Merge tag 'acpi-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI support updates from Rafael Wysocki:
 "These include an update of the CMOS RTC driver and the related ACPI
  and x86 code that, among other things, switches it over to using the
  platform device interface for device binding on x86 instead of the PNP
  device driver interface (which allows the code in question to be
  simplified quite a bit), a major update of the ACPI Time and Alarm
  Device (TAD) driver adding an RTC class device interface to it, and
  updates of core ACPI drivers that remove some unnecessary and not
  really useful code from them.

  Apart from that, two drivers are converted to using the platform
  driver interface for device binding instead of the ACPI driver one,
  which is slated for removal, support for the Performance Limited
  register is added to the ACPI CPPC library and there are some
  janitorial updates of it and the related cpufreq CPPC driver, the ACPI
  processor driver is fixed and cleaned up, and NVIDIA vendor CPER
  record handler is added to the APEI GHES code.

  Also, the interface for obtaining a CPU UID from ACPI is consolidated
  across architectures and used for fixing a problem with the PCI TPH
  Steering Tag on ARM64, there are two updates related to ACPICA, a
  minor ACPI OS Services Layer (OSL) update, and a few assorted updates
  related to ACPI tables parsing.

  Specifics:

   - Update maintainers information regarding ACPICA (Rafael Wysocki)

   - Replace strncpy() with strscpy_pad() in acpi_ut_safe_strncpy()
     (Kees Cook)

   - Trigger an ordered system power off after encountering a fatal
     error operator in AML (Armin Wolf)

   - Enable ACPI FPDT parsing on LoongArch (Xi Ruoyao)

   - Remove the temporary stop-gap acpi_pptt_cache_v1_full structure
     from the ACPI PPTT parser (Ben Horgan)

   - Add support for exposing ACPI FPDT subtables FBPT and S3PT (Nate
     DeSimone)

   - Address multiple assorted issues and clean up the code in the ACPI
     processor idle driver (Huisong Li)

   - Replace strlcat() in the ACPI processor idle drive with a better
     alternative (Andy Shevchenko)

   - Rearrange and clean up acpi_processor_errata_piix4() (Rafael
     Wysocki)

   - Move reference performance to capabilities and fix an uninitialized
     variable in the ACPI CPPC library (Pengjie Zhang)

   - Add support for the Performance Limited Register to the ACPI CPPC
     library (Sumit Gupta)

   - Add cppc_get_perf() API to read performance controls, extend
     cppc_set_epp_perf() for FFH/SystemMemory, and make the ACPI CPPC
     library warn on missing mandatory DESIRED_PERF register (Sumit
     Gupta)

   - Modify the cpufreq CPPC driver to update MIN_PERF/MAX_PERF in
     target callbacks to allow it to control performance bounds via
     standard scaling_min_freq and scaling_max_freq sysfs attributes and
     add sysfs documentation for the Performance Limited Register to it
     (Sumit Gupta)

   - Add ACPI support to the platform device interface in the CMOS RTC
     driver, make the ACPI core device enumeration code create a
     platform device for the CMOS RTC, and drop CMOS RTC PNP device
     support (Rafael Wysocki)

   - Consolidate the x86-specific CMOS RTC handling with the ACPI TAD
     driver and clean up the CMOS RTC ACPI address space handler (Rafael
     Wysocki)

   - Enable ACPI alarm in the CMOS RTC driver if advertised in ACPI FADT
     and allow that driver to work without a dedicated IRQ if the ACPI
     alarm is used (Rafael Wysocki)

   - Clean up the ACPI TAD driver in various ways and add an RTC class
     device interface, including both the RTC setting/reading and alarm
     timer support, to it (Rafael Wysocki)

   - Clean up the ACPI AC and ACPI PAD (processor aggregator device)
     drivers (Rafael Wysocki)

   - Rework checking for duplicate video bus devices and consolidate
     pnp.bus_id workarounds handling in the ACPI video bus driver
     (Rafael Wysocki)

   - Update the ACPI core device drivers to stop setting
     acpi_device_name() unnecessarily (Rafael Wysocki)

   - Rearrange code using acpi_device_class() in the ACPI core device
     drivers and update them to stop setting acpi_device_class()
     unnecessarily (Rafael Wysocki)

