4f37ab5e05
Currently arch_acpi_set_proc_cap_bits() clears ACPI_PDC_C_C2C3_FFH bit in case MWAIT instruction is not supported. It should also clear ACPI_PDC_C_C1_FFH, as when MWAIT is not supported, C1 is entered by executing the HLT instruction. Quote from the C_C1_FFH description: "If set, OSPM is capable of performing native C State instructions (beyond halt) for the C1 handler in multi-processor configurations". As without MWAIT there is no native C-state instructions beyond HALT, this bit should be toggled off." Clear ACPI_PDC_C_C1_FFH and ACPI_PDC_C_C2C3_FFH in arch_acpi_set_proc_cap_bits() in case MWAIT is not supported or overridden. Remove setting those bits from the processor_pdc.c code. Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
123 lines
2.6 KiB
C
123 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2005 Intel Corporation
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* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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*
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* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* - Added _PDC for platforms with Intel CPUs
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*/
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#define pr_fmt(fmt) "ACPI: " fmt
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <acpi/processor.h>
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#include "internal.h"
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static void acpi_set_pdc_bits(u32 *buf)
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{
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buf[0] = ACPI_PDC_REVISION_ID;
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buf[1] = 1;
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/* Enable coordination with firmware's _TSD info */
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buf[2] = ACPI_PROC_CAP_SMP_T_SWCOORD;
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/* Twiddle arch-specific bits needed for _PDC */
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arch_acpi_set_proc_cap_bits(&buf[2]);
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}
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static struct acpi_object_list *acpi_processor_alloc_pdc(void)
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{
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struct acpi_object_list *obj_list;
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union acpi_object *obj;
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u32 *buf;
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/* allocate and initialize pdc. It will be used later. */
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obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
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if (!obj_list)
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goto out;
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obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
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if (!obj) {
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kfree(obj_list);
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goto out;
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}
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buf = kmalloc(12, GFP_KERNEL);
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if (!buf) {
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kfree(obj);
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kfree(obj_list);
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goto out;
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}
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acpi_set_pdc_bits(buf);
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obj->type = ACPI_TYPE_BUFFER;
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obj->buffer.length = 12;
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obj->buffer.pointer = (u8 *) buf;
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obj_list->count = 1;
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obj_list->pointer = obj;
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return obj_list;
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out:
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pr_err("Memory allocation error\n");
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return NULL;
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}
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/*
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* _PDC is required for a BIOS-OS handshake for most of the newer
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* ACPI processor features.
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*/
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static acpi_status
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acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
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{
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acpi_status status = AE_OK;
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status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
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if (ACPI_FAILURE(status))
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acpi_handle_debug(handle,
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"Could not evaluate _PDC, using legacy perf control\n");
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return status;
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}
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void acpi_processor_set_pdc(acpi_handle handle)
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{
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struct acpi_object_list *obj_list;
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if (arch_has_acpi_pdc() == false)
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return;
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obj_list = acpi_processor_alloc_pdc();
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if (!obj_list)
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return;
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acpi_processor_eval_pdc(handle, obj_list);
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kfree(obj_list->pointer->buffer.pointer);
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kfree(obj_list->pointer);
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kfree(obj_list);
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}
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static acpi_status __init
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early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
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{
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if (processor_physically_present(handle) == false)
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return AE_OK;
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acpi_processor_set_pdc(handle);
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return AE_OK;
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}
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void __init acpi_early_processor_set_pdc(void)
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{
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acpi_proc_quirk_mwait_check();
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acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
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ACPI_UINT32_MAX,
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early_init_pdc, NULL, NULL, NULL);
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acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
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}
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