1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2019 Intel Corporation. 4 * 5 * Authors: 6 * Ramalingam C <ramalingam.c@intel.com> 7 */ 8 9 #include <linux/device.h> 10 #include <linux/err.h> 11 #include <linux/gfp.h> 12 #include <linux/export.h> 13 #include <linux/slab.h> 14 #include <linux/firmware.h> 15 16 #include <drm/display/drm_hdcp_helper.h> 17 #include <drm/drm_sysfs.h> 18 #include <drm/drm_print.h> 19 #include <drm/drm_device.h> 20 #include <drm/drm_property.h> 21 #include <drm/drm_mode_object.h> 22 #include <drm/drm_connector.h> 23 24 static inline void drm_hdcp_print_ksv(const u8 *ksv) 25 { 26 DRM_DEBUG("\t%#02x, %#02x, %#02x, %#02x, %#02x\n", 27 ksv[0], ksv[1], ksv[2], ksv[3], ksv[4]); 28 } 29 30 static u32 drm_hdcp_get_revoked_ksv_count(const u8 *buf, u32 vrls_length) 31 { 32 u32 parsed_bytes = 0, ksv_count = 0, vrl_ksv_cnt, vrl_sz; 33 34 while (parsed_bytes < vrls_length) { 35 vrl_ksv_cnt = *buf; 36 ksv_count += vrl_ksv_cnt; 37 38 vrl_sz = (vrl_ksv_cnt * DRM_HDCP_KSV_LEN) + 1; 39 buf += vrl_sz; 40 parsed_bytes += vrl_sz; 41 } 42 43 /* 44 * When vrls are not valid, ksvs are not considered. 45 * Hence SRM will be discarded. 46 */ 47 if (parsed_bytes != vrls_length) 48 ksv_count = 0; 49 50 return ksv_count; 51 } 52 53 static u32 drm_hdcp_get_revoked_ksvs(const u8 *buf, u8 **revoked_ksv_list, 54 u32 vrls_length) 55 { 56 u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 0; 57 u32 parsed_bytes = 0, ksv_count = 0; 58 59 do { 60 vrl_ksv_cnt = *buf; 61 vrl_ksv_sz = vrl_ksv_cnt * DRM_HDCP_KSV_LEN; 62 63 buf++; 64 65 DRM_DEBUG("vrl: %d, Revoked KSVs: %d\n", vrl_idx++, 66 vrl_ksv_cnt); 67 memcpy((*revoked_ksv_list) + (ksv_count * DRM_HDCP_KSV_LEN), 68 buf, vrl_ksv_sz); 69 70 ksv_count += vrl_ksv_cnt; 71 buf += vrl_ksv_sz; 72 73 parsed_bytes += (vrl_ksv_sz + 1); 74 } while (parsed_bytes < vrls_length); 75 76 return ksv_count; 77 } 78 79 static inline u32 get_vrl_length(const u8 *buf) 80 { 81 return drm_hdcp_be24_to_cpu(buf); 82 } 83 84 static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count, 85 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 86 { 87 struct hdcp_srm_header *header; 88 u32 vrl_length, ksv_count; 89 90 if (count < (sizeof(struct hdcp_srm_header) + 91 DRM_HDCP_1_4_VRL_LENGTH_SIZE + DRM_HDCP_1_4_DCP_SIG_SIZE)) { 92 DRM_ERROR("Invalid blob length\n"); 93 return -EINVAL; 94 } 95 96 header = (struct hdcp_srm_header *)buf; 97 DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n", 98 header->srm_id, 99 be16_to_cpu(header->srm_version), header->srm_gen_no); 100 101 WARN_ON(header->reserved); 102 103 buf = buf + sizeof(*header); 104 vrl_length = get_vrl_length(buf); 105 if (count < (sizeof(struct hdcp_srm_header) + vrl_length) || 106 vrl_length < (DRM_HDCP_1_4_VRL_LENGTH_SIZE + 107 DRM_HDCP_1_4_DCP_SIG_SIZE)) { 108 DRM_ERROR("Invalid blob length or vrl length\n"); 109 return -EINVAL; 110 } 111 112 /* Length of the all vrls combined */ 113 vrl_length -= (DRM_HDCP_1_4_VRL_LENGTH_SIZE + 114 DRM_HDCP_1_4_DCP_SIG_SIZE); 115 116 if (!vrl_length) { 117 DRM_ERROR("No vrl found\n"); 118 return -EINVAL; 119 } 120 121 buf += DRM_HDCP_1_4_VRL_LENGTH_SIZE; 122 ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length); 123 if (!ksv_count) { 124 DRM_DEBUG("Revoked KSV count is 0\n"); 125 return 0; 126 } 127 128 *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL); 129 if (!*revoked_ksv_list) { 130 DRM_ERROR("Out of Memory\n"); 131 return -ENOMEM; 132 } 133 134 if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list, 135 vrl_length) != ksv_count) { 136 *revoked_ksv_cnt = 0; 137 kfree(*revoked_ksv_list); 138 return -EINVAL; 139 } 140 141 *revoked_ksv_cnt = ksv_count; 142 return 0; 143 } 144 145 static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count, 146 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 147 { 148 struct hdcp_srm_header *header; 149 u32 vrl_length, ksv_count, ksv_sz; 150 151 if (count < (sizeof(struct hdcp_srm_header) + 152 DRM_HDCP_2_VRL_LENGTH_SIZE + DRM_HDCP_2_DCP_SIG_SIZE)) { 153 DRM_ERROR("Invalid blob length\n"); 154 return -EINVAL; 155 } 156 157 header = (struct hdcp_srm_header *)buf; 158 DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n", 159 header->srm_id & DRM_HDCP_SRM_ID_MASK, 160 be16_to_cpu(header->srm_version), header->srm_gen_no); 161 162 if (header->reserved) 163 return -EINVAL; 164 165 buf = buf + sizeof(*header); 166 vrl_length = get_vrl_length(buf); 