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alistair23-linux/drivers/idle/intel_idle.c
Andy Lutomirski 675357362a Revert "x86/mm: Stop calling leave_mm() in idle code" 
This reverts commit 43858b4f25.

The reason I removed the leave_mm() calls in question is because the
heuristic wasn't needed after that patch.  With the original version
of my PCID series, we never flushed a "lazy cpu" (i.e. a CPU running
kernel thread) due a flush on the loaded mm.

Unfortunately, that caused architectural issues, so now I've
reinstated these flushes on non-PCID systems in:

    commit b956575bed ("x86/mm: Flush more aggressively in lazy TLB mode").

That, in turn, gives us a power management and occasionally
performance regression as compared to old kernels: a process that
goes into a deep idle state on a given CPU and gets its mm flushed
due to activity on a different CPU will wake the idle CPU.

Reinstate the old ugly heuristic: if a CPU goes into ACPI C3 or an
intel_idle state that is likely to cause a TLB flush gets its mm
switched to init_mm before going idle.

FWIW, this heuristic is lousy.  Whether we should change CR3 before
idle isn't a good hint except insofar as the performance hit is a bit
lower if the TLB is getting flushed by the idle code anyway.  What we
really want to know is whether we anticipate being idle long enough
that the mm is likely to be flushed before we wake up.  This is more a
matter of the expected latency than the idle state that gets chosen.
This heuristic also completely fails on systems that don't know
whether the TLB will be flushed (e.g. AMD systems?).  OTOH it may be a
bit obsolete anyway -- PCID systems don't presently benefit from this
heuristic at all.

We also shouldn't do this callback from innermost bit of the idle code
due to the RCU nastiness it causes.  All the information need is
available before rcu_idle_enter() needs to happen.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 43858b4f25 "x86/mm: Stop calling leave_mm() in idle code"
Link: http://lkml.kernel.org/r/c513bbd4e653747213e05bc7062de000bf0202a5.1509793738.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-04 15:01:50 +01:00

1486 lines
36 KiB
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/*
* intel_idle.c - native hardware idle loop for modern Intel processors
*
* Copyright (c) 2013, 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.
*
*/
/* un-comment DEBUG to enable pr_debug() statements */
#define DEBUG
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/cpuidle.h>
#include <linux/tick.h>
#include <trace/events/power.h>
#include <linux/sched.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/mwait.h>
#include <asm/msr.h>
#define INTEL_IDLE_VERSION "0.4.1"
static struct cpuidle_driver intel_idle_driver = {
.name = "intel_idle",
.owner = THIS_MODULE,
};
/* intel_idle.max_cstate=0 disables driver */
static int max_cstate = CPUIDLE_STATE_MAX - 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;
bool byt_auto_demotion_disable_flag;
bool disable_promotion_to_c1e;
};
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 void intel_idle_s2idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index);
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
/*
* MWAIT takes an 8-bit "hint" in EAX "suggesting"
* the C-state (top nibble) and sub-state (bottom nibble)
* 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
*
* We store the hint at the top of our "flags" for each state.
