639 lines
16 KiB
C
639 lines
16 KiB
C
/*
|
|
* intel_idle.c - native hardware idle loop for modern Intel processors
|
|
*
|
|
* Copyright (c) 2010, Intel Corporation.
|
|
* Len Brown <len.brown@intel.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with
|
|
* this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
/*
|
|
* intel_idle is a cpuidle driver that loads on specific Intel processors
|
|
* in lieu of the legacy ACPI processor_idle driver. The intent is to
|
|
* make Linux more efficient on these processors, as intel_idle knows
|
|
* more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
|
|
*/
|
|
|
|
/*
|
|
* Design Assumptions
|
|
*
|
|
* All CPUs have same idle states as boot CPU
|
|
*
|
|
* Chipset BM_STS (bus master status) bit is a NOP
|
|
* for preventing entry into deep C-stats
|
|
*/
|
|
|
|
/*
|
|
* Known limitations
|
|
*
|
|
* The driver currently initializes for_each_online_cpu() upon modprobe.
|
|
* It it unaware of subsequent processors hot-added to the system.
|
|
* This means that if you boot with maxcpus=n and later online
|
|
* processors above n, those processors will use C1 only.
|
|
*
|
|
* ACPI has a .suspend hack to turn off deep c-statees during suspend
|
|
* to avoid complications with the lapic timer workaround.
|
|
* Have not seen issues with suspend, but may need same workaround here.
|
|
*
|
|
* There is currently no kernel-based automatic probing/loading mechanism
|
|
* if the driver is built as a module.
|
|
*/
|
|
|
|
/* un-comment DEBUG to enable pr_debug() statements */
|
|
#define DEBUG
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/clockchips.h>
|
|
#include <trace/events/power.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/module.h>
|
|
#include <asm/cpu_device_id.h>
|
|
#include <asm/mwait.h>
|
|
#include <asm/msr.h>
|
|
|
|
#define INTEL_IDLE_VERSION "0.4"
|
|
#define PREFIX "intel_idle: "
|
|
|
|
static struct cpuidle_driver intel_idle_driver = {
|
|
.name = "intel_idle",
|
|
.owner = THIS_MODULE,
|
|
.en_core_tk_irqen = 1,
|
|
};
|
|
/* intel_idle.max_cstate=0 disables driver */
|
|
static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1;
|
|
|
|
static unsigned int mwait_substates;
|
|
|
|
#define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
|
|
/* Reliable LAPIC Timer States, bit 1 for C1 etc. */
|
|
static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
|
|
|
|
struct idle_cpu {
|
|
struct cpuidle_state *state_table;
|
|
|
|
/*
|
|
* Hardware C-state auto-demotion may not always be optimal.
|
|
* Indicate which enable bits to clear here.
|
|
*/
|
|
unsigned long auto_demotion_disable_flags;
|
|
};
|
|
|
|
static const struct idle_cpu *icpu;
|
|
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
|
|
static int intel_idle(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv, int index);
|
|
static int intel_idle_cpu_init(int cpu);
|
|
|
|
static struct cpuidle_state *cpuidle_state_table;
|
|
|
|
/*
|
|
* Set this flag for states where the HW flushes the TLB for us
|
|
* and so we don't need cross-calls to keep it consistent.
|
|
* If this flag is set, SW flushes the TLB, so even if the
|
|
* HW doesn't do the flushing, this flag is safe to use.
|
|
*/
|
|
#define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
|
|
|
|
/*
|
|
* States are indexed by the cstate number,
|
|
* which is also the index into the MWAIT hint array.
|
|
* Thus C0 is a dummy.
