drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c

   1 /*
   2  * Copyright 2019 Advanced Micro Devices, Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: AMD
  23  *
  24  */
  25
  26 #include "amdgpu_dm_hdcp.h"
  27 #include "amdgpu.h"
  28 #include "amdgpu_dm.h"
  29 #include "dm_helpers.h"
  30 #include <drm/display/drm_hdcp_helper.h>
  31 #include "hdcp_psp.h"
  32
  33 /*
  34  * If the SRM version being loaded is less than or equal to the
  35  * currently loaded SRM, psp will return 0xFFFF as the version
  36  */
  37 #define PSP_SRM_VERSION_MAX 0xFFFF
  38
  39 static bool
  40 lp_write_i2c(void *handle, uint32_t address, const uint8_t *data, uint32_t size)
  41 {
  42
  43         struct dc_link *link = handle;
  44         struct i2c_payload i2c_payloads[] = {{true, address, size, (void *)data} };
  45         struct i2c_command cmd = {i2c_payloads, 1, I2C_COMMAND_ENGINE_HW, link->dc->caps.i2c_speed_in_khz};
  46
  47         return dm_helpers_submit_i2c(link->ctx, link, &cmd);
  48 }
  49
  50 static bool
  51 lp_read_i2c(void *handle, uint32_t address, uint8_t offset, uint8_t *data, uint32_t size)
  52 {
  53         struct dc_link *link = handle;
  54
  55         struct i2c_payload i2c_payloads[] = {{true, address, 1, &offset}, {false, address, size, data} };
  56         struct i2c_command cmd = {i2c_payloads, 2, I2C_COMMAND_ENGINE_HW, link->dc->caps.i2c_speed_in_khz};
  57
  58         return dm_helpers_submit_i2c(link->ctx, link, &cmd);
  59 }
  60
  61 static bool
  62 lp_write_dpcd(void *handle, uint32_t address, const uint8_t *data, uint32_t size)
  63 {
  64         struct dc_link *link = handle;
  65
  66         return dm_helpers_dp_write_dpcd(link->ctx, link, address, data, size);
  67 }
  68
  69 static bool
  70 lp_read_dpcd(void *handle, uint32_t address, uint8_t *data, uint32_t size)
  71 {
  72         struct dc_link *link = handle;
  73
  74         return dm_helpers_dp_read_dpcd(link->ctx, link, address, data, size);
  75 }
  76
  77 static uint8_t *psp_get_srm(struct psp_context *psp, uint32_t *srm_version, uint32_t *srm_size)
  78 {
  79
  80         struct ta_hdcp_shared_memory *hdcp_cmd;
  81
  82         if (!psp->hdcp_context.context.initialized) {
  83                 DRM_WARN("Failed to get hdcp srm. HDCP TA is not initialized.");
  84                 return NULL;
  85         }
  86
  87         hdcp_cmd = (struct ta_hdcp_shared_memory *)psp->hdcp_context.context.mem_context.shared_buf;
  88         memset(hdcp_cmd, 0, sizeof(struct ta_hdcp_shared_memory));
  89
  90         hdcp_cmd->cmd_id = TA_HDCP_COMMAND__HDCP_GET_SRM;
  91         psp_hdcp_invoke(psp, hdcp_cmd->cmd_id);
  92
  93         if (hdcp_cmd->hdcp_status != TA_HDCP_STATUS__SUCCESS)
  94                 return NULL;
  95
  96         *srm_version = hdcp_cmd->out_msg.hdcp_get_srm.srm_version;
  97         *srm_size = hdcp_cmd->out_msg.hdcp_get_srm.srm_buf_size;
  98
  99
 100         return hdcp_cmd->out_msg.hdcp_get_srm.srm_buf;
 101 }
 102
 103 static int psp_set_srm(struct psp_context *psp, uint8_t *srm, uint32_t srm_size, uint32_t *srm_version)
 104 {
 105
 106         struct ta_hdcp_shared_memory *hdcp_cmd;
 107
 108         if (!psp->hdcp_context.context.initialized) {
 109                 DRM_WARN("Failed to get hdcp srm. HDCP TA is not initialized.");
 110                 return -EINVAL;
 111         }
 112
 113         hdcp_cmd = (struct ta_hdcp_shared_memory *)psp->hdcp_context.context.mem_context.shared_buf;
 114         memset(hdcp_cmd, 0, sizeof(struct ta_hdcp_shared_memory));
 115
 116         memcpy(hdcp_cmd->in_msg.hdcp_set_srm.srm_buf, srm, srm_size);
 117         hdcp_cmd->in_msg.hdcp_set_srm.srm_buf_size = srm_size;
