x86/acpi/acpi_cpu_md.c

/* $NetBSD: acpi_cpu_md.c,v 1.9 2010/08/09 15:46:17 jruoho Exp $ */

/*-
 * Copyright (c) 2010 Jukka Ruohonen <jruohonen (at) iki.fi>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.9 2010/08/09 15:46:17 jruoho Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kcore.h>
#include <sys/sysctl.h>
#include <sys/xcall.h>

#include <x86/cpu.h>
#include <x86/cpufunc.h>
#include <x86/cputypes.h>
#include <x86/cpuvar.h>
#include <x86/cpu_msr.h>
#include <x86/machdep.h>

#include <dev/acpi/acpica.h>
#include <dev/acpi/acpi_cpu.h>

static char	  native_idle_text[16];
void		(*native_idle)(void) = NULL;
void		(*native_cpu_freq_init)(int) = NULL;

static int	 acpicpu_md_pstate_sysctl_get(SYSCTLFN_PROTO);
static int	 acpicpu_md_pstate_sysctl_set(SYSCTLFN_PROTO);
static int	 acpicpu_md_pstate_sysctl_all(SYSCTLFN_PROTO);

extern uint32_t cpus_running;
extern struct acpicpu_softc **acpicpu_sc;

uint32_t
acpicpu_md_cap(void)
{
	struct cpu_info *ci = curcpu();
	uint32_t val = 0;

	if (cpu_vendor != CPUVENDOR_INTEL)
		return val;

	/*
	 * Basic SMP C-states (required for _CST).
	 */
	val |= ACPICPU_PDC_C_C1PT | ACPICPU_PDC_C_C2C3;

        /*
	 * If MONITOR/MWAIT is available, announce
	 * support for native instructions in all C-states.
	 */
        if ((ci->ci_feat_val[1] & CPUID2_MONITOR) != 0)
		val |= ACPICPU_PDC_C_C1_FFH | ACPICPU_PDC_C_C2C3_FFH;

	/*
	 * Set native P-states if EST is available.
	 */
        if ((ci->ci_feat_val[1] & CPUID2_EST) != 0)
		val |= ACPICPU_PDC_P_FFH;

	return val;
}

uint32_t
acpicpu_md_quirks(void)
{
	struct cpu_info *ci = curcpu();
	uint32_t val = 0;

	if (acpicpu_md_cpus_running() == 1)
		val |= ACPICPU_FLAG_C_BM;

	if ((ci->ci_feat_val[1] & CPUID2_MONITOR) != 0)
		val |= ACPICPU_FLAG_C_FFH;

	switch (cpu_vendor) {

	case CPUVENDOR_INTEL:

		val |= ACPICPU_FLAG_C_BM | ACPICPU_FLAG_C_ARB;

		if ((ci->ci_feat_val[1] & CPUID2_EST) != 0)
			val |= ACPICPU_FLAG_P_FFH;

		/*
		 * Bus master arbitration is not
		 * needed on some recent Intel CPUs.
		 */
		if (CPUID2FAMILY(ci->ci_signature) > 15)
			val &= ~ACPICPU_FLAG_C_ARB;

		if (CPUID2FAMILY(ci->ci_signature) == 6 &&
		    CPUID2MODEL(ci->ci_signature) >= 15)
			val &= ~ACPICPU_FLAG_C_ARB;

		break;

	case CPUVENDOR_AMD:

		/*
		 * XXX: Deal with the AMD C1E extension here.
		 */
		break;
	}

	return val;
}

uint32_t
acpicpu_md_cpus_running(void)
{

	return popcount32(cpus_running);
}

int
acpicpu_md_idle_start(void)
{
	const size_t size = sizeof(native_idle_text);

	x86_disable_intr();
	x86_cpu_idle_get(&native_idle, native_idle_text, size);
	x86_cpu_idle_set(acpicpu_cstate_idle, "acpi");
	x86_enable_intr();

	return 0;
}

int
acpicpu_md_idle_stop(void)
{
	uint64_t xc;

	x86_disable_intr();
	x86_cpu_idle_set(native_idle, native_idle_text);
	x86_enable_intr();

