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processor_idle.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* processor_idle - idle state submodule to the ACPI processor driver
*
* Copyright (C) 2001, 2002 Andy Grover <[email protected]>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
* Copyright (C) 2004, 2005 Dominik Brodowski <[email protected]>
* Copyright (C) 2004 Anil S Keshavamurthy <[email protected]>
* - Added processor hotplug support
* Copyright (C) 2005 Venkatesh Pallipadi <[email protected]>
* - Added support for C3 on SMP
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/sched.h> /* need_resched() */
#include <linux/tick.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
#include <acpi/processor.h>
/*
* Include the apic definitions for x86 to have the APIC timer related defines
* available also for UP (on SMP it gets magically included via linux/smp.h).
* asm/acpi.h is not an option, as it would require more include magic. Also
* creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
*/
#ifdef CONFIG_X86
#include <asm/apic.h>
#endif
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_idle");
#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
module_param(max_cstate, uint, 0000);
static unsigned int nocst __read_mostly;
module_param(nocst, uint, 0000);
static int bm_check_disable __read_mostly;
module_param(bm_check_disable, uint, 0000);
static unsigned int latency_factor __read_mostly = 2;
module_param(latency_factor, uint, 0644);
static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
struct cpuidle_driver acpi_idle_driver = {
.name = "acpi_idle",
.owner = THIS_MODULE,
};
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
static
DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
static int disabled_by_idle_boot_param(void)
{
return boot_option_idle_override == IDLE_POLL ||
boot_option_idle_override == IDLE_HALT;
}
/*
* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
* For now disable this. Probably a bug somewhere else.
*
* To skip this limit, boot/load with a large max_cstate limit.
*/
static int set_max_cstate(const struct dmi_system_id *id)
{
if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
return 0;
pr_notice("%s detected - limiting to C%ld max_cstate."
" Override with \"processor.max_cstate=%d\"\n", id->ident,
(long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
max_cstate = (long)id->driver_data;
return 0;
}
static const struct dmi_system_id processor_power_dmi_table[] = {
{ set_max_cstate, "Clevo 5600D", {
DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
(void *)2},
{ set_max_cstate, "Pavilion zv5000", {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
(void *)1},
{ set_max_cstate, "Asus L8400B", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
(void *)1},
{},
};
/*
* Callers should disable interrupts before the call and enable
* interrupts after return.
*/
static void __cpuidle acpi_safe_halt(void)
{
if (!tif_need_resched()) {
safe_halt();
local_irq_disable();
}
}
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/*
* Some BIOS implementations switch to C3 in the published C2 state.
* This seems to be a common problem on AMD boxen, but other vendors
* are affected too. We pick the most conservative approach: we assume
* that the local APIC stops in both C2 and C3.
*/
static void lapic_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
struct acpi_processor_power *pwr = &pr->power;
u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
return;
if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
type = ACPI_STATE_C1;
/*
* Check, if one of the previous states already marked the lapic
* unstable
*/
if (pwr->timer_broadcast_on_state < state)
return;
if (cx->type >= type)
pr->power.timer_broadcast_on_state = state;
}
static void __lapic_timer_propagate_broadcast(void *arg)
{
struct acpi_processor *pr = (struct acpi_processor *) arg;
if (pr->power.timer_broadcast_on_state < INT_MAX)
tick_broadcast_enable();
else
tick_broadcast_disable();
}
static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
{
smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
(void *)pr, 1);
}
/* Power(C) State timer broadcast control */
static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
}
#else
static void lapic_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cstate) { }
static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
return false;
}
#endif
#if defined(CONFIG_X86)
static void tsc_check_state(int state)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
case X86_VENDOR_INTEL:
case X86_VENDOR_CENTAUR:
case X86_VENDOR_ZHAOXIN:
/*
* AMD Fam10h TSC will tick in all
* C/P/S0/S1 states when this bit is set.
*/
if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
return;
fallthrough;
default:
/* TSC could halt in idle, so notify users */
if (state > ACPI_STATE_C1)
mark_tsc_unstable("TSC halts in idle");
}
}
#else
static void tsc_check_state(int state) { return; }
#endif
static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
{
if (!pr->pblk)
return -ENODEV;
/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
#ifndef CONFIG_HOTPLUG_CPU
/*
* Check for P_LVL2_UP flag before entering C2 and above on
* an SMP system.
