src/southbridge/intel/i82870/ioapic.c

#include <console/console.h>
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <device/pci_ops.h>
#include <pc80/mc146818rtc.h>
#include <assert.h>
#include "82870.h"

static int num_p64h2_ioapics = 0;

static void p64h2_ioapic_enable(device_t dev)
{
    /* We have to enable MEM and Bus Master for IOAPIC */
    uint16_t command = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;


    pci_write_config16(dev, PCI_COMMAND, command);
}

/**
 * Configure one of the IOAPICs in a P64H2.
 *
 * Note that a PCI bus scan will detect both IOAPICs, so this function
 * will be called twice for each P64H2 in the system.
 *
 * @param dev PCI bus/device/function of P64H2 IOAPIC.
 *            NOTE: There are two IOAPICs per P64H2, at D28:F0 and D30:F0.
 */
static void p64h2_ioapic_init(device_t dev)
{
    uint32_t memoryBase;
    int apic_index, apic_id;

    volatile uint32_t* pIndexRegister;    /* io apic io memory space command address */
    volatile uint32_t* pWindowRegister;    /* io apic io memory space data address */

    apic_index = num_p64h2_ioapics;
    num_p64h2_ioapics++;

    // A note on IOAPIC addresses:
    //  0 and 1 are used for the local APICs of the dual virtual
    //  (hyper-threaded) CPUs of physical CPU 0 (devicetree.cb).
    //  6 and 7 are used for the local APICs of the dual virtual
    //  (hyper-threaded) CPUs of physical CPU 1 (devicetree.cb).
    //  2 is used for the IOAPIC in the 82801 southbridge (hard-coded in i82801xx_lpc.c)

    // Map APIC index into APIC ID
    // IDs 3, 4, 5, and 8+ are available (see above note)

    if (apic_index < 3)
        apic_id = apic_index + 3;
    else
        apic_id = apic_index + 5;

    ASSERT(apic_id < 16);       // ID is only 4 bits

    // Read the MBAR address for setting up the IOAPIC in memory space
    // NOTE: this address was assigned during enumeration of the bus

    memoryBase = pci_read_config32(dev, PCI_BASE_ADDRESS_0);
    pIndexRegister  = (volatile uint32_t*) memoryBase;
    pWindowRegister = (volatile uint32_t*)(memoryBase + 0x10);

    printk(BIOS_DEBUG, "IOAPIC %d at %02x:%02x.%01x  MBAR = %p DataAddr = %p\n",
                 apic_id, dev->bus->secondary, PCI_SLOT(dev->path.pci.devfn),
                 PCI_FUNC(dev->path.pci.devfn), pIndexRegister, pWindowRegister);

    apic_id <<= 24;             // Convert ID to bitmask

    *pIndexRegister = 0;        // Select APIC ID register
    *pWindowRegister = (*pWindowRegister & ~(0xF<<24)) | apic_id;   // Set the ID

    if ((*pWindowRegister & (0xF<<24)) != apic_id)
        die("p64h2_ioapic_init failed");

    *pIndexRegister  = 3;   // Select Boot Configuration register
    *pWindowRegister |= 1;  // Use Processor System Bus to deliver interrupts

    if (!(*pWindowRegister & 1))
        die("p64h2_ioapic_init failed");
}

static struct device_operations ioapic_ops = {
        .read_resources   = pci_dev_read_resources,
        .set_resources    = pci_dev_set_resources,
        .enable_resources = pci_dev_enable_resources,
        .init     = p64h2_ioapic_init,
        .scan_bus = 0,
        .enable   = p64h2_ioapic_enable,
};

static const struct pci_driver ioapic_driver __pci_driver = {
        .ops    = &ioapic_ops,
        .vendor = PCI_VENDOR_ID_INTEL,
        .device = PCI_DEVICE_ID_INTEL_82870_1E0,

};