os/cpupm/speedstep.c

	speedstep.c revision f34a71784df3fbc5d1227a7b6201fd318ad1667e
/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/x86_archext.h>
#include <sys/machsystm.h>
#include <sys/archsystm.h>
#include <sys/x_call.h>
#include <sys/acpi/acpi.h>
#include <sys/acpica.h>
#include <sys/speedstep.h>
#include <sys/cpu_acpi.h>
#include <sys/cpupm.h>
#include <sys/dtrace.h>
#include <sys/sdt.h>

/*
 * turbo related structure definitions
 */
typedef struct cpupm_turbo_info {
    kstat_t     *turbo_ksp;     /* turbo kstat */
    int     in_turbo;       /* in turbo? */
    int     turbo_supported;    /* turbo flag */
    uint64_t    t_mcnt;         /* turbo mcnt */
    uint64_t    t_acnt;         /* turbo acnt */
} cpupm_turbo_info_t;

typedef struct turbo_kstat_s {
    struct kstat_named  turbo_supported;    /* turbo flag */
    struct kstat_named  t_mcnt;         /* IA32_MPERF_MSR */
    struct kstat_named  t_acnt;         /* IA32_APERF_MSR */
} turbo_kstat_t;

static int speedstep_init(cpu_t *);
static void speedstep_fini(cpu_t *);
static void speedstep_power(cpuset_t, uint32_t);
static boolean_t turbo_supported(void);
static int turbo_kstat_update(kstat_t *, int);
static void get_turbo_info(cpupm_turbo_info_t *);
static void reset_turbo_info(void);
static void record_turbo_info(cpupm_turbo_info_t *, uint32_t, uint32_t);
static void update_turbo_info(cpupm_turbo_info_t *);

/*
 * Interfaces for modules implementing Intel's Enhanced SpeedStep.
 */
cpupm_state_ops_t speedstep_ops = {
    "Enhanced SpeedStep Technology",
    speedstep_init,
    speedstep_fini,
    speedstep_power
};

/*
 * Error returns
 */
#define ESS_RET_SUCCESS     0x00
#define ESS_RET_NO_PM       0x01
#define ESS_RET_UNSUP_STATE 0x02

/*
 * MSR registers for changing and reading processor power state.
 */
#define IA32_PERF_STAT_MSR      0x198
#define IA32_PERF_CTL_MSR       0x199

#define IA32_CPUID_TSC_CONSTANT     0xF30
#define IA32_MISC_ENABLE_MSR        0x1A0
#define IA32_MISC_ENABLE_EST        (1<<16)
#define IA32_MISC_ENABLE_CXE        (1<<25)

#define CPUID_TURBO_SUPPORT     (1 << 1)
#define CPU_ACPI_P0         0
#define CPU_IN_TURBO            1

/*
 * MSR for hardware coordination feedback mechanism
 *   - IA32_MPERF: increments in proportion to a fixed frequency
 *   - IA32_APERF: increments in proportion to actual performance
 */
#define IA32_MPERF_MSR          0xE7
#define IA32_APERF_MSR          0xE8

/*
 * Debugging support
 */
#ifdef  DEBUG
volatile int ess_debug = 0;
#define ESSDEBUG(arglist) if (ess_debug) printf arglist;
#else
#define ESSDEBUG(arglist)
#endif

static kmutex_t turbo_mutex;

turbo_kstat_t turbo_kstat = {
    { "turbo_supported",    KSTAT_DATA_UINT32 },
    { "turbo_mcnt",     KSTAT_DATA_UINT64 },
    { "turbo_acnt",     KSTAT_DATA_UINT64 },
};

/*
 * kstat update function of the turbo mode info
 */
static int
turbo_kstat_update(kstat_t *ksp, int flag)
{
    cpupm_turbo_info_t *turbo_info = ksp->ks_private;

    if (flag == KSTAT_WRITE) {
        return (EACCES);
    }

    /*
     * update the count in case CPU is in the turbo
     * mode for a long time
     */
    if (turbo_info->in_turbo == CPU_IN_TURBO)
        update_turbo_info(turbo_info);

    turbo_kstat.turbo_supported.value.ui32 =
        turbo_info->turbo_supported;
    turbo_kstat.t_mcnt.value.ui64 = turbo_info->t_mcnt;
    turbo_kstat.t_acnt.value.ui64 = turbo_info->t_acnt;

    return (0);
}

/*
 * Get count of MPERF/APERF MSR
 */
static void
get_turbo_info(cpupm_turbo_info_t *turbo_info)
{
    ulong_t     iflag;
    uint64_t    mcnt, acnt;

    iflag = intr_clear();
    mcnt = rdmsr(IA32_MPERF_MSR);
    acnt = rdmsr(IA32_APERF_MSR);
    turbo_info->t_mcnt += mcnt;
    turbo_info->t_acnt += acnt;
    intr_restore(iflag);
}

