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 8 #include <asm/cpu_device_id.h> 9 10 #include "ifs.h" 11 12 #define X86_MATCH(model) \ 13 X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \ 14 INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL) 15 16 static const struct x86_cpu_id ifs_cpu_ids[] __initconst = { 17 X86_MATCH(SAPPHIRERAPIDS_X), 18 {} 19 }; 20 MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids); 21 22 static struct ifs_device ifs_device = { 23 .data = { 24 .integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT, 25 }, 26 .misc = { 27 .name = "intel_ifs_0", 28 .nodename = "intel_ifs/0", 29 .minor = MISC_DYNAMIC_MINOR, 30 }, 31 }; 32 33 static int __init ifs_init(void) 34 { 35 const struct x86_cpu_id *m; 36 u64 msrval; 37 38 m = x86_match_cpu(ifs_cpu_ids); 39 if (!m) 40 return -ENODEV; 41 42 if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval)) 43 return -ENODEV; 44 45 if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS)) 46 return -ENODEV; 47 48 if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval)) 49 return -ENODEV; 50 51 ifs_device.misc.groups = ifs_get_groups(); 52 53 if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) && 54 !misc_register(&ifs_device.misc)) { 55 down(&ifs_sem); 56 ifs_load_firmware(ifs_device.misc.this_device); 57 up(&ifs_sem); 58 return 0; 59 } 60 61 return -ENODEV; 62 } 63 64 static void __exit ifs_exit(void) 65 { 66 misc_deregister(&ifs_device.misc); 67 } 68 69 module_init(ifs_init); 70 module_exit(ifs_exit); 71 72 MODULE_LICENSE("GPL"); 73 MODULE_DESCRIPTION("Intel In Field Scan (IFS) device"); 74