Merge branches 'pm-cpuidle' and 'powercap'

* pm-cpuidle:
  ACPI / processor: Set P_LVL{2,3} idle state descriptions
  intel_idle: add support for Jacobsville
  cpuidle: dt: bail out if the idle-state DT node is not compatible
  cpuidle: use BIT() for idle state flags and remove CPUIDLE_DRIVER_FLAGS_MASK
  Documentation: driver-api: PM: Add cpuidle document
  cpuidle: New timer events oriented governor for tickless systems

* powercap:
  powercap/intel_rapl: add Ice Lake mobile
  powercap: intel_rapl: add support for Jacobsville

Documentation/admin-guide/pm/cpuidle.rst

@@ -155,14 +155,14 @@ governor uses that information depends on what algorithm is implemented by it
 and that is the primary reason for having more than one governor in the
 ``CPUIdle`` subsystem.
 
-There are two ``CPUIdle`` governors available, ``menu`` and ``ladder``.  Which
-of them is used depends on the configuration of the kernel and in particular on
-whether or not the scheduler tick can be `stopped by the idle
-loop <idle-cpus-and-tick_>`_.  It is possible to change the governor at run time
-if the ``cpuidle_sysfs_switch`` command line parameter has been passed to the
-kernel, but that is not safe in general, so it should not be done on production
-systems (that may change in the future, though).  The name of the ``CPUIdle``
-governor currently used by the kernel can be read from the
+There are three ``CPUIdle`` governors available, ``menu``, `TEO <teo-gov_>`_
+and ``ladder``.  Which of them is used by default depends on the configuration
+of the kernel and in particular on whether or not the scheduler tick can be
+`stopped by the idle loop <idle-cpus-and-tick_>`_.  It is possible to change the
+governor at run time if the ``cpuidle_sysfs_switch`` command line parameter has
+been passed to the kernel, but that is not safe in general, so it should not be
+done on production systems (that may change in the future, though).  The name of
+the ``CPUIdle`` governor currently used by the kernel can be read from the
 :file:`current_governor_ro` (or :file:`current_governor` if
 ``cpuidle_sysfs_switch`` is present in the kernel command line) file under
 :file:`/sys/devices/system/cpu/cpuidle/` in ``sysfs``.
@@ -256,6 +256,8 @@ the ``menu`` governor by default and if it is not tickless, the default
 ``CPUIdle`` governor on it will be ``ladder``.
 
 
+.. _menu-gov:
+
 The ``menu`` Governor
 =====================
 
@@ -333,6 +335,92 @@ that time, the governor may need to select a shallower state with a suitable
 target residency.
 