|
|
*/
|
|
static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
|
|
{ /* MWAIT C0 */ },
|
|
{ /* MWAIT C1 */
|
|
.name = "C1-NHM",
|
|
.desc = "MWAIT 0x00",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
|
.exit_latency = 3,
|
|
.target_residency = 6,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C2 */
|
|
.name = "C3-NHM",
|
|
.desc = "MWAIT 0x10",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 20,
|
|
.target_residency = 80,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C3 */
|
|
.name = "C6-NHM",
|
|
.desc = "MWAIT 0x20",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 200,
|
|
.target_residency = 800,
|
|
.enter = &intel_idle },
|
|
};
|
|
|
|
static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
|
|
{ /* MWAIT C0 */ },
|
|
{ /* MWAIT C1 */
|
|
.name = "C1-SNB",
|
|
.desc = "MWAIT 0x00",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
|
.exit_latency = 1,
|
|
.target_residency = 1,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C2 */
|
|
.name = "C3-SNB",
|
|
.desc = "MWAIT 0x10",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 80,
|
|
.target_residency = 211,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C3 */
|
|
.name = "C6-SNB",
|
|
.desc = "MWAIT 0x20",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 104,
|
|
.target_residency = 345,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C4 */
|
|
.name = "C7-SNB",
|
|
.desc = "MWAIT 0x30",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 109,
|
|
.target_residency = 345,
|
|
.enter = &intel_idle },
|
|
};
|
|
|
|
static struct cpuidle_state ivb_cstates[MWAIT_MAX_NUM_CSTATES] = {
|
|
{ /* MWAIT C0 */ },
|
|
{ /* MWAIT C1 */
|
|
.name = "C1-IVB",
|
|
.desc = "MWAIT 0x00",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
|
.exit_latency = 1,
|
|
.target_residency = 1,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C2 */
|
|
.name = "C3-IVB",
|
|
.desc = "MWAIT 0x10",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 59,
|
|
.target_residency = 156,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C3 */
|
|
.name = "C6-IVB",
|
|
.desc = "MWAIT 0x20",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 80,
|
|
.target_residency = 300,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C4 */
|
|
.name = "C7-IVB",
|
|
.desc = "MWAIT 0x30",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 87,
|
|
.target_residency = 300,
|
|
.enter = &intel_idle },
|
|
};
|
|
|
|
static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
|
|
{ /* MWAIT C0 */ },
|
|
{ /* MWAIT C1 */
|
|
.name = "C1-ATM",
|
|
.desc = "MWAIT 0x00",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
|
.exit_latency = 1,
|
|
.target_residency = 4,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C2 */
|
|
.name = "C2-ATM",
|
|
.desc = "MWAIT 0x10",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
|
.exit_latency = 20,
|
|
.target_residency = 80,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C3 */ },
|
|
{ /* MWAIT C4 */
|
|
.name = "C4-ATM",
|
|
.desc = "MWAIT 0x30",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 100,
|
|
.target_residency = 400,
|
|
.enter = &intel_idle },
|
|
{ /* MWAIT C5 */ },
|
|
{ /* MWAIT C6 */
|
|
.name = "C6-ATM",
|
|
.desc = "MWAIT 0x52",
|
|
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
|
|
.exit_latency = 140,
|
|
.target_residency = 560,
|
|
.enter = &intel_idle },
|
|
};
|
|
|
|
static long get_driver_data(int cstate)
|
|
{
|
|
int driver_data;
|
|
switch (cstate) {
|
|
|
|
case 1: /* MWAIT C1 */
|
|
driver_data = 0x00;
|
|
break;
|
|
case 2: /* MWAIT C2 */
|
|
driver_data = 0x10;
|
|
break;
|
|
case 3: /* MWAIT C3 */
|
|
driver_data = 0x20;
|
|
break;
|
|
case 4: /* MWAIT C4 */
|
|
driver_data = 0x30;
|
|
break;
|
|
case 5: /* MWAIT C5 */
|
|
driver_data = 0x40;
|
|
break;
|
|
case 6: /* MWAIT C6 */
|
|
driver_data = 0x52;
|
|
break;
|
|
default:
|
|
driver_data = 0x00;
|
|
}
|
|
return driver_data;
|
|
}
|
|
|
|
/**
|
|
* intel_idle
|
|
* @dev: cpuidle_device
|
|
* @drv: cpuidle driver
|
|
* @index: index of cpuidle state
|
|
*
|
|
* Must be called under local_irq_disable().