/*
 * Clear MPERF/APERF MSR
 */
static void
reset_turbo_info(void)
{
    ulong_t     iflag;

    iflag = intr_clear();
    wrmsr(IA32_MPERF_MSR, 0);
    wrmsr(IA32_APERF_MSR, 0);
    intr_restore(iflag);
}

/*
 * sum up the count of one CPU_ACPI_P0 transition
 */
static void
record_turbo_info(cpupm_turbo_info_t *turbo_info,
    uint32_t cur_state, uint32_t req_state)
{
    if (!turbo_info->turbo_supported)
        return;
    /*
     * enter P0 state
     */
    if (req_state == CPU_ACPI_P0) {
        reset_turbo_info();
        turbo_info->in_turbo = CPU_IN_TURBO;
    }
    /*
     * Leave P0 state
     */
    else if (cur_state == CPU_ACPI_P0) {
        turbo_info->in_turbo = 0;
        get_turbo_info(turbo_info);
    }
}

/*
 * update the sum of counts and clear MSRs
 */
static void
update_turbo_info(cpupm_turbo_info_t *turbo_info)
{
    ulong_t     iflag;
    uint64_t    mcnt, acnt;

    iflag = intr_clear();
    mcnt = rdmsr(IA32_MPERF_MSR);
    acnt = rdmsr(IA32_APERF_MSR);
    wrmsr(IA32_MPERF_MSR, 0);
    wrmsr(IA32_APERF_MSR, 0);
    turbo_info->t_mcnt += mcnt;
    turbo_info->t_acnt += acnt;
    intr_restore(iflag);
}

/*
 * Write the ctrl register. How it is written, depends upon the _PCT
 * APCI object value.
 */
static void
write_ctrl(cpu_acpi_handle_t handle, uint32_t ctrl)
{
    cpu_acpi_pct_t *pct_ctrl;
    uint64_t reg;

    pct_ctrl = CPU_ACPI_PCT_CTRL(handle);

    switch (pct_ctrl->cr_addrspace_id) {
    case ACPI_ADR_SPACE_FIXED_HARDWARE:
        /*
         * Read current power state because reserved bits must be
         * preserved, compose new value, and write it.
         */
        reg = rdmsr(IA32_PERF_CTL_MSR);
        reg &= ~((uint64_t)0xFFFF);
        reg |= ctrl;
        wrmsr(IA32_PERF_CTL_MSR, reg);
        break;

    case ACPI_ADR_SPACE_SYSTEM_IO:
        (void) cpu_acpi_write_port(pct_ctrl->cr_address, ctrl,
            pct_ctrl->cr_width);
        break;

    default:
        DTRACE_PROBE1(ess_ctrl_unsupported_type, uint8_t,
            pct_ctrl->cr_addrspace_id);
        return;
    }

    DTRACE_PROBE1(ess_ctrl_write, uint32_t, ctrl);
}

/*
 * Transition the current processor to the requested state.
 */
void
speedstep_pstate_transition(uint32_t req_state)
{
    cpupm_mach_state_t *mach_state =
        (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state;
    cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
    cpu_acpi_pstate_t *req_pstate;
    uint32_t ctrl;
    cpupm_turbo_info_t *turbo_info =
        (cpupm_turbo_info_t *)(mach_state->ms_vendor);

    req_pstate = (cpu_acpi_pstate_t *)CPU_ACPI_PSTATES(handle);
    req_pstate += req_state;

    DTRACE_PROBE1(ess_transition, uint32_t, CPU_ACPI_FREQ(req_pstate));

    /*
     * Initiate the processor p-state change.
     */
    ctrl = CPU_ACPI_PSTATE_CTRL(req_pstate);
    write_ctrl(handle, ctrl);

    if (turbo_info)
        record_turbo_info(turbo_info,
            mach_state->ms_pstate.cma_state.pstate, req_state);


    mach_state->ms_pstate.cma_state.pstate = req_state;
    cpu_set_curr_clock(((uint64_t)CPU_ACPI_FREQ(req_pstate) * 1000000));
}

static void
speedstep_power(cpuset_t set, uint32_t req_state)
{
    /*
     * If thread is already running on target CPU then just
     * make the transition request. Otherwise, we'll need to
     * make a cross-call.
     */
    kpreempt_disable();
    if (CPU_IN_SET(set, CPU->cpu_id)) {
        speedstep_pstate_transition(req_state);
        CPUSET_DEL(set, CPU->cpu_id);
    }
    if (!CPUSET_ISNULL(set)) {
        xc_call((xc_arg_t)req_state, NULL, NULL, CPUSET2BV(set),
            (xc_func_t)speedstep_pstate_transition);
    }
    kpreempt_enable();
}