*/
#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
#define MWAIT2flg(eax) ((eax & 0xFF) << 24)
/*
* 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[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 3,
.target_residency = 6,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 20,
.target_residency = 80,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 200,
.target_residency = 800,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state snb_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 80,
.target_residency = 211,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 104,
.target_residency = 345,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7",
.desc = "MWAIT 0x30",
.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 109,
.target_residency = 345,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state byt_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6N",
.desc = "MWAIT 0x58",
.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 300,
.target_residency = 275,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6S",
.desc = "MWAIT 0x52",
.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 500,
.target_residency = 560,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 1200,
.target_residency = 4000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7S",
.desc = "MWAIT 0x64",
.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 10000,
.target_residency = 20000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state cht_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6N",
.desc = "MWAIT 0x58",
.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 80,
.target_residency = 275,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6S",
.desc = "MWAIT 0x52",
.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 200,
.target_residency = 560,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 1200,
.target_residency = 4000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7S",
.desc = "MWAIT 0x64",
.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 10000,
.target_residency = 20000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state ivb_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 59,
.target_residency = 156,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 80,
.target_residency = 300,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7",
.desc = "MWAIT 0x30",
.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 87,
.target_residency = 300,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state ivt_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 80,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 59,
.target_residency = 156,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 82,
.target_residency = 300,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state ivt_cstates_4s[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 250,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 59,
.target_residency = 300,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 84,
.target_residency = 400,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state ivt_cstates_8s[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 1,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 500,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 59,
.target_residency = 600,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 88,
.target_residency = 700,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state hsw_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 33,
.target_residency = 100,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 133,
.target_residency = 400,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7s",
.desc = "MWAIT 0x32",
.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 166,
.target_residency = 500,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C8",
.desc = "MWAIT 0x40",
.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 300,
.target_residency = 900,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C9",
.desc = "MWAIT 0x50",
.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 600,
.target_residency = 1800,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C10",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 2600,
.target_residency = 7700,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state bdw_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 40,
.target_residency = 100,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 133,
.target_residency = 400,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7s",
.desc = "MWAIT 0x32",
.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 166,
.target_residency = 500,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C8",
.desc = "MWAIT 0x40",
.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 300,
.target_residency = 900,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C9",
.desc = "MWAIT 0x50",
.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 600,
.target_residency = 1800,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C10",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 2600,
.target_residency = 7700,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state skl_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C3",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 70,
.target_residency = 100,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 85,
.target_residency = 200,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7s",
.desc = "MWAIT 0x33",
.flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 124,
.target_residency = 800,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C8",
.desc = "MWAIT 0x40",
.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 200,
.target_residency = 800,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C9",
.desc = "MWAIT 0x50",
.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 480,
.target_residency = 5000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C10",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 890,
.target_residency = 5000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state skx_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 133,
.target_residency = 600,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state atom_cstates[] = {
{
.name = "C1E",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C2",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10),
.exit_latency = 20,
.target_residency = 80,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C4",
.desc = "MWAIT 0x30",
.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 100,
.target_residency = 400,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x52",
.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 140,
.target_residency = 560,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state tangier_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 4,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C4",
.desc = "MWAIT 0x30",
.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 100,
.target_residency = 400,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x52",
.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 140,
.target_residency = 560,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 1200,
.target_residency = 4000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C9",
.desc = "MWAIT 0x64",
.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 10000,
.target_residency = 20000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state avn_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x51",
.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 15,
.target_residency = 45,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state knl_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 1,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle },
{
.name = "C6",
.desc = "MWAIT 0x10",
.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 120,
.target_residency = 500,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle },
{
.enter = NULL }
};
static struct cpuidle_state bxt_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 133,
.target_residency = 133,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C7s",
.desc = "MWAIT 0x31",
.flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 155,
.target_residency = 155,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C8",
.desc = "MWAIT 0x40",
.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 1000,
.target_residency = 1000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C9",
.desc = "MWAIT 0x50",
.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 2000,
.target_residency = 2000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C10",
.desc = "MWAIT 0x60",
.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 10000,
.target_residency = 10000,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
static struct cpuidle_state dnv_cstates[] = {
{
.name = "C1",
.desc = "MWAIT 0x00",
.flags = MWAIT2flg(0x00),
.exit_latency = 2,
.target_residency = 2,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C1E",
.desc = "MWAIT 0x01",
.flags = MWAIT2flg(0x01),
.exit_latency = 10,
.target_residency = 20,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.name = "C6",
.desc = "MWAIT 0x20",
.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 50,
.target_residency = 500,
.enter = &intel_idle,
.enter_s2idle = intel_idle_s2idle, },
{
.enter = NULL }
};
/**
* intel_idle
* @dev: cpuidle_device
* @drv: cpuidle driver
* @index: index of cpuidle state
*
* Must be called under local_irq_disable().
