drivers/platform/x86/intel/tpmi_power_domains.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Mapping of TPMI power domains CPU mapping
   4  *
   5  * Copyright (c) 2024, Intel Corporation.
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/cleanup.h>
  10 #include <linux/cpuhotplug.h>
  11 #include <linux/cpumask.h>
  12 #include <linux/errno.h>
  13 #include <linux/export.h>
  14 #include <linux/hashtable.h>
  15 #include <linux/module.h>
  16 #include <linux/mutex.h>
  17 #include <linux/overflow.h>
  18 #include <linux/slab.h>
  19 #include <linux/topology.h>
  20 #include <linux/types.h>
  21
  22 #include <asm/cpu_device_id.h>
  23 #include <asm/intel-family.h>
  24 #include <asm/msr.h>
  25
  26 #include "tpmi_power_domains.h"
  27
  28 #define MSR_PM_LOGICAL_ID       0x54
  29
  30 /*
  31  * Struct of MSR 0x54
  32  * [15:11] PM_DOMAIN_ID
  33  * [10:3] MODULE_ID (aka IDI_AGENT_ID)
  34  * [2:0] LP_ID
  35  * For Atom:
  36  *   [2] Always 0
  37  *   [1:0] core ID within module
  38  * For Core
  39  *   [2:1] Always 0
  40  *   [0] thread ID
  41  */
  42
  43 #define LP_ID_MASK              GENMASK_ULL(2, 0)
  44 #define MODULE_ID_MASK          GENMASK_ULL(10, 3)
  45 #define PM_DOMAIN_ID_MASK       GENMASK_ULL(15, 11)
  46
  47 /**
  48  * struct tpmi_cpu_info - Mapping information for a CPU
  49  * @hnode: Used to add mapping information to hash list
  50  * @linux_cpu:  Linux CPU number
  51  * @pkg_id: Package ID of this CPU
  52  * @punit_thread_id: Punit thread id of this CPU
  53  * @punit_core_id: Punit core id
  54  * @punit_domain_id: Power domain id from Punit
  55  *
  56  * Structure to store mapping information for a Linux CPU
  57  * to a Punit core, thread and power domain.
  58  */
  59 struct tpmi_cpu_info {
  60         struct hlist_node hnode;
  61         int linux_cpu;
  62         u8 pkg_id;
  63         u8 punit_thread_id;
  64         u8 punit_core_id;
  65         u8 punit_domain_id;
  66 };
  67
  68 static DEFINE_PER_CPU(struct tpmi_cpu_info, tpmi_cpu_info);
  69
  70 /* The dynamically assigned cpu hotplug state to free later */
  71 static enum cpuhp_state tpmi_hp_state __read_mostly;
  72
  73 #define MAX_POWER_DOMAINS       8
  74
  75 static cpumask_t *tpmi_power_domain_mask;
  76
  77 /* Lock to protect tpmi_power_domain_mask and tpmi_cpu_hash */
  78 static DEFINE_MUTEX(tpmi_lock);
  79
  80 static const struct x86_cpu_id tpmi_cpu_ids[] = {
  81         X86_MATCH_VFM(INTEL_GRANITERAPIDS_X,    NULL),
  82         X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X,   NULL),
  83         X86_MATCH_VFM(INTEL_ATOM_CRESTMONT,     NULL),
  84         X86_MATCH_VFM(INTEL_GRANITERAPIDS_D,    NULL),
  85         {}
  86 };
  87 MODULE_DEVICE_TABLE(x86cpu, tpmi_cpu_ids);
  88
  89 static DECLARE_HASHTABLE(tpmi_cpu_hash, 8);
  90
  91 static bool tpmi_domain_is_valid(struct tpmi_cpu_info *info)
  92 {
  93         return info->pkg_id < topology_max_packages() &&
  94                 info->punit_domain_id < MAX_POWER_DOMAINS;
  95 }
  96
  97 int tpmi_get_linux_cpu_number(int package_id, int domain_id, int punit_core_id)
  98 {
  99         struct tpmi_cpu_info *info;
 100         int ret = -EINVAL;
 101
 102         guard(mutex)(&tpmi_lock);
 103         hash_for_each_possible(tpmi_cpu_hash, info, hnode, punit_core_id) {
 104                 if (info->punit_domain_id == domain_id && info->pkg_id == package_id) {
 105                         ret = info->linux_cpu;
 106                         break;
 107                 }
 108         }
 109
 110         return ret;
 111 }
 112 EXPORT_SYMBOL_NS_GPL(tpmi_get_linux_cpu_number, INTEL_TPMI_POWER_DOMAIN);
 113
 114 int tpmi_get_punit_core_number(int cpu_no)
 115 {
 116         if (cpu_no >= num_possible_cpus())
 117                 return -EINVAL;
 118
 119         return per_cpu(tpmi_cpu_info, cpu_no).punit_core_id;
