linux/drivers/acpi/acpi_processor.c
Srinivas Pandruvada a21211672c ACPI / processor: Request native thermal interrupt handling via _OSC
There are several reports of freeze on enabling HWP (Hardware PStates)
feature on Skylake-based systems by the Intel P-states driver. The root
cause is identified as the HWP interrupts causing BIOS code to freeze.

HWP interrupts use the thermal LVT which can be handled by Linux
natively, but on the affected Skylake-based systems SMM will respond
to it by default.  This is a problem for several reasons:
 - On the affected systems the SMM thermal LVT handler is broken (it
   will crash when invoked) and a BIOS update is necessary to fix it.
 - With thermal interrupt handled in SMM we lose all of the reporting
   features of the arch/x86/kernel/cpu/mcheck/therm_throt driver.
 - Some thermal drivers like x86-package-temp depend on the thermal
   threshold interrupts signaled via the thermal LVT.
 - The HWP interrupts are useful for debugging and tuning
   performance (if the kernel can handle them).
The native handling of thermal interrupts needs to be enabled
because of that.

This requires some way to tell SMM that the OS can handle thermal
interrupts.  That can be done by using _OSC/_PDC in processor
scope very early during ACPI initialization.

The meaning of _OSC/_PDC bit 12 in processor scope is whether or
not the OS supports native handling of interrupts for Collaborative
Processor Performance Control (CPPC) notifications.  Since on
HWP-capable systems CPPC is a firmware interface to HWP, setting
this bit effectively tells the firmware that the OS will handle
thermal interrupts natively going forward.

For details on _OSC/_PDC refer to:
http://www.intel.com/content/www/us/en/standards/processor-vendor-specific-acpi-specification.html

To implement the _OSC/_PDC handshake as described, introduce a new
function, acpi_early_processor_osc(), that walks the ACPI
namespace looking for ACPI processor objects and invokes _OSC for
them with bit 12 in the capabilities buffer set and terminates the
namespace walk on the first success.

Also modify intel_thermal_interrupt() to clear HWP status bits in
the HWP_STATUS MSR to acknowledge HWP interrupts (which prevents
them from firing continuously).

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject & changelog, function rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-26 02:00:38 +01:00

