xref: /linux/drivers/platform/x86/intel/tpmi_power_domains.c (revision 7110f24f9e33979fd704f7a4a595a9d3e9bdacb7)
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_ATOM_DARKMONT_X,	NULL),
85 	X86_MATCH_VFM(INTEL_GRANITERAPIDS_D,	NULL),
86 	X86_MATCH_VFM(INTEL_PANTHERCOVE_X,	NULL),
87 	{}
88 };
89 MODULE_DEVICE_TABLE(x86cpu, tpmi_cpu_ids);
90 
91 static DECLARE_HASHTABLE(tpmi_cpu_hash, 8);
92 
93 static bool tpmi_domain_is_valid(struct tpmi_cpu_info *info)
94 {
95 	return info->pkg_id < topology_max_packages() &&
96 		info->punit_domain_id < MAX_POWER_DOMAINS;
97 }
98 
99 int tpmi_get_linux_cpu_number(int package_id, int domain_id, int punit_core_id)
100 {
101 	struct tpmi_cpu_info *info;
102 	int ret = -EINVAL;
103 
104 	guard(mutex)(&tpmi_lock);
105 	hash_for_each_possible(tpmi_cpu_hash, info, hnode, punit_core_id) {
106 		if (info->punit_domain_id == domain_id && info->pkg_id == package_id) {
107 			ret = info->linux_cpu;
108 			break;
109 		}
110 	}
111 
112 	return ret;
113 }
114 EXPORT_SYMBOL_NS_GPL(tpmi_get_linux_cpu_number, "INTEL_TPMI_POWER_DOMAIN");
115 
116 int tpmi_get_punit_core_number(int cpu_no)
117 {
118 	if (cpu_no >= num_possible_cpus())
119 		return -EINVAL;
120 
121 	return per_cpu(tpmi_cpu_info, cpu_no).punit_core_id;
122 }
123 EXPORT_SYMBOL_NS_GPL(tpmi_get_punit_core_number, "INTEL_TPMI_POWER_DOMAIN");
124 
125 int tpmi_get_power_domain_id(int cpu_no)
126 {
127 	if (cpu_no >= num_possible_cpus())
128 		return -EINVAL;
129 
130 	return per_cpu(tpmi_cpu_info, cpu_no).punit_domain_id;
131 }
132 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_id, "INTEL_TPMI_POWER_DOMAIN");
133 
134 cpumask_t *tpmi_get_power_domain_mask(int cpu_no)
135 {
136 	struct tpmi_cpu_info *info;
137 	cpumask_t *mask;
138 	int index;
139 
140 	if (cpu_no >= num_possible_cpus())
141 		return NULL;
142 
143 	info = &per_cpu(tpmi_cpu_info, cpu_no);
144 	if (!tpmi_domain_is_valid(info))
145 		return NULL;
146 
147 	index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
148 	guard(mutex)(&tpmi_lock);
149 	mask = &tpmi_power_domain_mask[index];
150 
151 	return mask;
152 }
153 EXPORT_SYMBOL_NS_GPL(tpmi_get_power_domain_mask, "INTEL_TPMI_POWER_DOMAIN");
154 
155 static int tpmi_get_logical_id(unsigned int cpu, struct tpmi_cpu_info *info)
156 {
157 	u64 data;
158 	int ret;
159 
160 	ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
161 	if (ret)
162 		return ret;
163 
164 	info->punit_domain_id = FIELD_GET(PM_DOMAIN_ID_MASK, data);
165 	if (info->punit_domain_id >= MAX_POWER_DOMAINS)
166 		return -EINVAL;
167 
168 	info->punit_thread_id = FIELD_GET(LP_ID_MASK, data);
169 	info->punit_core_id = FIELD_GET(MODULE_ID_MASK, data);
170 	info->pkg_id = topology_physical_package_id(cpu);
171 	info->linux_cpu = cpu;
172 
173 	return 0;
174 }
175 
176 static int tpmi_cpu_online(unsigned int cpu)
177 {
178 	struct tpmi_cpu_info *info = &per_cpu(tpmi_cpu_info, cpu);
179 	int ret, index;
180 
181 	/* Don't fail CPU online for some bad mapping of CPUs */
182 	ret = tpmi_get_logical_id(cpu, info);
183 	if (ret)
184 		return 0;
185 
186 	index = info->pkg_id * MAX_POWER_DOMAINS + info->punit_domain_id;
187 
188 	guard(mutex)(&tpmi_lock);
189 	cpumask_set_cpu(cpu, &tpmi_power_domain_mask[index]);
190 	hash_add(tpmi_cpu_hash, &info->hnode, info->punit_core_id);
191 
192 	return 0;
193 }
194 
195 static int __init tpmi_init(void)
196 {
197 	const struct x86_cpu_id *id;
198 	u64 data;
199 	int ret;
200 
201 	id = x86_match_cpu(tpmi_cpu_ids);
202 	if (!id)
203 		return -ENODEV;
204 
205 	/* Check for MSR 0x54 presence */
206 	ret = rdmsrl_safe(MSR_PM_LOGICAL_ID, &data);
207 	if (ret)
208 		return ret;
209 
210 	tpmi_power_domain_mask = kcalloc(size_mul(topology_max_packages(), MAX_POWER_DOMAINS),
211 					 sizeof(*tpmi_power_domain_mask), GFP_KERNEL);
212 	if (!tpmi_power_domain_mask)
213 		return -ENOMEM;
214 
215 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
216 				"platform/x86/tpmi_power_domains:online",
217 				tpmi_cpu_online, NULL);
218 	if (ret < 0) {
219 		kfree(tpmi_power_domain_mask);
220 		return ret;
221 	}
222 
223 	tpmi_hp_state = ret;
224 
225 	return 0;
226 }
227 module_init(tpmi_init)
228 
229 static void __exit tpmi_exit(void)
230 {
231 	cpuhp_remove_state(tpmi_hp_state);
232 	kfree(tpmi_power_domain_mask);
233 }
234 module_exit(tpmi_exit)
235 
236 MODULE_DESCRIPTION("TPMI Power Domains Mapping");
237 MODULE_LICENSE("GPL");
238