 
+.. _teo-gov:
+
+The Timer Events Oriented (TEO) Governor
+========================================
+
+The timer events oriented (TEO) governor is an alternative ``CPUIdle`` governor
+for tickless systems.  It follows the same basic strategy as the ``menu`` `one
+<menu-gov_>`_: it always tries to find the deepest idle state suitable for the
+given conditions.  However, it applies a different approach to that problem.
+
+First, it does not use sleep length correction factors, but instead it attempts
+to correlate the observed idle duration values with the available idle states
+and use that information to pick up the idle state that is most likely to
+"match" the upcoming CPU idle interval.   Second, it does not take the tasks
+that were running on the given CPU in the past and are waiting on some I/O
+operations to complete now at all (there is no guarantee that they will run on
+the same CPU when they become runnable again) and the pattern detection code in
+it avoids taking timer wakeups into account.  It also only uses idle duration
+values less than the current time till the closest timer (with the scheduler
+tick excluded) for that purpose.
+
+Like in the ``menu`` governor `case <menu-gov_>`_, the first step is to obtain
+the *sleep length*, which is the time until the closest timer event with the
+assumption that the scheduler tick will be stopped (that also is the upper bound
+on the time until the next CPU wakeup).  That value is then used to preselect an
+idle state on the basis of three metrics maintained for each idle state provided
+by the ``CPUIdle`` driver: ``hits``, ``misses`` and ``early_hits``.
+
+The ``hits`` and ``misses`` metrics measure the likelihood that a given idle
+state will "match" the observed (post-wakeup) idle duration if it "matches" the
+sleep length.  They both are subject to decay (after a CPU wakeup) every time
+the target residency of the idle state corresponding to them is less than or
+equal to the sleep length and the target residency of the next idle state is
+greater than the sleep length (that is, when the idle state corresponding to
+them "matches" the sleep length).  The ``hits`` metric is increased if the
+former condition is satisfied and the target residency of the given idle state
+is less than or equal to the observed idle duration and the target residency of
+the next idle state is greater than the observed idle duration at the same time
+(that is, it is increased when the given idle state "matches" both the sleep
+length and the observed idle duration).  In turn, the ``misses`` metric is
+increased when the given idle state "matches" the sleep length only and the
+observed idle duration is too short for its target residency.
+
+The ``early_hits`` metric measures the likelihood that a given idle state will
+"match" the observed (post-wakeup) idle duration if it does not "match" the
+sleep length.  It is subject to decay on every CPU wakeup and it is increased
+when the idle state corresponding to it "matches" the observed (post-wakeup)
+idle duration and the target residency of the next idle state is less than or
+equal to the sleep length (i.e. the idle state "matching" the sleep length is
+deeper than the given one).
+
+The governor walks the list of idle states provided by the ``CPUIdle`` driver
+and finds the last (deepest) one with the target residency less than or equal
+to the sleep length.  Then, the ``hits`` and ``misses`` metrics of that idle
+state are compared with each other and it is preselected if the ``hits`` one is
+greater (which means that that idle state is likely to "match" the observed idle
+duration after CPU wakeup).  If the ``misses`` one is greater, the governor
+preselects the shallower idle state with the maximum ``early_hits`` metric
+(or if there are multiple shallower idle states with equal ``early_hits``
+metric which also is the maximum, the shallowest of them will be preselected).
+[If there is a wakeup latency constraint coming from the `PM QoS framework
+<cpu-pm-qos_>`_ which is hit before reaching the deepest idle state with the
+target residency within the sleep length, the deepest idle state with the exit
+latency within the constraint is preselected without consulting the ``hits``,
+``misses`` and ``early_hits`` metrics.]
+
+Next, the governor takes several idle duration values observed most recently
+into consideration and if at least a half of them are greater than or equal to
+the target residency of the preselected idle state, that idle state becomes the
+final candidate to ask for.  Otherwise, the average of the most recent idle
+duration values below the target residency of the preselected idle state is
+computed and the governor walks the idle states shallower than the preselected
+one and finds the deepest of them with the target residency within that average.
+That idle state is then taken as the final candidate to ask for.
+
+Still, at this point the governor may need to refine the idle state selection if
+it has not decided to `stop the scheduler tick <idle-cpus-and-tick_>`_.  That
+generally happens if the target residency of the idle state selected so far is
+less than the tick period and the tick has not been stopped already (in a
+previous iteration of the idle loop).  Then, like in the ``menu`` governor
+`case <menu-gov_>`_, the sleep length used in the previous computations may not
+reflect the real time until the closest timer event and if it really is greater
+than that time, a shallower state with a suitable target residency may need to
+be selected.
+
+
 .. _idle-states-representation:
 
 Representation of Idle States

Documentation/cpuidle/driver.txt

-
-
-		Supporting multiple CPU idle levels in kernel
-
-				cpuidle drivers
-
-
-
-
-cpuidle driver hooks into the cpuidle infrastructure and handles the
-architecture/platform dependent part of CPU idle states. Driver
-provides the platform idle state detection capability and also
-has mechanisms in place to support actual entry-exit into CPU idle states.
-
-cpuidle driver initializes the cpuidle_device structure for each CPU device
-and registers with cpuidle using cpuidle_register_device.
-
-If all the idle states are the same, the wrapper function cpuidle_register
-could be used instead.
-
-It can also support the dynamic changes (like battery <-> AC), by using
-cpuidle_pause_and_lock, cpuidle_disable_device and cpuidle_enable_device,
-cpuidle_resume_and_unlock.
-
-Interfaces:
-extern int cpuidle_register(struct cpuidle_driver *drv,
-                            const struct cpumask *const coupled_cpus);
-extern int cpuidle_unregister(struct cpuidle_driver *drv);
-extern int cpuidle_register_driver(struct cpuidle_driver *drv);
-extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
-extern int cpuidle_register_device(struct cpuidle_device *dev);
-extern void cpuidle_unregister_device(struct cpuidle_device *dev);
-
-extern void cpuidle_pause_and_lock(void);
-extern void cpuidle_resume_and_unlock(void);
-extern int cpuidle_enable_device(struct cpuidle_device *dev);
-extern void cpuidle_disable_device(struct cpuidle_device *dev);