590 lines
15 KiB
C

/*
* acpi_processor.c - ACPI processor enumeration support
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* Copyright (C) 2013, Intel Corporation
* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <acpi/processor.h>
#include <asm/cpu.h>
#include "internal.h"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor");
DEFINE_PER_CPU(struct acpi_processor *, processors);
EXPORT_PER_CPU_SYMBOL(processors);
/* --------------------------------------------------------------------------
Errata Handling
-------------------------------------------------------------------------- */
struct acpi_processor_errata errata __read_mostly;
EXPORT_SYMBOL_GPL(errata);
static int acpi_processor_errata_piix4(struct pci_dev *dev)
{
u8 value1 = 0;
u8 value2 = 0;
if (!dev)
return -EINVAL;
/*
* Note that 'dev' references the PIIX4 ACPI Controller.
*/
switch (dev->revision) {
case 0:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
break;
case 1:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
break;
case 2:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
break;
case 3:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
break;
}
switch (dev->revision) {
case 0: /* PIIX4 A-step */
case 1: /* PIIX4 B-step */
/*
* See specification changes #13 ("Manual Throttle Duty Cycle")
* and #14 ("Enabling and Disabling Manual Throttle"), plus
* erratum #5 ("STPCLK# Deassertion Time") from the January
* 2002 PIIX4 specification update. Applies to only older
* PIIX4 models.
*/
errata.piix4.throttle = 1;
case 2: /* PIIX4E */
case 3: /* PIIX4M */
/*
* See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
* Livelock") from the January 2002 PIIX4 specification update.
* Applies to all PIIX4 models.
*/
/*
* BM-IDE
* ------
* Find the PIIX4 IDE Controller and get the Bus Master IDE
* Status register address. We'll use this later to read
* each IDE controller's DMA status to make sure we catch all
* DMA activity.
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB,
PCI_ANY_ID, PCI_ANY_ID, NULL);
if (dev) {
errata.piix4.bmisx = pci_resource_start(dev, 4);
pci_dev_put(dev);
}
/*
* Type-F DMA
* ----------
* Find the PIIX4 ISA Controller and read the Motherboard
* DMA controller's status to see if Type-F (Fast) DMA mode
* is enabled (bit 7) on either channel. Note that we'll
* disable C3 support if this is enabled, as some legacy
* devices won't operate well if fast DMA is disabled.
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB_0,
PCI_ANY_ID, PCI_ANY_ID, NULL);
if (dev) {
pci_read_config_byte(dev, 0x76, &value1);
pci_read_config_byte(dev, 0x77, &value2);
if ((value1 & 0x80) || (value2 & 0x80))
errata.piix4.fdma = 1;
pci_dev_put(dev);
}
break;
}
if (errata.piix4.bmisx)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Bus master activity detection (BM-IDE) erratum enabled\n"));
if (errata.piix4.fdma)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Type-F DMA livelock erratum (C3 disabled)\n"));
return 0;
}
static int acpi_processor_errata(void)
{
int result = 0;
struct pci_dev *dev = NULL;
/*
* PIIX4
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
PCI_ANY_ID, NULL);
if (dev) {
result = acpi_processor_errata_piix4(dev);
pci_dev_put(dev);
}
return result;
}
/* --------------------------------------------------------------------------
Initialization
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_HOTPLUG_CPU
int __weak acpi_map_cpu(acpi_handle handle,
phys_cpuid_t physid, int *pcpu)
{
return -ENODEV;
}
int __weak acpi_unmap_cpu(int cpu)
{
return -ENODEV;
}
int __weak arch_register_cpu(int cpu)
{
return -ENODEV;
}
void __weak arch_unregister_cpu(int cpu) {}
static int acpi_processor_hotadd_init(struct acpi_processor *pr)
{
unsigned long long sta;
acpi_status status;
int ret;
if (invalid_phys_cpuid(pr->phys_id))
return -ENODEV;
status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
return -ENODEV;
cpu_maps_update_begin();
cpu_hotplug_begin();
ret = acpi_map_cpu(pr->handle, pr->phys_id, &pr->id);
if (ret)
goto out;
ret = arch_register_cpu(pr->id);
if (ret) {
acpi_unmap_cpu(pr->id);
goto out;
}
/*
* CPU got hot-added, but cpu_data is not initialized yet. Set a flag
* to delay cpu_idle/throttling initialization and do it when the CPU
* gets online for the first time.
*/
pr_info("CPU%d has been hot-added\n", pr->id);
pr->flags.need_hotplug_init = 1;
out:
cpu_hotplug_done();
cpu_maps_update_done();
return ret;
}
#else
static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
{
return -ENODEV;
}
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
static int acpi_processor_get_info(struct acpi_device *device)
{
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
struct acpi_processor *pr = acpi_driver_data(device);
int device_declaration = 0;
acpi_status status = AE_OK;
static int cpu0_initialized;
unsigned long long value;
acpi_processor_errata();
/*
* Check to see if we have bus mastering arbitration control. This
* is required for proper C3 usage (to maintain cache coherency).
*/
if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
pr->flags.bm_control = 1;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Bus mastering arbitration control present\n"));
} else
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No bus mastering arbitration control\n"));
if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
/* Declared with "Processor" statement; match ProcessorID */
status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev,
"Failed to evaluate processor object (0x%x)\n",
status);
return -ENODEV;
}
pr->acpi_id = object.processor.proc_id;
} else {
/*
* Declared with "Device" statement; match _UID.
* Note that we don't handle string _UIDs yet.
*/
status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
NULL, &value);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev,
"Failed to evaluate processor _UID (0x%x)\n",
status);
return -ENODEV;
}
device_declaration = 1;
pr->acpi_id = value;
}
pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
pr->acpi_id);
if (invalid_phys_cpuid(pr->phys_id))
acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
cpu0_initialized = 1;
/*
* Handle UP system running SMP kernel, with no CPU
* entry in MADT
*/
if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
pr->id = 0;
}
/*
* Extra Processor objects may be enumerated on MP systems with
* less than the max # of CPUs. They should be ignored _iff
* they are physically not present.
*/
if (invalid_logical_cpuid(pr->id)) {
int ret = acpi_processor_hotadd_init(pr);
if (ret)
return ret;
}
/*
* On some boxes several processors use the same processor bus id.
