt Controller (PLIC).
//
void
plicinit(void)
{
// set uart's priority to be non-zero (otherwise disabled).
*(uint32*)(PLIC + UART0_IRQ*4) = 1;
}
void
plicinithart(void)
{
int hart = cpuid();
// set uart's enable bit for this hart's S-mode.
//*(uint32*)(PLIC + 0x2080)= (1 << UART0_IRQ);
*(uint32*)PLIC_SENABLE(hart)= (1 << UART0_IRQ);
// set this hart's S-mode priority threshold to 0.
//*(uint32*)(PLIC + 0x201000) = 0;
*(uint32*)PLIC_SPRIORITY(hart) = 0;
}
// return a bitmap of which IRQs are waiting
// to be served.
uint64
plic_pending(void)
{
uint64 mask;
//mask = *(uint32*)(PLIC + 0x1000);
//mask |= (uint64)*(uint32*)(PLIC + 0x1004) << 32;
mask = *(uint64*)PLIC_PENDING;
return mask;
}
// ask the PLIC what interrupt we should serve.
int
plic_claim(void)
{
int hart = cpuid();
//int irq = *(uint32*)(PLIC + 0x201004);
int irq = *(uint32*)PLIC_SCLAIM(hart);
return irq;
}
// tell the PLIC we've served this IRQ.
void
plic_complete(int irq)
{
int hart = cpuid();
//*(uint32*)(PLIC + 0x201004) = irq;
*(uint32*)PLIC_SCLAIM(hart) = irq;
}