path: root/src/soc/intel/skylake/acpi.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2009 coresystems GmbH
 * Copyright (C) 2014 Google Inc.
 * Copyright (C) 2015 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <arch/acpi.h>
#include <arch/acpigen.h>
#include <arch/cpu.h>
#include <arch/io.h>
#include <arch/ioapic.h>
#include <arch/smp/mpspec.h>
#include <cbmem.h>
#include <chip.h>
#include <console/console.h>
#include <cpu/cpu.h>
#include <cpu/x86/smm.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/tsc.h>
#include <cpu/intel/turbo.h>
#include <ec/google/chromeec/ec.h>
#include <soc/intel/common/acpi.h>
#include <soc/acpi.h>
#include <soc/cpu.h>
#include <soc/iomap.h>
#include <soc/lpc.h>
#include <soc/msr.h>
#include <soc/pci_devs.h>
#include <soc/pm.h>
#include <soc/ramstage.h>
#include <string.h>
#include <types.h>
#include <vendorcode/google/chromeos/gnvs.h>
#include <wrdd.h>

/*
 * List of suported C-states in this processor.
 */
enum {
	C_STATE_C0,		/* 0 */
	C_STATE_C1,		/* 1 */
	C_STATE_C1E,		/* 2 */
	C_STATE_C3,		/* 3 */
	C_STATE_C6_SHORT_LAT,	/* 4 */
	C_STATE_C6_LONG_LAT,	/* 5 */
	C_STATE_C7_SHORT_LAT,	/* 6 */
	C_STATE_C7_LONG_LAT,	/* 7 */
	C_STATE_C7S_SHORT_LAT,	/* 8 */
	C_STATE_C7S_LONG_LAT,	/* 9 */
	C_STATE_C8,		/* 10 */
	C_STATE_C9,		/* 11 */
	C_STATE_C10,		/* 12 */
	NUM_C_STATES
};
#define MWAIT_RES(state, sub_state)				\
	{							\
		.addrl = (((state) << 4) | (sub_state)),	\
		.space_id = ACPI_ADDRESS_SPACE_FIXED,		\
		.bit_width = ACPI_FFIXEDHW_VENDOR_INTEL,	\
		.bit_offset = ACPI_FFIXEDHW_CLASS_MWAIT,	\
		.access_size = ACPI_FFIXEDHW_FLAG_HW_COORD,	\
	}

static acpi_cstate_t cstate_map[NUM_C_STATES] = {
	[C_STATE_C0] = { },
	[C_STATE_C1] = {
		.latency = 0,
		.power = C1_POWER,
		.resource = MWAIT_RES(0, 0),
	},
	[C_STATE_C1E] = {
		.latency = 0,
		.power = C1_POWER,
		.resource = MWAIT_RES(0, 1),
	},
	[C_STATE_C3] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(0),
		.power = C3_POWER,
		.resource = MWAIT_RES(1, 0),
	},
	[C_STATE_C6_SHORT_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(1),
		.power = C6_POWER,
		.resource = MWAIT_RES(2, 0),
	},
	[C_STATE_C6_LONG_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(2),
		.power = C6_POWER,
		.resource = MWAIT_RES(2, 1),
	},
	[C_STATE_C7_SHORT_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(1),
		.power = C7_POWER,
		.resource = MWAIT_RES(3, 0),
	},
	[C_STATE_C7_LONG_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(2),
		.power = C7_POWER,
		.resource = MWAIT_RES(3, 1),
	},
	[C_STATE_C7S_SHORT_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(1),
		.power = C7_POWER,
		.resource = MWAIT_RES(3, 2),
	},
	[C_STATE_C7S_LONG_LAT] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(2),
		.power = C7_POWER,
		.resource = MWAIT_RES(3, 3),
	},
	[C_STATE_C8] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(3),
		.power = C8_POWER,
		.resource = MWAIT_RES(4, 0),
	},
	[C_STATE_C9] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(4),
		.power = C9_POWER,
		.resource = MWAIT_RES(5, 0),
	},
	[C_STATE_C10] = {
		.latency = C_STATE_LATENCY_FROM_LAT_REG(5),
		.power = C10_POWER,
		.resource = MWAIT_RES(6, 0),
	},
};

