io/pcplusmp/apic_regops.c

	apic_regops.c revision 325e77f4fc68ea7eea21f5e705d3cf89fd3a7e3d
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/cpuvar.h>
#include <sys/psm.h>
#include <sys/archsystm.h>
#include <sys/apic.h>
#include <sys/sunddi.h>
#include <sys/ddi_impldefs.h>
#include <sys/mach_intr.h>
#include <sys/sysmacros.h>
#include <sys/trap.h>
#include <sys/x86_archext.h>
#include <sys/privregs.h>
#include <sys/psm_common.h>

/* Function prototypes of local apic and X2APIC */
static uint64_t local_apic_read(uint32_t reg);
static void local_apic_write(uint32_t reg, uint64_t value);
static int get_local_apic_pri(void);
static void local_apic_write_task_reg(uint64_t value);
static void local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);
static uint64_t local_x2apic_read(uint32_t msr);
static void local_x2apic_write(uint32_t msr, uint64_t value);
static int get_local_x2apic_pri(void);
static void local_x2apic_write_task_reg(uint64_t value);
static void local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);

/*
 * According to the X2APIC specification:
 *
 *   xAPIC global enable    X2APIC enable         Description
 *   (IA32_APIC_BASE[11])   (IA32_APIC_BASE[10])
 * -----------------------------------------------------------
 *      0           0   APIC is disabled
 *  0           1   Invalid
 *  1           0   APIC is enabled in xAPIC mode
 *  1           1   APIC is enabled in X2APIC mode
 * -----------------------------------------------------------
 */
int x2apic_enable = 1;
int     apic_mode = LOCAL_APIC;     /* Default mode is Local APIC */

/* Uses MMIO (Memory Mapped IO) */
static apic_reg_ops_t local_apic_regs_ops = {
    local_apic_read,
    local_apic_write,
    get_local_apic_pri,
    local_apic_write_task_reg,
    local_apic_write_int_cmd,
    apic_send_EOI,
};

/* X2APIC : Uses RDMSR/WRMSR instructions to access APIC registers */
static apic_reg_ops_t x2apic_regs_ops = {
    local_x2apic_read,
    local_x2apic_write,
    get_local_x2apic_pri,
    local_x2apic_write_task_reg,
    local_x2apic_write_int_cmd,
    apic_send_EOI,
};


/* The default ops is local APIC (Memory Mapped IO) */
apic_reg_ops_t *apic_reg_ops = &local_apic_regs_ops;

/*
 * APIC register ops related data sturctures and functions.
 */
int apic_direct_EOI = 0;            /* Directed EOI Support */

void apic_send_EOI();
void apic_send_directed_EOI(uint32_t irq);

#define X2APIC_CPUID_BIT    21
#define X2APIC_ENABLE_BIT   10

/*
 * Local APIC Implementation
 */
static uint64_t
local_apic_read(uint32_t reg)
{
    return ((uint32_t)apicadr[reg]);
}

static void
local_apic_write(uint32_t reg, uint64_t value)
{
    apicadr[reg] = (uint32_t)value;
}

static int
get_local_apic_pri(void)
{
#if defined(__amd64)
    return ((int)getcr8());
#else
    return (apicadr[APIC_TASK_REG]);
#endif
}

static void
local_apic_write_task_reg(uint64_t value)
{
#if defined(__amd64)
    setcr8((ulong_t)(value >> APIC_IPL_SHIFT));
#else
    apicadr[APIC_TASK_REG] = (uint32_t)value;
#endif
}

static void
local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
{
    apicadr[APIC_INT_CMD2] = cpu_id << APIC_ICR_ID_BIT_OFFSET;
    apicadr[APIC_INT_CMD1] = cmd1;
}

/*
 * X2APIC Implementation.
 */
static uint64_t
local_x2apic_read(uint32_t msr)
{
    uint64_t i;

    i = (uint64_t)(rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2)) & 0xffffffff);
    return (i);
}

static void
local_x2apic_write(uint32_t msr, uint64_t value)
{
    uint64_t tmp;

    if (msr != APIC_EOI_REG) {
        tmp = rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2));
        tmp = (tmp & 0xffffffff00000000) | value;
    } else {
        tmp = 0;
    }

    wrmsr((REG_X2APIC_BASE_MSR + (msr >> 2)), tmp);
}

static int
get_local_x2apic_pri(void)
{
    return (rdmsr(REG_X2APIC_BASE_MSR + (APIC_TASK_REG >> 2)));
}

static void
local_x2apic_write_task_reg(uint64_t value)
{
    X2APIC_WRITE(APIC_TASK_REG, value);
}

static void
local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
{
    wrmsr((REG_X2APIC_BASE_MSR + (APIC_INT_CMD1 >> 2)),
        (((uint64_t)cpu_id << 32) | cmd1));
}

/*ARGSUSED*/
void
apic_send_EOI(uint32_t irq)
{
    apic_reg_ops->apic_write(APIC_EOI_REG, 0);
}

void
apic_send_directed_EOI(uint32_t irq)
{
    uchar_t ioapicindex;
    uchar_t vector;
    apic_irq_t *apic_irq;
    short intr_index;