*/
static __cpuidle 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];
unsigned long eax = flg2MWAIT(state->flags);
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))))
tick_broadcast_enter();
mwait_idle_with_hints(eax, ecx);
if (!(lapic_timer_reliable_states & (1 << (cstate))))
tick_broadcast_exit();
return index;
}
/**
* intel_idle_s2idle - simplified "enter" callback routine for suspend-to-idle
* @dev: cpuidle_device
* @drv: cpuidle driver
* @index: state index
*/
static void intel_idle_s2idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
unsigned long ecx = 1; /* break on interrupt flag */
unsigned long eax = flg2MWAIT(drv->states[index].flags);
mwait_idle_with_hints(eax, ecx);
}
static void __setup_broadcast_timer(bool on)
{
if (on)
tick_broadcast_enable();
else
tick_broadcast_disable();
}
static void auto_demotion_disable(void)
{
unsigned long long msr_bits;
rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
msr_bits &= ~(icpu->auto_demotion_disable_flags);
wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
}
static void c1e_promotion_disable(void)
{
unsigned long long msr_bits;
rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
msr_bits &= ~0x2;
wrmsrl(MSR_IA32_POWER_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,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_atom = {
.state_table = atom_cstates,
};
static const struct idle_cpu idle_cpu_tangier = {
.state_table = tangier_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,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_byt = {
.state_table = byt_cstates,
.disable_promotion_to_c1e = true,
.byt_auto_demotion_disable_flag = true,
};
static const struct idle_cpu idle_cpu_cht = {
.state_table = cht_cstates,
.disable_promotion_to_c1e = true,
.byt_auto_demotion_disable_flag = true,
};
static const struct idle_cpu idle_cpu_ivb = {
.state_table = ivb_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_ivt = {
.state_table = ivt_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_hsw = {
.state_table = hsw_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_bdw = {
.state_table = bdw_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_skl = {
.state_table = skl_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_skx = {
.state_table = skx_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_avn = {
.state_table = avn_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_knl = {
.state_table = knl_cstates,
};
static const struct idle_cpu idle_cpu_bxt = {
.state_table = bxt_cstates,
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_dnv = {
.state_table = dnv_cstates,
.disable_promotion_to_c1e = true,
};
#define ICPU(model, cpu) \
{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
static const struct x86_cpu_id intel_idle_ids[] __initconst = {
ICPU(INTEL_FAM6_NEHALEM_EP, idle_cpu_nehalem),
ICPU(INTEL_FAM6_NEHALEM, idle_cpu_nehalem),
ICPU(INTEL_FAM6_NEHALEM_G, idle_cpu_nehalem),
ICPU(INTEL_FAM6_WESTMERE, idle_cpu_nehalem),
ICPU(INTEL_FAM6_WESTMERE_EP, idle_cpu_nehalem),
ICPU(INTEL_FAM6_NEHALEM_EX, idle_cpu_nehalem),
ICPU(INTEL_FAM6_ATOM_PINEVIEW, idle_cpu_atom),
ICPU(INTEL_FAM6_ATOM_LINCROFT, idle_cpu_lincroft),
ICPU(INTEL_FAM6_WESTMERE_EX, idle_cpu_nehalem),
ICPU(INTEL_FAM6_SANDYBRIDGE, idle_cpu_snb),
ICPU(INTEL_FAM6_SANDYBRIDGE_X, idle_cpu_snb),
ICPU(INTEL_FAM6_ATOM_CEDARVIEW, idle_cpu_atom),
ICPU(INTEL_FAM6_ATOM_SILVERMONT1, idle_cpu_byt),
ICPU(INTEL_FAM6_ATOM_MERRIFIELD, idle_cpu_tangier),
ICPU(INTEL_FAM6_ATOM_AIRMONT, idle_cpu_cht),
ICPU(INTEL_FAM6_IVYBRIDGE, idle_cpu_ivb),
ICPU(INTEL_FAM6_IVYBRIDGE_X, idle_cpu_ivt),
ICPU(INTEL_FAM6_HASWELL_CORE, idle_cpu_hsw),
ICPU(INTEL_FAM6_HASWELL_X, idle_cpu_hsw),
ICPU(INTEL_FAM6_HASWELL_ULT, idle_cpu_hsw),
ICPU(INTEL_FAM6_HASWELL_GT3E, idle_cpu_hsw),
ICPU(INTEL_FAM6_ATOM_SILVERMONT2, idle_cpu_avn),
ICPU(INTEL_FAM6_BROADWELL_CORE, idle_cpu_bdw),