*/
if ((num_online_cpus() > 1) &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
return -ENODEV;
#endif
/* determine C2 and C3 address from pblk */
pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
/* determine latencies from FADT */
pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
/*
* FADT specified C2 latency must be less than or equal to
* 100 microseconds.
*/
if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
/* invalidate C2 */
pr->power.states[ACPI_STATE_C2].address = 0;
}
/*
* FADT supplied C3 latency must be less than or equal to
* 1000 microseconds.
*/
if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
/* invalidate C3 */
pr->power.states[ACPI_STATE_C3].address = 0;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"lvl2[0x%08x] lvl3[0x%08x]\n",
pr->power.states[ACPI_STATE_C2].address,
pr->power.states[ACPI_STATE_C3].address));
snprintf(pr->power.states[ACPI_STATE_C2].desc,
ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
pr->power.states[ACPI_STATE_C2].address);
snprintf(pr->power.states[ACPI_STATE_C3].desc,
ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
pr->power.states[ACPI_STATE_C3].address);
return 0;
}
static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
{
if (!pr->power.states[ACPI_STATE_C1].valid) {
/* set the first C-State to C1 */
/* all processors need to support C1 */
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
pr->power.states[ACPI_STATE_C1].valid = 1;
pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
snprintf(pr->power.states[ACPI_STATE_C1].desc,
ACPI_CX_DESC_LEN, "ACPI HLT");
}
/* the C0 state only exists as a filler in our array */
pr->power.states[ACPI_STATE_C0].valid = 1;
return 0;
}
static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
{
int ret;
if (nocst)
return -ENODEV;
ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
if (ret)
return ret;
if (!pr->power.count)
return -EFAULT;
pr->flags.has_cst = 1;
return 0;
}
static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
static int bm_check_flag = -1;
static int bm_control_flag = -1;
if (!cx->address)
return;
/*
* PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
* DMA transfers are used by any ISA device to avoid livelock.
* Note that we could disable Type-F DMA (as recommended by
* the erratum), but this is known to disrupt certain ISA
* devices thus we take the conservative approach.
*/
else if (errata.piix4.fdma) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 not supported on PIIX4 with Type-F DMA\n"));
return;
}
/* All the logic here assumes flags.bm_check is same across all CPUs */
if (bm_check_flag == -1) {
/* Determine whether bm_check is needed based on CPU */
acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
bm_check_flag = pr->flags.bm_check;
bm_control_flag = pr->flags.bm_control;
} else {
pr->flags.bm_check = bm_check_flag;
pr->flags.bm_control = bm_control_flag;
}
if (pr->flags.bm_check) {
if (!pr->flags.bm_control) {
if (pr->flags.has_cst != 1) {
/* bus mastering control is necessary */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 support requires BM control\n"));
return;
} else {
/* Here we enter C3 without bus mastering */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 support without BM control\n"));
}
}
} else {
/*
* WBINVD should be set in fadt, for C3 state to be
* supported on when bm_check is not required.
*/
if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Cache invalidation should work properly"
" for C3 to be enabled on SMP systems\n"));
return;
}
}
/*
* Otherwise we've met all of our C3 requirements.
* Normalize the C3 latency to expidite policy. Enable
* checking of bus mastering status (bm_check) so we can
* use this in our C3 policy
*/
cx->valid = 1;
/*
* On older chipsets, BM_RLD needs to be set
* in order for Bus Master activity to wake the
* system from C3. Newer chipsets handle DMA
* during C3 automatically and BM_RLD is a NOP.
* In either case, the proper way to
* handle BM_RLD is to set it and leave it set.
