diff options
Diffstat (limited to 'drivers/acpi/processor_pdc.c')
| -rw-r--r-- | drivers/acpi/processor_pdc.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c new file mode 100644 index 000000000..c0d2d9a2c --- /dev/null +++ b/drivers/acpi/processor_pdc.c @@ -0,0 +1,215 @@ +// 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/dmi.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <acpi/processor.h> + +#include <xen/xen.h> + +#include "internal.h" + +#define _COMPONENT ACPI_PROCESSOR_COMPONENT +ACPI_MODULE_NAME("processor_pdc"); + +static bool __init processor_physically_present(acpi_handle handle) +{ + int cpuid, type; + u32 acpi_id; + acpi_status status; + acpi_object_type acpi_type; + unsigned long long tmp; + union acpi_object object = { 0 }; + struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; + + status = acpi_get_type(handle, &acpi_type); + if (ACPI_FAILURE(status)) + return false; + + switch (acpi_type) { + case ACPI_TYPE_PROCESSOR: + status = acpi_evaluate_object(handle, NULL, NULL, &buffer); + if (ACPI_FAILURE(status)) + return false; + acpi_id = object.processor.proc_id; + break; + case ACPI_TYPE_DEVICE: + status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp); + if (ACPI_FAILURE(status)) + return false; + acpi_id = tmp; + break; + default: + return false; + } + + if (xen_initial_domain()) + /* + * When running as a Xen dom0 the number of processors Linux + * sees can be different from the real number of processors on + * the system, and we still need to execute _PDC for all of + * them. + */ + return xen_processor_present(acpi_id); + + type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; + cpuid = acpi_get_cpuid(handle, type, acpi_id); + + return !invalid_logical_cpuid(cpuid); +} + +static void acpi_set_pdc_bits(u32 *buf) +{ + buf[0] = ACPI_PDC_REVISION_ID; + buf[1] = 1; + + /* Enable coordination with firmware's _TSD info */ + buf[2] = ACPI_PDC_SMP_T_SWCOORD; + + /* Twiddle arch-specific bits needed for _PDC */ + arch_acpi_set_pdc_bits(buf); +} + +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(sizeof(struct acpi_object_list), GFP_KERNEL); + if (!obj_list) + goto out; + + obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); + 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_status +acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) +{ + acpi_status status = AE_OK; + + if (boot_option_idle_override == IDLE_NOMWAIT) { + /* + * If mwait is disabled for CPU C-states, the C2C3_FFH access + * mode will be disabled in the parameter of _PDC object. + * Of course C1_FFH access mode will also be disabled. + */ + union acpi_object *obj; + u32 *buffer = NULL; + + obj = pdc_in->pointer; + buffer = (u32 *)(obj->buffer.pointer); + buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); + + } + status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); + + if (ACPI_FAILURE(status)) + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "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 __init +early_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; +} + +static int __init set_no_mwait(const struct dmi_system_id *id) +{ + pr_notice("%s detected - disabling mwait for CPU C-states\n", + id->ident); + boot_option_idle_override = IDLE_NOMWAIT; + return 0; +} + +static const struct dmi_system_id processor_idle_dmi_table[] __initconst = { + { + set_no_mwait, "Extensa 5220", { + DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"), + DMI_MATCH(DMI_SYS_VENDOR, "Acer"), + DMI_MATCH(DMI_PRODUCT_VERSION, "0100"), + DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL}, + {}, +}; + +static void __init processor_dmi_check(void) +{ + /* + * Check whether the system is DMI table. If yes, OSPM + * should not use mwait for CPU-states. + */ + dmi_check_system(processor_idle_dmi_table); +} + +void __init acpi_early_processor_set_pdc(void) +{ + processor_dmi_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); +} |