Merge branch 'thermal-hfi'

Merge Intel Hardware Feedback Interface (HFI) thermal driver for
5.18-rc1 and update the intel-speed-select utility to support that
driver.

* thermal-hfi:
  tools/power/x86/intel-speed-select: v1.12 release
  tools/power/x86/intel-speed-select: HFI support
  tools/power/x86/intel-speed-select: OOB daemon mode
  thermal: intel: hfi: INTEL_HFI_THERMAL depends on NET
  thermal: netlink: Fix parameter type of thermal_genl_cpu_capability_event() stub
  thermal: intel: hfi: Notify user space for HFI events
  thermal: netlink: Add a new event to notify CPU capabilities change
  thermal: intel: hfi: Enable notification interrupt
  thermal: intel: hfi: Handle CPU hotplug events
  thermal: intel: hfi: Minimally initialize the Hardware Feedback Interface
  x86/cpu: Add definitions for the Intel Hardware Feedback Interface
  x86/Documentation: Describe the Intel Hardware Feedback Interface

Documentation/x86/index.rst

@@ -21,6 +21,7 @@ x86-specific Documentation
    tlb
    mtrr
    pat
+   intel-hfi
    intel-iommu
    intel_txt
    amd-memory-encryption

Documentation/x86/intel-hfi.rst

@@ -0,0 +1,72 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================================================
+Hardware-Feedback Interface for scheduling on Intel Hardware
+============================================================
+
+Overview
+--------
+
+Intel has described the Hardware Feedback Interface (HFI) in the Intel 64 and
+IA-32 Architectures Software Developer's Manual (Intel SDM) Volume 3 Section
+14.6 [1]_.
+
+The HFI gives the operating system a performance and energy efficiency
+capability data for each CPU in the system. Linux can use the information from
+the HFI to influence task placement decisions.
+
+The Hardware Feedback Interface
+-------------------------------
+
+The Hardware Feedback Interface provides to the operating system information
+about the performance and energy efficiency of each CPU in the system. Each
+capability is given as a unit-less quantity in the range [0-255]. Higher values
+indicate higher capability. Energy efficiency and performance are reported in
+separate capabilities. Even though on some systems these two metrics may be
+related, they are specified as independent capabilities in the Intel SDM.
+
+These capabilities may change at runtime as a result of changes in the
+operating conditions of the system or the action of external factors. The rate
+at which these capabilities are updated is specific to each processor model. On
+some models, capabilities are set at boot time and never change. On others,
+capabilities may change every tens of milliseconds. For instance, a remote
+mechanism may be used to lower Thermal Design Power. Such change can be
+reflected in the HFI. Likewise, if the system needs to be throttled due to
+excessive heat, the HFI may reflect reduced performance on specific CPUs.
+
+The kernel or a userspace policy daemon can use these capabilities to modify
+task placement decisions. For instance, if either the performance or energy
+capabilities of a given logical processor becomes zero, it is an indication that
+the hardware recommends to the operating system to not schedule any tasks on
+that processor for performance or energy efficiency reasons, respectively.
+
+Implementation details for Linux
+--------------------------------
+
+The infrastructure to handle thermal event interrupts has two parts. In the
+Local Vector Table of a CPU's local APIC, there exists a register for the
+Thermal Monitor Register. This register controls how interrupts are delivered
+to a CPU when the thermal monitor generates and interrupt. Further details
+can be found in the Intel SDM Vol. 3 Section 10.5 [1]_.
+
+The thermal monitor may generate interrupts per CPU or per package. The HFI
+generates package-level interrupts. This monitor is configured and initialized
+via a set of machine-specific registers. Specifically, the HFI interrupt and
+status are controlled via designated bits in the IA32_PACKAGE_THERM_INTERRUPT
+and IA32_PACKAGE_THERM_STATUS registers, respectively. There exists one HFI
+table per package. Further details can be found in the Intel SDM Vol. 3
+Section 14.9 [1]_.
+
+The hardware issues an HFI interrupt after updating the HFI table and is ready
+for the operating system to consume it. CPUs receive such interrupt via the
+thermal entry in the Local APIC's Local Vector Table.
+
+When servicing such interrupt, the HFI driver parses the updated table and
+relays the update to userspace using the thermal notification framework. Given
+that there may be many HFI updates every second, the updates relayed to
+userspace are throttled at a rate of CONFIG_HZ jiffies.
+
+References
+----------
+
+.. [1] https://www.intel.com/sdm