|
|
*/
|
|
static int intel_idle(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv, int index)
|
|
{
|
|
unsigned long ecx = 1; /* break on interrupt flag */
|
|
struct cpuidle_state *state = &drv->states[index];
|
|
struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
|
|
unsigned long eax = (unsigned long)cpuidle_get_statedata(state_usage);
|
|
unsigned int cstate;
|
|
int cpu = smp_processor_id();
|
|
|
|
cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
|
|
|
|
/*
|
|
* leave_mm() to avoid costly and often unnecessary wakeups
|
|
* for flushing the user TLB's associated with the active mm.
|
|
*/
|
|
if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
|
|
leave_mm(cpu);
|
|
|
|
if (!(lapic_timer_reliable_states & (1 << (cstate))))
|
|
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
|
|
|
|
stop_critical_timings();
|
|
if (!need_resched()) {
|
|
|
|
__monitor((void *)¤t_thread_info()->flags, 0, 0);
|
|
smp_mb();
|
|
if (!need_resched())
|
|
__mwait(eax, ecx);
|
|
}
|
|
|
|
start_critical_timings();
|
|
|
|
if (!(lapic_timer_reliable_states & (1 << (cstate))))
|
|
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
|
|
|
|
return index;
|
|
}
|
|
|
|
static void __setup_broadcast_timer(void *arg)
|
|
{
|
|
unsigned long reason = (unsigned long)arg;
|
|
int cpu = smp_processor_id();
|
|
|
|
reason = reason ?
|
|
CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
|
|
|
|
clockevents_notify(reason, &cpu);
|
|
}
|
|
|
|
static int cpu_hotplug_notify(struct notifier_block *n,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
int hotcpu = (unsigned long)hcpu;
|
|
struct cpuidle_device *dev;
|
|
|
|
switch (action & 0xf) {
|
|
case CPU_ONLINE:
|
|
|
|
if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
|
|
smp_call_function_single(hotcpu, __setup_broadcast_timer,
|
|
(void *)true, 1);
|
|
|
|
/*
|
|
* Some systems can hotplug a cpu at runtime after
|
|
* the kernel has booted, we have to initialize the
|
|
* driver in this case
|
|
*/
|
|
dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
|
|
if (!dev->registered)
|
|
intel_idle_cpu_init(hotcpu);
|
|
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block cpu_hotplug_notifier = {
|
|
.notifier_call = cpu_hotplug_notify,
|
|
};
|
|
|
|
static void auto_demotion_disable(void *dummy)
|
|
{
|
|
unsigned long long msr_bits;
|
|
|
|
rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
|
|
msr_bits &= ~(icpu->auto_demotion_disable_flags);
|
|
wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
|
|
}
|
|
|
|
static const struct idle_cpu idle_cpu_nehalem = {
|
|
.state_table = nehalem_cstates,
|
|
.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
|
|
};
|
|
|
|
static const struct idle_cpu idle_cpu_atom = {
|
|
.state_table = atom_cstates,
|
|
};
|
|
|
|
static const struct idle_cpu idle_cpu_lincroft = {
|
|
.state_table = atom_cstates,
|
|
.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
|
|
};
|
|
|
|
static const struct idle_cpu idle_cpu_snb = {
|
|
.state_table = snb_cstates,
|
|
};
|
|
|
|
static const struct idle_cpu idle_cpu_ivb = {
|
|
.state_table = ivb_cstates,
|
|
};
|
|
|
|
#define ICPU(model, cpu) \
|
|
{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
|
|
|
|