	/*
	 * Run a cross-call to ensure that all CPUs are
	 * out from the ACPI idle-loop before detachment.
	 */
	xc = xc_broadcast(0, (xcfunc_t)nullop, NULL, NULL);
	xc_wait(xc);

	return 0;
}

/*
 * The MD idle loop. Called with interrupts disabled.
 */
void
acpicpu_md_idle_enter(int method, int state)
{
	struct cpu_info *ci = curcpu();

	switch (method) {

	case ACPICPU_C_STATE_FFH:

		x86_enable_intr();
		x86_monitor(&ci->ci_want_resched, 0, 0);

		if (__predict_false(ci->ci_want_resched) != 0)
			return;

		x86_mwait((state - 1) << 4, 0);
		break;

	case ACPICPU_C_STATE_HALT:

		if (__predict_false(ci->ci_want_resched) != 0) {
			x86_enable_intr();
			return;
		}

		x86_stihlt();
		break;
	}
}

int
acpicpu_md_pstate_start(void)
{
	const struct sysctlnode	*fnode, *mnode, *rnode;
	const char *str;
	int rv;

	switch (cpu_vendor) {

	case CPUVENDOR_INTEL:
		str = "est";
		break;

	default:
		return ENODEV;
	}

	/*
	 * A kludge for backwards compatibility.
	 */
	native_cpu_freq_init = cpu_freq_init;

	if (cpu_freq_sysctllog != NULL) {
		sysctl_teardown(&cpu_freq_sysctllog);
		cpu_freq_sysctllog = NULL;
	}

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, NULL, &rnode,
	    CTLFLAG_PERMANENT, CTLTYPE_NODE, "machdep", NULL,
	    NULL, 0, NULL, 0, CTL_MACHDEP, CTL_EOL);

	if (rv != 0)
		goto fail;

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, &rnode, &mnode,
	    0, CTLTYPE_NODE, str, NULL,
	    NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);

	if (rv != 0)
		goto fail;

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, &mnode, &fnode,
	    0, CTLTYPE_NODE, "frequency", NULL,
	    NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);

	if (rv != 0)
		goto fail;

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, &fnode, &rnode,
	    CTLFLAG_READWRITE, CTLTYPE_INT, "target", NULL,
	    acpicpu_md_pstate_sysctl_set, 0, NULL, 0, CTL_CREATE, CTL_EOL);

	if (rv != 0)
		goto fail;

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, &fnode, &rnode,
	    CTLFLAG_READONLY, CTLTYPE_INT, "current", NULL,
	    acpicpu_md_pstate_sysctl_get, 0, NULL, 0, CTL_CREATE, CTL_EOL);

	if (rv != 0)
		goto fail;

	rv = sysctl_createv(&cpu_freq_sysctllog, 0, &fnode, &rnode,
	    CTLFLAG_READONLY, CTLTYPE_STRING, "available", NULL,
	    acpicpu_md_pstate_sysctl_all, 0, NULL, 0, CTL_CREATE, CTL_EOL);

	if (rv != 0)
		goto fail;

	return 0;

fail:
	if (cpu_freq_sysctllog != NULL) {
		sysctl_teardown(&cpu_freq_sysctllog);
		cpu_freq_sysctllog = NULL;
	}

	if (native_cpu_freq_init != NULL)
		(*native_cpu_freq_init)(cpu_vendor);

	return rv;
}

int
acpicpu_md_pstate_stop(void)
{

	if (cpu_freq_sysctllog != NULL) {
		sysctl_teardown(&cpu_freq_sysctllog);
		cpu_freq_sysctllog = NULL;
	}

	if (native_cpu_freq_init != NULL)
		(*native_cpu_freq_init)(cpu_vendor);

	return 0;
}

static int
acpicpu_md_pstate_sysctl_get(SYSCTLFN_ARGS)
{
	struct cpu_info *ci = curcpu();
	struct acpicpu_softc *sc;
	struct sysctlnode node;
	uint32_t freq;
	int err;