arch/x86/include/asm/cpufeatures.h

@@ -330,6 +330,7 @@
 #define X86_FEATURE_HWP_ACT_WINDOW	(14*32+ 9) /* HWP Activity Window */
 #define X86_FEATURE_HWP_EPP		(14*32+10) /* HWP Energy Perf. Preference */
 #define X86_FEATURE_HWP_PKG_REQ		(14*32+11) /* HWP Package Level Request */
+#define X86_FEATURE_HFI			(14*32+19) /* Hardware Feedback Interface */
 
 /* AMD SVM Feature Identification, CPUID level 0x8000000a (EDX), word 15 */
 #define X86_FEATURE_NPT			(15*32+ 0) /* Nested Page Table support */

arch/x86/include/asm/msr-index.h

@@ -705,12 +705,14 @@
 
 #define PACKAGE_THERM_STATUS_PROCHOT		(1 << 0)
 #define PACKAGE_THERM_STATUS_POWER_LIMIT	(1 << 10)
+#define PACKAGE_THERM_STATUS_HFI_UPDATED	(1 << 26)
 
 #define MSR_IA32_PACKAGE_THERM_INTERRUPT	0x000001b2
 
 #define PACKAGE_THERM_INT_HIGH_ENABLE		(1 << 0)
 #define PACKAGE_THERM_INT_LOW_ENABLE		(1 << 1)
 #define PACKAGE_THERM_INT_PLN_ENABLE		(1 << 24)
+#define PACKAGE_THERM_INT_HFI_ENABLE		(1 << 25)
 
 /* Thermal Thresholds Support */
 #define THERM_INT_THRESHOLD0_ENABLE    (1 << 15)
@@ -959,4 +961,8 @@
 #define MSR_VM_IGNNE                    0xc0010115
 #define MSR_VM_HSAVE_PA                 0xc0010117
 
+/* Hardware Feedback Interface */
+#define MSR_IA32_HW_FEEDBACK_PTR        0x17d0
+#define MSR_IA32_HW_FEEDBACK_CONFIG     0x17d1
+
 #endif /* _ASM_X86_MSR_INDEX_H */

drivers/thermal/intel/Kconfig

@@ -99,3 +99,17 @@ config INTEL_MENLOW
 	  Intel Menlow platform.
 
 	  If unsure, say N.
+
+config INTEL_HFI_THERMAL
+	bool "Intel Hardware Feedback Interface"
+	depends on NET
+	depends on CPU_SUP_INTEL
+	depends on X86_THERMAL_VECTOR
+	select THERMAL_NETLINK
+	help
+	  Select this option to enable the Hardware Feedback Interface. If
+	  selected, hardware provides guidance to the operating system on
+	  the performance and energy efficiency capabilities of each CPU.
+	  These capabilities may change as a result of changes in the operating
+	  conditions of the system such power and thermal limits. If selected,
+	  the kernel relays updates in CPUs' capabilities to userspace.

drivers/thermal/intel/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_INTEL_PCH_THERMAL)	+= intel_pch_thermal.o
 obj-$(CONFIG_INTEL_TCC_COOLING)	+= intel_tcc_cooling.o
 obj-$(CONFIG_X86_THERMAL_VECTOR) += therm_throt.o
 obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o
+obj-$(CONFIG_INTEL_HFI_THERMAL) += intel_hfi.o