static int cstate_set_s0ix[] = {
	C_STATE_C1E,
	C_STATE_C7S_LONG_LAT,
	C_STATE_C10
};

static int cstate_set_non_s0ix[] = {
	C_STATE_C1E,
	C_STATE_C3,
	C_STATE_C7S_LONG_LAT,
};

static int get_cores_per_package(void)
{
	struct cpuinfo_x86 c;
	struct cpuid_result result;
	int cores = 1;

	get_fms(&c, cpuid_eax(1));
	if (c.x86 != 6)
		return 1;

	result = cpuid_ext(0xb, 1);
	cores = result.ebx & 0xff;

	return cores;
}

static void acpi_create_gnvs(global_nvs_t *gnvs)
{
	const struct device *dev = dev_find_slot(0, PCH_DEVFN_LPC);
	const struct soc_intel_skylake_config *config = dev->chip_info;

	/* Set unknown wake source */
	gnvs->pm1i = -1;

	/* CPU core count */
	gnvs->pcnt = dev_count_cpu();

#if IS_ENABLED(CONFIG_CONSOLE_CBMEM)
	/* Update the mem console pointer. */
	gnvs->cbmc = (u32)cbmem_find(CBMEM_ID_CONSOLE);
#endif

#if IS_ENABLED(CONFIG_CHROMEOS)
	/* Initialize Verified Boot data */
	chromeos_init_vboot(&(gnvs->chromeos));
#if IS_ENABLED(CONFIG_EC_GOOGLE_CHROMEEC)
	gnvs->chromeos.vbt2 = google_ec_running_ro() ?
		ACTIVE_ECFW_RO : ACTIVE_ECFW_RW;
#endif
	gnvs->chromeos.vbt2 = ACTIVE_ECFW_RO;
#endif

	/* Enable DPTF based on mainboard configuration */
	gnvs->dpte = config->dptf_enable;

	/* Fill in the Wifi Region id */
	gnvs->cid1 = wifi_regulatory_domain();

	/* Set USB2/USB3 wake enable bitmaps. */
	gnvs->u2we = config->usb2_wake_enable_bitmap;
	gnvs->u3we = config->usb3_wake_enable_bitmap;
}

unsigned long acpi_fill_mcfg(unsigned long current)
{
	current += acpi_create_mcfg_mmconfig((acpi_mcfg_mmconfig_t *)current,
					     MCFG_BASE_ADDRESS, 0, 0, 255);
	return current;
}

unsigned long acpi_fill_madt(unsigned long current)
{
	/* Local APICs */
	current = acpi_create_madt_lapics(current);

	/* IOAPIC */
	current += acpi_create_madt_ioapic((acpi_madt_ioapic_t *) current,
				2, IO_APIC_ADDR, 0);

	return acpi_madt_irq_overrides(current);
}

void acpi_fill_fadt(acpi_fadt_t *fadt)
{
	const uint16_t pmbase = ACPI_BASE_ADDRESS;
	const struct device *dev = dev_find_slot(0, PCH_DEVFN_LPC);
	config_t *config = dev->chip_info;

