5b53496a5a
991528d734
(ACPI: Processor native C-states using MWAIT)
started passing C2C3_FFH to _PDC to tell the BIOS
that Linux supports MWAIT for deep C-states.
However, we should first double check with the hardware
that it actually supports MWAIT before potentially exposing
a BIOS bug of an MWAIT _CST on HW that doesn't support MWAIT.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
88 lines
2.0 KiB
C
88 lines
2.0 KiB
C
/*
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* Copyright (C) 2005 Intel Corporation
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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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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/acpi.h>
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#include <acpi/processor.h>
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#include <asm/acpi.h>
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static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c)
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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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printk(KERN_ERR "Memory allocation error\n");
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return;
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}
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obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
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if (!obj) {
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printk(KERN_ERR "Memory allocation error\n");
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kfree(obj_list);
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return;
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}
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buf = kmalloc(12, GFP_KERNEL);
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if (!buf) {
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printk(KERN_ERR "Memory allocation error\n");
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kfree(obj);
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kfree(obj_list);
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return;
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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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buf[2] = ACPI_PDC_C_CAPABILITY_SMP;
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/*
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* The default of PDC_SMP_T_SWCOORD bit is set for intel x86 cpu so
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* that OSPM is capable of native ACPI throttling software
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* coordination using BIOS supplied _TSD info.
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*/
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buf[2] |= ACPI_PDC_SMP_T_SWCOORD;
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if (cpu_has(c, X86_FEATURE_EST))
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buf[2] |= ACPI_PDC_EST_CAPABILITY_SWSMP;
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if (cpu_has(c, X86_FEATURE_ACPI))
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buf[2] |= ACPI_PDC_T_FFH;
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/*
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* If mwait/monitor is unsupported, C2/C3_FFH will be disabled
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*/
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if (!cpu_has(c, X86_FEATURE_MWAIT))
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buf[2] &= ~(ACPI_PDC_C_C2C3_FFH);
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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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pr->pdc = obj_list;
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return;
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}
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/* Initialize _PDC data based on the CPU vendor */
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void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
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{
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struct cpuinfo_x86 *c = &cpu_data(pr->id);
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pr->pdc = NULL;
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if (c->x86_vendor == X86_VENDOR_INTEL)
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init_intel_pdc(pr, c);
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return;
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}
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EXPORT_SYMBOL(arch_acpi_processor_init_pdc);
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