167 168 if (count < (sizeof(struct hdcp_srm_header) + vrl_length) || 169 vrl_length < (DRM_HDCP_2_VRL_LENGTH_SIZE + 170 DRM_HDCP_2_DCP_SIG_SIZE)) { 171 DRM_ERROR("Invalid blob length or vrl length\n"); 172 return -EINVAL; 173 } 174 175 /* Length of the all vrls combined */ 176 vrl_length -= (DRM_HDCP_2_VRL_LENGTH_SIZE + 177 DRM_HDCP_2_DCP_SIG_SIZE); 178 179 if (!vrl_length) { 180 DRM_ERROR("No vrl found\n"); 181 return -EINVAL; 182 } 183 184 buf += DRM_HDCP_2_VRL_LENGTH_SIZE; 185 ksv_count = (*buf << 2) | DRM_HDCP_2_KSV_COUNT_2_LSBITS(*(buf + 1)); 186 if (!ksv_count) { 187 DRM_DEBUG("Revoked KSV count is 0\n"); 188 return 0; 189 } 190 191 *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL); 192 if (!*revoked_ksv_list) { 193 DRM_ERROR("Out of Memory\n"); 194 return -ENOMEM; 195 } 196 197 ksv_sz = ksv_count * DRM_HDCP_KSV_LEN; 198 buf += DRM_HDCP_2_NO_OF_DEV_PLUS_RESERVED_SZ; 199 200 DRM_DEBUG("Revoked KSVs: %d\n", ksv_count); 201 memcpy(*revoked_ksv_list, buf, ksv_sz); 202 203 *revoked_ksv_cnt = ksv_count; 204 return 0; 205 } 206 207 static inline bool is_srm_version_hdcp1(const u8 *buf) 208 { 209 return *buf == (u8)(DRM_HDCP_1_4_SRM_ID << 4); 210 } 211 212 static inline bool is_srm_version_hdcp2(const u8 *buf) 213 { 214 return *buf == (u8)(DRM_HDCP_2_SRM_ID << 4 | DRM_HDCP_2_INDICATOR); 215 } 216 217 static int drm_hdcp_srm_update(const u8 *buf, size_t count, 218 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 219 { 220 if (count < sizeof(struct hdcp_srm_header)) 221 return -EINVAL; 222 223 if (is_srm_version_hdcp1(buf)) 224 return drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list, 225 revoked_ksv_cnt); 226 else if (is_srm_version_hdcp2(buf)) 227 return drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list, 228 revoked_ksv_cnt); 229 else 230 return -EINVAL; 231 } 232 233 static int drm_hdcp_request_srm(struct drm_device *drm_dev, 234 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 235 { 236 char fw_name[36] = "display_hdcp_srm.bin"; 237 const struct firmware *fw; 238 int ret; 239 240 ret = request_firmware_direct(&fw, (const char *)fw_name, 241 drm_dev->dev); 242 if (ret < 0) { 243 *revoked_ksv_cnt = 0; 244 *revoked_ksv_list = NULL; 245 ret = 0; 246 goto exit; 247 } 248 249 if (fw->size && fw->data) 250 ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list, 251 revoked_ksv_cnt); 252 253 exit: 254 release_firmware(fw); 255 return ret; 256 } 257 258 /** 259 * drm_hdcp_check_ksvs_revoked - Check the revoked status of the IDs 260 * 261 * @drm_dev: drm_device for which HDCP revocation check is requested 262 * @ksvs: List of KSVs (HDCP receiver IDs) 263 * @ksv_count: KSV count passed in through @ksvs 264 * 265 * This function reads the HDCP System renewability Message(SRM Table) 266 * from userspace as a firmware and parses it for the revoked HDCP 267 * KSVs(Receiver IDs) detected by DCP LLC. Once the revoked KSVs are known, 268 * revoked state of the KSVs in the list passed in by display drivers are 269 * decided and response is sent. 270 * 271 * SRM should be presented in the name of "display_hdcp_srm.bin". 272 * 273 * Format of the SRM table, that userspace needs to write into the binary file, 274 * is defined at: 275 * 1. Renewability chapter on 55th page of HDCP 1.4 specification 276 * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Specification%20Rev1_4_Secure.pdf 277 * 2. Renewability chapter on 63rd page of HDCP 2.2 specification 278 * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf 279 * 280 * Returns: 281 * Count of the revoked KSVs or -ve error number in case of the failure. 282 */ 283 int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs, 284 u32 ksv_count) 285 { 286 u32 revoked_ksv_cnt = 0, i, j; 287 u8 *revoked_ksv_list = NULL; 288 int ret = 0; 289 290 ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list, 291 &revoked_ksv_cnt); 292 if (ret) 293 return ret; 294 295 /* revoked_ksv_cnt will be zero when above function failed */ 296 for (i = 0; i < revoked_ksv_cnt; i++) 297 for (j = 0; j < ksv_count; j++) 298 if (!memcmp(&ksvs[j * DRM_HDCP_KSV_LEN], 299 &revoked_ksv_list[i * DRM_HDCP_KSV_LEN], 300 DRM_HDCP_KSV_LEN)) { 301 DRM_DEBUG("Revoked KSV is "); 302 drm_hdcp_print_ksv(&ksvs[j * DRM_HDCP_KSV_LEN]); 303 ret++; 304 } 305 306 kfree(revoked_ksv_list); 307 return ret; 308 } 309 EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked); 310 311 static struct