	/* Use ACPI 3.0 revision */
	fadt->header.revision = ACPI_FADT_REV_ACPI_3_0;

	fadt->sci_int = acpi_sci_irq();
	fadt->smi_cmd = APM_CNT;
	fadt->acpi_enable = APM_CNT_ACPI_ENABLE;
	fadt->acpi_disable = APM_CNT_ACPI_DISABLE;
	fadt->s4bios_req = 0x0;
	fadt->pstate_cnt = 0;

	fadt->pm1a_evt_blk = pmbase + PM1_STS;
	fadt->pm1b_evt_blk = 0x0;
	fadt->pm1a_cnt_blk = pmbase + PM1_CNT;
	fadt->pm1b_cnt_blk = 0x0;
	fadt->pm2_cnt_blk = pmbase + PM2_CNT;
	if (config->PmTimerDisabled == 0)
		fadt->pm_tmr_blk = pmbase + PM1_TMR;
	fadt->gpe0_blk = pmbase + GPE0_STS(0);
	fadt->gpe1_blk = 0;

	fadt->pm1_evt_len = 4;
	fadt->pm1_cnt_len = 2;
	fadt->pm2_cnt_len = 1;
	if (config->PmTimerDisabled == 0)
		fadt->pm_tmr_len = 4;
	/* There are 4 GPE0 STS/EN pairs each 32 bits wide. */
	fadt->gpe0_blk_len = 2 * GPE0_REG_MAX * sizeof(uint32_t);
	fadt->gpe1_blk_len = 0;
	fadt->gpe1_base = 0;
	fadt->cst_cnt = 0;
	fadt->p_lvl2_lat = 1;
	fadt->p_lvl3_lat = 87;
	fadt->flush_size = 1024;
	fadt->flush_stride = 16;
	fadt->duty_offset = 1;
	fadt->duty_width = 0;
	fadt->day_alrm = 0xd;
	fadt->mon_alrm = 0x00;
	fadt->century = 0x00;
	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES;
	if (!IS_ENABLED(CONFIG_NO_FADT_8042))
		fadt->iapc_boot_arch |= ACPI_FADT_8042;

	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;

	fadt->reset_reg.space_id = 1;
	fadt->reset_reg.bit_width = 8;
	fadt->reset_reg.bit_offset = 0;
	fadt->reset_reg.resv = 0;
	fadt->reset_reg.addrl = 0xcf9;
	fadt->reset_reg.addrh = 0;
	fadt->reset_value = 6;

	fadt->x_pm1a_evt_blk.space_id = 1;
	fadt->x_pm1a_evt_blk.bit_width = fadt->pm1_evt_len * 8;
	fadt->x_pm1a_evt_blk.bit_offset = 0;
	fadt->x_pm1a_evt_blk.resv = 0;
	fadt->x_pm1a_evt_blk.addrl = pmbase + PM1_STS;
	fadt->x_pm1a_evt_blk.addrh = 0x0;

	fadt->x_pm1b_evt_blk.space_id = 1;
	fadt->x_pm1b_evt_blk.bit_width = 0;
	fadt->x_pm1b_evt_blk.bit_offset = 0;
	fadt->x_pm1b_evt_blk.resv = 0;
	fadt->x_pm1b_evt_blk.addrl = 0x0;
	fadt->x_pm1b_evt_blk.addrh = 0x0;

	fadt->x_pm1a_cnt_blk.space_id = 1;
	fadt->x_pm1a_cnt_blk.bit_width = fadt->pm1_cnt_len * 8;
	fadt->x_pm1a_cnt_blk.bit_offset = 0;
	fadt->x_pm1a_cnt_blk.resv = 0;
	fadt->x_pm1a_cnt_blk.addrl = pmbase + PM1_CNT;
	fadt->x_pm1a_cnt_blk.addrh = 0x0;

	fadt->x_pm1b_cnt_blk.space_id = 1;
	fadt->x_pm1b_cnt_blk.bit_width = 0;
	fadt->x_pm1b_cnt_blk.bit_offset = 0;
	fadt->x_pm1b_cnt_blk.resv = 0;
	fadt->x_pm1b_cnt_blk.addrl = 0x0;
	fadt->x_pm1b_cnt_blk.addrh = 0x0;

