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/drm_hdcp.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#include "drm_internal.h" 25 26static inline void drm_hdcp_print_ksv(const u8 *ksv) 27{ 28 DRM_DEBUG("\t%#02x, %#02x, %#02x, %#02x, %#02x\n", 29 ksv[0], ksv[1], ksv[2], ksv[3], ksv[4]); 30} 31 32static u32 drm_hdcp_get_revoked_ksv_count(const u8 *buf, u32 vrls_length) 33{ 34 u32 parsed_bytes = 0, ksv_count = 0, vrl_ksv_cnt, vrl_sz; 35 36 while (parsed_bytes < vrls_length) { 37 vrl_ksv_cnt = *buf; 38 ksv_count += vrl_ksv_cnt; 39 40 vrl_sz = (vrl_ksv_cnt * DRM_HDCP_KSV_LEN) + 1; 41 buf += vrl_sz; 42 parsed_bytes += vrl_sz; 43 } 44 45 /* 46 * When vrls are not valid, ksvs are not considered. 47 * Hence SRM will be discarded. 48 */ 49 if (parsed_bytes != vrls_length) 50 ksv_count = 0; 51 52 return ksv_count; 53} 54 55static u32 drm_hdcp_get_revoked_ksvs(const u8 *buf, u8 **revoked_ksv_list, 56 u32 vrls_length) 57{ 58 u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 0; 59 u32 parsed_bytes = 0, ksv_count = 0; 60 61 do { 62 vrl_ksv_cnt = *buf; 63 vrl_ksv_sz = vrl_ksv_cnt * DRM_HDCP_KSV_LEN; 64 65 buf++; 66 67 DRM_DEBUG("vrl: %d, Revoked KSVs: %d\n", vrl_idx++, 68 vrl_ksv_cnt); 69 memcpy((*revoked_ksv_list) + (ksv_count * DRM_HDCP_KSV_LEN), 70 buf, vrl_ksv_sz); 71 72 ksv_count += vrl_ksv_cnt; 73 buf += vrl_ksv_sz; 74 75 parsed_bytes += (vrl_ksv_sz + 1); 76 } while (parsed_bytes < vrls_length); 77 78 return ksv_count; 79} 80 81static inline u32 get_vrl_length(const u8 *buf) 82{ 83 return drm_hdcp_be24_to_cpu(buf); 84} 85 86static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count, 87 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 88{ 89 struct hdcp_srm_header *header; 90 u32 vrl_length, ksv_count; 91 92 if (count < (sizeof(struct hdcp_srm_header) + 93 DRM_HDCP_1_4_VRL_LENGTH_SIZE + DRM_HDCP_1_4_DCP_SIG_SIZE)) { 94 DRM_ERROR("Invalid blob length\n"); 95 return -EINVAL; 96 } 97 98 header = (struct hdcp_srm_header *)buf; 99 DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n", 100 header->srm_id, 101 be16_to_cpu(header->srm_version), header->srm_gen_no); 102 103 WARN_ON(header->reserved); 104 105 buf = buf + sizeof(*header); 106 vrl_length = get_vrl_length(buf); 107 if (count < (sizeof(struct hdcp_srm_header) + vrl_length) || 108 vrl_length < (DRM_HDCP_1_4_VRL_LENGTH_SIZE + 109 DRM_HDCP_1_4_DCP_SIG_SIZE)) { 110 DRM_ERROR("Invalid blob length or vrl length\n"); 111 return -EINVAL; 112 } 113 114 /* Length of the all vrls combined */ 115 vrl_length -= (DRM_HDCP_1_4_VRL_LENGTH_SIZE + 116 DRM_HDCP_1_4_DCP_SIG_SIZE); 117 118 if (!vrl_length) { 119 DRM_ERROR("No vrl found\n"); 120 return -EINVAL; 121 } 122 123 buf += DRM_HDCP_1_4_VRL_LENGTH_SIZE; 124 ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length); 125 if (!ksv_count) { 126 DRM_DEBUG("Revoked KSV count is 0\n"); 127 return 0; 128 } 129 130 *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL); 131 if (!*revoked_ksv_list) { 132 DRM_ERROR("Out of Memory\n"); 133 return -ENOMEM; 134 } 135 136 if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list, 137 vrl_length) != ksv_count) { 138 *revoked_ksv_cnt = 0; 139 kfree(*revoked_ksv_list); 140 return -EINVAL; 141 } 142 143 *revoked_ksv_cnt = ksv_count; 144 return 0; 145} 146 147static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count, 148 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 149{ 150 struct hdcp_srm_header *header; 151 u32 vrl_length, ksv_count, ksv_sz; 152 153 if (count < (sizeof(struct hdcp_srm_header) + 154 DRM_HDCP_2_VRL_LENGTH_SIZE + DRM_HDCP_2_DCP_SIG_SIZE)) { 155 DRM_ERROR("Invalid blob length\n"); 156 return -EINVAL; 157 } 158 159 header = (struct hdcp_srm_header *)buf; 160 DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n", 161 header->srm_id & DRM_HDCP_SRM_ID_MASK, 162 be16_to_cpu(header->srm_version), header->srm_gen_no); 163 164 if (header->reserved) 165 return -EINVAL; 166 167 buf = buf + sizeof(*header); 168 vrl_length = get_vrl_length(buf); 169 170 if (count < (sizeof(struct hdcp_srm_header) + vrl_length) || 171 vrl_length < (DRM_HDCP_2_VRL_LENGTH_SIZE + 172 DRM_HDCP_2_DCP_SIG_SIZE)) { 173 DRM_ERROR("Invalid blob length or vrl length\n"); 174 return -EINVAL; 175 } 176 177 /* Length of the all vrls combined */ 178 vrl_length -= (DRM_HDCP_2_VRL_LENGTH_SIZE + 179 DRM_HDCP_2_DCP_SIG_SIZE); 180 181 if (!vrl_length) { 182 DRM_ERROR("No vrl found\n"); 183 return -EINVAL; 184 } 185 186 buf += DRM_HDCP_2_VRL_LENGTH_SIZE; 187 ksv_count = (*buf << 2) | DRM_HDCP_2_KSV_COUNT_2_LSBITS(*(buf + 1)); 188 if (!ksv_count) { 189 DRM_DEBUG("Revoked KSV count is 0\n"); 190 return 0; 191 } 192 193 *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL); 194 if (!