1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Secure Processor device driver, security attributes 4 * 5 * Copyright (C) 2023-2024 Advanced Micro Devices, Inc. 6 * 7 * Author: Mario Limonciello <mario.limonciello@amd.com> 8 */ 9 10 #include <linux/device.h> 11 12 #include "psp-dev.h" 13 #include "hsti.h" 14 15 #define PSP_CAPABILITY_PSP_SECURITY_OFFSET 8 16 17 struct hsti_request { 18 struct psp_req_buffer_hdr header; 19 u32 hsti; 20 } __packed; 21 22 #define security_attribute_show(name) \ 23 static ssize_t name##_show(struct device *d, struct device_attribute *attr, \ 24 char *buf) \ 25 { \ 26 struct sp_device *sp = dev_get_drvdata(d); \ 27 struct psp_device *psp = sp->psp_data; \ 28 return sysfs_emit(buf, "%d\n", psp->capability.name); \ 29 } 30 31 security_attribute_show(fused_part) 32 static DEVICE_ATTR_RO(fused_part); 33 security_attribute_show(debug_lock_on) 34 static DEVICE_ATTR_RO(debug_lock_on); 35 security_attribute_show(tsme_status) 36 static DEVICE_ATTR_RO(tsme_status); 37 security_attribute_show(anti_rollback_status) 38 static DEVICE_ATTR_RO(anti_rollback_status); 39 security_attribute_show(rpmc_production_enabled) 40 static DEVICE_ATTR_RO(rpmc_production_enabled); 41 security_attribute_show(rpmc_spirom_available) 42 static DEVICE_ATTR_RO(rpmc_spirom_available); 43 security_attribute_show(hsp_tpm_available) 44 static DEVICE_ATTR_RO(hsp_tpm_available); 45 security_attribute_show(rom_armor_enforced) 46 static DEVICE_ATTR_RO(rom_armor_enforced); 47 48 static struct attribute *psp_security_attrs[] = { 49 &dev_attr_fused_part.attr, 50 &dev_attr_debug_lock_on.attr, 51 &dev_attr_tsme_status.attr, 52 &dev_attr_anti_rollback_status.attr, 53 &dev_attr_rpmc_production_enabled.attr, 54 &dev_attr_rpmc_spirom_available.attr, 55 &dev_attr_hsp_tpm_available.attr, 56 &dev_attr_rom_armor_enforced.attr, 57 NULL 58 }; 59 60 static umode_t psp_security_is_visible(struct kobject *kobj, struct attribute *attr, int idx) 61 { 62 struct device *dev = kobj_to_dev(kobj); 63 struct sp_device *sp = dev_get_drvdata(dev); 64 struct psp_device *psp = sp->psp_data; 65 66 if (psp && psp->capability.security_reporting) 67 return 0444; 68 69 return 0; 70 } 71 72 struct attribute_group psp_security_attr_group = { 73 .attrs = psp_security_attrs, 74 .is_visible = psp_security_is_visible, 75 }; 76 77 static int psp_poulate_hsti(struct psp_device *psp) 78 { 79 struct hsti_request *req; 80 int ret; 81 82 /* Are the security attributes already reported? */ 83 if (psp->capability.security_reporting) 84 return 0; 85 86 /* Allocate command-response buffer */ 87 req = kzalloc(sizeof(*req), GFP_KERNEL | __GFP_ZERO); 88 if (!req) 89 return -ENOMEM; 90 91 req->header.payload_size = sizeof(req); 92 93 ret = psp_send_platform_access_msg(PSP_CMD_HSTI_QUERY, (struct psp_request *)req); 94 if (ret) 95 goto out; 96 97 if (req->header.status != 0) { 98 dev_dbg(psp->dev, "failed to populate HSTI state: %d\n", req->header.status); 99 ret = -EINVAL; 100 goto out; 101 } 102 103 psp->capability.security_reporting = 1; 104 psp->capability.raw |= req->hsti << PSP_CAPABILITY_PSP_SECURITY_OFFSET; 105 106 out: 107 kfree(req); 108 109 return ret; 110 } 111 112 int psp_init_hsti(struct psp_device *psp) 113 { 114 int ret; 115 116 if (PSP_FEATURE(psp, HSTI)) { 117 ret = psp_poulate_hsti(psp); 118 if (ret) 119 return ret; 120 } 121 122 /* 123 * At this stage, if security information hasn't been populated by 124 * either the PSP or by the driver through the platform command, 125 * then there is nothing more to do. 126 */ 127 if (!psp->capability.security_reporting) 128 return 0; 129 130 if (psp->capability.tsme_status) { 131 if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) 132 dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n"); 133 else 134 dev_notice(psp->dev, "psp: TSME enabled\n"); 135 } 136 137 return 0; 138 } 139