/*
 * Validate that this processor supports Speedstep and if so,
 * get the P-state data from ACPI and cache it.
 */
static int
speedstep_init(cpu_t *cp)
{
    cpupm_mach_state_t *mach_state =
        (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state;
    cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
    cpu_acpi_pct_t *pct_stat;
    cpupm_turbo_info_t *turbo_info;

    ESSDEBUG(("speedstep_init: processor %d\n", cp->cpu_id));

    /*
     * Cache the P-state specific ACPI data.
     */
    if (cpu_acpi_cache_pstate_data(handle) != 0) {
        ESSDEBUG(("Failed to cache ACPI data\n"));
        speedstep_fini(cp);
        return (ESS_RET_NO_PM);
    }

    pct_stat = CPU_ACPI_PCT_STATUS(handle);
    switch (pct_stat->cr_addrspace_id) {
    case ACPI_ADR_SPACE_FIXED_HARDWARE:
        ESSDEBUG(("Transitions will use fixed hardware\n"));
        break;
    case ACPI_ADR_SPACE_SYSTEM_IO:
        ESSDEBUG(("Transitions will use system IO\n"));
        break;
    default:
        cmn_err(CE_WARN, "!_PCT conifgured for unsupported "
            "addrspace = %d.", pct_stat->cr_addrspace_id);
        cmn_err(CE_NOTE, "!CPU power management will not function.");
        speedstep_fini(cp);
        return (ESS_RET_NO_PM);
    }

    cpupm_alloc_domains(cp, CPUPM_P_STATES);

    if (!turbo_supported()) {
        mach_state->ms_vendor = NULL;
        goto ess_ret_success;
    }
    /*
     * turbo mode supported
     */
    turbo_info = mach_state->ms_vendor =
        kmem_zalloc(sizeof (cpupm_turbo_info_t), KM_SLEEP);
    turbo_info->turbo_supported = 1;
    turbo_info->turbo_ksp = kstat_create("turbo", cp->cpu_id,
        "turbo", "misc", KSTAT_TYPE_NAMED,
        sizeof (turbo_kstat) / sizeof (kstat_named_t),
        KSTAT_FLAG_VIRTUAL);

    if (turbo_info->turbo_ksp == NULL) {
        cmn_err(CE_NOTE, "kstat_create(turbo) fail");
    } else {
        turbo_info->turbo_ksp->ks_data = &turbo_kstat;
        turbo_info->turbo_ksp->ks_lock = &turbo_mutex;
        turbo_info->turbo_ksp->ks_update = turbo_kstat_update;
        turbo_info->turbo_ksp->ks_data_size += MAXNAMELEN;
        turbo_info->turbo_ksp->ks_private = turbo_info;

        kstat_install(turbo_info->turbo_ksp);
    }

ess_ret_success:

    ESSDEBUG(("Processor %d succeeded.\n", cp->cpu_id))
    return (ESS_RET_SUCCESS);
}

/*
 * Free resources allocated by speedstep_init().
 */
static void
speedstep_fini(cpu_t *cp)
{
    cpupm_mach_state_t *mach_state =
        (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state);
    cpu_acpi_handle_t handle = mach_state->ms_acpi_handle;
    cpupm_turbo_info_t *turbo_info =
        (cpupm_turbo_info_t *)(mach_state->ms_vendor);

    cpupm_free_domains(&cpupm_pstate_domains);
    cpu_acpi_free_pstate_data(handle);

    if (turbo_info) {
        if (turbo_info->turbo_ksp != NULL)
            kstat_delete(turbo_info->turbo_ksp);
        kmem_free(turbo_info, sizeof (cpupm_turbo_info_t));
    }
}

boolean_t
speedstep_supported(uint_t family, uint_t model)
{
    struct cpuid_regs cpu_regs;

    /* Required features */
    if (!(x86_feature & X86_CPUID) ||
        !(x86_feature & X86_MSR)) {
        return (B_FALSE);
    }

    /*
     * We only support family/model combinations which
     * are P-state TSC invariant.
     */
    if (!((family == 0xf && model >= 0x3) ||
        (family == 0x6 && model >= 0xe))) {
        return (B_FALSE);
    }

    /*
     * Enhanced SpeedStep supported?
     */
    cpu_regs.cp_eax = 0x1;
    (void) __cpuid_insn(&cpu_regs);
    if (!(cpu_regs.cp_ecx & CPUID_INTC_ECX_EST)) {
        return (B_FALSE);
    }

    return (B_TRUE);
}

boolean_t
turbo_supported(void)
{
    struct cpuid_regs cpu_regs;

    /* Required features */
    if (!(x86_feature & X86_CPUID) ||
        !(x86_feature & X86_MSR)) {
        return (B_FALSE);
    }

    /*
     * turbo mode supported?
     */
    cpu_regs.cp_eax = 0x6;
    (void) __cpuid_insn(&cpu_regs);
    if (!(cpu_regs.cp_eax & CPUID_TURBO_SUPPORT)) {
        return (B_FALSE);
    }

    return (B_TRUE);
}