*/
acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
return;
}
static int acpi_processor_power_verify(struct acpi_processor *pr)
{
unsigned int i;
unsigned int working = 0;
pr->power.timer_broadcast_on_state = INT_MAX;
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
struct acpi_processor_cx *cx = &pr->power.states[i];
switch (cx->type) {
case ACPI_STATE_C1:
cx->valid = 1;
break;
case ACPI_STATE_C2:
if (!cx->address)
break;
cx->valid = 1;
break;
case ACPI_STATE_C3:
acpi_processor_power_verify_c3(pr, cx);
break;
}
if (!cx->valid)
continue;
lapic_timer_check_state(i, pr, cx);
tsc_check_state(cx->type);
working++;
}
lapic_timer_propagate_broadcast(pr);
return (working);
}
static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
{
unsigned int i;
int result;
/* NOTE: the idle thread may not be running while calling
* this function */
/* Zero initialize all the C-states info. */
memset(pr->power.states, 0, sizeof(pr->power.states));
result = acpi_processor_get_power_info_cst(pr);
if (result == -ENODEV)
result = acpi_processor_get_power_info_fadt(pr);
if (result)
return result;
acpi_processor_get_power_info_default(pr);
pr->power.count = acpi_processor_power_verify(pr);
/*
* if one state of type C2 or C3 is available, mark this
* CPU as being "idle manageable"
*/
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
if (pr->power.states[i].valid) {
pr->power.count = i;
pr->flags.power = 1;
}
}
return 0;
}
/**
* acpi_idle_bm_check - checks if bus master activity was detected
*/
static int acpi_idle_bm_check(void)
{
u32 bm_status = 0;
if (bm_check_disable)
return 0;
acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
if (bm_status)
acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
/*
* PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
* the true state of bus mastering activity; forcing us to
* manually check the BMIDEA bit of each IDE channel.
*/
else if (errata.piix4.bmisx) {
if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
|| (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
bm_status = 1;
}
return bm_status;
}
static void wait_for_freeze(void)
{
#ifdef CONFIG_X86
/* No delay is needed if we are in guest */
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return;
#endif
/* Dummy wait op - must do something useless after P_LVL2 read
because chipsets cannot guarantee that STPCLK# signal
gets asserted in time to freeze execution properly. */
inl(acpi_gbl_FADT.xpm_timer_block.address);
}
/**
* acpi_idle_do_entry - enter idle state using the appropriate method
* @cx: cstate data
*
* Caller disables interrupt before call and enables interrupt after return.
*/
static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
} else if (cx->entry_method == ACPI_CSTATE_HALT) {
acpi_safe_halt();
} else {
/* IO port based C-state */
inb(cx->address);
wait_for_freeze();
}
}
/**
* acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
* @dev: the target CPU
* @index: the index of suggested state
*/
static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
{
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
ACPI_FLUSH_CPU_CACHE();
while (1) {
if (cx->entry_method == ACPI_CSTATE_HALT)
safe_halt();
else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
inb(cx->address);
wait_for_freeze();
} else
return -ENODEV;
}
/* Never reached */
return 0;
}
static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
{
return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
}
static int c3_cpu_count;
static DEFINE_RAW_SPINLOCK(c3_lock);
/**
* acpi_idle_enter_bm - enters C3 with proper BM handling
* @drv: cpuidle driver
* @pr: Target processor
* @cx: Target state context
* @index: index of target state
*/
static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
struct acpi_processor *pr,
struct acpi_processor_cx *cx,
int index)
{
static struct acpi_processor_cx safe_cx = {
.entry_method = ACPI_CSTATE_HALT,
};
/*
* disable bus master
* bm_check implies we need ARB_DIS
* bm_control implies whether we can do ARB_DIS
*
* That leaves a case where bm_check is set and bm_control is not set.
* In that case we cannot do much, we enter C3 without doing anything.
