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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2005 Intel Corporation * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. * * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> * - Added _PDC for platforms with Intel CPUs */
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/slab.h>#include <linux/acpi.h>#include <acpi/processor.h>
#include "internal.h"
static void acpi_set_pdc_bits(u32 *buf){ buf[0] = ACPI_PDC_REVISION_ID; buf[1] = 1; buf[2] = 0;
/* Twiddle arch-specific bits needed for _PDC */ arch_acpi_set_proc_cap_bits(&buf[2]);}
static struct acpi_object_list *acpi_processor_alloc_pdc(void){ struct acpi_object_list *obj_list; union acpi_object *obj; u32 *buf;
/* allocate and initialize pdc. It will be used later. */ obj_list = kmalloc_obj(struct acpi_object_list); if (!obj_list) goto out;
obj = kmalloc_obj(union acpi_object); if (!obj) { kfree(obj_list); goto out; }
buf = kmalloc(12, GFP_KERNEL); if (!buf) { kfree(obj); kfree(obj_list); goto out; }
acpi_set_pdc_bits(buf);
obj->type = ACPI_TYPE_BUFFER; obj->buffer.length = 12; obj->buffer.pointer = (u8 *) buf; obj_list->count = 1; obj_list->pointer = obj;
return obj_list;out: pr_err("Memory allocation error\n"); return NULL;}
/* * _PDC is required for a BIOS-OS handshake for most of the newer * ACPI processor features. */static acpi_statusacpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in){ acpi_status status = AE_OK;
status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
if (ACPI_FAILURE(status)) acpi_handle_debug(handle, "Could not evaluate _PDC, using legacy perf control\n");
return status;}
void acpi_processor_set_pdc(acpi_handle handle){ struct acpi_object_list *obj_list;
if (arch_has_acpi_pdc() == false) return;
obj_list = acpi_processor_alloc_pdc(); if (!obj_list) return;
acpi_processor_eval_pdc(handle, obj_list);
kfree(obj_list->pointer->buffer.pointer); kfree(obj_list->pointer); kfree(obj_list);}
static acpi_status __initearly_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv){ if (processor_physically_present(handle) == false) return AE_OK;
acpi_processor_set_pdc(handle); return AE_OK;}
void __init acpi_early_processor_set_pdc(void){ acpi_proc_quirk_mwait_check();
acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, early_init_pdc, NULL, NULL, NULL); acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);}