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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/acpi.h>#include <linux/cpu.h>#include <linux/device.h>#include <linux/dmi.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/pci.h>#include <linux/platform_device.h>
#include <acpi/processor.h>
#include <asm/cpu.h>
#include <xen/xen.h>
#include "internal.h"
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);
acpi_handle acpi_get_processor_handle(int cpu){ struct acpi_processor *pr;
pr = per_cpu(processors, cpu); if (pr) return pr->handle;
return NULL;}
static int acpi_processor_errata_piix4(struct pci_dev *dev){ if (!dev) return -EINVAL;
/* * Note that 'dev' references the PIIX4 ACPI Controller. */
switch (dev->revision) { case 0: dev_dbg(&dev->dev, "Found PIIX4 A-step\n"); break; case 1: dev_dbg(&dev->dev, "Found PIIX4 B-step\n"); break; case 2: dev_dbg(&dev->dev, "Found PIIX4E\n"); break; case 3: dev_dbg(&dev->dev, "Found PIIX4M\n"); break; default: dev_dbg(&dev->dev, "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; fallthrough;
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); if (errata.piix4.bmisx) dev_dbg(&dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
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) { u8 value1 = 0, value2 = 0;
pci_read_config_byte(dev, 0x76, &value1); pci_read_config_byte(dev, 0x77, &value2); if ((value1 & 0x80) || (value2 & 0x80)) { errata.piix4.fdma = 1; dev_dbg(&dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n"); } pci_dev_put(dev); }
break; }
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;}
/* Create a platform device to represent a CPU frequency control mechanism. */static void cpufreq_add_device(const char *name){ struct platform_device *pdev;
pdev = platform_device_register_simple(name, PLATFORM_DEVID_NONE, NULL, 0); if (IS_ERR(pdev)) pr_info("%s device creation failed: %pe\n", name, pdev);}
#ifdef CONFIG_X86/* Check presence of Processor Clocking Control by searching for \_SB.PCCH. */static void __init acpi_pcc_cpufreq_init(void){ acpi_status status; acpi_handle handle;
status = acpi_get_handle(NULL, "\\_SB", &handle); if (ACPI_FAILURE(status)) return;
if (acpi_has_method(handle, "PCCH")) cpufreq_add_device("pcc-cpufreq");}#elsestatic void __init acpi_pcc_cpufreq_init(void) {}#endif /* CONFIG_X86 */
/* Initialization */static DEFINE_PER_CPU(void *, processor_device_array);
static int acpi_processor_set_per_cpu(struct acpi_processor *pr, struct acpi_device *device){ 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); return -EINVAL; } /* * 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;
return 0;}
#ifdef CONFIG_ACPI_HOTPLUG_CPUstatic int acpi_processor_hotadd_init(struct acpi_processor *pr, struct acpi_device *device){ int ret;
if (invalid_phys_cpuid(pr->phys_id)) return -ENODEV;
cpu_maps_update_begin(); cpus_write_lock();
ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id); if (ret) goto out;
ret = acpi_processor_set_per_cpu(pr, device); if (ret) { acpi_unmap_cpu(pr->id); goto out; }
ret = arch_register_cpu(pr->id); if (ret) { /* Leave the processor device array in place to detect buggy bios */ per_cpu(processors, pr->id) = NULL; acpi_unmap_cpu(pr->id); goto out; }
/* * CPU got hot-added, but cpu_data is not initialized yet. Do * cpu_idle/throttling initialization when the CPU gets online for * the first time. */ pr_info("CPU%d has been hot-added\n", pr->id);
out: cpus_write_unlock(); cpu_maps_update_done(); return ret;}#elsestatic inline int acpi_processor_hotadd_init(struct acpi_processor *pr, struct acpi_device *device){ return -ENODEV;}#endif /* CONFIG_ACPI_HOTPLUG_CPU */
static int acpi_processor_get_info(struct acpi_device *device){ union acpi_object object = { .processor = { 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; int ret;
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; dev_dbg(&device->dev, "Bus mastering arbitration control present\n"); } else dev_dbg(&device->dev, "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. */ 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; }