	fadt->x_pm2_cnt_blk.space_id = 1;
	fadt->x_pm2_cnt_blk.bit_width = fadt->pm2_cnt_len * 8;
	fadt->x_pm2_cnt_blk.bit_offset = 0;
	fadt->x_pm2_cnt_blk.resv = 0;
	fadt->x_pm2_cnt_blk.addrl = pmbase + PM2_CNT;
	fadt->x_pm2_cnt_blk.addrh = 0x0;

	if (config->PmTimerDisabled == 0) {
		fadt->x_pm_tmr_blk.space_id = 1;
		fadt->x_pm_tmr_blk.bit_width = fadt->pm_tmr_len * 8;
		fadt->x_pm_tmr_blk.bit_offset = 0;
		fadt->x_pm_tmr_blk.resv = 0;
		fadt->x_pm_tmr_blk.addrl = pmbase + PM1_TMR;
		fadt->x_pm_tmr_blk.addrh = 0x0;
	}

	fadt->x_gpe0_blk.space_id = 0;
	fadt->x_gpe0_blk.bit_width = 0;
	fadt->x_gpe0_blk.bit_offset = 0;
	fadt->x_gpe0_blk.resv = 0;
	fadt->x_gpe0_blk.addrl = 0;
	fadt->x_gpe0_blk.addrh = 0;

	fadt->x_gpe1_blk.space_id = 1;
	fadt->x_gpe1_blk.bit_width = 0;
	fadt->x_gpe1_blk.bit_offset = 0;
	fadt->x_gpe1_blk.resv = 0;
	fadt->x_gpe1_blk.addrl = 0x0;
	fadt->x_gpe1_blk.addrh = 0x0;
}

static void generate_c_state_entries(int s0ix_enable, int max_cstate)
{

	acpi_cstate_t map[max_cstate];
	int *set;
	int i;

	if (s0ix_enable)
		set = cstate_set_s0ix;
	else
		set = cstate_set_non_s0ix;

	for (i = 0; i < max_cstate; i++) {
		memcpy(&map[i], &cstate_map[set[i]], sizeof(acpi_cstate_t));
		map[i].ctype = i + 1;
	}

	/* Generate C-state tables */
	acpigen_write_CST_package(map, ARRAY_SIZE(map));
}

static int calculate_power(int tdp, int p1_ratio, int ratio)
{
	u32 m;
	u32 power;

	/*
	 * M = ((1.1 - ((p1_ratio - ratio) * 0.00625)) / 1.1) ^ 2
	 *
	 * Power = (ratio / p1_ratio) * m * tdp
	 */

	m = (110000 - ((p1_ratio - ratio) * 625)) / 11;
	m = (m * m) / 1000;

	power = ((ratio * 100000 / p1_ratio) / 100);
	power *= (m / 100) * (tdp / 1000);
	power /= 1000;

	return (int)power;
}

static void generate_p_state_entries(int core, int cores_per_package)
{
	int ratio_min, ratio_max, ratio_turbo, ratio_step;
	int coord_type, power_max, power_unit, num_entries;
	int ratio, power, clock, clock_max;
	msr_t msr;

	/* Determine P-state coordination type from MISC_PWR_MGMT[0] */
	msr = rdmsr(MSR_MISC_PWR_MGMT);
	if (msr.lo & MISC_PWR_MGMT_EIST_HW_DIS)
		coord_type = SW_ANY;
	else
		coord_type = HW_ALL;

	/* Get bus ratio limits and calculate clock speeds */
	msr = rdmsr(MSR_PLATFORM_INFO);
	ratio_min = (msr.hi >> (40-32)) & 0xff; /* Max Efficiency Ratio */

	/* Determine if this CPU has configurable TDP */
	if (cpu_config_tdp_levels()) {
		/* Set max ratio to nominal TDP ratio */
		msr = rdmsr(MSR_CONFIG_TDP_NOMINAL);
		ratio_max = msr.lo & 0xff;
	} else {
		/* Max Non-Turbo Ratio */
		ratio_max = (msr.lo >> 8) & 0xff;
	}
	clock_max = ratio_max * CPU_BCLK;