drm_prop_enum_list drm_cp_enum_list[] = { 312 { DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" }, 313 { DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" }, 314 { DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" }, 315 }; 316 DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list) 317 318 static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = { 319 { DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" }, 320 { DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" }, 321 }; 322 DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name, 323 drm_hdcp_content_type_enum_list) 324 325 /** 326 * drm_connector_attach_content_protection_property - attach content protection 327 * property 328 * 329 * @connector: connector to attach CP property on. 330 * @hdcp_content_type: is HDCP Content Type property needed for connector 331 * 332 * This is used to add support for content protection on select connectors. 333 * Content Protection is intentionally vague to allow for different underlying 334 * technologies, however it is most implemented by HDCP. 335 * 336 * When hdcp_content_type is true enum property called HDCP Content Type is 337 * created (if it is not already) and attached to the connector. 338 * 339 * This property is used for sending the protected content's stream type 340 * from userspace to kernel on selected connectors. Protected content provider 341 * will decide their type of their content and declare the same to kernel. 342 * 343 * Content type will be used during the HDCP 2.2 authentication. 344 * Content type will be set to &drm_connector_state.hdcp_content_type. 345 * 346 * The content protection will be set to &drm_connector_state.content_protection 347 * 348 * When kernel triggered content protection state change like DESIRED->ENABLED 349 * and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update 350 * the content protection state of a connector. 351 * 352 * Returns: 353 * Zero on success, negative errno on failure. 354 */ 355 int drm_connector_attach_content_protection_property( 356 struct drm_connector *connector, bool hdcp_content_type) 357 { 358 struct drm_device *dev = connector->dev; 359 struct drm_property *prop = 360 dev->mode_config.content_protection_property; 361 362 if (!prop) 363 prop = drm_property_create_enum(dev, 0, "Content Protection", 364 drm_cp_enum_list, 365 ARRAY_SIZE(drm_cp_enum_list)); 366 if (!prop) 367 return -ENOMEM; 368 369 drm_object_attach_property(&connector->base, prop, 370 DRM_MODE_CONTENT_PROTECTION_UNDESIRED); 371 dev->mode_config.content_protection_property = prop; 372 373 if (!hdcp_content_type) 374 return 0; 375 376 prop = dev->mode_config.hdcp_content_type_property; 377 if (!prop) 378 prop = drm_property_create_enum(dev, 0, "HDCP Content Type", 379 drm_hdcp_content_type_enum_list, 380 ARRAY_SIZE( 381 drm_hdcp_content_type_enum_list)); 382 if (!prop) 383 return -ENOMEM; 384 385 drm_object_attach_property(&connector->base, prop, 386 DRM_MODE_HDCP_CONTENT_TYPE0); 387 dev->mode_config.hdcp_content_type_property = prop; 388 389 return 0; 390 } 391 EXPORT_SYMBOL(drm_connector_attach_content_protection_property); 392 393 /** 394 * drm_hdcp_update_content_protection - Updates the content protection state 395 * of a connector 396 * 397 * @connector: drm_connector on which content protection state needs an update 398 * @val: New state of the content protection property 399 * 400 * This function can be used by display drivers, to update the kernel triggered 401 * content protection state changes of a drm_connector such as DESIRED->ENABLED 402 * and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED, 403 * as userspace is triggering such state change and kernel performs it without 404 * fail.This function update the new state of the property into the connector's 405 * state and generate an uevent to notify the userspace. 406 */ 407 void drm_hdcp_update_content_protection(struct drm_connector *connector, 408 u64 val) 409 { 410 struct drm_device *dev = connector->dev; 411 struct drm_connector_state *state = connector->state; 412 413 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); 414 if (state->content_protection == val) 415 return; 416 417 state->content_protection = val; 418 drm_sysfs_connector_property_event(connector, 419 dev->mode_config.content_protection_property); 420 } 421 EXPORT_SYMBOL(drm_hdcp_update_content_protection); 422