1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright(c) 2022 Intel Corporation. */ 3 4 #include <linux/module.h> 5 #include <linux/kdev_t.h> 6 #include <linux/semaphore.h> 7 #include <linux/slab.h> 8 9 #include <asm/cpu_device_id.h> 10 11 #include "ifs.h" 12 13 #define X86_MATCH(model) \ 14 X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \ 15 INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL) 16 17 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = { 18 X86_MATCH(SAPPHIRERAPIDS_X), 19 {} 20 }; 21 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids); 22 23 static struct ifs_device ifs_device = { 24 .data = { 25 .integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT, 26 .test_num = 0, 27 }, 28 .misc = { 29 .name = "intel_ifs_0", 30 .nodename = "intel_ifs/0", 31 .minor = MISC_DYNAMIC_MINOR, 32 }, 33 }; 34 35 static int __init ifs_init(void) 36 { 37 const struct x86_cpu_id *m; 38 u64 msrval; 39 int ret; 40 41 m = x86_match_cpu(ifs_cpu_ids); 42 if (!m) 43 return -ENODEV; 44 45 if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval)) 46 return -ENODEV; 47 48 if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS)) 49 return -ENODEV; 50 51 if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval)) 52 return -ENODEV; 53 54 ifs_device.misc.groups = ifs_get_groups(); 55 56 if (!(msrval & BIT(ifs_device.data.integrity_cap_bit))) 57 return -ENODEV; 58 59 ifs_device.data.pkg_auth = kmalloc_array(topology_max_packages(), sizeof(bool), GFP_KERNEL); 60 if (!ifs_device.data.pkg_auth) 61 return -ENOMEM; 62 63 ret = misc_register(&ifs_device.misc); 64 if (ret) { 65 kfree(ifs_device.data.pkg_auth); 66 return ret; 67 } 68 69 return 0; 70 } 71 72 static void __exit ifs_exit(void) 73 { 74 misc_deregister(&ifs_device.misc); 75 kfree(ifs_device.data.pkg_auth); 76 } 77 78 module_init(ifs_init); 79 module_exit(ifs_exit); 80 81 MODULE_LICENSE("GPL"); 82 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device"); 83