	/* Calculate CPU TDP in mW */
	msr = rdmsr(MSR_PKG_POWER_SKU_UNIT);
	power_unit = 2 << ((msr.lo & 0xf) - 1);
	msr = rdmsr(MSR_PKG_POWER_SKU);
	power_max = ((msr.lo & 0x7fff) / power_unit) * 1000;

	/* Write _PCT indicating use of FFixedHW */
	acpigen_write_empty_PCT();

	/* Write _PPC with no limit on supported P-state */
	acpigen_write_PPC_NVS();

	/* Write PSD indicating configured coordination type */
	acpigen_write_PSD_package(core, 1, coord_type);

	/* Add P-state entries in _PSS table */
	acpigen_write_name("_PSS");

	/* Determine ratio points */
	ratio_step = PSS_RATIO_STEP;
	num_entries = ((ratio_max - ratio_min) / ratio_step) + 1;
	if (num_entries > PSS_MAX_ENTRIES) {
		ratio_step += 1;
		num_entries = ((ratio_max - ratio_min) / ratio_step) + 1;
	}

	/* P[T] is Turbo state if enabled */
	if (get_turbo_state() == TURBO_ENABLED) {
		/* _PSS package count including Turbo */
		acpigen_write_package(num_entries + 2);

		msr = rdmsr(MSR_TURBO_RATIO_LIMIT);
		ratio_turbo = msr.lo & 0xff;

		/* Add entry for Turbo ratio */
		acpigen_write_PSS_package(
			clock_max + 1,		/* MHz */
			power_max,		/* mW */
			PSS_LATENCY_TRANSITION,	/* lat1 */
			PSS_LATENCY_BUSMASTER,	/* lat2 */
			ratio_turbo << 8,	/* control */
			ratio_turbo << 8);	/* status */
	} else {
		/* _PSS package count without Turbo */
		acpigen_write_package(num_entries + 1);
	}

	/* First regular entry is max non-turbo ratio */
	acpigen_write_PSS_package(
		clock_max,		/* MHz */
		power_max,		/* mW */
		PSS_LATENCY_TRANSITION,	/* lat1 */
		PSS_LATENCY_BUSMASTER,	/* lat2 */
		ratio_max << 8,		/* control */
		ratio_max << 8);	/* status */

	/* Generate the remaining entries */
	for (ratio = ratio_min + ((num_entries - 1) * ratio_step);
	     ratio >= ratio_min; ratio -= ratio_step) {

		/* Calculate power at this ratio */
		power = calculate_power(power_max, ratio_max, ratio);
		clock = ratio * CPU_BCLK;

		acpigen_write_PSS_package(
			clock,			/* MHz */
			power,			/* mW */
			PSS_LATENCY_TRANSITION,	/* lat1 */
			PSS_LATENCY_BUSMASTER,	/* lat2 */
			ratio << 8,		/* control */
			ratio << 8);		/* status */
	}

	/* Fix package length */
	acpigen_pop_len();
}

void generate_cpu_entries(device_t device)
{
	int core_id, cpu_id, pcontrol_blk = ACPI_BASE_ADDRESS, plen = 6;
	int totalcores = dev_count_cpu();
	int cores_per_package = get_cores_per_package();
	int numcpus = totalcores/cores_per_package;
	device_t dev = SA_DEV_ROOT;
	config_t *config = dev->chip_info;
	int is_s0ix_enable = config->s0ix_enable;
	int max_c_state;

	if (is_s0ix_enable)
		max_c_state = ARRAY_SIZE(cstate_set_s0ix);
	else
		max_c_state = ARRAY_SIZE(cstate_set_non_s0ix);

	printk(BIOS_DEBUG, "Found %d CPU(s) with %d core(s) each.\n",
	       numcpus, cores_per_package);

	for (cpu_id = 0; cpu_id < numcpus; cpu_id++) {
		for (core_id = 0; core_id < cores_per_package; core_id++) {
			if (core_id > 0) {
				pcontrol_blk = 0;
				plen = 0;
			}