   - Define ACPI_AC_CLASS in one place (Rafael Wysocki)

   - Convert the ni903x_wdt watchdog driver and the xen ACPI PAD driver
     to bind to platform devices instead of ACPI devices (Rafael
     Wysocki)

   - Add devm_ghes_register_vendor_record_notifier(), use it in the PCI
     hisi driver, and Add NVIDIA vendor CPER record handler (Kai-Heng
     Feng)

   - Consolidate the interface for obtaining a CPU UID from ACPI across
     architectures and use it to address incorrect PCI TPH Steering Tag
     on ARM64 resulting from the invalid assumption that the ACPI
     Processor UID would always be the same as the corresponding logical
     CPU ID in Linux (Chengwen Feng)"

* tag 'acpi-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (73 commits)
  ACPICA: Update maintainers information
  watchdog: ni903x_wdt: Convert to a platform driver
  ACPI: PAD: xen: Convert to a platform driver
  ACPI: processor: idle: Reset cpuidle on C-state list changes
  cpuidle: Extract and export no-lock variants of cpuidle_unregister_device()
  PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM
  ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()
  perf: arm_cspmu: Switch to acpi_get_cpu_uid() from get_acpi_id_for_cpu()
  ACPI: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h
  x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  ACPI: APEI: GHES: Add NVIDIA vendor CPER record handler
  PCI: hisi: Use devm_ghes_register_vendor_record_notifier()
  ACPI: APEI: GHES: Add devm_ghes_register_vendor_record_notifier()
  ACPI: tables: Enable FPDT on LoongArch
  ACPI: processor: idle: Fix NULL pointer dereference in hotplug path
  ACPI: processor: idle: Reset power_setup_done flag on initialization failure
  ACPI: TAD: Add alarm support to the RTC class device interface
  ...

Author: torvalds

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -327,6 +327,24 @@ Description:	Energy performance preference
 
 		This file is only present if the cppc-cpufreq driver is in use.
 
+What:		/sys/devices/system/cpu/cpuX/cpufreq/perf_limited
+Date:		February 2026
+Contact:	linux-pm@vger.kernel.org
+Description:	Performance Limited
+
+		Read to check if platform throttling (thermal/power/current
+		limits) caused delivered performance to fall below the
+		requested level. A non-zero value indicates throttling occurred.
+
+		Write the bitmask of bits to clear:
+
+		  - 0x1 = clear bit 0 (desired performance excursion)
+		  - 0x2 = clear bit 1 (minimum performance excursion)
+		  - 0x3 = clear both bits
+
+		The platform sets these bits; OSPM can only clear them.
+
+		This file is only present if the cppc-cpufreq driver is in use.
 
 What:		/sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
 Date:		August 2008

Documentation/ABI/testing/sysfs-firmware-acpi

@@ -41,6 +41,12 @@ Description:
 				platform runtime firmware S3 resume, just prior to
 				handoff to the OS waking vector. In nanoseconds.
 
+		FBPT: The raw binary contents of the Firmware Basic Boot
+			Performance Table (FBPT) subtable.
+
+		S3PT: The raw binary contents of the S3 Performance Table
+			(S3PT) subtable.
+
 What:		/sys/firmware/acpi/bgrt/
 Date:		January 2012
 Contact:	Matthew Garrett <mjg@redhat.com>

Documentation/PCI/tph.rst

@@ -79,10 +79,10 @@ To retrieve a Steering Tag for a target memory associated with a specific
 CPU, use the following function::
 
   int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type type,
-                          unsigned int cpu_uid, u16 *tag);
+                          unsigned int cpu, u16 *tag);
 
 The `type` argument is used to specify the memory type, either volatile
-or persistent, of the target memory. The `cpu_uid` argument specifies the
+or persistent, of the target memory. The `cpu` argument specifies the
 CPU where the memory is associated to.
 
 After the ST value is retrieved, the device driver can use the following

Documentation/admin-guide/kernel-parameters.txt

@@ -190,6 +190,14 @@ Kernel parameters
 			unusable.  The "log_buf_len" parameter may be useful
 			if you need to capture more output.
 
