/**
 * PROJECT:         ExectOS
 * COPYRIGHT:       See COPYING.md in the top level directory
 * FILE:            xtoskrnl/hl/x86/cpu.c
 * DESCRIPTION:     HAL x86 (i686/AMD64) processor support
 * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
 */

#include <xtos.h>


/**
 * Initializes the processor.
 *
 * @param CpuNumber
 *        Supplies the number of the CPU, that is being initialized.
 *
 * @return This routine does not return any value.
 *
 * @since XT 1.0
 */
XTAPI
VOID
HlInitializeProcessor(VOID)
{
    PKPROCESSOR_BLOCK ProcessorBlock;
    KAFFINITY Affinity;

    /* Get current processor block */
    ProcessorBlock = KeGetCurrentProcessorBlock();

    /* Set initial stall factor, CPU number and mask interrupts */
    ProcessorBlock->StallScaleFactor = INITIAL_STALL_FACTOR;
    ProcessorBlock->Idr = 0xFFFFFFFF;

    /* Set processor affinity */
    Affinity = (KAFFINITY) 1 << ProcessorBlock->CpuNumber;

    /* Apply affinity to a set of processors */
    HlpActiveProcessors |= Affinity;

    /* Initialize APIC for this processor */
    HlpInitializePic();

    /* Set the APIC running level */
    HlSetRunLevel(KeGetCurrentProcessorBlock()->RunLevel);
}

XTAPI
XTSTATUS
HlStartProcessor(IN ULONG CpuId,
                 IN PHYSICAL_ADDRESS EntryPoint)
{
    ULONG Attempt;

    /* Wait until command register is clear */
    while((HlReadApicRegister(APIC_ICR0) & APIC_DELIVERY_PENDING) != 0);

    /* Trigger INIT IPI and wait for delivery bit to be cleared */
    HlpSendIpi(CpuId, APIC_DM_INIT | APIC_DM_LEVEL | APIC_DM_ASSERT);
    while((HlReadApicRegister(APIC_ICR0) & APIC_DELIVERY_PENDING) != 0);

    /* Deassert INIT IPI to take CPU out of reset and wait for delivery bit to be cleared */
    HlpSendIpi(CpuId, APIC_DM_INIT | APIC_DM_LEVEL);
    while((HlReadApicRegister(APIC_ICR0) & APIC_DELIVERY_PENDING) != 0);

    /* Two attempts to send STARTUP IPI */
    for(Attempt = 0; Attempt < 2; Attempt++)
    {
        /* Trigger STARTUP IPI and wait for delivery bit to be cleared */
        HlpSendIpi(CpuId, APIC_DM_STARTUP | (EntryPoint.LowPart >> 12));
        while((HlReadApicRegister(APIC_ICR0) & APIC_DELIVERY_PENDING) != 0);
    }

    /* Memory barrier */
    ArMemoryBarrier();

    /* Return success */
    return STATUS_SUCCESS;
}