			/* Generate processor \_PR.CPUx */
			acpigen_write_processor(
				cpu_id*cores_per_package+core_id,
				pcontrol_blk, plen);
			/* Generate C-state tables */
			generate_c_state_entries(is_s0ix_enable,
				max_c_state);

			if (config->eist_enable)
				/* Generate P-state tables */
				generate_p_state_entries(core_id,
						cores_per_package);

			acpigen_pop_len();
		}
	}
}

unsigned long acpi_madt_irq_overrides(unsigned long current)
{
	int sci = acpi_sci_irq();
	acpi_madt_irqoverride_t *irqovr;
	uint16_t flags = MP_IRQ_TRIGGER_LEVEL;

	/* INT_SRC_OVR */
	irqovr = (void *)current;
	current += acpi_create_madt_irqoverride(irqovr, 0, 0, 2, 0);

	if (sci >= 20)
		flags |= MP_IRQ_POLARITY_LOW;
	else
		flags |= MP_IRQ_POLARITY_HIGH;

	/* SCI */
	irqovr = (void *)current;
	current += acpi_create_madt_irqoverride(irqovr, 0, sci, sci, flags);

	return current;
}

unsigned long southcluster_write_acpi_tables(device_t device,
					     unsigned long current,
					     struct acpi_rsdp *rsdp)
{
	current = acpi_write_hpet(device, current, rsdp);
	return acpi_align_current(current);
}

void southcluster_inject_dsdt(device_t device)
{
	global_nvs_t *gnvs;

	gnvs = cbmem_find(CBMEM_ID_ACPI_GNVS);
	if (!gnvs) {
		gnvs = cbmem_add(CBMEM_ID_ACPI_GNVS, sizeof(*gnvs));
		if (gnvs)
			memset(gnvs, 0, sizeof(*gnvs));
	}

	if (gnvs) {
		acpi_create_gnvs(gnvs);
		acpi_mainboard_gnvs(gnvs);
		acpi_save_gnvs((unsigned long)gnvs);
		/* And tell SMI about it */
		smm_setup_structures(gnvs, NULL, NULL);

		/* Add it to DSDT.  */
		acpigen_write_scope("\\");
		acpigen_write_name_dword("NVSA", (u32) gnvs);
		acpigen_pop_len();
	}
}

/* Save wake source information for calculating ACPI _SWS values */
int soc_fill_acpi_wake(uint32_t *pm1, uint32_t **gpe0)
{
	const struct device *dev = dev_find_slot(0, PCH_DEVFN_LPC);
	const struct soc_intel_skylake_config *config = dev->chip_info;
	struct chipset_power_state *ps;
	static uint32_t gpe0_sts[GPE0_REG_MAX];
	uint32_t pm1_en;
	uint32_t gpe0_std;
	int i;
	const int last_index = GPE0_REG_MAX - 1;

	ps = cbmem_find(CBMEM_ID_POWER_STATE);
	if (ps == NULL)
		return -1;

	pm1_en = ps->pm1_en;
	gpe0_std = ps->gpe0_en[3];

	/*
	 * Chipset state in the suspend well (but not RTC) is lost in Deep S3
	 * so enable Deep S3 wake events that are configured by the mainboard
	 */
	if (ps->prev_sleep_state == ACPI_S3 &&
	    (config->deep_s3_enable_ac || config->deep_s3_enable_dc)) {
		pm1_en |= PWRBTN_STS; /* Always enabled as wake source */
		if (config->deep_sx_config & DSX_EN_LAN_WAKE_PIN)
			gpe0_std |= LAN_WAK_EN;
		if (config->deep_sx_config & DSX_EN_WAKE_PIN)
			pm1_en |= PCIEXPWAK_STS;
	}