    ASSERT(apic_mode == LOCAL_X2APIC);

    apic_irq = apic_irq_table[irq];

    while (apic_irq) {
        intr_index = apic_irq->airq_mps_intr_index;
        if (intr_index == ACPI_INDEX || intr_index >= 0) {
            ioapicindex = apic_irq->airq_ioapicindex;
            vector = apic_irq->airq_vector;
            ioapic_write_eoi(ioapicindex, vector);
        }
        apic_irq = apic_irq->airq_next;
    }
}

int
apic_detect_x2apic(void)
{
    struct cpuid_regs cp;

    if (x2apic_enable == 0)
        return (0);

    cp.cp_eax = 1;
    (void) __cpuid_insn(&cp);

    return ((cp.cp_ecx & (0x1 << X2APIC_CPUID_BIT)) ? 1 : 0);
}

void
apic_enable_x2apic(void)
{
    uint64_t apic_base_msr;

    if (apic_local_mode() == LOCAL_X2APIC) {
        /* BIOS apparently has enabled X2APIC */
        if (apic_mode != LOCAL_X2APIC)
            x2apic_update_psm();
        return;
    }

    /*
     * This is the first time we are enabling X2APIC on this CPU
     */
    apic_base_msr = rdmsr(REG_APIC_BASE_MSR);
    apic_base_msr = apic_base_msr | (0x1 << X2APIC_ENABLE_BIT);
    wrmsr(REG_APIC_BASE_MSR, apic_base_msr);

    if (apic_mode != LOCAL_X2APIC)
        x2apic_update_psm();
}

/*
 * Determine which mode the current CPU is in. See the table above.
 * (IA32_APIC_BASE[11])   (IA32_APIC_BASE[10])
 */
int
apic_local_mode(void)
{
    uint64_t apic_base_msr;
    int bit = ((0x1 << (X2APIC_ENABLE_BIT + 1)) |
        (0x1 << X2APIC_ENABLE_BIT));

    apic_base_msr = rdmsr(REG_APIC_BASE_MSR);

    if ((apic_base_msr & bit) == bit)
        return (LOCAL_X2APIC);
    else
        return (LOCAL_APIC);
}

void
apic_change_eoi()
{
    apic_reg_ops->apic_send_eoi = apic_send_directed_EOI;
}

/*
 * Change apic_reg_ops depending upon the apic_mode.
 */
void
apic_change_ops()
{
    if (apic_mode == LOCAL_APIC)
        apic_reg_ops = &local_apic_regs_ops;
    else if (apic_mode == LOCAL_X2APIC)
        apic_reg_ops = &x2apic_regs_ops;
}

/*
 * Generates an interprocessor interrupt to another CPU when X2APIC mode is
 * enabled.
 */
void
x2apic_send_ipi(int cpun, int ipl)
{
    int vector;
    ulong_t flag;

    /*
     * With X2APIC, Intel relaxed the semantics of the
     * WRMSR instruction such that references to the X2APIC
     * MSR registers are no longer serializing instructions.
     * The code that initiates IPIs assumes that some sort
     * of memory serialization occurs. The old APIC code
     * did a write to uncachable memory mapped registers.
     * Any reference to uncached memory is a serializing
     * operation. To mimic those semantics here, we do an
     * atomic operation, which translates to a LOCK OR instruction,
     * which is serializing.
     */
    atomic_or_ulong(&flag, 1);

    vector = apic_resv_vector[ipl];

    flag = intr_clear();

    /*
     * According to X2APIC specification in section '2.3.5.1' of
     * Interrupt Command Register Semantics, the semantics of
     * programming Interrupt Command Register to dispatch an interrupt
     * is simplified. A single MSR write to the 64-bit ICR is required
     * for dispatching an interrupt. Specifically with the 64-bit MSR
     * interface to ICR, system software is not required to check the
     * status of the delivery status bit prior to writing to the ICR
     * to send an IPI. With the removal of the Delivery Status bit,
     * system software no longer has a reason to read the ICR. It remains
     * readable only to aid in debugging.
     */
#ifdef  DEBUG
    APIC_AV_PENDING_SET();
#endif  /* DEBUG */

    if ((cpun == psm_get_cpu_id()))
        apic_reg_ops->apic_write(X2APIC_SELF_IPI, vector);
    else
        apic_reg_ops->apic_write_int_cmd(
            apic_cpus[cpun].aci_local_id, vector);

    intr_restore(flag);
}

/*
 * Generates IPI to another CPU depending on the local APIC mode.
 * apic_send_ipi() and x2apic_send_ipi() depends on the configured
 * mode of the local APIC, but that may not match the actual mode
 * early in CPU startup.
 *
 * Any changes made to this routine must be accompanied by similar
 * changes to apic_send_ipi().
 */
void
apic_common_send_ipi(int cpun, int ipl)
{
    int vector;
    ulong_t flag;
    int mode = apic_local_mode();

    if (mode == LOCAL_X2APIC) {
        x2apic_send_ipi(cpun, ipl);
        return;
    }

    ASSERT(mode == LOCAL_APIC);

    vector = apic_resv_vector[ipl];
    ASSERT((vector >= APIC_BASE_VECT) && (vector <= APIC_SPUR_INTR));
    flag = intr_clear();
    while (local_apic_regs_ops.apic_read(APIC_INT_CMD1) & AV_PENDING)
        apic_ret();
    local_apic_regs_ops.apic_write_int_cmd(apic_cpus[cpun].aci_local_id,
        vector);
    intr_restore(flag);
}