platform/x86/intel/pmt: Add PMT Discovery driver

This patch introduces a new driver to enumerate and expose Intel Platform
Monitoring Technology (PMT) capabilities via a simple discovery mechanism.
The PMT Discovery driver parses hardware-provided discovery tables from
Intel Out of Band Management Services Modules (OOBMSM) and extracts feature
information for various providers (such as TPMI, Telemetry, Crash Log,
etc). This unified interface simplifies the process of determining which
manageability and telemetry features are supported by a given platform.

This new feature is described in the Intel Platform Monitoring Technology
3.0 specification, section 6.6 Capability.

Key changes and additions:

New file drivers/platform/x86/intel/pmt/discovery.c:
  – Implements the discovery logic to map the discovery resource, read
    the feature discovery table, and validate feature parameters.
New file drivers/platform/x86/intel/pmt/features.c:
  – Defines feature names, layouts, and associated capability masks.
  – Provides a mapping between raw hardware attributes and sysfs
    representations for easier integration with user-space tools.
New header include/linux/intel_pmt_features.h:
  – Declares constants, masks, and feature identifiers used across the
    PMT framework.
Sysfs integration:
  – Feature attributes are exposed under /sys/class/intel_pmt.
  – Each device is represented by a subfolder within the intel_pmt class,
    named using its DBDF (Domain:Bus:Device.Function), e.g.:
        features-0000:00:03.1
  – Example directory layout for a device:

    /sys/class/intel_pmt/features-0000:00:03.1/
    ├── accelerator_telemetry
    ├── crash_log
    ├── per_core_environment_telemetry
    ├── per_core_performance_telemetry
    ├── per_rmid_energy_telemetry
    ├── per_rmid_perf_telemetry
    ├── tpmi_control
    ├── tracing
    └── uncore_telemetry

By exposing PMT feature details through sysfs and integrating with the
existing PMT class, this driver paves the way for more streamlined
integration of PMT-based manageability and telemetry tools.