Documentation/cpuidle/governor.txt

-
-
-
-		Supporting multiple CPU idle levels in kernel
-
-				cpuidle governors
-
-
-
-
-cpuidle governor is policy routine that decides what idle state to enter at
-any given time. cpuidle core uses different callbacks to the governor.
-
-* enable() to enable governor for a particular device
-* disable() to disable governor for a particular device
-* select() to select an idle state to enter
-* reflect() called after returning from the idle state, which can be used
-  by the governor for some record keeping.
-
-More than one governor can be registered at the same time and
-users can switch between drivers using /sysfs interface (when enabled).
-More than one governor part is supported for developers to easily experiment
-with different governors. By default, most optimal governor based on your
-kernel configuration and platform will be selected by cpuidle.
-
-Interfaces:
-extern int cpuidle_register_governor(struct cpuidle_governor *gov);
-struct cpuidle_governor

Documentation/driver-api/pm/index.rst

-=======================
-Device Power Management
-=======================
+===============================
+CPU and Device Power Management
+===============================
 
 .. toctree::
 
+   cpuidle
    devices
    notifiers
    types

MAINTAINERS

@@ -4021,6 +4021,7 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
 B:	https://bugzilla.kernel.org
 F:	Documentation/admin-guide/pm/cpuidle.rst
+F:	Documentation/driver-api/pm/cpuidle.rst
 F:	drivers/cpuidle/*
 F:	include/linux/cpuidle.h
 

drivers/acpi/processor_idle.c

@@ -282,6 +282,13 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 			  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;
 }
 

drivers/cpuidle/Kconfig

@@ -4,7 +4,7 @@ config CPU_IDLE
 	bool "CPU idle PM support"
 	default y if ACPI || PPC_PSERIES
 	select CPU_IDLE_GOV_LADDER if (!NO_HZ && !NO_HZ_IDLE)
-	select CPU_IDLE_GOV_MENU if (NO_HZ || NO_HZ_IDLE)
+	select CPU_IDLE_GOV_MENU if (NO_HZ || NO_HZ_IDLE) && !CPU_IDLE_GOV_TEO
 	help
 	  CPU idle is a generic framework for supporting software-controlled
 	  idle processor power management.  It includes modular cross-platform
@@ -23,6 +23,15 @@ config CPU_IDLE_GOV_LADDER
 config CPU_IDLE_GOV_MENU
 	bool "Menu governor (for tickless system)"
 
+config CPU_IDLE_GOV_TEO
+	bool "Timer events oriented (TEO) governor (for tickless systems)"
+	help
+	  This governor implements a simplified idle state selection method
+	  focused on timer events and does not do any interactivity boosting.
+
+	  Some workloads benefit from using it and it generally should be safe
+	  to use.  Say Y here if you are not happy with the alternatives.
+
 config DT_IDLE_STATES
 	bool
 

drivers/cpuidle/dt_idle_states.c

@@ -22,16 +22,12 @@
 #include "dt_idle_states.h"
 
 static int init_state_node(struct cpuidle_state *idle_state,
-			   const struct of_device_id *matches,
+			   const struct of_device_id *match_id,
 			   struct device_node *state_node)
 {
 	int err;
-	const struct of_device_id *match_id;
 	const char *desc;
 