ICPU(INTEL_FAM6_BROADWELL_GT3E, idle_cpu_bdw),
ICPU(INTEL_FAM6_BROADWELL_X, idle_cpu_bdw),
ICPU(INTEL_FAM6_BROADWELL_XEON_D, idle_cpu_bdw),
ICPU(INTEL_FAM6_SKYLAKE_MOBILE, idle_cpu_skl),
ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, idle_cpu_skl),
ICPU(INTEL_FAM6_KABYLAKE_MOBILE, idle_cpu_skl),
ICPU(INTEL_FAM6_KABYLAKE_DESKTOP, idle_cpu_skl),
ICPU(INTEL_FAM6_SKYLAKE_X, idle_cpu_skx),
ICPU(INTEL_FAM6_XEON_PHI_KNL, idle_cpu_knl),
ICPU(INTEL_FAM6_XEON_PHI_KNM, idle_cpu_knl),
ICPU(INTEL_FAM6_ATOM_GOLDMONT, idle_cpu_bxt),
ICPU(INTEL_FAM6_ATOM_GEMINI_LAKE, idle_cpu_bxt),
ICPU(INTEL_FAM6_ATOM_DENVERTON, idle_cpu_dnv),
{}
};
/*
* intel_idle_probe()
*/
static int __init intel_idle_probe(void)
{
unsigned int eax, ebx, ecx;
const struct x86_cpu_id *id;
if (max_cstate == 0) {
pr_debug("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("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("MWAIT substates: 0x%x\n", mwait_substates);
icpu = (const struct idle_cpu *)id->driver_data;
cpuidle_state_table = icpu->state_table;
pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
boot_cpu_data.x86_model);
return 0;
}
/*
* intel_idle_cpuidle_devices_uninit()
* Unregisters the 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);
}
}
/*
* ivt_idle_state_table_update(void)
*
* Tune IVT multi-socket targets
* Assumption: num_sockets == (max_package_num + 1)
*/
static void ivt_idle_state_table_update(void)
{
/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
int cpu, package_num, num_sockets = 1;
for_each_online_cpu(cpu) {
package_num = topology_physical_package_id(cpu);
if (package_num + 1 > num_sockets) {
num_sockets = package_num + 1;
if (num_sockets > 4) {
cpuidle_state_table = ivt_cstates_8s;
return;
}
}
}
if (num_sockets > 2)
cpuidle_state_table = ivt_cstates_4s;
/* else, 1 and 2 socket systems use default ivt_cstates */
}
/*
* Translate IRTL (Interrupt Response Time Limit) MSR to usec
*/
static unsigned int irtl_ns_units[] = {
1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
static unsigned long long irtl_2_usec(unsigned long long irtl)
{
unsigned long long ns;
if (!irtl)
return 0;
ns = irtl_ns_units[(irtl >> 10) & 0x7];
return div64_u64((irtl & 0x3FF) * ns, 1000);
}
/*
* bxt_idle_state_table_update(void)
*
* On BXT, we trust the IRTL to show the definitive maximum latency
* We use the same value for target_residency.
*/
static void bxt_idle_state_table_update(void)
{
unsigned long long msr;
unsigned int usec;
rdmsrl(MSR_PKGC6_IRTL, msr);
usec = irtl_2_usec(msr);
if (usec) {
bxt_cstates[2].exit_latency = usec;
bxt_cstates[2].target_residency = usec;
}
rdmsrl(MSR_PKGC7_IRTL, msr);
usec = irtl_2_usec(msr);
if (usec) {
bxt_cstates[3].exit_latency = usec;
bxt_cstates[3].target_residency = usec;
}
rdmsrl(MSR_PKGC8_IRTL, msr);
usec = irtl_2_usec(msr);
if (usec) {
bxt_cstates[4].exit_latency = usec;
bxt_cstates[4].target_residency = usec;
}
rdmsrl(MSR_PKGC9_IRTL, msr);
usec = irtl_2_usec(msr);
if (usec) {
bxt_cstates[5].exit_latency = usec;
bxt_cstates[5].target_residency = usec;
}
rdmsrl(MSR_PKGC10_IRTL, msr);
usec = irtl_2_usec(msr);
if (usec) {
bxt_cstates[6].exit_latency = usec;
bxt_cstates[6].target_residency = usec;
}
}
/*
* sklh_idle_state_table_update(void)
*
* On SKL-H (model 0x5e) disable C8 and C9 if:
* C10 is enabled and SGX disabled
*/
static void sklh_idle_state_table_update(void)
{
unsigned long long msr;
unsigned int eax, ebx, ecx, edx;
/* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
if (max_cstate <= 7)
return;
/* if PC10 not present in CPUID.MWAIT.EDX */
if ((mwait_substates & (0xF << 28)) == 0)
return;
rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
/* PC10 is not enabled in PKG C-state limit */
if ((msr & 0xF) != 8)
return;
ecx = 0;
cpuid(7, &eax, &ebx, &ecx, &edx);
/* if SGX is present */
if (ebx & (1 << 2)) {
rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