Link: https://www.intel.com/content/www/us/en/content-details/710389/intel-platform-monitoring-technology-intel-pmt-external-specification.html
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20250703022832.1302928-9-david.e.box@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/platform/x86/intel/pmt/features.c b/drivers/platform/x86/intel/pmt/features.c
new file mode 100644
index 000000000000..8a39cddc75c8
--- /dev/null
+++ b/drivers/platform/x86/intel/pmt/features.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: "David E. Box" <david.e.box@linux.intel.com>
+ */
+
+#include <linux/export.h>
+#include <linux/types.h>
+
+#include <linux/intel_pmt_features.h>
+
+const char * const pmt_feature_names[] = {
+	[FEATURE_PER_CORE_PERF_TELEM]	= "per_core_performance_telemetry",
+	[FEATURE_PER_CORE_ENV_TELEM]	= "per_core_environment_telemetry",
+	[FEATURE_PER_RMID_PERF_TELEM]	= "per_rmid_perf_telemetry",
+	[FEATURE_ACCEL_TELEM]		= "accelerator_telemetry",
+	[FEATURE_UNCORE_TELEM]		= "uncore_telemetry",
+	[FEATURE_CRASH_LOG]		= "crash_log",
+	[FEATURE_PETE_LOG]		= "pete_log",
+	[FEATURE_TPMI_CTRL]		= "tpmi_control",
+	[FEATURE_TRACING]		= "tracing",
+	[FEATURE_PER_RMID_ENERGY_TELEM]	= "per_rmid_energy_telemetry",
+};
+EXPORT_SYMBOL_NS_GPL(pmt_feature_names, "INTEL_PMT_DISCOVERY");
+
+enum feature_layout feature_layout[] = {
+	[FEATURE_PER_CORE_PERF_TELEM]	= LAYOUT_WATCHER,
+	[FEATURE_PER_CORE_ENV_TELEM]	= LAYOUT_WATCHER,
+	[FEATURE_PER_RMID_PERF_TELEM]	= LAYOUT_RMID,
+	[FEATURE_ACCEL_TELEM]		= LAYOUT_WATCHER,
+	[FEATURE_UNCORE_TELEM]		= LAYOUT_WATCHER,
+	[FEATURE_CRASH_LOG]		= LAYOUT_COMMAND,
+	[FEATURE_PETE_LOG]		= LAYOUT_COMMAND,
+	[FEATURE_TPMI_CTRL]		= LAYOUT_CAPS_ONLY,
+	[FEATURE_TRACING]		= LAYOUT_CAPS_ONLY,
+	[FEATURE_PER_RMID_ENERGY_TELEM]	= LAYOUT_RMID,
+};
+
+struct pmt_cap pmt_cap_common[] = {
+	{PMT_CAP_TELEM,		"telemetry"},
+	{PMT_CAP_WATCHER,	"watcher"},
+	{PMT_CAP_CRASHLOG,	"crashlog"},
+	{PMT_CAP_STREAMING,	"streaming"},
+	{PMT_CAP_THRESHOLD,	"threshold"},
+	{PMT_CAP_WINDOW,	"window"},
+	{PMT_CAP_CONFIG,	"config"},
+	{PMT_CAP_TRACING,	"tracing"},
+	{PMT_CAP_INBAND,	"inband"},
+	{PMT_CAP_OOB,		"oob"},
+	{PMT_CAP_SECURED_CHAN,	"secure_chan"},
+	{PMT_CAP_PMT_SP,	"pmt_sp"},
+	{PMT_CAP_PMT_SP_POLICY,	"pmt_sp_policy"},
+	{}
+};
+
+struct pmt_cap pmt_cap_pcpt[] = {
+	{PMT_CAP_PCPT_CORE_PERF,	"core_performance"},
+	{PMT_CAP_PCPT_CORE_C0_RES,	"core_c0_residency"},
+	{PMT_CAP_PCPT_CORE_ACTIVITY,	"core_activity"},
+	{PMT_CAP_PCPT_CACHE_PERF,	"cache_performance"},
+	{PMT_CAP_PCPT_QUALITY_TELEM,	"quality_telemetry"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_pcpt[] = {
+	pmt_cap_common,
+	pmt_cap_pcpt,
+	NULL
+};
+
+struct pmt_cap pmt_cap_pcet[] = {
+	{PMT_CAP_PCET_WORKPOINT_HIST,	"workpoint_histogram"},
+	{PMT_CAP_PCET_CORE_CURR_TEMP,	"core_current_temp"},
+	{PMT_CAP_PCET_CORE_INST_RES,	"core_inst_residency"},
+	{PMT_CAP_PCET_QUALITY_TELEM,	"quality_telemetry"},
+	{PMT_CAP_PCET_CORE_CDYN_LVL,	"core_cdyn_level"},
+	{PMT_CAP_PCET_CORE_STRESS_LVL,	"core_stress_level"},