static const struct x86_cpu_id intel_idle_ids[] = {
|
|
ICPU(0x1a, idle_cpu_nehalem),
|
|
ICPU(0x1e, idle_cpu_nehalem),
|
|
ICPU(0x1f, idle_cpu_nehalem),
|
|
ICPU(0x25, idle_cpu_nehalem),
|
|
ICPU(0x2c, idle_cpu_nehalem),
|
|
ICPU(0x2e, idle_cpu_nehalem),
|
|
ICPU(0x1c, idle_cpu_atom),
|
|
ICPU(0x26, idle_cpu_lincroft),
|
|
ICPU(0x2f, idle_cpu_nehalem),
|
|
ICPU(0x2a, idle_cpu_snb),
|
|
ICPU(0x2d, idle_cpu_snb),
|
|
ICPU(0x3a, idle_cpu_ivb),
|
|
ICPU(0x3e, idle_cpu_ivb),
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
|
|
|
|
/*
|
|
* intel_idle_probe()
|
|
*/
|
|
static int intel_idle_probe(void)
|
|
{
|
|
unsigned int eax, ebx, ecx;
|
|
const struct x86_cpu_id *id;
|
|
|
|
if (max_cstate == 0) {
|
|
pr_debug(PREFIX "disabled\n");
|
|
return -EPERM;
|
|
}
|
|
|
|
id = x86_match_cpu(intel_idle_ids);
|
|
if (!id) {
|
|
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
|
|
boot_cpu_data.x86 == 6)
|
|
pr_debug(PREFIX "does not run on family %d model %d\n",
|
|
boot_cpu_data.x86, boot_cpu_data.x86_model);
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
|
|
return -ENODEV;
|
|
|
|
cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
|
|
|
|
if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
|
|
!(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
|
|
!mwait_substates)
|
|
return -ENODEV;
|
|
|
|
pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
|
|
|
|
icpu = (const struct idle_cpu *)id->driver_data;
|
|
cpuidle_state_table = icpu->state_table;
|
|
|
|
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
|
|
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
|
|
else
|
|
on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
|
|
|
|
pr_debug(PREFIX "v" INTEL_IDLE_VERSION
|
|
" model 0x%X\n", boot_cpu_data.x86_model);
|
|
|
|
pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
|
|
lapic_timer_reliable_states);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* intel_idle_cpuidle_devices_uninit()
|
|
* unregister, free cpuidle_devices
|
|
*/
|
|
static void intel_idle_cpuidle_devices_uninit(void)
|
|
{
|
|
int i;
|
|
struct cpuidle_device *dev;
|
|
|
|
for_each_online_cpu(i) {
|
|
dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
|
|
cpuidle_unregister_device(dev);
|
|
}
|
|
|
|
free_percpu(intel_idle_cpuidle_devices);
|
|
return;
|
|
}
|
|
/*
|
|
* intel_idle_cpuidle_driver_init()
|
|
* allocate, initialize cpuidle_states
|
|
*/
|
|
static int intel_idle_cpuidle_driver_init(void)
|
|
{
|
|
int cstate;
|
|
struct cpuidle_driver *drv = &intel_idle_driver;
|
|
|
|
drv->state_count = 1;
|
|
|
|
for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
|
|
int num_substates;
|
|
|
|
if (cstate > max_cstate) {
|
|
printk(PREFIX "max_cstate %d reached\n",
|
|
max_cstate);
|
|
break;
|
|
}
|
|
|
|
/* does the state exist in CPUID.MWAIT? */
|
|
num_substates = (mwait_substates >> ((cstate) * 4))
|
|
& MWAIT_SUBSTATE_MASK;
|
|
if (num_substates == 0)
|
|
continue;
|
|
/* is the state not enabled? */
|
|
if (cpuidle_state_table[cstate].enter == NULL) {
|
|
/* does the driver not know about the state? */
|
|
if (*cpuidle_state_table[cstate].name == '\0')
|
|
pr_debug(PREFIX "unaware of model 0x%x"
|
|
" MWAIT %d please"
|
|
" contact lenb@kernel.org\n",
|
|