	*pm1 = ps->pm1_sts & pm1_en;

	/* Mask off GPE0 status bits that are not enabled */
	*gpe0 = &gpe0_sts[0];
	for (i = 0; i < last_index; i++)
		gpe0_sts[i] = ps->gpe0_sts[i] & ps->gpe0_en[i];
	gpe0_sts[last_index] = ps->gpe0_sts[last_index] & gpe0_std;

	return GPE0_REG_MAX;
}

__attribute__((weak)) void acpi_mainboard_gnvs(global_nvs_t *gnvs)
{
}

const char *soc_acpi_name(struct device *dev)
{
	if (dev->path.type == DEVICE_PATH_DOMAIN)
		return "PCI0";

	if (dev->path.type != DEVICE_PATH_PCI)
		return NULL;

	switch (dev->path.pci.devfn) {
	case SA_DEVFN_ROOT:	return "MCHC";
	case SA_DEVFN_IGD:	return "GFX0";
	case PCH_DEVFN_ISH:	return "ISHB";
	case PCH_DEVFN_XHCI:	return "XHCI";
	case PCH_DEVFN_USBOTG:	return "XDCI";
	case PCH_DEVFN_THERMAL:	return "THRM";
	case PCH_DEVFN_CIO:	return "ICIO";
	case PCH_DEVFN_I2C0:	return "I2C0";
	case PCH_DEVFN_I2C1:	return "I2C1";
	case PCH_DEVFN_I2C2:	return "I2C2";
	case PCH_DEVFN_I2C3:	return "I2C3";
	case PCH_DEVFN_CSE:	return "CSE1";
	case PCH_DEVFN_CSE_2:	return "CSE2";
	case PCH_DEVFN_CSE_IDER:	return "CSED";
	case PCH_DEVFN_CSE_KT:	return "CSKT";
	case PCH_DEVFN_CSE_3:	return "CSE3";
	case PCH_DEVFN_SATA:	return "SATA";
	case PCH_DEVFN_UART2:	return "UAR2";
	case PCH_DEVFN_I2C4:	return "I2C4";
	case PCH_DEVFN_I2C5:	return "I2C5";
	case PCH_DEVFN_PCIE1:	return "RP01";
	case PCH_DEVFN_PCIE2:	return "RP02";
	case PCH_DEVFN_PCIE3:	return "RP03";
	case PCH_DEVFN_PCIE4:	return "RP04";
	case PCH_DEVFN_PCIE5:	return "RP05";
	case PCH_DEVFN_PCIE6:	return "RP06";
	case PCH_DEVFN_PCIE7:	return "RP07";
	case PCH_DEVFN_PCIE8:	return "RP08";
	case PCH_DEVFN_PCIE9:	return "RP09";
	case PCH_DEVFN_PCIE10:	return "RP10";
	case PCH_DEVFN_PCIE11:	return "RP11";
	case PCH_DEVFN_PCIE12:	return "RP12";
	case PCH_DEVFN_UART0:	return "UAR0";
	case PCH_DEVFN_UART1:	return "UAR1";
	case PCH_DEVFN_GSPI0:	return "SPI0";
	case PCH_DEVFN_GSPI1:	return "SPI1";
	case PCH_DEVFN_EMMC:	return "EMMC";
	case PCH_DEVFN_SDIO:	return "SDIO";
	case PCH_DEVFN_SDCARD:	return "SDXC";
	case PCH_DEVFN_LPC:	return "LPCB";
	case PCH_DEVFN_P2SB:	return "P2SB";
	case PCH_DEVFN_PMC:	return "PMC_";
	case PCH_DEVFN_HDA:	return "HDAS";
	case PCH_DEVFN_SMBUS:	return "SBUS";
	case PCH_DEVFN_SPI:	return "FSPI";
	case PCH_DEVFN_GBE:	return "IGBE";
	case PCH_DEVFN_TRACEHUB:return "THUB";
	}

	return NULL;
}