if (acpi_duplicate_processor_id(pr->acpi_id)) { if (pr->acpi_id == 0xff) dev_info_once(&device->dev, "Entry not well-defined, consider updating BIOS\n"); else dev_err(&device->dev, "Failed to get unique processor _UID (0x%x)\n", pr->acpi_id); return -ENODEV; }
pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration, pr->acpi_id); if (invalid_phys_cpuid(pr->phys_id)) dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id); if (!cpu0_initialized) { cpu0_initialized = 1; /* * Handle UP system running SMP kernel, with no CPU * entry in MADT */ if (!acpi_has_cpu_in_madt() && invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1)) pr->id = 0; /* * Check availability of Processor Performance Control by * looking at the presence of the _PCT object under the first * processor definition. */ if (acpi_has_method(pr->handle, "_PCT")) cpufreq_add_device("acpi-cpufreq"); }
/* * This code is not called unless we know the CPU is present and * enabled. The two paths are: * a) Initially present CPUs on architectures that do not defer * their arch_register_cpu() calls until this point. * b) Hotplugged CPUs (enabled bit in _STA has transitioned from not * enabled to enabled) */ if (!get_cpu_device(pr->id)) ret = acpi_processor_hotadd_init(pr, device); else ret = acpi_processor_set_per_cpu(pr, device); 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); dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
if (!object.processor.pblk_address) dev_dbg(&device->dev, "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; }
/* * 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 int acpi_processor_add(struct acpi_device *device, const struct acpi_device_id *id){ struct acpi_processor *pr; struct device *dev; int result = 0;
if (!acpi_device_is_enabled(device)) return -ENODEV;
pr = kzalloc_obj(struct acpi_processor); 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; device->driver_data = pr;
result = acpi_processor_get_info(device); if (result) /* Processor is not physically present or unavailable */ goto err_clear_driver_data;
dev = get_cpu_device(pr->id); if (!dev) { result = -ENODEV; goto err_clear_per_cpu; }
result = acpi_bind_one(dev, device); if (result) goto err_clear_per_cpu;
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_clear_per_cpu: per_cpu(processors, pr->id) = NULL; err_clear_driver_data: device->driver_data = NULL; free_cpumask_var(pr->throttling.shared_cpu_map); err_free_pr: kfree(pr); return result;}
#ifdef CONFIG_ACPI_HOTPLUG_CPU/* Removal */static void acpi_processor_post_eject(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);
cpu_maps_update_begin(); cpus_write_lock();
/* Remove the CPU. */ arch_unregister_cpu(pr->id); acpi_unmap_cpu(pr->id);
/* Clean up. */ per_cpu(processor_device_array, pr->id) = NULL; per_cpu(processors, pr->id) = NULL;
cpus_write_unlock(); 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_ARCH_MIGHT_HAVE_ACPI_PDCbool __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 = {}; 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, METHOD_NAME__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 or _OSC 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);}
/* vendor specific UUID indicating an Intel platform */static u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
static acpi_status __init acpi_processor_osc(acpi_handle handle, u32 lvl, void *context, void **rv){ u32 capbuf[2] = {}; struct acpi_osc_context osc_context = { .uuid_str = sb_uuid_str, .rev = 1, .cap.length = 8, .cap.pointer = capbuf, }; acpi_status status;
if (!processor_physically_present(handle)) return AE_OK;
arch_acpi_set_proc_cap_bits(&capbuf[OSC_SUPPORT_DWORD]);
status = acpi_run_osc(handle, &osc_context); if (ACPI_FAILURE(status)) return status;
kfree(osc_context.ret.pointer);
return AE_OK;}
static bool __init acpi_early_processor_osc(void){ acpi_status status;
acpi_proc_quirk_mwait_check();
status = acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, acpi_processor_osc, NULL, NULL, NULL); if (ACPI_FAILURE(status)) return false;
status = acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_osc, NULL, NULL); if (ACPI_FAILURE(status)) return false;
return true;}