* But they are located in different scope. For example:
* \_SB.SCK0.CPU0
* \_SB.SCK1.CPU0
* Rename the processor device bus id. And the new bus id will be
* generated as the following format:
* CPU+CPU ID.
*/
sprintf(acpi_device_bid(device), "CPU%X", pr->id);
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
pr->acpi_id));
if (!object.processor.pblk_address)
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
else if (object.processor.pblk_length != 6)
dev_err(&device->dev, "Invalid PBLK length [%d]\n",
object.processor.pblk_length);
else {
pr->throttling.address = object.processor.pblk_address;
pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
pr->pblk = object.processor.pblk_address;
/*
* We don't care about error returns - we just try to mark
* these reserved so that nobody else is confused into thinking
* that this region might be unused..
*
* (In particular, allocating the IO range for Cardbus)
*/
request_region(pr->throttling.address, 6, "ACPI CPU throttle");
}
/*
* If ACPI describes a slot number for this CPU, we can use it to
* ensure we get the right value in the "physical id" field
* of /proc/cpuinfo
*/
status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
if (ACPI_SUCCESS(status))
arch_fix_phys_package_id(pr->id, value);
return 0;
}
/*
* Do not put anything in here which needs the core to be online.
* For example MSR access or setting up things which check for cpuinfo_x86
* (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
* Such things have to be put in and set up by the processor driver's .probe().
*/
static DEFINE_PER_CPU(void *, processor_device_array);
static int acpi_processor_add(struct acpi_device *device,
const struct acpi_device_id *id)
{
struct acpi_processor *pr;
struct device *dev;
int result = 0;
pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
if (!pr)
return -ENOMEM;
if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
result = -ENOMEM;
goto err_free_pr;
}
pr->handle = device->handle;
strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
device->driver_data = pr;
result = acpi_processor_get_info(device);
if (result) /* Processor is not physically present or unavailable */
return 0;
#ifdef CONFIG_SMP
if (pr->id >= setup_max_cpus && pr->id != 0)
return 0;
#endif
BUG_ON(pr->id >= nr_cpu_ids);
/*
* Buggy BIOS check.
* ACPI id of processors can be reported wrongly by the BIOS.
* Don't trust it blindly
*/
if (per_cpu(processor_device_array, pr->id) != NULL &&
per_cpu(processor_device_array, pr->id) != device) {
dev_warn(&device->dev,
"BIOS reported wrong ACPI id %d for the processor\n",
pr->id);
/* Give up, but do not abort the namespace scan. */
goto err;
}
/*
* processor_device_array is not cleared on errors to allow buggy BIOS
* checks.
*/
per_cpu(processor_device_array, pr->id) = device;
per_cpu(processors, pr->id) = pr;
dev = get_cpu_device(pr->id);
if (!dev) {
result = -ENODEV;
goto err;
}
result = acpi_bind_one(dev, device);
if (result)
goto err;
pr->dev = dev;
/* Trigger the processor driver's .probe() if present. */
if (device_attach(dev) >= 0)
return 1;
dev_err(dev, "Processor driver could not be attached\n");
acpi_unbind_one(dev);
err:
free_cpumask_var(pr->throttling.shared_cpu_map);
device->driver_data = NULL;
per_cpu(processors, pr->id) = NULL;
err_free_pr:
kfree(pr);
return result;
}
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* --------------------------------------------------------------------------
Removal
-------------------------------------------------------------------------- */
static void acpi_processor_remove(struct acpi_device *device)
{
struct acpi_processor *pr;
if (!device || !acpi_driver_data(device))
return;
pr = acpi_driver_data(device);
if (pr->id >= nr_cpu_ids)
goto out;
/*
* The only reason why we ever get here is CPU hot-removal. The CPU is
* already offline and the ACPI device removal locking prevents it from
* being put back online at this point.
*
* Unbind the driver from the processor device and detach it from the
* ACPI companion object.
*/
device_release_driver(pr->dev);
acpi_unbind_one(pr->dev);
/* Clean up. */
per_cpu(processor_device_array, pr->id) = NULL;
per_cpu(processors, pr->id) = NULL;
cpu_maps_update_begin();
cpu_hotplug_begin();
/* Remove the CPU. */
arch_unregister_cpu(pr->id);
acpi_unmap_cpu(pr->id);
cpu_hotplug_done();
cpu_maps_update_done();
try_offline_node(cpu_to_node(pr->id));
out:
free_cpumask_var(pr->throttling.shared_cpu_map);
kfree(pr);
}
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
#ifdef CONFIG_X86
static bool acpi_hwp_native_thermal_lvt_set;
static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
u32 lvl,
void *context,
void **rv)
{
u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
u32 capbuf[2];
struct acpi_osc_context osc_context = {
.uuid_str = sb_uuid_str,
.rev = 1,
.cap.length = 8,
.cap.pointer = capbuf,
};
if (acpi_hwp_native_thermal_lvt_set)
return AE_CTRL_TERMINATE;
capbuf[0] = 0x0000;
capbuf[1] = 0x1000; /* set bit 12 */
if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
if (osc_context.ret.pointer && osc_context.ret.length > 1) {
u32 *capbuf_ret = osc_context.ret.pointer;
if (capbuf_ret[1] & 0x1000) {
acpi_handle_info(handle,
"_OSC native thermal LVT Acked\n");
acpi_hwp_native_thermal_lvt_set = true;
}
}
kfree(osc_context.ret.pointer);
}
return AE_OK;
}
void __init acpi_early_processor_osc(void)
{
if (boot_cpu_has(X86_FEATURE_HWP)) {
acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
acpi_hwp_native_thermal_lvt_osc,
NULL, NULL, NULL);
acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
acpi_hwp_native_thermal_lvt_osc,
NULL, NULL);
}
}
#endif
/*
* The following ACPI IDs are known to be suitable for representing as
* processor devices.
*/
static const struct acpi_device_id processor_device_ids[] = {
{ ACPI_PROCESSOR_OBJECT_HID, },
{ ACPI_PROCESSOR_DEVICE_HID, },
{ }
};
static struct acpi_scan_handler processor_handler = {
.ids = processor_device_ids,
.attach = acpi_processor_add,
#ifdef CONFIG_ACPI_HOTPLUG_CPU
.detach = acpi_processor_remove,
#endif
.hotplug = {
.enabled = true,
},
};
static int acpi_processor_container_attach(struct acpi_device *dev,
const struct acpi_device_id *id)
{
return 1;
}
static const struct acpi_device_id processor_container_ids[] = {
{ ACPI_PROCESSOR_CONTAINER_HID, },
{ }
};
static struct acpi_scan_handler processor_container_handler = {
.ids = processor_container_ids,
.attach = acpi_processor_container_attach,
};
void __init acpi_processor_init(void)
{
acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
acpi_scan_add_handler(&processor_container_handler);
}