 118         hdcp_cmd->cmd_id = TA_HDCP_COMMAND__HDCP_SET_SRM;
 119
 120         psp_hdcp_invoke(psp, hdcp_cmd->cmd_id);
 121
 122         if (hdcp_cmd->hdcp_status != TA_HDCP_STATUS__SUCCESS || hdcp_cmd->out_msg.hdcp_set_srm.valid_signature != 1 ||
 123             hdcp_cmd->out_msg.hdcp_set_srm.srm_version == PSP_SRM_VERSION_MAX)
 124                 return -EINVAL;
 125
 126         *srm_version = hdcp_cmd->out_msg.hdcp_set_srm.srm_version;
 127         return 0;
 128 }
 129
 130 static void process_output(struct hdcp_workqueue *hdcp_work)
 131 {
 132         struct mod_hdcp_output output = hdcp_work->output;
 133
 134         if (output.callback_stop)
 135                 cancel_delayed_work(&hdcp_work->callback_dwork);
 136
 137         if (output.callback_needed)
 138                 schedule_delayed_work(&hdcp_work->callback_dwork,
 139                                       msecs_to_jiffies(output.callback_delay));
 140
 141         if (output.watchdog_timer_stop)
 142                 cancel_delayed_work(&hdcp_work->watchdog_timer_dwork);
 143
 144         if (output.watchdog_timer_needed)
 145                 schedule_delayed_work(&hdcp_work->watchdog_timer_dwork,
 146                                       msecs_to_jiffies(output.watchdog_timer_delay));
 147
 148         schedule_delayed_work(&hdcp_work->property_validate_dwork, msecs_to_jiffies(0));
 149 }
 150
 151 static void link_lock(struct hdcp_workqueue *work, bool lock)
 152 {
 153
 154         int i = 0;
 155
 156         for (i = 0; i < work->max_link; i++) {
 157                 if (lock)
 158                         mutex_lock(&work[i].mutex);
 159                 else
 160                         mutex_unlock(&work[i].mutex);
 161         }
 162 }
 163 void hdcp_update_display(struct hdcp_workqueue *hdcp_work,
 164                          unsigned int link_index,
 165                          struct amdgpu_dm_connector *aconnector,
 166                          uint8_t content_type,
 167                          bool enable_encryption)
 168 {
 169         struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
 170         struct mod_hdcp_display *display = &hdcp_work[link_index].display;
 171         struct mod_hdcp_link *link = &hdcp_work[link_index].link;
 172         struct mod_hdcp_display_query query;
 173
 174         mutex_lock(&hdcp_w->mutex);
 175         hdcp_w->aconnector = aconnector;
 176
 177         query.display = NULL;
 178         mod_hdcp_query_display(&hdcp_w->hdcp, aconnector->base.index, &query);
 179
 180         if (query.display != NULL) {
 181                 memcpy(display, query.display, sizeof(struct mod_hdcp_display));
 182                 mod_hdcp_remove_display(&hdcp_w->hdcp, aconnector->base.index, &hdcp_w->output);
 183
 184                 hdcp_w->link.adjust.hdcp2.force_type = MOD_HDCP_FORCE_TYPE_0;
 185
 186                 if (enable_encryption) {
 187                         /* Explicitly set the saved SRM as sysfs call will be after we already enabled hdcp
 188                          * (s3 resume case)
 189                          */
 190                         if (hdcp_work->srm_size > 0)
 191                                 psp_set_srm(hdcp_work->hdcp.config.psp.handle, hdcp_work->srm, hdcp_work->srm_size,
 192                                             &hdcp_work->srm_version);
 193
 194                         display->adjust.disable = MOD_HDCP_DISPLAY_NOT_DISABLE;
 195                         if (content_type == DRM_MODE_HDCP_CONTENT_TYPE0) {
 196                                 hdcp_w->link.adjust.hdcp1.disable = 0;
 197                                 hdcp_w->link.adjust.hdcp2.force_type = MOD_HDCP_FORCE_TYPE_0;