void __init acpi_early_processor_control_setup(void){ if (acpi_early_processor_osc()) { pr_debug("_OSC evaluated successfully for all CPUs\n"); } else { pr_debug("_OSC evaluation for CPUs failed, trying _PDC\n"); acpi_early_processor_set_pdc(); }}#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 .post_eject = acpi_processor_post_eject,#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,};
/* The number of the unique processor IDs */static int nr_unique_ids __initdata;
/* The number of the duplicate processor IDs */static int nr_duplicate_ids;
/* Used to store the unique processor IDs */static int unique_processor_ids[] __initdata = { [0 ... NR_CPUS - 1] = -1,};
/* Used to store the duplicate processor IDs */static int duplicate_processor_ids[] = { [0 ... NR_CPUS - 1] = -1,};
static void __init processor_validated_ids_update(int proc_id){ int i;
if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS) return;
/* * Firstly, compare the proc_id with duplicate IDs, if the proc_id is * already in the IDs, do nothing. */ for (i = 0; i < nr_duplicate_ids; i++) { if (duplicate_processor_ids[i] == proc_id) return; }
/* * Secondly, compare the proc_id with unique IDs, if the proc_id is in * the IDs, put it in the duplicate IDs. */ for (i = 0; i < nr_unique_ids; i++) { if (unique_processor_ids[i] == proc_id) { duplicate_processor_ids[nr_duplicate_ids] = proc_id; nr_duplicate_ids++; return; } }
/* * Lastly, the proc_id is a unique ID, put it in the unique IDs. */ unique_processor_ids[nr_unique_ids] = proc_id; nr_unique_ids++;}
static acpi_status __init acpi_processor_ids_walk(acpi_handle handle, u32 lvl, void *context, void **rv){ acpi_status status; acpi_object_type acpi_type; unsigned long long uid; 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 status;
switch (acpi_type) { case ACPI_TYPE_PROCESSOR: status = acpi_evaluate_object(handle, NULL, NULL, &buffer); if (ACPI_FAILURE(status)) goto err; uid = object.processor.proc_id; break;
case ACPI_TYPE_DEVICE: status = acpi_evaluate_integer(handle, "_UID", NULL, &uid); if (ACPI_FAILURE(status)) goto err; break; default: goto err; }
processor_validated_ids_update(uid); return AE_OK;
err: /* Exit on error, but don't abort the namespace walk */ acpi_handle_info(handle, "Invalid processor object\n"); return AE_OK;
}
static void __init acpi_processor_check_duplicates(void){ /* check the correctness for all processors in ACPI namespace */ acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, acpi_processor_ids_walk, NULL, NULL, NULL); acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk, NULL, NULL);}
bool acpi_duplicate_processor_id(int proc_id){ int i;
/* * compare the proc_id with duplicate IDs, if the proc_id is already * in the duplicate IDs, return true, otherwise, return false. */ for (i = 0; i < nr_duplicate_ids; i++) { if (duplicate_processor_ids[i] == proc_id) return true; } return false;}
void __init acpi_processor_init(void){ acpi_processor_check_duplicates(); acpi_scan_add_handler_with_hotplug(&processor_handler, "processor"); acpi_scan_add_handler(&processor_container_handler); acpi_pcc_cpufreq_init();}
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE/** * acpi_processor_claim_cst_control - Request _CST control from the platform. */bool acpi_processor_claim_cst_control(void){ static bool cst_control_claimed; acpi_status status;
if (!acpi_gbl_FADT.cst_control || cst_control_claimed) return true;
status = acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8); if (ACPI_FAILURE(status)) { pr_warn("ACPI: Failed to claim processor _CST control\n"); return false; }
cst_control_claimed = true; return true;}EXPORT_SYMBOL_NS_GPL(acpi_processor_claim_cst_control, "ACPI_PROCESSOR_IDLE");
/** * acpi_processor_evaluate_cst - Evaluate the processor _CST control method. * @handle: ACPI handle of the processor object containing the _CST. * @cpu: The numeric ID of the target CPU. * @info: Object write the C-states information into. * * Extract the C-state information for the given CPU from the output of the _CST * control method under the corresponding ACPI processor object (or processor * device object) and populate @info with it. * * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke * acpi_processor_ffh_cstate_probe() to verify them and update the * cpu_cstate_entry data for @cpu. */int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu, struct acpi_processor_power *info){ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *cst; acpi_status status; u64 count; int last_index = 0; int i, ret = 0;
