intel/intel_tcc_cooling.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * cooling device driver that activates the processor throttling by
   4  * programming the TCC Offset register.
   5  * Copyright (c) 2021, Intel Corporation.
   6  */
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9 #include <linux/device.h>
  10 #include <linux/intel_tcc.h>
  11 #include <linux/module.h>
  12 #include <linux/thermal.h>
  13 #include <asm/cpu_device_id.h>
  14
  15 #define TCC_PROGRAMMABLE        BIT(30)
  16 #define TCC_LOCKED              BIT(31)
  17
  18 static struct thermal_cooling_device *tcc_cdev;
  19
  20 static int tcc_get_max_state(struct thermal_cooling_device *cdev, unsigned long
  21                              *state)
  22 {
  23         *state = 0x3f;
  24         return 0;
  25 }
  26
  27 static int tcc_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
  28                              *state)
  29 {
  30         int offset = intel_tcc_get_offset(-1);
  31
  32         if (offset < 0)
  33                 return offset;
  34
  35         *state = offset;
  36         return 0;
  37 }
  38
  39 static int tcc_set_cur_state(struct thermal_cooling_device *cdev, unsigned long
  40                              state)
  41 {
  42         return intel_tcc_set_offset(-1, (int)state);
  43 }
  44
  45 static const struct thermal_cooling_device_ops tcc_cooling_ops = {
  46         .get_max_state = tcc_get_max_state,
  47         .get_cur_state = tcc_get_cur_state,
  48         .set_cur_state = tcc_set_cur_state,
  49 };
  50
  51 static const struct x86_cpu_id tcc_ids[] __initconst = {
  52         X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE, NULL),
  53         X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L, NULL),
  54         X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE, NULL),
  55         X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L, NULL),
  56         X86_MATCH_INTEL_FAM6_MODEL(ICELAKE, NULL),
  57         X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, NULL),
  58         X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE, NULL),
  59         X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L, NULL),
  60         X86_MATCH_INTEL_FAM6_MODEL(COMETLAKE, NULL),
  61         X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE, NULL),
  62         X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L, NULL),
  63         X86_MATCH_INTEL_FAM6_MODEL(ATOM_GRACEMONT, NULL),
  64         X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE, NULL),
  65         X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_P, NULL),
  66         X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE_S, NULL),
  67         {}
  68 };
  69
  70 MODULE_DEVICE_TABLE(x86cpu, tcc_ids);
  71
  72 static int __init tcc_cooling_init(void)
  73 {
  74         int ret;
  75         u64 val;
  76         const struct x86_cpu_id *id;
  77
  78         int err;
  79
  80         id = x86_match_cpu(tcc_ids);
  81         if (!id)
  82                 return -ENODEV;
  83
  84         err = rdmsrl_safe(MSR_PLATFORM_INFO, &val);
  85         if (err)
  86                 return err;
  87
  88         if (!(val & TCC_PROGRAMMABLE))
  89                 return -ENODEV;
  90
  91         err = rdmsrl_safe(MSR_IA32_TEMPERATURE_TARGET, &val);
  92         if (err)
  93                 return err;
  94
  95         if (val & TCC_LOCKED) {
  96                 pr_info("TCC Offset locked\n");
  97                 return -ENODEV;
  98         }
  99
 100         pr_info("Programmable TCC Offset detected\n");
 101
 102         tcc_cdev =
 103             thermal_cooling_device_register("TCC Offset", NULL,
 104                                             &tcc_cooling_ops);
 105         if (IS_ERR(tcc_cdev)) {
 106                 ret = PTR_ERR(tcc_cdev);
 107                 return ret;
 108         }
 109         return 0;
 110 }
 111
 112 module_init(tcc_cooling_init)
 113
 114 static void __exit tcc_cooling_exit(void)
 115 {
 116         thermal_cooling_device_unregister(tcc_cdev);
 117 }
 118
 119 module_exit(tcc_cooling_exit)
 120
 121 MODULE_IMPORT_NS(INTEL_TCC);
 122 MODULE_DESCRIPTION("TCC offset cooling device Driver");
 123 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
 124 MODULE_LICENSE("GPL v2");