 198                         } else if (content_type == DRM_MODE_HDCP_CONTENT_TYPE1) {
 199                                 hdcp_w->link.adjust.hdcp1.disable = 1;
 200                                 hdcp_w->link.adjust.hdcp2.force_type = MOD_HDCP_FORCE_TYPE_1;
 201                         }
 202
 203                         schedule_delayed_work(&hdcp_w->property_validate_dwork,
 204                                               msecs_to_jiffies(DRM_HDCP_CHECK_PERIOD_MS));
 205                 } else {
 206                         display->adjust.disable = MOD_HDCP_DISPLAY_DISABLE_AUTHENTICATION;
 207                         hdcp_w->encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
 208                         cancel_delayed_work(&hdcp_w->property_validate_dwork);
 209                 }
 210
 211                 display->state = MOD_HDCP_DISPLAY_ACTIVE;
 212         }
 213
 214         mod_hdcp_add_display(&hdcp_w->hdcp, link, display, &hdcp_w->output);
 215
 216         process_output(hdcp_w);
 217         mutex_unlock(&hdcp_w->mutex);
 218 }
 219
 220 static void hdcp_remove_display(struct hdcp_workqueue *hdcp_work,
 221                          unsigned int link_index,
 222                          struct amdgpu_dm_connector *aconnector)
 223 {
 224         struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
 225         struct drm_connector_state *conn_state = aconnector->base.state;
 226
 227         mutex_lock(&hdcp_w->mutex);
 228         hdcp_w->aconnector = aconnector;
 229
 230         /* the removal of display will invoke auth reset -> hdcp destroy and
 231          * we'd expect the Content Protection (CP) property changed back to
 232          * DESIRED if at the time ENABLED. CP property change should occur
 233          * before the element removed from linked list.
 234          */
 235         if (conn_state && conn_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
 236                 conn_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
 237
 238                 DRM_DEBUG_DRIVER("[HDCP_DM] display %d, CP 2 -> 1, type %u, DPMS %u\n",
 239                          aconnector->base.index, conn_state->hdcp_content_type, aconnector->base.dpms);
 240         }
 241
 242         mod_hdcp_remove_display(&hdcp_w->hdcp, aconnector->base.index, &hdcp_w->output);
 243
 244         process_output(hdcp_w);
 245         mutex_unlock(&hdcp_w->mutex);
 246 }
 247 void hdcp_reset_display(struct hdcp_workqueue *hdcp_work, unsigned int link_index)
 248 {
 249         struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
 250
 251         mutex_lock(&hdcp_w->mutex);
 252
 253         mod_hdcp_reset_connection(&hdcp_w->hdcp,  &hdcp_w->output);
 254
 255         cancel_delayed_work(&hdcp_w->property_validate_dwork);
 256         hdcp_w->encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
 257
 258         process_output(hdcp_w);
 259
 260         mutex_unlock(&hdcp_w->mutex);
 261 }
 262
 263 void hdcp_handle_cpirq(struct hdcp_workqueue *hdcp_work, unsigned int link_index)
 264 {
 265         struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
 266
 267         schedule_work(&hdcp_w->cpirq_work);
 268 }
 269
 270
 271
 272
 273 static void event_callback(struct work_struct *work)
 274 {
 275         struct hdcp_workqueue *hdcp_work;
 276
 277         hdcp_work = container_of(to_delayed_work(work), struct hdcp_workqueue,
 278                                       callback_dwork);
 279
 280         mutex_lock(&hdcp_work->mutex);
 281
 282         cancel_delayed_work(&hdcp_work->callback_dwork);
 283
 284         mod_hdcp_process_event(&hdcp_work->hdcp, MOD_HDCP_EVENT_CALLBACK,