*/
bool dis_bm = pr->flags.bm_control;
/* If we can skip BM, demote to a safe state. */
if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
dis_bm = false;
index = drv->safe_state_index;
if (index >= 0) {
cx = this_cpu_read(acpi_cstate[index]);
} else {
cx = &safe_cx;
index = -EBUSY;
}
}
if (dis_bm) {
raw_spin_lock(&c3_lock);
c3_cpu_count++;
/* Disable bus master arbitration when all CPUs are in C3 */
if (c3_cpu_count == num_online_cpus())
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
raw_spin_unlock(&c3_lock);
}
rcu_idle_enter();
acpi_idle_do_entry(cx);
rcu_idle_exit();
/* Re-enable bus master arbitration */
if (dis_bm) {
raw_spin_lock(&c3_lock);
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
c3_cpu_count--;
raw_spin_unlock(&c3_lock);
}
return index;
}
static int acpi_idle_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
struct acpi_processor *pr;
pr = __this_cpu_read(processors);
if (unlikely(!pr))
return -EINVAL;
if (cx->type != ACPI_STATE_C1) {
if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
return acpi_idle_enter_bm(drv, pr, cx, index);
/* C2 to C1 demotion. */
if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
index = ACPI_IDLE_STATE_START;
cx = per_cpu(acpi_cstate[index], dev->cpu);
}
}
if (cx->type == ACPI_STATE_C3)
ACPI_FLUSH_CPU_CACHE();
acpi_idle_do_entry(cx);
return index;
}
static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
if (cx->type == ACPI_STATE_C3) {
struct acpi_processor *pr = __this_cpu_read(processors);
if (unlikely(!pr))
return 0;
if (pr->flags.bm_check) {
u8 bm_sts_skip = cx->bm_sts_skip;
/* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
cx->bm_sts_skip = 1;
acpi_idle_enter_bm(drv, pr, cx, index);
cx->bm_sts_skip = bm_sts_skip;
return 0;
} else {
ACPI_FLUSH_CPU_CACHE();
}
}
acpi_idle_do_entry(cx);
return 0;
}
static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
struct cpuidle_device *dev)
{
int i, count = ACPI_IDLE_STATE_START;
struct acpi_processor_cx *cx;
struct cpuidle_state *state;
if (max_cstate == 0)
max_cstate = 1;
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
state = &acpi_idle_driver.states[count];
cx = &pr->power.states[i];
if (!cx->valid)
continue;
per_cpu(acpi_cstate[count], dev->cpu) = cx;
if (lapic_timer_needs_broadcast(pr, cx))
state->flags |= CPUIDLE_FLAG_TIMER_STOP;
if (cx->type == ACPI_STATE_C3) {
state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
if (pr->flags.bm_check)
state->flags |= CPUIDLE_FLAG_RCU_IDLE;
}
count++;
if (count == CPUIDLE_STATE_MAX)
break;
}
if (!count)
return -EINVAL;
return 0;
}
static int acpi_processor_setup_cstates(struct acpi_processor *pr)
{
int i, count;
struct acpi_processor_cx *cx;
struct cpuidle_state *state;
struct cpuidle_driver *drv = &acpi_idle_driver;
if (max_cstate == 0)
max_cstate = 1;
if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
cpuidle_poll_state_init(drv);
count = 1;
} else {
count = 0;
}
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
cx = &pr->power.states[i];
if (!cx->valid)
continue;
state = &drv->states[count];
snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
state->exit_latency = cx->latency;
state->target_residency = cx->latency * latency_factor;
state->enter = acpi_idle_enter;
state->flags = 0;
if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
state->enter_dead = acpi_idle_play_dead;
drv->safe_state_index = count;
}
/*
* Halt-induced C1 is not good for ->enter_s2idle, because it
* re-enables interrupts on exit. Moreover, C1 is generally not
* particularly interesting from the suspend-to-idle angle, so
* avoid C1 and the situations in which we may need to fall back
* to it altogether.