	/*
	 * We can use any ACPI CPU to manipulate the
	 * frequencies. In MP environments all CPUs
	 * are mandated to support the same number of
	 * P-states and each state must have identical
	 * parameters across processors.
	 */
	sc = acpicpu_sc[ci->ci_acpiid];

	if (sc == NULL)
		return ENXIO;

	err = acpicpu_pstate_get(sc, &freq);

	if (err != 0)
		return err;

	node = *rnode;
	node.sysctl_data = &freq;

	err = sysctl_lookup(SYSCTLFN_CALL(&node));

	if (err != 0 || newp == NULL)
		return err;

	return 0;
}

static int
acpicpu_md_pstate_sysctl_set(SYSCTLFN_ARGS)
{
	struct cpu_info *ci = curcpu();
	struct acpicpu_softc *sc;
	struct sysctlnode node;
	uint32_t freq;
	int err;

	sc = acpicpu_sc[ci->ci_acpiid];

	if (sc == NULL)
		return ENXIO;

	err = acpicpu_pstate_get(sc, &freq);

	if (err != 0)
		return err;

	node = *rnode;
	node.sysctl_data = &freq;

	err = sysctl_lookup(SYSCTLFN_CALL(&node));

	if (err != 0 || newp == NULL)
		return err;

	err = acpicpu_pstate_set(sc, freq);

	if (err != 0)
		return err;

	return 0;
}

static int
acpicpu_md_pstate_sysctl_all(SYSCTLFN_ARGS)
{
	struct cpu_info *ci = curcpu();
	struct acpicpu_softc *sc;
	struct sysctlnode node;
	char buf[1024];
	size_t len;
	uint32_t i;
	int err;

	sc = acpicpu_sc[ci->ci_acpiid];

	if (sc == NULL)
		return ENXIO;

	(void)memset(&buf, 0, sizeof(buf));

	mutex_enter(&sc->sc_mtx);

	for (len = 0, i = sc->sc_pstate_max; i < sc->sc_pstate_count; i++) {

		if (sc->sc_pstate[i].ps_freq == 0)
			continue;

		len += snprintf(buf + len, sizeof(buf) - len, "%u%s",
		    sc->sc_pstate[i].ps_freq,
		    i < (sc->sc_pstate_count - 1) ? " " : "");
	}

	mutex_exit(&sc->sc_mtx);

	node = *rnode;
	node.sysctl_data = buf;

	err = sysctl_lookup(SYSCTLFN_CALL(&node));

	if (err != 0 || newp == NULL)
		return err;

	return 0;
}

int
acpicpu_md_pstate_get(struct acpicpu_softc *sc, uint32_t *freq)
{
	struct acpicpu_pstate *ps;
	uint64_t val;
	uint32_t i;

	switch (cpu_vendor) {

	case CPUVENDOR_INTEL:

		val = rdmsr(MSR_PERF_STATUS);
		val = val & 0xffff;

		mutex_enter(&sc->sc_mtx);

		for (i = 0; i < sc->sc_pstate_count; i++) {

			ps = &sc->sc_pstate[i];

			if (ps->ps_freq == 0)
				continue;

			if (val == ps->ps_status) {
				mutex_exit(&sc->sc_mtx);
				*freq = ps->ps_freq;
				return 0;
			}
		}

		mutex_exit(&sc->sc_mtx);

		return EIO;

	default:
		return ENODEV;
	}

	return 0;
}

int
acpicpu_md_pstate_set(struct acpicpu_pstate *ps)
{
	struct msr_rw_info msr;
	uint64_t xc, val;
	int i;

	switch (cpu_vendor) {

	case CPUVENDOR_INTEL:
		msr.msr_read  = true;
		msr.msr_type  = MSR_PERF_CTL;
		msr.msr_value = ps->ps_control;
		msr.msr_mask  = 0xffffULL;
		break;

	default:
		return ENODEV;
	}

	xc = xc_broadcast(0, (xcfunc_t)x86_msr_xcall, &msr, NULL);
	xc_wait(xc);

	for (i = val = 0; i < ACPICPU_P_STATE_RETRY; i++) {

		val = rdmsr(MSR_PERF_STATUS);
		val = val & 0xffff;

		if (val == ps->ps_status)
			return 0;

		DELAY(ps->ps_latency);
	}

	return EAGAIN;
}