--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Mapping of TPMI power domains CPU mapping
+ *
+ * Copyright (c) 2024, Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/hashtable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/topology.h>
+#include <linux/types.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/msr.h>
+
+#include "tpmi_power_domains.h"
+
+#define MSR_PM_LOGICAL_ID 0x54
+
+/*
+ * Struct of MSR 0x54
+ * [15:11] PM_DOMAIN_ID
+ * [10:3] MODULE_ID (aka IDI_AGENT_ID)
+ * [2:0] LP_ID
+ * For Atom:
+ * [2] Always 0
+ * [1:0] core ID within module
+ * For Core
+ * [2:1] Always 0
+ * [0] thread ID
+ */
+
+#define LP_ID_MASK GENMASK_ULL(2, 0)
+#define MODULE_ID_MASK GENMASK_ULL(10, 3)
+#define PM_DOMAIN_ID_MASK GENMASK_ULL(15, 11)
+
+/**
+ * struct tpmi_cpu_info - Mapping information for a CPU
+ * @hnode: Used to add mapping information to hash list
+ * @linux_cpu: Linux CPU number
+ * @pkg_id: Package ID of this CPU
+ * @punit_thread_id: Punit thread id of this CPU
+ * @punit_core_id: Punit core id
+ * @punit_domain_id: Power domain id from Punit
+ *
+ * Structure to store mapping information for a Linux CPU
+ * to a Punit core, thread and power domain.
+ */
+struct tpmi_cpu_info {
+ struct hlist_node hnode;
+ int linux_cpu;
+ u8 pkg_id;
+ u8 punit_thread_id;
+ u8 punit_core_id;
+ u8 punit_domain_id;
+};
+
+static DEFINE_PER_CPU(struct tpmi_cpu_info, tpmi_cpu_info);
+
+/* The dynamically assigned cpu hotplug state to free later */
+static enum cpuhp_state tpmi_hp_state __read_mostly;
+
+#define MAX_POWER_DOMAINS 8
+
+static cpumask_t *tpmi_power_domain_mask;
+
+/* Lock to protect tpmi_power_domain_mask and tpmi_cpu_hash */
+static DEFINE_MUTEX(tpmi_lock);
+
+static const struct x86_cpu_id tpmi_cpu_ids[] = {
+ X86_MATCH_VFM(INTEL_GRANITERAPIDS_X, NULL),
+ X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X, NULL),
+ X86_MATCH_VFM(INTEL_ATOM_CRESTMONT, NULL),
+ X86_MATCH_VFM(INTEL_GRANITERAPIDS_D, NULL),
+ {}
+};
+MODULE_DEVICE_TABLE(x86cpu, tpmi_cpu_ids);
+
+static DECLARE_HASHTABLE(tpmi_cpu_hash, 8);
+
+static bool tpmi_domain_is_valid(struct tpmi_cpu_info *info)
+{
+ return info->pkg_id < topology_max_packages() &&
+ info->punit_domain_id < MAX_POWER_DOMAINS;
+}
+
+int tpmi_get_linux_cpu_number(int package_id, int domain_id, int punit_core_id)
+{
+ struct tpmi_cpu_info *info;
+ int ret = -EINVAL;
+
+ guard(mutex)(&tpmi_lock);
+ hash_for_each_possible(tpmi_cpu_hash, info, hnode, punit_core_id) {
+ if (info->punit_domain_id == domain_id && info->pkg_id == package_id) {
+ ret = info->linux_cpu;
+ break;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_linux_cpu_number, INTEL_TPMI_POWER_DOMAIN);
+
+int tpmi_get_punit_core_number(int cpu_no)
+{
+ if (cpu_no >= num_possible_cpus())
+ return -EINVAL;
+
+ return per_cpu(tpmi_cpu_info, cpu_no).punit_core_id;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_punit_core_number, INTEL_TPMI_POWER_DOMAIN);
+
+int tpmi_get_power_domain_id(int cpu_no)
+{
+ if (cpu_no >= num_possible_cpus())
+ return -EINVAL;
+
+ return per_cpu(tpmi_cpu_info, cpu_no).punit_domain_id;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_id, INTEL_TPMI_POWER_DOMAIN);
+
+cpumask_t *tpmi_get_power_domain_mask(int cpu_no)
+{
+ struct tpmi_cpu_info *info;
+ cpumask_t *mask;
+ int index;
+
+ if (cpu_no >= num_possible_cpus())
+ return NULL;
+
+ info = &per_cpu(tpmi_cpu_info, cpu_no);
+ if (!tpmi_domain_is_valid(info))
+ return NULL;
+
+ index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
+ guard(mutex)(&tpmi_lock);
+ mask = &tpmi_power_domain_mask[index];
+
+ return mask;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_mask, INTEL_TPMI_POWER_DOMAIN);
+
+static int tpmi_get_logical_id(unsigned int cpu, struct tpmi_cpu_info *info)
+{
+ u64 data;
+ int ret;
+
+ ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
+ if (ret)
+ return ret;
+
+ info->punit_domain_id = FIELD_GET(PM_DOMAIN_ID_MASK, data);
+ if (info->punit_domain_id >= MAX_POWER_DOMAINS)
+ return -EINVAL;
+
+ info->punit_thread_id = FIELD_GET(LP_ID_MASK, data);
+ info->punit_core_id = FIELD_GET(MODULE_ID_MASK, data);
+ info->pkg_id = topology_physical_package_id(cpu);
+ info->linux_cpu = cpu;
+
+ return 0;
+}
+
+static int tpmi_cpu_online(unsigned int cpu)
+{
+ struct tpmi_cpu_info *info = &per_cpu(tpmi_cpu_info, cpu);
+ int ret, index;
+
+ /* Don't fail CPU online for some bad mapping of CPUs */
+ ret = tpmi_get_logical_id(cpu, info);
+ if (ret)
+ return 0;
+
+ index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
+
+ guard(mutex)(&tpmi_lock);
+ cpumask_set_cpu(cpu, &tpmi_power_domain_mask[index]);
+ hash_add(tpmi_cpu_hash, &info->hnode, info->punit_core_id);
+
+ return 0;
+}
+
+static int __init tpmi_init(void)
+{
+ const struct x86_cpu_id *id;
+ u64 data;
+ int ret;
+
+ id = x86_match_cpu(tpmi_cpu_ids);
+ if (!id)
+ return -ENODEV;
+
+ /* Check for MSR 0x54 presence */
+ ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
+ if (ret)
+ return ret;
+
+ tpmi_power_domain_mask = kcalloc(size_mul(topology_max_packages(), MAX_POWER_DOMAINS),
+ sizeof(*tpmi_power_domain_mask), GFP_KERNEL);
+ if (!tpmi_power_domain_mask)
+ return -ENOMEM;
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "platform/x86/tpmi_power_domains:online",
+ tpmi_cpu_online, NULL);
+ if (ret < 0) {
+ kfree(tpmi_power_domain_mask);
+ return ret;
+ }
+
+ tpmi_hp_state = ret;
+
+ return 0;
+}
+module_init(tpmi_init)
+
+static void __exit tpmi_exit(void)
+{
+ cpuhp_remove_state(tpmi_hp_state);
+ kfree(tpmi_power_domain_mask);
+}
+module_exit(tpmi_exit)
+
+MODULE_DESCRIPTION("TPMI Power Domains Mapping");
+MODULE_LICENSE("GPL");
projects / users / dwmw2 / linux.git / commitdiff