ioapic.c

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/*
 * IOAPIC
 */
 
#include <stdbool.h>
#include <stdint.h>
 
#include <sys/kassert.h>
#include <sys/kdebug.h>
#include <sys/cdefs.h>
 
#include <machine/amd64.h>
#include <machine/pmap.h>
#include <machine/trap.h>
 
#define IOAPICBASE  0xFEC00000
 
#define IOAPICID    0x00 /* IOAPIC ID */
#define IOAPICVER   0x01 /* IOAPIC Version */
#define IOAPICARB   0x02 /* IOAPIC Arbitration ID */
#define IOREDTBL0   0x10
#define IOREDTBL23  0x3E
 
#define IOREDTBL_LEN    24
 
#define IOREDTBL_MASK       0x00010000
#define IOREDTBL_LOGICAL    0x00000800
 
uint32_t
IOAPIC_Read(uint32_t reg)
{
    uint32_t volatile *addr = (uint32_t volatile *)DMPA2VA(IOAPICBASE);
    uint32_t volatile *cmd = (uint32_t volatile *)DMPA2VA(IOAPICBASE + 0x10);
 
    ASSERT(reg <= 0xFF);
 
    *addr = reg;
    return *cmd;
}
 
void
IOAPIC_Write(uint32_t reg, uint32_t val)
{
    uint32_t volatile *addr = (uint32_t volatile *)DMPA2VA(IOAPICBASE);
    uint32_t volatile *cmd = (uint32_t volatile *)DMPA2VA(IOAPICBASE + 0x10);
 
    ASSERT(reg <= 0xFF);
 
    *addr = reg;
    *cmd = val;
}
 
void
IOAPIC_Init()
{
    int i;
    uint32_t id = (IOAPIC_Read(IOAPICID) >> 24) & 0x0F;
    uint32_t maxInts = (IOAPIC_Read(IOAPICVER) >> 16) & 0xFF;
 
    kprintf("IOAPIC: ID:%d Max Interrupts: %d\n", id, maxInts);
 
    for (i = 0; i < IOREDTBL_LEN; i++)
    {
        IOAPIC_Write(IOREDTBL0 + 2*i, IOREDTBL_MASK | (T_IRQ_BASE + i));
        IOAPIC_Write(IOREDTBL0 + 2*i + 1, 0);
    }
}
 
void
IOAPIC_Enable(int irq)
{
    uint32_t val = IOAPIC_Read(IOREDTBL0 + 2*irq);
    IOAPIC_Write(IOREDTBL0 + 2*irq, val & ~IOREDTBL_MASK);
}
 
void
IOAPIC_Disable(int irq)
{
    uint32_t val = IOAPIC_Read(IOREDTBL0 + 2*irq);
    IOAPIC_Write(IOREDTBL0 + 2*irq, val | IOREDTBL_MASK);
}
 
static void
Debug_IOAPIC(int argc, const char *argv[])
{
    int i;
 
    kprintf("IOAPIC ID:      %08x\n", IOAPIC_Read(IOAPICID));
    kprintf("IOAPIC VERSION: %08x\n", IOAPIC_Read(IOAPICVER));
 
    for (i = 0; i < IOREDTBL_LEN; i++)
    {
        uint32_t irqInfo = IOAPIC_Read(IOREDTBL0 + 2*i);
        uint32_t cpuInfo = IOAPIC_Read(IOREDTBL0 + 2*i + 1);
        kprintf("%02x: %08x %08x\n", i, irqInfo, cpuInfo);
    }
}
 
REGISTER_DBGCMD(ioapic, "IOAPIC Dump", Debug_IOAPIC);