drivers/platform/x86/intel/ifs/core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright(c) 2022 Intel Corporation. */
   3
   4 #include <linux/bitfield.h>
   5 #include <linux/module.h>
   6 #include <linux/kdev_t.h>
   7 #include <linux/semaphore.h>
   8 #include <linux/slab.h>
   9
  10 #include <asm/cpu_device_id.h>
  11
  12 #include "ifs.h"
  13
  14 #define X86_MATCH(model, array_gen)                             \
  15         X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,    \
  16                 INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, array_gen)
  17
  18 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
  19         X86_MATCH(SAPPHIRERAPIDS_X, ARRAY_GEN0),
  20         X86_MATCH(EMERALDRAPIDS_X, ARRAY_GEN0),
  21         X86_MATCH(GRANITERAPIDS_X, ARRAY_GEN0),
  22         X86_MATCH(GRANITERAPIDS_D, ARRAY_GEN0),
  23         X86_MATCH(ATOM_CRESTMONT_X, ARRAY_GEN1),
  24         {}
  25 };
  26 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
  27
  28 ATTRIBUTE_GROUPS(plat_ifs);
  29 ATTRIBUTE_GROUPS(plat_ifs_array);
  30
  31 bool *ifs_pkg_auth;
  32
  33 static const struct ifs_test_caps scan_test = {
  34         .integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
  35         .test_num = IFS_TYPE_SAF,
  36 };
  37
  38 static const struct ifs_test_caps array_test = {
  39         .integrity_cap_bit = MSR_INTEGRITY_CAPS_ARRAY_BIST_BIT,
  40         .test_num = IFS_TYPE_ARRAY_BIST,
  41 };
  42
  43 static struct ifs_device ifs_devices[] = {
  44         [IFS_TYPE_SAF] = {
  45                 .test_caps = &scan_test,
  46                 .misc = {
  47                         .name = "intel_ifs_0",
  48                         .minor = MISC_DYNAMIC_MINOR,
  49                         .groups = plat_ifs_groups,
  50                 },
  51         },
  52         [IFS_TYPE_ARRAY_BIST] = {
  53                 .test_caps = &array_test,
  54                 .misc = {
  55                         .name = "intel_ifs_1",
  56                         .minor = MISC_DYNAMIC_MINOR,
  57                         .groups = plat_ifs_array_groups,
  58                 },
  59         },
  60 };
  61
  62 #define IFS_NUMTESTS ARRAY_SIZE(ifs_devices)
  63
  64 static void ifs_cleanup(void)
  65 {
  66         int i;
  67
  68         for (i = 0; i < IFS_NUMTESTS; i++) {
  69                 if (ifs_devices[i].misc.this_device)
  70                         misc_deregister(&ifs_devices[i].misc);
  71         }
  72         kfree(ifs_pkg_auth);
  73 }
  74
  75 static int __init ifs_init(void)
  76 {
  77         const struct x86_cpu_id *m;
  78         u64 msrval;
  79         int i, ret;
  80
  81         m = x86_match_cpu(ifs_cpu_ids);
  82         if (!m)
  83                 return -ENODEV;
  84
  85         if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
  86                 return -ENODEV;
  87
  88         if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
  89                 return -ENODEV;
  90
  91         if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
  92                 return -ENODEV;
  93
  94         ifs_pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL);
  95         if (!ifs_pkg_auth)
  96                 return -ENOMEM;
  97
  98         for (i = 0; i < IFS_NUMTESTS; i++) {
  99                 if (!(msrval & BIT(ifs_devices[i].test_caps->integrity_cap_bit)))
 100                         continue;
 101                 ifs_devices[i].rw_data.generation = FIELD_GET(MSR_INTEGRITY_CAPS_SAF_GEN_MASK,
 102                                                               msrval);
 103                 ifs_devices[i].rw_data.array_gen = (u32)m->driver_data;
 104                 ret = misc_register(&ifs_devices[i].misc);
 105                 if (ret)
 106                         goto err_exit;
 107         }
 108         return 0;
 109
 110 err_exit:
 111         ifs_cleanup();
 112         return ret;
 113 }
 114
 115 static void __exit ifs_exit(void)
 116 {
 117         ifs_cleanup();
 118 }
 119
 120 module_init(ifs_init);
 121 module_exit(ifs_exit);
 122
 123 MODULE_LICENSE("GPL");
 124 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");