Merge tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "The new feaures here are the support for ACPI overlays (allowing ACPI
  tables to be loaded at any time from EFI variables or via configfs)
  and the LPI (Low-Power Idle) support.  Also notable is the ACPI-based
  NUMA support for ARM64.

  Apart from that we have two new drivers, for the DPTF (Dynamic Power
  and Thermal Framework) power participant device and for the Intel
  Broxton WhiskeyCove PMIC, some more PMIC-related changes, support for
  the Boot Error Record Table (BERT) in APEI and support for
  platform-initiated graceful shutdown.

  Plus two new pieces of documentation and usual assorted fixes and
  cleanups in quite a few places.

  Specifics:

   - Support for ACPI SSDT overlays allowing Secondary System
     Description Tables (SSDTs) to be loaded at any time from EFI
     variables or via configfs (Octavian Purdila, Mika Westerberg).

   - Support for the ACPI LPI (Low-Power Idle) feature introduced in
     ACPI 6.0 and allowing processor idle states to be represented in
     ACPI tables in a hierarchical way (with the help of Processor
     Container objects) and support for ACPI idle states management on
     ARM64, based on LPI (Sudeep Holla).

   - General improvements of ACPI support for NUMA and ARM64 support for
     ACPI-based NUMA (Hanjun Guo, David Daney, Robert Richter).

   - General improvements of the ACPI table upgrade mechanism and ARM64
     support for that feature (Aleksey Makarov, Jon Masters).

   - Support for the Boot Error Record Table (BERT) in APEI and
     improvements of kernel messages printed by the error injection code
     (Huang Ying, Borislav Petkov).

   - New driver for the Intel Broxton WhiskeyCove PMIC operation region
     and support for the REGS operation region on Broxton, PMIC code
     cleanups (Bin Gao, Felipe Balbi, Paul Gortmaker).

   - New driver for the power participant device which is part of the
     Dynamic Power and Thermal Framework (DPTF) and DPTF-related code
     reorganization (Srinivas Pandruvada).

   - Support for the platform-initiated graceful shutdown feature
     introduced in ACPI 6.1 (Prashanth Prakash).

   - ACPI button driver update related to lid input events generated
     automatically on initialization and system resume that have been
     problematic for some time (Lv Zheng).

   - ACPI EC driver cleanups (Lv Zheng).

   - Documentation of the ACPICA release automation process and the
     in-kernel ACPI AML debugger (Lv Zheng).

   - New blacklist entry and two fixes for the ACPI backlight driver
     (Alex Hung, Arvind Yadav, Ralf Gerbig).

   - Cleanups of the ACPI pci_slot driver (Joe Perches, Paul Gortmaker).

   - ACPI CPPC code changes to make it more robust against possible
     defects in ACPI tables and new symbol definitions for PCC (Hoan
     Tran).

   - System reboot code modification to execute the ACPI _PTS (Prepare
     To Sleep) method in addition to _TTS (Ocean He).

   - ACPICA-related change to carry out lock ordering checks in ACPICA
     if ACPICA debug is enabled in the kernel (Lv Zheng).

   - Assorted minor fixes and cleanups (Andy Shevchenko, Baoquan He,
     Bhaktipriya Shridhar, Paul Gortmaker, Rafael Wysocki)"

* tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (71 commits)
  ACPI: enable ACPI_PROCESSOR_IDLE on ARM64
  arm64: add support for ACPI Low Power Idle(LPI)
  drivers: firmware: psci: initialise idle states using ACPI LPI
  cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}
  arm64: cpuidle: drop __init section marker to arm_cpuidle_init
  ACPI / processor_idle: Add support for Low Power Idle(LPI) states
  ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE
  ACPI / DPTF: move int340x_thermal.c to the DPTF folder
  ACPI / DPTF: Add DPTF power participant driver
  ACPI / lpat: make it explicitly non-modular
  ACPI / dock: make dock explicitly non-modular
  ACPI / PCI: make pci_slot explicitly non-modular
  ACPI / PMIC: remove modular references from non-modular code
  ACPICA: Linux: Enable ACPI_MUTEX_DEBUG for Linux kernel
  ACPI: Rename configfs.c to acpi_configfs.c to prevent link error
  ACPI / debugger: Add AML debugger documentation
  ACPI: Add documentation describing ACPICA release automation
  ACPI: add support for loading SSDTs via configfs
  ACPI: add support for configfs
  efi / ACPI: load SSTDs from EFI variables
  ...

1 files changed, 96 insertions, 0 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 05509f3aaee8..8730fd475bf3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -24,6 +24,9 @@
 #include <linux/of_fdt.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/ucs2_string.h>
 
 #include <asm/early_ioremap.h>
 
@@ -195,6 +198,96 @@ static void generic_ops_unregister(void)
 	efivars_unregister(&generic_efivars);
 }
 
+#if IS_ENABLED(CONFIG_ACPI)
+#define EFIVAR_SSDT_NAME_MAX	16
+static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
+static int __init efivar_ssdt_setup(char *str)
+{
+	if (strlen(str) < sizeof(efivar_ssdt))
+		memcpy(efivar_ssdt, str, strlen(str));
+	else
+		pr_warn("efivar_ssdt: name too long: %s\n", str);
+	return 0;
+}
+__setup("efivar_ssdt=", efivar_ssdt_setup);
+
+static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
+				   unsigned long name_size, void *data)
+{
+	struct efivar_entry *entry;
+	struct list_head *list = data;
+	char utf8_name[EFIVAR_SSDT_NAME_MAX];
+	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
+
+	ucs2_as_utf8(utf8_name, name, limit - 1);
+	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
+		return 0;
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return 0;
+
+	memcpy(entry->var.VariableName, name, name_size);
+	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
+
+	efivar_entry_add(entry, list);
+
+	return 0;
+}
+
+static __init int efivar_ssdt_load(void)
+{
+	LIST_HEAD(entries);
+	struct efivar_entry *entry, *aux;
+	unsigned long size;
+	void *data;
+	int ret;
+
+	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
+
+	list_for_each_entry_safe(entry, aux, &entries, list) {
+		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
+			&entry->var.VendorGuid);
+
+		list_del(&entry->list);
+
+		ret = efivar_entry_size(entry, &size);
+		if (ret) {
+			pr_err("failed to get var size\n");
+			goto free_entry;
+		}
+
+		data = kmalloc(size, GFP_KERNEL);
+		if (!data)
+			goto free_entry;
+
+		ret = efivar_entry_get(entry, NULL, &size, data);
+		if (ret) {
+			pr_err("failed to get var data\n");
+			goto free_data;
+		}
+
+		ret = acpi_load_table(data);
+		if (ret) {
+			pr_err("failed to load table: %d\n", ret);
+			goto free_data;
+		}
+
+		goto free_entry;
+
+free_data:
+		kfree(data);
+
+free_entry:
+		kfree(entry);
+	}
+
+	return ret;
+}
+#else
+static inline int efivar_ssdt_load(void) { return 0; }
+#endif
+
 /*
  * We register the efi subsystem with the firmware subsystem and the
  * efivars subsystem with the efi subsystem, if the system was booted with
@@ -218,6 +311,9 @@ static int __init efisubsys_init(void)
 	if (error)
 		goto err_put;
 
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		efivar_ssdt_load();
+
 	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
 	if (error) {
 		pr_err("efi: Sysfs attribute export failed with error %d.\n",