/* if SGX is enabled */
if (msr & (1 << 18))
return;
}
skl_cstates[5].disabled = 1; /* C8-SKL */
skl_cstates[6].disabled = 1; /* C9-SKL */
}
/*
* intel_idle_state_table_update()
*
* Update the default state_table for this CPU-id
*/
static void intel_idle_state_table_update(void)
{
switch (boot_cpu_data.x86_model) {
case INTEL_FAM6_IVYBRIDGE_X:
ivt_idle_state_table_update();
break;
case INTEL_FAM6_ATOM_GOLDMONT:
case INTEL_FAM6_ATOM_GEMINI_LAKE:
bxt_idle_state_table_update();
break;
case INTEL_FAM6_SKYLAKE_DESKTOP:
sklh_idle_state_table_update();
break;
}
}
/*
* intel_idle_cpuidle_driver_init()
* allocate, initialize cpuidle_states
*/
static void __init intel_idle_cpuidle_driver_init(void)
{
int cstate;
struct cpuidle_driver *drv = &intel_idle_driver;
intel_idle_state_table_update();
cpuidle_poll_state_init(drv);
drv->state_count = 1;
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
int num_substates, mwait_hint, mwait_cstate;
if ((cpuidle_state_table[cstate].enter == NULL) &&
(cpuidle_state_table[cstate].enter_s2idle == NULL))
break;
if (cstate + 1 > max_cstate) {
pr_info("max_cstate %d reached\n", max_cstate);
break;
}
mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
/* number of sub-states for this state in CPUID.MWAIT */
num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
& MWAIT_SUBSTATE_MASK;
/* if NO sub-states for this state in CPUID, skip it */
if (num_substates == 0)
continue;
/* if state marked as disabled, skip it */
if (cpuidle_state_table[cstate].disabled != 0) {
pr_debug("state %s is disabled\n",
cpuidle_state_table[cstate].name);
continue;
}
if (((mwait_cstate + 1) > 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->byt_auto_demotion_disable_flag) {
wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
}
}
/*
* intel_idle_cpu_init()
* allocate, initialize, register cpuidle_devices
* @cpu: cpu/core to initialize
*/
static int intel_idle_cpu_init(unsigned int cpu)
{
struct cpuidle_device *dev;
dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
dev->cpu = cpu;
if (cpuidle_register_device(dev)) {
pr_debug("cpuidle_register_device %d failed!\n", cpu);
return -EIO;
}
if (icpu->auto_demotion_disable_flags)
auto_demotion_disable();
if (icpu->disable_promotion_to_c1e)
c1e_promotion_disable();
return 0;
}
static int intel_idle_cpu_online(unsigned int cpu)
{
struct cpuidle_device *dev;
if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
__setup_broadcast_timer(true);
/*
* 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, cpu);
if (!dev->registered)
return intel_idle_cpu_init(cpu);
return 0;
}
static int __init intel_idle_init(void)
{
int retval;
/* 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_devices = alloc_percpu(struct cpuidle_device);
if (intel_idle_cpuidle_devices == NULL)
return -ENOMEM;
intel_idle_cpuidle_driver_init();
retval = cpuidle_register_driver(&intel_idle_driver);
if (retval) {
struct cpuidle_driver *drv = cpuidle_get_driver();
printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
drv ? drv->name : "none");
goto init_driver_fail;
}
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
intel_idle_cpu_online, NULL);
if (retval < 0)
goto hp_setup_fail;
pr_debug("lapic_timer_reliable_states 0x%x\n",
lapic_timer_reliable_states);
return 0;
hp_setup_fail:
intel_idle_cpuidle_devices_uninit();
cpuidle_unregister_driver(&intel_idle_driver);
init_driver_fail:
free_percpu(intel_idle_cpuidle_devices);
return retval;
}
device_initcall(intel_idle_init);
/*
* We are not really modular, but we used to support that. Meaning we also
* support "intel_idle.max_cstate=..." at boot and also a read-only export of
* it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
* is the easiest way (currently) to continue doing that.
*/
module_param(max_cstate, int, 0444);
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