+	acpi.poweroff_on_fatal=	[ACPI]
+			{0 | 1}
+			Causes the system to poweroff when the ACPI bytecode signals
+			a fatal error. The default value of this setting is 1.
+			Overriding this value should only be done for diagnosing
+			ACPI firmware problems, as the system might behave erratically
+			after having encountered a fatal ACPI error.
+
 	acpi_enforce_resources=	[ACPI]
 			{ strict | lax | no }
 			Check for resource conflicts between native drivers

MAINTAINERS

@@ -318,7 +318,7 @@ F:	drivers/firmware/efi/cper*
 
 ACPI COMPONENT ARCHITECTURE (ACPICA)
 M:	"Rafael J. Wysocki" <rafael@kernel.org>
-M:	Robert Moore <robert.moore@intel.com>
+M:	Saket Dumbre <saket.dumbre@intel.com>
 L:	linux-acpi@vger.kernel.org
 L:	acpica-devel@lists.linux.dev
 S:	Supported
@@ -18923,6 +18923,12 @@ S:	Maintained
 F:	drivers/video/fbdev/nvidia/
 F:	drivers/video/fbdev/riva/
 
+NVIDIA GHES VENDOR CPER RECORD HANDLER
+M:	Kai-Heng Feng <kaihengf@nvidia.com>
+L:	linux-acpi@vger.kernel.org
+S:	Maintained
+F:	drivers/acpi/apei/nvidia-ghes.c
+
 NVIDIA VRS RTC DRIVER
 M:	Shubhi Garg <shgarg@nvidia.com>
 L:	linux-tegra@vger.kernel.org

arch/arm64/include/asm/acpi.h

@@ -114,22 +114,7 @@ static inline bool acpi_has_cpu_in_madt(void)
 }
 
 struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu);
-static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
-{
-	return	acpi_cpu_get_madt_gicc(cpu)->uid;
-}
-
-static inline int get_cpu_for_acpi_id(u32 uid)
-{
-	int cpu;
-
-	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
-		if (acpi_cpu_get_madt_gicc(cpu) &&
-		    uid == get_acpi_id_for_cpu(cpu))
-			return cpu;
-
-	return -EINVAL;
-}
+int get_cpu_for_acpi_id(u32 uid);
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);

arch/arm64/kernel/acpi.c

@@ -458,3 +458,33 @@ int acpi_unmap_cpu(int cpu)
 }
 EXPORT_SYMBOL(acpi_unmap_cpu);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+	struct acpi_madt_generic_interrupt *gicc;
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	gicc = acpi_cpu_get_madt_gicc(cpu);
+	if (!gicc)
+		return -ENODEV;
+
+	*uid = gicc->uid;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
+
+int get_cpu_for_acpi_id(u32 uid)
+{
+	u32 cpu_uid;
+	int ret;
+
+	for (int cpu = 0; cpu < nr_cpu_ids; cpu++) {
+		ret = acpi_get_cpu_uid(cpu, &cpu_uid);
+		if (ret == 0 && uid == cpu_uid)
+			return cpu;
+	}
+
+	return -EINVAL;
+}

arch/loongarch/include/asm/acpi.h

@@ -40,11 +40,6 @@ extern struct acpi_madt_core_pic acpi_core_pic[MAX_CORE_PIC];
 
 extern int __init parse_acpi_topology(void);
 
-static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
-{
-	return acpi_core_pic[cpu_logical_map(cpu)].processor_id;
-}
-
 #endif /* !CONFIG_ACPI */
 
 #define ACPI_TABLE_UPGRADE_MAX_PHYS ARCH_LOW_ADDRESS_LIMIT

arch/loongarch/kernel/acpi.c

@@ -385,3 +385,12 @@ int acpi_unmap_cpu(int cpu)
 EXPORT_SYMBOL(acpi_unmap_cpu);
 
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+	*uid = acpi_core_pic[cpu_logical_map(cpu)].processor_id;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);

arch/riscv/include/asm/acpi.h

@@ -61,10 +61,6 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 
 void acpi_init_rintc_map(void);
 struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu);
-static inline u32 get_acpi_id_for_cpu(int cpu)
-{
-	return acpi_cpu_get_madt_rintc(cpu)->uid;
-}
 
 int acpi_get_riscv_isa(struct acpi_table_header *table,
 		       unsigned int cpu, const char **isa);