+	{PMT_CAP_PCET_CORE_DAS,		"core_digital_aging_sensor"},
+	{PMT_CAP_PCET_FIVR_HEALTH,	"fivr_health"},
+	{PMT_CAP_PCET_ENERGY,		"energy"},
+	{PMT_CAP_PCET_PEM_STATUS,	"pem_status"},
+	{PMT_CAP_PCET_CORE_C_STATE,	"core_c_state"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_pcet[] = {
+	pmt_cap_common,
+	pmt_cap_pcet,
+	NULL
+};
+
+struct pmt_cap pmt_cap_rmid_perf[] = {
+	{PMT_CAP_RMID_CORES_PERF,	"core_performance"},
+	{PMT_CAP_RMID_CACHE_PERF,	"cache_performance"},
+	{PMT_CAP_RMID_PERF_QUAL,	"performance_quality"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_rmid_perf[] = {
+	pmt_cap_common,
+	pmt_cap_rmid_perf,
+	NULL
+};
+
+struct pmt_cap pmt_cap_accel[] = {
+	{PMT_CAP_ACCEL_CPM_TELEM,	"content_processing_module"},
+	{PMT_CAP_ACCEL_TIP_TELEM,	"content_turbo_ip"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_accel[] = {
+	pmt_cap_common,
+	pmt_cap_accel,
+	NULL
+};
+
+struct pmt_cap pmt_cap_uncore[] = {
+	{PMT_CAP_UNCORE_IO_CA_TELEM,	"io_ca"},
+	{PMT_CAP_UNCORE_RMID_TELEM,	"rmid"},
+	{PMT_CAP_UNCORE_D2D_ULA_TELEM,	"d2d_ula"},
+	{PMT_CAP_UNCORE_PKGC_TELEM,	"package_c"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_uncore[] = {
+	pmt_cap_common,
+	pmt_cap_uncore,
+	NULL
+};
+
+struct pmt_cap pmt_cap_crashlog[] = {
+	{PMT_CAP_CRASHLOG_MAN_TRIG,	"manual_trigger"},
+	{PMT_CAP_CRASHLOG_CORE,		"core"},
+	{PMT_CAP_CRASHLOG_UNCORE,	"uncore"},
+	{PMT_CAP_CRASHLOG_TOR,		"tor"},
+	{PMT_CAP_CRASHLOG_S3M,		"s3m"},
+	{PMT_CAP_CRASHLOG_PERSISTENCY,	"persistency"},
+	{PMT_CAP_CRASHLOG_CLIP_GPIO,	"crashlog_in_progress"},
+	{PMT_CAP_CRASHLOG_PRE_RESET,	"pre_reset_extraction"},
+	{PMT_CAP_CRASHLOG_POST_RESET,	"post_reset_extraction"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_crashlog[] = {
+	pmt_cap_common,
+	pmt_cap_crashlog,
+	NULL
+};
+
+struct pmt_cap pmt_cap_pete[] = {
+	{PMT_CAP_PETE_MAN_TRIG,		"manual_trigger"},
+	{PMT_CAP_PETE_ENCRYPTION,	"encryption"},
+	{PMT_CAP_PETE_PERSISTENCY,	"persistency"},
+	{PMT_CAP_PETE_REQ_TOKENS,	"required_tokens"},
+	{PMT_CAP_PETE_PROD_ENABLED,	"production_enabled"},
+	{PMT_CAP_PETE_DEBUG_ENABLED,	"debug_enabled"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_pete[] = {
+	pmt_cap_common,
+	pmt_cap_pete,
+	NULL
+};
+
+struct pmt_cap pmt_cap_tpmi[] = {
+	{PMT_CAP_TPMI_MAILBOX,		"mailbox"},
+	{PMT_CAP_TPMI_LOCK,		"bios_lock"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_tpmi[] = {
+	pmt_cap_common,
+	pmt_cap_tpmi,
+	NULL
+};
+
+struct pmt_cap pmt_cap_tracing[] = {
+	{PMT_CAP_TRACE_SRAR,		"srar_errors"},
+	{PMT_CAP_TRACE_CORRECTABLE,	"correctable_errors"},
+	{PMT_CAP_TRACE_MCTP,		"mctp"},
+	{PMT_CAP_TRACE_MRT,		"memory_resiliency"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_tracing[] = {
+	pmt_cap_common,
+	pmt_cap_tracing,
+	NULL
+};
+
+struct pmt_cap pmt_cap_rmid_energy[] = {
+	{PMT_CAP_RMID_ENERGY,		"energy"},
+	{PMT_CAP_RMID_ACTIVITY,		"activity"},
+	{PMT_CAP_RMID_ENERGY_QUAL,	"energy_quality"},
+	{}
+};
+
+struct pmt_cap *pmt_caps_rmid_energy[] = {
+	pmt_cap_common,
+	pmt_cap_rmid_energy,
+	NULL
+};