*/
if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
state->enter_s2idle = acpi_idle_enter_s2idle;
count++;
if (count == CPUIDLE_STATE_MAX)
break;
}
drv->state_count = count;
if (!count)
return -EINVAL;
return 0;
}
static inline void acpi_processor_cstate_first_run_checks(void)
{
static int first_run;
if (first_run)
return;
dmi_check_system(processor_power_dmi_table);
max_cstate = acpi_processor_cstate_check(max_cstate);
if (max_cstate < ACPI_C_STATES_MAX)
pr_notice("ACPI: processor limited to max C-state %d\n",
max_cstate);
first_run++;
if (nocst)
return;
acpi_processor_claim_cst_control();
}
#else
static inline int disabled_by_idle_boot_param(void) { return 0; }
static inline void acpi_processor_cstate_first_run_checks(void) { }
static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
{
return -ENODEV;
}
static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
struct cpuidle_device *dev)
{
return -EINVAL;
}
static int acpi_processor_setup_cstates(struct acpi_processor *pr)
{
return -EINVAL;
}
#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
struct acpi_lpi_states_array {
unsigned int size;
unsigned int composite_states_size;
struct acpi_lpi_state *entries;
struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
};
static int obj_get_integer(union acpi_object *obj, u32 *value)
{
if (obj->type != ACPI_TYPE_INTEGER)
return -EINVAL;
*value = obj->integer.value;
return 0;
}
static int acpi_processor_evaluate_lpi(acpi_handle handle,
struct acpi_lpi_states_array *info)
{
acpi_status status;
int ret = 0;
int pkg_count, state_idx = 1, loop;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *lpi_data;
struct acpi_lpi_state *lpi_state;
status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
return -ENODEV;
}
lpi_data = buffer.pointer;
/* There must be at least 4 elements = 3 elements + 1 package */
if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
lpi_data->package.count < 4) {
pr_debug("not enough elements in _LPI\n");
ret = -ENODATA;
goto end;
}
pkg_count = lpi_data->package.elements[2].integer.value;
/* Validate number of power states. */
if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
pr_debug("count given by _LPI is not valid\n");
ret = -ENODATA;
goto end;
}
lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
if (!lpi_state) {
ret = -ENOMEM;
goto end;
}
info->size = pkg_count;
info->entries = lpi_state;
/* LPI States start at index 3 */
for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
union acpi_object *element, *pkg_elem, *obj;
element = &lpi_data->package.elements[loop];
if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
continue;
pkg_elem = element->package.elements;
obj = pkg_elem + 6;
if (obj->type == ACPI_TYPE_BUFFER) {
struct acpi_power_register *reg;
reg = (struct acpi_power_register *)obj->buffer.pointer;
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
continue;
lpi_state->address = reg->address;
lpi_state->entry_method =
reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
} else if (obj->type == ACPI_TYPE_INTEGER) {
lpi_state->entry_method = ACPI_CSTATE_INTEGER;
lpi_state->address = obj->integer.value;
} else {
continue;
}
/* elements[7,8] skipped for now i.e. Residency/Usage counter*/
obj = pkg_elem + 9;
if (obj->type == ACPI_TYPE_STRING)
strlcpy(lpi_state->desc, obj->string.pointer,
ACPI_CX_DESC_LEN);
lpi_state->index = state_idx;
if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
pr_debug("No min. residency found, assuming 10 us\n");
lpi_state->min_residency = 10;
}
if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
pr_debug("No wakeup residency found, assuming 10 us\n");
lpi_state->wake_latency = 10;
}
if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
lpi_state->flags = 0;
if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
lpi_state->arch_flags = 0;
if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
lpi_state->res_cnt_freq = 1;
if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
lpi_state->enable_parent_state = 0;
}
acpi_handle_debug(handle, "Found %d power states\n", state_idx);
end:
kfree(buffer.pointer);
return ret;
}
/*
* flat_state_cnt - the number of composite LPI states after the process of flattening
*/
static int flat_state_cnt;
/**
* combine_lpi_states - combine local and parent LPI states to form a composite LPI state
*
* @local: local LPI state
* @parent: parent LPI state
* @result: composite LPI state
*/
static bool combine_lpi_states(struct acpi_lpi_state *local,
struct acpi_lpi_state *parent,
struct acpi_lpi_state *result)
{
if (parent->entry_method == ACPI_CSTATE_INTEGER) {
if (!parent->address) /* 0 means autopromotable */
return false;
result->address = local->address + parent->address;
} else {
result->address = parent->address;
}
result->min_residency = max(local->min_residency, parent->min_residency);
result->wake_latency = local->wake_latency + parent->wake_latency;
result->enable_parent_state = parent->enable_parent_state;
result->entry_method = local->entry_method;
result->flags = parent->flags;
result->arch_flags = parent->arch_flags;
result->index = parent->index;
strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
return true;
}
#define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0)
static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
struct acpi_lpi_state *t)
{
curr_level->composite_states[curr_level->composite_states_size++] = t;
}
static int flatten_lpi_states(struct acpi_processor *pr,
struct acpi_lpi_states_array *curr_level,
struct acpi_lpi_states_array *prev_level)
{
int i, j, state_count = curr_level->size;
struct acpi_lpi_state *p, *t = curr_level->entries;
curr_level->composite_states_size = 0;
for (j = 0; j < state_count; j++, t++) {