 120 }
 121 EXPORT_SYMBOL_NS_GPL(tpmi_get_punit_core_number, INTEL_TPMI_POWER_DOMAIN);
 122
 123 int tpmi_get_power_domain_id(int cpu_no)
 124 {
 125         if (cpu_no >= num_possible_cpus())
 126                 return -EINVAL;
 127
 128         return per_cpu(tpmi_cpu_info, cpu_no).punit_domain_id;
 129 }
 130 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_id, INTEL_TPMI_POWER_DOMAIN);
 131
 132 cpumask_t *tpmi_get_power_domain_mask(int cpu_no)
 133 {
 134         struct tpmi_cpu_info *info;
 135         cpumask_t *mask;
 136         int index;
 137
 138         if (cpu_no >= num_possible_cpus())
 139                 return NULL;
 140
 141         info = &per_cpu(tpmi_cpu_info, cpu_no);
 142         if (!tpmi_domain_is_valid(info))
 143                 return NULL;
 144
 145         index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
 146         guard(mutex)(&tpmi_lock);
 147         mask = &tpmi_power_domain_mask[index];
 148
 149         return mask;
 150 }
 151 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_mask, INTEL_TPMI_POWER_DOMAIN);
 152
 153 static int tpmi_get_logical_id(unsigned int cpu, struct tpmi_cpu_info *info)
 154 {
 155         u64 data;
 156         int ret;
 157
 158         ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
 159         if (ret)
 160                 return ret;
 161
 162         info->punit_domain_id = FIELD_GET(PM_DOMAIN_ID_MASK, data);
 163         if (info->punit_domain_id >= MAX_POWER_DOMAINS)
 164                 return -EINVAL;
 165
 166         info->punit_thread_id = FIELD_GET(LP_ID_MASK, data);
 167         info->punit_core_id = FIELD_GET(MODULE_ID_MASK, data);
 168         info->pkg_id = topology_physical_package_id(cpu);
 169         info->linux_cpu = cpu;
 170
 171         return 0;
 172 }
 173
 174 static int tpmi_cpu_online(unsigned int cpu)
 175 {
 176         struct tpmi_cpu_info *info = &per_cpu(tpmi_cpu_info, cpu);
 177         int ret, index;
 178
 179         /* Don't fail CPU online for some bad mapping of CPUs */
 180         ret = tpmi_get_logical_id(cpu, info);
 181         if (ret)
 182                 return 0;
 183
 184         index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
 185
 186         guard(mutex)(&tpmi_lock);
 187         cpumask_set_cpu(cpu, &tpmi_power_domain_mask[index]);
 188         hash_add(tpmi_cpu_hash, &info->hnode, info->punit_core_id);
 189
 190         return 0;
 191 }
 192
 193 static int __init tpmi_init(void)
 194 {
 195         const struct x86_cpu_id *id;
 196         u64 data;
 197         int ret;
 198
 199         id = x86_match_cpu(tpmi_cpu_ids);
 200         if (!id)
 201                 return -ENODEV;
 202
 203         /* Check for MSR 0x54 presence */
 204         ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
 205         if (ret)
 206                 return ret;
 207
 208         tpmi_power_domain_mask = kcalloc(size_mul(topology_max_packages(), MAX_POWER_DOMAINS),
 209                                          sizeof(*tpmi_power_domain_mask), GFP_KERNEL);
 210         if (!tpmi_power_domain_mask)
 211                 return -ENOMEM;
 212
 213         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 214                                 "platform/x86/tpmi_power_domains:online",
 215                                 tpmi_cpu_online, NULL);
 216         if (ret < 0) {
 217                 kfree(tpmi_power_domain_mask);
 218                 return ret;
 219         }
 220
 221         tpmi_hp_state = ret;
 222
 223         return 0;
 224 }
 225 module_init(tpmi_init)
 226
 227 static void __exit tpmi_exit(void)
 228 {
 229         cpuhp_remove_state(tpmi_hp_state);
 230         kfree(tpmi_power_domain_mask);
 231 }
 232 module_exit(tpmi_exit)
 233
 234 MODULE_DESCRIPTION("TPMI Power Domains Mapping");
 235 MODULE_LICENSE("GPL");