boot_cpu_data.x86_model, cstate);
|
|
continue;
|
|
}
|
|
|
|
if ((cstate > 2) &&
|
|
!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
|
|
mark_tsc_unstable("TSC halts in idle"
|
|
" states deeper than C2");
|
|
|
|
drv->states[drv->state_count] = /* structure copy */
|
|
cpuidle_state_table[cstate];
|
|
|
|
drv->state_count += 1;
|
|
}
|
|
|
|
if (icpu->auto_demotion_disable_flags)
|
|
on_each_cpu(auto_demotion_disable, NULL, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* intel_idle_cpu_init()
|
|
* allocate, initialize, register cpuidle_devices
|
|
* @cpu: cpu/core to initialize
|
|
*/
|
|
static int intel_idle_cpu_init(int cpu)
|
|
{
|
|
int cstate;
|
|
struct cpuidle_device *dev;
|
|
|
|
dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
|
|
|
|
dev->state_count = 1;
|
|
|
|
for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
|
|
int num_substates;
|
|
|
|
if (cstate > max_cstate) {
|
|
printk(PREFIX "max_cstate %d reached\n", max_cstate);
|
|
break;
|
|
}
|
|
|
|
/* does the state exist in CPUID.MWAIT? */
|
|
num_substates = (mwait_substates >> ((cstate) * 4))
|
|
& MWAIT_SUBSTATE_MASK;
|
|
if (num_substates == 0)
|
|
continue;
|
|
/* is the state not enabled? */
|
|
if (cpuidle_state_table[cstate].enter == NULL)
|
|
continue;
|
|
|
|
dev->states_usage[dev->state_count].driver_data =
|
|
(void *)get_driver_data(cstate);
|
|
|
|
dev->state_count += 1;
|
|
}
|
|
|
|
dev->cpu = cpu;
|
|
|
|
if (cpuidle_register_device(dev)) {
|
|
pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
|
|
intel_idle_cpuidle_devices_uninit();
|
|
return -EIO;
|
|
}
|
|
|
|
if (icpu->auto_demotion_disable_flags)
|
|
smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init intel_idle_init(void)
|
|
{
|
|
int retval, i;
|
|
|
|
/* Do not load intel_idle at all for now if idle= is passed */
|
|
if (boot_option_idle_override != IDLE_NO_OVERRIDE)
|
|
return -ENODEV;
|
|
|
|
retval = intel_idle_probe();
|
|
if (retval)
|
|
return retval;
|
|
|
|
intel_idle_cpuidle_driver_init();
|
|
retval = cpuidle_register_driver(&intel_idle_driver);
|
|
if (retval) {
|
|
struct cpuidle_driver *drv = cpuidle_get_driver();
|
|
printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
|
|
drv ? drv->name : "none");
|
|
return retval;
|
|
}
|
|
|
|
intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
|
|
if (intel_idle_cpuidle_devices == NULL)
|
|
return -ENOMEM;
|
|
|
|
for_each_online_cpu(i) {
|
|
retval = intel_idle_cpu_init(i);
|
|
if (retval) {
|
|
cpuidle_unregister_driver(&intel_idle_driver);
|
|
return retval;
|
|
}
|
|
}
|
|
register_cpu_notifier(&cpu_hotplug_notifier);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit intel_idle_exit(void)
|
|
{
|
|
intel_idle_cpuidle_devices_uninit();
|
|
cpuidle_unregister_driver(&intel_idle_driver);
|
|
|
|
|
|
if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
|
|
on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
|
|
unregister_cpu_notifier(&cpu_hotplug_notifier);
|
|
|
|
return;
|
|
}
|
|
|
|
module_init(intel_idle_init);
|
|
module_exit(intel_idle_exit);
|
|
|
|
module_param(max_cstate, int, 0444);
|
|
|
|
MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
|
|
MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
|
|
MODULE_LICENSE("GPL");
|