-	match_id = of_match_node(matches, state_node);
-	if (!match_id)
-		return -ENODEV;
 	/*
 	 * CPUidle drivers are expected to initialize the const void *data
 	 * pointer of the passed in struct of_device_id array to the idle
@@ -160,6 +156,7 @@ int dt_init_idle_driver(struct cpuidle_driver *drv,
 {
 	struct cpuidle_state *idle_state;
 	struct device_node *state_node, *cpu_node;
+	const struct of_device_id *match_id;
 	int i, err = 0;
 	const cpumask_t *cpumask;
 	unsigned int state_idx = start_idx;
@@ -180,6 +177,12 @@ int dt_init_idle_driver(struct cpuidle_driver *drv,
 		if (!state_node)
 			break;
 
+		match_id = of_match_node(matches, state_node);
+		if (!match_id) {
+			err = -ENODEV;
+			break;
+		}
+
 		if (!of_device_is_available(state_node)) {
 			of_node_put(state_node);
 			continue;
@@ -198,7 +201,7 @@ int dt_init_idle_driver(struct cpuidle_driver *drv,
 		}
 
 		idle_state = &drv->states[state_idx++];
-		err = init_state_node(idle_state, matches, state_node);
+		err = init_state_node(idle_state, match_id, state_node);
 		if (err) {
 			pr_err("Parsing idle state node %pOF failed with err %d\n",
 			       state_node, err);

drivers/cpuidle/governors/Makefile

@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_CPU_IDLE_GOV_LADDER) += ladder.o
 obj-$(CONFIG_CPU_IDLE_GOV_MENU) += menu.o
+obj-$(CONFIG_CPU_IDLE_GOV_TEO) += teo.o

drivers/idle/intel_idle.c

@@ -1103,6 +1103,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	INTEL_CPU_FAM6(ATOM_GOLDMONT,		idle_cpu_bxt),
 	INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS,	idle_cpu_bxt),
 	INTEL_CPU_FAM6(ATOM_GOLDMONT_X,		idle_cpu_dnv),
+	INTEL_CPU_FAM6(ATOM_TREMONT_X,		idle_cpu_dnv),
 	{}
 };
 

drivers/powercap/intel_rapl.c

@@ -1156,6 +1156,7 @@ static const struct x86_cpu_id rapl_ids[] __initconst = {
 	INTEL_CPU_FAM6(KABYLAKE_MOBILE,		rapl_defaults_core),
 	INTEL_CPU_FAM6(KABYLAKE_DESKTOP,	rapl_defaults_core),
 	INTEL_CPU_FAM6(CANNONLAKE_MOBILE,	rapl_defaults_core),
+	INTEL_CPU_FAM6(ICELAKE_MOBILE,		rapl_defaults_core),
 
 	INTEL_CPU_FAM6(ATOM_SILVERMONT,		rapl_defaults_byt),
 	INTEL_CPU_FAM6(ATOM_AIRMONT,		rapl_defaults_cht),
@@ -1164,6 +1165,7 @@ static const struct x86_cpu_id rapl_ids[] __initconst = {
 	INTEL_CPU_FAM6(ATOM_GOLDMONT,		rapl_defaults_core),
 	INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS,	rapl_defaults_core),
 	INTEL_CPU_FAM6(ATOM_GOLDMONT_X,		rapl_defaults_core),
+	INTEL_CPU_FAM6(ATOM_TREMONT_X,		rapl_defaults_core),
 
 	INTEL_CPU_FAM6(XEON_PHI_KNL,		rapl_defaults_hsw_server),
 	INTEL_CPU_FAM6(XEON_PHI_KNM,		rapl_defaults_hsw_server),

include/linux/cpuidle.h

@@ -69,11 +69,9 @@ struct cpuidle_state {
 
 /* Idle State Flags */
 #define CPUIDLE_FLAG_NONE       (0x00)
-#define CPUIDLE_FLAG_POLLING	(0x01) /* polling state */
-#define CPUIDLE_FLAG_COUPLED	(0x02) /* state applies to multiple cpus */
-#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
-
-#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
+#define CPUIDLE_FLAG_POLLING	BIT(0) /* polling state */
+#define CPUIDLE_FLAG_COUPLED	BIT(1) /* state applies to multiple cpus */
+#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
 
 struct cpuidle_device_kobj;
 struct cpuidle_state_kobj;