*revoked_ksv_list) { 195 DRM_ERROR("Out of Memory\n"); 196 return -ENOMEM; 197 } 198 199 ksv_sz = ksv_count * DRM_HDCP_KSV_LEN; 200 buf += DRM_HDCP_2_NO_OF_DEV_PLUS_RESERVED_SZ; 201 202 DRM_DEBUG("Revoked KSVs: %d\n", ksv_count); 203 memcpy(*revoked_ksv_list, buf, ksv_sz); 204 205 *revoked_ksv_cnt = ksv_count; 206 return 0; 207} 208 209static inline bool is_srm_version_hdcp1(const u8 *buf) 210{ 211 return *buf == (u8)(DRM_HDCP_1_4_SRM_ID << 4); 212} 213 214static inline bool is_srm_version_hdcp2(const u8 *buf) 215{ 216 return *buf == (u8)(DRM_HDCP_2_SRM_ID << 4 | DRM_HDCP_2_INDICATOR); 217} 218 219static int drm_hdcp_srm_update(const u8 *buf, size_t count, 220 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 221{ 222 if (count < sizeof(struct hdcp_srm_header)) 223 return -EINVAL; 224 225 if (is_srm_version_hdcp1(buf)) 226 return drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list, 227 revoked_ksv_cnt); 228 else if (is_srm_version_hdcp2(buf)) 229 return drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list, 230 revoked_ksv_cnt); 231 else 232 return -EINVAL; 233} 234 235static int drm_hdcp_request_srm(struct drm_device *drm_dev, 236 u8 **revoked_ksv_list, u32 *revoked_ksv_cnt) 237{ 238 char fw_name[36] = "display_hdcp_srm.bin"; 239 const struct firmware *fw; 240 int ret; 241 242 ret = request_firmware_direct(&fw, (const char *)fw_name, 243 drm_dev->dev); 244 if (ret < 0) { 245 *revoked_ksv_cnt = 0; 246 *revoked_ksv_list = NULL; 247 ret = 0; 248 goto exit; 249 } 250 251 if (fw->size && fw->data) 252 ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list, 253 revoked_ksv_cnt); 254 255exit: 256 release_firmware(fw); 257 return ret; 258} 259 260/** 261 * drm_hdcp_check_ksvs_revoked - Check the revoked status of the IDs 262 * 263 * @drm_dev: drm_device for which HDCP revocation check is requested 264 * @ksvs: List of KSVs (HDCP receiver IDs) 265 * @ksv_count: KSV count passed in through @ksvs 266 * 267 * This function reads the HDCP System renewability Message(SRM Table) 268 * from userspace as a firmware and parses it for the revoked HDCP 269 * KSVs(Receiver IDs) detected by DCP LLC. Once the revoked KSVs are known, 270 * revoked state of the KSVs in the list passed in by display drivers are 271 * decided and response is sent. 272 * 273 * SRM should be presented in the name of "display_hdcp_srm.bin". 274 * 275 * Format of the SRM table, that userspace needs to write into the binary file, 276 * is defined at: 277 * 1. Renewability chapter on 55th page of HDCP 1.4 specification 278 * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Specification%20Rev1_4_Secure.pdf 279 * 2. Renewability chapter on 63rd page of HDCP 2.2 specification 280 * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf 281 * 282 * Returns: 283 * Count of the revoked KSVs or -ve error number incase of the failure. 284 */ 285int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs, 286 u32 ksv_count) 287{ 288 u32 revoked_ksv_cnt = 0, i, j; 289 u8 *revoked_ksv_list = NULL; 290 int ret = 0; 291 292 ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list, 293 &revoked_ksv_cnt); 294 if (ret) 295 return ret; 296 297 /* revoked_ksv_cnt will be zero when above function failed */ 298 for (i = 0; i < revoked_ksv_cnt; i++) 299 for (j = 0; j < ksv_count; j++) 300 if (!memcmp(&ksvs[j * DRM_HDCP_KSV_LEN], 301 &revoked_ksv_list[i * DRM_HDCP_KSV_LEN], 302 DRM_HDCP_KSV_LEN)) { 303 DRM_DEBUG("Revoked KSV is "); 304 drm_hdcp_print_ksv(&ksvs[j * DRM_HDCP_KSV_LEN]); 305 ret++; 306 } 307 308 kfree(revoked_ksv_list); 309 return ret; 310} 311EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked); 312 313static struct drm_prop_enum_list drm_cp_enum_list[] = { 314 { DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" }, 315 { DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" }, 316 { DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" }, 317}; 318DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list) 319 320static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = { 321 { DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" }, 322 { DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" }, 323}; 324DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name, 325 drm_hdcp_content_type_enum_list) 326 327/** 328 * drm_connector_attach_content_protection_property - attach content protection 329 * property 330 * 331 * @connector: connector to attach CP property on. 332 * @hdcp_content_type: is HDCP Content Type property needed for connector 333 * 334 * This is used to add support for content protection on select connectors. 335 * Content Protection is intentionally vague to allow for different underlying 336 * technologies, however it is most implemented by HDCP. 337 * 338 * When hdcp_content_type is true enum property called HDCP Content Type is 339 * created (if it is not already) and attached to the connector. 340 * 341 * This property is used for sending the protected content's stream type 342 * from userspace to kernel on selected connectors. Protected content provider 343 * will decide their type of their content and declare the same to kernel. 344 * 345 * Content type will be used during the HDCP 2.2 authentication. 346 * Content type will be set to &drm_connector_state.hdcp_content_type. 347 * 348 * The content protection will be set to &drm_connector_state.content_protection 349 * 350 * When kernel triggered content protection state change like DESIRED->ENABLED 351 * and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update 352 * the content protection state of a connector. 353 * 354 * Returns: 355 * Zero on success, negative errno on failure. 356 */ 357int drm_connector_attach_content_protection_property( 358 struct drm_connector *connector, bool hdcp_content_type) 359{ 360 struct drm_device *dev = connector->dev; 361 struct drm_property *prop = 362 dev->mode_config.content_protection_property; 363 364 if (!prop) 365 prop = drm_property_create_enum(dev, 0, "Content Protection", 366 drm_cp_enum_list, 367 ARRAY_SIZE(drm_cp_enum_list)); 368 if (!prop) 369 return -ENOMEM; 370 371 drm_object_attach_property(&connector->base, prop, 372 DRM_MODE_CONTENT_PROTECTION_UNDESIRED); 373 dev->mode_config.content_protection_property = prop; 374 375 if (!hdcp_content_type) 376 return 0; 377 378 prop = dev->mode_config.hdcp_content_type_property; 379 if (!prop) 380 prop = drm_property_create_enum(dev, 0, "HDCP Content Type", 381 drm_hdcp_content_type_enum_list, 382 ARRAY_SIZE( 383 drm_hdcp_content_type_enum_list)); 384 if (!prop) 385 return -ENOMEM; 386 387 drm_object_attach_property(&connector->base, prop, 388 DRM_MODE_HDCP_CONTENT_TYPE0); 389 dev->mode_config.hdcp_content_type_property = prop; 390 391 return 0; 392} 393EXPORT_SYMBOL(drm_connector_attach_content_protection_property); 394 395/** 396 * drm_hdcp_update_content_protection - Updates the content protection state 397 * of a connector 398 * 399 * @connector: drm_connector on which content protection state needs an update 400 * @val: New state of the content protection property 401 * 402 * This function can be used by display drivers, to update the kernel triggered 403 * content protection state changes of a drm_connector such as DESIRED->ENABLED 404 * and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED, 405 * as userspace is triggering such state change and kernel performs it without 406 * fail.This function update the new state of the property into the connector's 407 * state and generate an uevent to notify the userspace. 408 */ 409void drm_hdcp_update_content_protection(struct drm_connector *connector, 410 u64 val) 411{ 412 struct drm_device *dev = connector->dev; 413 struct drm_connector_state *state = connector->state; 414 415 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); 416 if (state->content_protection == val) 417 return; 418 419 state->content_protection = val; 420 drm_sysfs_connector_status_event(connector, 421 dev->mode_config.content_protection_property); 422} 423EXPORT_SYMBOL(drm_hdcp_update_content_protection); 424