status = acpi_evaluate_object(handle, "_CST", NULL, &buffer); if (ACPI_FAILURE(status)) { acpi_handle_debug(handle, "No _CST\n"); return -ENODEV; }
cst = buffer.pointer;
/* There must be at least 2 elements. */ if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) { acpi_handle_warn(handle, "Invalid _CST output\n"); ret = -EFAULT; goto end; }
count = cst->package.elements[0].integer.value;
/* Validate the number of C-states. */ if (count < 1 || count != cst->package.count - 1) { acpi_handle_warn(handle, "Inconsistent _CST data\n"); ret = -EFAULT; goto end; }
for (i = 1; i <= count; i++) { union acpi_object *element; union acpi_object *obj; struct acpi_power_register *reg; struct acpi_processor_cx cx;
/* * If there is not enough space for all C-states, skip the * excess ones and log a warning. */ if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) { acpi_handle_warn(handle, "No room for more idle states (limit: %d)\n", ACPI_PROCESSOR_MAX_POWER - 1); break; }
memset(&cx, 0, sizeof(cx));
element = &cst->package.elements[i]; if (element->type != ACPI_TYPE_PACKAGE) { acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n", i, element->type); continue; }
if (element->package.count != 4) { acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n", i, element->package.count); continue; }
obj = &element->package.elements[0];
if (obj->type != ACPI_TYPE_BUFFER) { acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n", i, obj->type); continue; }
reg = (struct acpi_power_register *)obj->buffer.pointer;
obj = &element->package.elements[1]; if (obj->type != ACPI_TYPE_INTEGER) { acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n", i, obj->type); continue; }
cx.type = obj->integer.value; /* * There are known cases in which the _CST output does not * contain C1, so if the type of the first state found is not * C1, leave an empty slot for C1 to be filled in later. */ if (i == 1 && cx.type != ACPI_STATE_C1) last_index = 1;
cx.address = reg->address; cx.index = last_index + 1;
if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) { /* * In the majority of cases _CST describes C1 as * a FIXED_HARDWARE C-state, but if the command * line forbids using MWAIT, use CSTATE_HALT for * C1 regardless. */ if (cx.type == ACPI_STATE_C1 && boot_option_idle_override == IDLE_NOMWAIT) { cx.entry_method = ACPI_CSTATE_HALT; snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); } else { cx.entry_method = ACPI_CSTATE_FFH; } } else if (cx.type == ACPI_STATE_C1) { /* * In the special case of C1, FIXED_HARDWARE can * be handled by executing the HLT instruction. */ cx.entry_method = ACPI_CSTATE_HALT; snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); } else { acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n", i); continue; } } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { cx.entry_method = ACPI_CSTATE_SYSTEMIO; snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", cx.address); } else { acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n", i, reg->space_id); continue; }
if (cx.type == ACPI_STATE_C1) cx.valid = 1;
obj = &element->package.elements[2]; if (obj->type != ACPI_TYPE_INTEGER) { acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n", i, obj->type); continue; }
cx.latency = obj->integer.value;
obj = &element->package.elements[3]; if (obj->type != ACPI_TYPE_INTEGER) { acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n", i, obj->type); continue; }
memcpy(&info->states[++last_index], &cx, sizeof(cx)); }
acpi_handle_debug(handle, "Found %d idle states\n", last_index);
info->count = last_index;
end: kfree(buffer.pointer);
return ret;}EXPORT_SYMBOL_NS_GPL(acpi_processor_evaluate_cst, "ACPI_PROCESSOR_IDLE");#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */