// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2012 by Oracle Inc * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> * * This code borrows ideas from * https://lore.kernel.org/lkml/1322673664-14642-6-git-send-email-konrad.wilk@oracle.com * so many thanks go to Kevin Tian <kevin.tian@intel.com> * and Yu Ke <ke.yu@intel.com>. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/cpumask.h> #include <linux/cpufreq.h> #include <linux/freezer.h> #include <linux/kernel.h> #include <linux/kthread.h> #include <linux/init.h> #include <linux/module.h> #include <linux/types.h> #include <linux/syscore_ops.h> #include <linux/acpi.h> #include <acpi/processor.h> #include <xen/xen.h> #include <xen/interface/platform.h> #include <asm/xen/hypercall.h> static int no_hypercall; MODULE_PARM_DESC(off, "Inhibit the hypercall."); module_param_named(off, no_hypercall, int, 0400); /* * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which * can be less than what we want to put in. Instead use the 'nr_acpi_bits' * which is dynamically computed based on the MADT or x2APIC table. */ static unsigned int nr_acpi_bits; /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */ static DEFINE_MUTEX(acpi_ids_mutex); /* Which ACPI ID we have processed from 'struct acpi_processor'. */ static unsigned long *acpi_ids_done; /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */ static unsigned long *acpi_id_present; /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */ static unsigned long *acpi_id_cst_present; /* Which ACPI P-State dependencies for a enumerated processor */ static struct acpi_psd_package *acpi_psd; static int push_cxx_to_hypervisor(struct acpi_processor *_pr) { struct xen_platform_op op = { .cmd = XENPF_set_processor_pminfo, .interface_version = XENPF_INTERFACE_VERSION, .u.set_pminfo.id = _pr->acpi_id, .u.set_pminfo.type = XEN_PM_CX, }; struct xen_processor_cx *dst_cx, *dst_cx_states = NULL; struct acpi_processor_cx *cx; unsigned int i, ok; int ret = 0; dst_cx_states = kcalloc(_pr->power.count, sizeof(struct xen_processor_cx), GFP_KERNEL); if (!dst_cx_states) return -ENOMEM; for (ok = 0, i = 1; i <= _pr->power.count; i++) { cx = &_pr->power.states[i]; if (!cx->valid) continue; dst_cx = &(dst_cx_states[ok++]); dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO; if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { dst_cx->reg.bit_width = 8; dst_cx->reg.bit_offset = 0; dst_cx->reg.access_size = 1; } else { dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE; if (cx->entry_method == ACPI_CSTATE_FFH) { /* NATIVE_CSTATE_BEYOND_HALT */ dst_cx->reg.bit_offset = 2; dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */ } dst_cx->reg.access_size = 0; } dst_cx->reg.address = cx->address; dst_cx->type = cx->type; dst_cx->latency = cx->latency; dst_cx->dpcnt = 0; set_xen_guest_handle(dst_cx->dp, NULL); } if (!ok) { pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id); kfree(dst_cx_states); return -EINVAL; } op.u.set_pminfo.power.count = ok; op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control; op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check; op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst; op.u.set_pminfo.power.flags.power_setup_done = _pr->flags.power_setup_done; set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states); if (!no_hypercall) ret = HYPERVISOR_platform_op(&op); if (!ret) { pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id); for (i = 1; i <= _pr->power.count; i++) { cx = &_pr->power.states[i]; if (!cx->valid) continue; pr_debug(" C%d: %s %d uS\n", cx->type, cx->desc, (u32)cx->latency); } } else if ((ret != -EINVAL) && (ret != -ENOSYS)) /* EINVAL means the ACPI ID is incorrect - meaning the ACPI * table is referencing a non-existing CPU - which can happen * with broken ACPI tables. */ pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n", ret, _pr->acpi_id); kfree(dst_cx_states); return ret; } static struct xen_processor_px * xen_copy_pss_data(struct acpi_processor *_pr, struct xen_processor_performance *dst_perf) { struct xen_processor_px *dst_states = NULL; unsigned int i; BUILD_BUG_ON(sizeof(struct xen_processor_px) != sizeof(struct acpi_processor_px)); dst_states = kcalloc(_pr->performance->state_count, sizeof(struct xen_processor_px), GFP_KERNEL); if (!dst_states) return ERR_PTR(-ENOMEM); dst_perf->state_count = _pr->performance->state_count; for (i = 0; i < _pr->performance->state_count; i++) { /* Fortunatly for us, they are both the same size */ memcpy(&(dst_states[i]), &(_pr->performance->states[i]), sizeof(struct acpi_processor_px)); } return dst_states; } static int xen_copy_psd_data(struct acpi_processor *_pr, struct xen_processor_performance *dst) { struct acpi_psd_package *pdomain; BUILD_BUG_ON(sizeof(struct xen_psd_package) != sizeof(struct acpi_psd_package)); /* This information is enumerated only if acpi_processor_preregister_performance * has been called. */ dst->shared_type = _pr->performance->shared_type; pdomain = &(_pr->performance->domain_info); /* 'acpi_processor_preregister_performance' does not parse if the * num_processors <= 1, but Xen still requires it. Do it manually here. */ if (pdomain->num_processors <= 1) { if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) dst->shared_type = CPUFREQ_SHARED_TYPE_ALL; else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) dst->shared_type = CPUFREQ_SHARED_TYPE_HW; else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) dst->shared_type = CPUFREQ_SHARED_TYPE_ANY; } memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package)); return 0; } static int xen_copy_pct_data(struct acpi_pct_register *pct, struct xen_pct_register *dst_pct) { /* It would be nice if you could just do 'memcpy(pct, dst_pct') but * sadly the Xen structure did not have the proper padding so the * descriptor field takes two (dst_pct) bytes instead of one (pct). */ dst_pct->descriptor = pct->descriptor; dst_pct->length = pct->length; dst_pct->space_id = pct->space_id; dst_pct->bit_width = pct->bit_width; dst_pct->bit_offset = pct->bit_offset; dst_pct->reserved = pct->reserved; dst_pct->address = pct->address; return 0; } static int push_pxx_to_hypervisor(struct acpi_processor *_pr) { int ret = 0; struct xen_platform_op op = { .cmd = XENPF_set_processor_pminfo, .interface_version = XENPF_INTERFACE_VERSION, .u.set_pminfo.id = _pr->acpi_id, .u.set_pminfo.type = XEN_PM_PX, }; struct xen_processor_performance *dst_perf; struct xen_processor_px *dst_states = NULL; dst_perf = &op.u.set_pminfo.perf; dst_perf->platform_limit = _pr->performance_platform_limit; dst_perf->flags |= XEN_PX_PPC; xen_copy_pct_data(&(_pr->performance->control_register), &dst_perf->control_register); xen_copy_pct_data(&(_pr->performance->status_register), &dst_perf->status_register); dst_perf->flags |= XEN_PX_PCT; dst_states = xen_copy_pss_data(_pr, dst_perf); if (!IS_ERR_OR_NULL(dst_states)) { set_xen_guest_handle(dst_perf->states, dst_states); dst_perf->flags |= XEN_PX_PSS; } if (!xen_copy_psd_data(_pr, dst_perf)) dst_perf->flags |= XEN_PX_PSD; if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) { pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n", _pr->acpi_id, dst_perf->flags); ret = -ENODEV; goto err_free; } if (!no_hypercall) ret = HYPERVISOR_platform_op(&op); if (!ret) { struct acpi_processor_performance *perf; unsigned int i; perf = _pr->performance; pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id); for (i = 0; i < perf->state_count; i++) { pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n", (i == perf->state ? '*' : ' '), i, (u32) perf->states[i].core_frequency, (u32) perf->states[i].power, (u32) perf->states[i].transition_latency); } } else if ((ret != -EINVAL) && (ret != -ENOSYS)) /* EINVAL means the ACPI ID is incorrect - meaning the ACPI * table is referencing a non-existing CPU - which can happen * with broken ACPI tables. */ pr_warn("(_PXX): Hypervisor error (%d) for ACPI CPU%u\n", ret, _pr->acpi_id); err_free: if (!IS_ERR_OR_NULL(dst_states)) kfree(dst_states); return ret; } static int upload_pm_data(struct acpi_processor *_pr) { int err = 0; mutex_lock(&acpi_ids_mutex); if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) { mutex_unlock(&acpi_ids_mutex); return -EBUSY; } if (_pr->flags.power) err = push_cxx_to_hypervisor(_pr); if (_pr->performance && _pr->performance->states) err |= push_pxx_to_hypervisor(_pr); mutex_unlock(&acpi_ids_mutex); return err; } static unsigned int __init get_max_acpi_id(void) { struct xenpf_pcpuinfo *info; struct xen_platform_op op = { .cmd = XENPF_get_cpuinfo, .interface_version = XENPF_INTERFACE_VERSION, }; int ret = 0; unsigned int i, last_cpu, max_acpi_id = 0; info = &op.u.pcpu_info; info->xen_cpuid = 0; ret = HYPERVISOR_platform_op(&op); if (ret) return NR_CPUS; /* The max_present is the same irregardless of the xen_cpuid */ last_cpu = op.u.pcpu_info.max_present; for (i = 0; i <= last_cpu; i++) { info->xen_cpuid = i; ret = HYPERVISOR_platform_op(&op); if (ret) continue; max_acpi_id = max(info->acpi_id, max_acpi_id); } max_acpi_id *= 2; /* Slack for CPU hotplug support. */ pr_debug("Max ACPI ID: %u\n", max_acpi_id); return max_acpi_id; } /* * The read_acpi_id and check_acpi_ids are there to support the Xen * oddity of virtual CPUs != physical CPUs in the initial domain. * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line * which will band the amount of CPUs the initial domain can see. * In general that is OK, except it plays havoc with any of the * for_each_[present|online]_cpu macros which are banded to the virtual * CPU amount. */ static acpi_status read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv) { 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 }; acpi_io_address pblk = 0; status = acpi_get_type(handle, &acpi_type); if (ACPI_FAILURE(status)) return AE_OK; switch (acpi_type) { case ACPI_TYPE_PROCESSOR: status = acpi_evaluate_object(handle, NULL, NULL, &buffer); if (ACPI_FAILURE(status)) return AE_OK; acpi_id = object.processor.proc_id; pblk = object.processor.pblk_address; break; case ACPI_TYPE_DEVICE: status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp); if (ACPI_FAILURE(status)) return AE_OK; acpi_id = tmp; break; default: return AE_OK; } if (invalid_phys_cpuid(acpi_get_phys_id(handle, acpi_type == ACPI_TYPE_DEVICE, acpi_id))) { pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id); return AE_OK; } /* There are more ACPI Processor objects than in x2APIC or MADT. * This can happen with incorrect ACPI SSDT declerations. */ if (acpi_id >= nr_acpi_bits) { pr_debug("max acpi id %u, trying to set %u\n", nr_acpi_bits - 1, acpi_id); return AE_OK; } /* OK, There is a ACPI Processor object */ __set_bit(acpi_id, acpi_id_present); pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk); /* It has P-state dependencies */ if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) { pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n", acpi_id, acpi_psd[acpi_id].coord_type, acpi_psd[acpi_id].domain); } status = acpi_evaluate_object(handle, "_CST", NULL, &buffer); if (ACPI_FAILURE(status)) { if (!pblk) return AE_OK; } /* .. and it has a C-state */ __set_bit(acpi_id, acpi_id_cst_present); return AE_OK; } static int check_acpi_ids(struct acpi_processor *pr_backup) { if (!pr_backup) return -ENODEV; if (acpi_id_present && acpi_id_cst_present) /* OK, done this once .. skip to uploading */ goto upload; /* All online CPUs have been processed at this stage. Now verify * whether in fact "online CPUs" == physical CPUs. */ acpi_id_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); if (!acpi_id_present) return -ENOMEM; acpi_id_cst_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); if (!acpi_id_cst_present) { bitmap_free(acpi_id_present); return -ENOMEM; } acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package), GFP_KERNEL); if (!acpi_psd) { bitmap_free(acpi_id_present); bitmap_free(acpi_id_cst_present); return -ENOMEM; } acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, read_acpi_id, NULL, NULL, NULL); acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, read_acpi_id, NULL, NULL); upload: if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) { unsigned int i; for_each_set_bit(i, acpi_id_present, nr_acpi_bits) { pr_backup->acpi_id = i; /* Mask out C-states if there are no _CST or PBLK */ pr_backup->flags.power = test_bit(i, acpi_id_cst_present); /* num_entries is non-zero if we evaluated _PSD */ if (acpi_psd[i].num_entries) { memcpy(&pr_backup->performance->domain_info, &acpi_psd[i], sizeof(struct acpi_psd_package)); } (void)upload_pm_data(pr_backup); } } return 0; } /* acpi_perf_data is a pointer to percpu data. */ static struct acpi_processor_performance __percpu *acpi_perf_data; static void free_acpi_perf_data(void) { unsigned int i; /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */ for_each_possible_cpu(i) free_cpumask_var(per_cpu_ptr(acpi_perf_data, i) ->shared_cpu_map); free_percpu(acpi_perf_data); } static int xen_upload_processor_pm_data(void) { struct acpi_processor *pr_backup = NULL; unsigned int i; int rc = 0; pr_info("Uploading Xen processor PM info\n"); for_each_possible_cpu(i) { struct acpi_processor *_pr; _pr = per_cpu(processors, i /* APIC ID */); if (!_pr) continue; if (!pr_backup) { pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); if (pr_backup) memcpy(pr_backup, _pr, sizeof(struct acpi_processor)); } (void)upload_pm_data(_pr); } rc = check_acpi_ids(pr_backup); kfree(pr_backup); return rc; } static void xen_acpi_processor_resume_worker(struct work_struct *dummy) { int rc; bitmap_zero(acpi_ids_done, nr_acpi_bits); rc = xen_upload_processor_pm_data(); if (rc != 0) pr_info("ACPI data upload failed, error = %d\n", rc); } static void xen_acpi_processor_resume(void) { static DECLARE_WORK(wq, xen_acpi_processor_resume_worker); /* * xen_upload_processor_pm_data() calls non-atomic code. * However, the context for xen_acpi_processor_resume is syscore * with only the boot CPU online and in an atomic context. * * So defer the upload for some point safer. */ schedule_work(&wq); } static struct syscore_ops xap_syscore_ops = { .resume = xen_acpi_processor_resume, }; static int __init xen_acpi_processor_init(void) { unsigned int i; int rc; if (!xen_initial_domain()) return -ENODEV; nr_acpi_bits = get_max_acpi_id() + 1; acpi_ids_done = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); if (!acpi_ids_done) return -ENOMEM; acpi_perf_data = alloc_percpu(struct acpi_processor_performance); if (!acpi_perf_data) { pr_debug("Memory allocation error for acpi_perf_data\n"); bitmap_free(acpi_ids_done); return -ENOMEM; } for_each_possible_cpu(i) { if (!zalloc_cpumask_var_node( &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map, GFP_KERNEL, cpu_to_node(i))) { rc = -ENOMEM; goto err_out; } } /* Do initialization in ACPI core. It is OK to fail here. */ (void)acpi_processor_preregister_performance(acpi_perf_data); for_each_possible_cpu(i) { struct acpi_processor *pr; struct acpi_processor_performance *perf; pr = per_cpu(processors, i); perf = per_cpu_ptr(acpi_perf_data, i); if (!pr) continue; pr->performance = perf; rc = acpi_processor_get_performance_info(pr); if (rc) goto err_out; } rc = xen_upload_processor_pm_data(); if (rc) goto err_unregister; register_syscore_ops(&xap_syscore_ops); return 0; err_unregister: for_each_possible_cpu(i) acpi_processor_unregister_performance(i); err_out: /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ free_acpi_perf_data(); bitmap_free(acpi_ids_done); return rc; } static void __exit xen_acpi_processor_exit(void) { int i; unregister_syscore_ops(&xap_syscore_ops); bitmap_free(acpi_ids_done); bitmap_free(acpi_id_present); bitmap_free(acpi_id_cst_present); kfree(acpi_psd); for_each_possible_cpu(i) acpi_processor_unregister_performance(i); free_acpi_perf_data(); } MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>"); MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor"); MODULE_LICENSE("GPL"); /* We want to be loaded before the CPU freq scaling drivers are loaded. * They are loaded in late_initcall. */ device_initcall(xen_acpi_processor_init); module_exit(xen_acpi_processor_exit);