 285                                &hdcp_work->output);
 286
 287         process_output(hdcp_work);
 288
 289         mutex_unlock(&hdcp_work->mutex);
 290
 291
 292 }
 293 static void event_property_update(struct work_struct *work)
 294 {
 295
 296         struct hdcp_workqueue *hdcp_work = container_of(work, struct hdcp_workqueue, property_update_work);
 297         struct amdgpu_dm_connector *aconnector = hdcp_work->aconnector;
 298         struct drm_device *dev = hdcp_work->aconnector->base.dev;
 299         long ret;
 300
 301         drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 302         mutex_lock(&hdcp_work->mutex);
 303
 304
 305         if (aconnector->base.state && aconnector->base.state->commit) {
 306                 ret = wait_for_completion_interruptible_timeout(&aconnector->base.state->commit->hw_done, 10 * HZ);
 307
 308                 if (ret == 0) {
 309                         DRM_ERROR("HDCP state unknown! Setting it to DESIRED");
 310                         hdcp_work->encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
 311                 }
 312         }
 313
 314         if (aconnector->base.state) {
 315                 if (hdcp_work->encryption_status != MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF) {
 316                         if (aconnector->base.state->hdcp_content_type ==
 317                                 DRM_MODE_HDCP_CONTENT_TYPE0 &&
 318                         hdcp_work->encryption_status <=
 319                                 MOD_HDCP_ENCRYPTION_STATUS_HDCP2_TYPE0_ON)
 320                                 drm_hdcp_update_content_protection(&aconnector->base,
 321                                         DRM_MODE_CONTENT_PROTECTION_ENABLED);
 322                         else if (aconnector->base.state->hdcp_content_type ==
 323                                         DRM_MODE_HDCP_CONTENT_TYPE1 &&
 324                                 hdcp_work->encryption_status ==
 325                                         MOD_HDCP_ENCRYPTION_STATUS_HDCP2_TYPE1_ON)
 326                                 drm_hdcp_update_content_protection(&aconnector->base,
 327                                         DRM_MODE_CONTENT_PROTECTION_ENABLED);
 328                 } else {
 329                         drm_hdcp_update_content_protection(&aconnector->base,
 330                                 DRM_MODE_CONTENT_PROTECTION_DESIRED);
 331                 }
 332         }
 333
 334         mutex_unlock(&hdcp_work->mutex);
 335         drm_modeset_unlock(&dev->mode_config.connection_mutex);
 336 }
 337
 338 static void event_property_validate(struct work_struct *work)
 339 {
 340         struct hdcp_workqueue *hdcp_work =
 341                 container_of(to_delayed_work(work), struct hdcp_workqueue, property_validate_dwork);
 342         struct mod_hdcp_display_query query;
 343         struct amdgpu_dm_connector *aconnector = hdcp_work->aconnector;
 344
 345         if (!aconnector)
 346                 return;
 347
 348         mutex_lock(&hdcp_work->mutex);
 349
 350         query.encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
 351         mod_hdcp_query_display(&hdcp_work->hdcp, aconnector->base.index, &query);
 352
 353         if (query.encryption_status != hdcp_work->encryption_status) {
 354                 hdcp_work->encryption_status = query.encryption_status;
 355                 schedule_work(&hdcp_work->property_update_work);
 356         }
 357
 358         mutex_unlock(&hdcp_work->mutex);
 359 }
 360
 361 static void event_watchdog_timer(struct work_struct *work)
 362 {
 363         struct hdcp_workqueue *hdcp_work;
 364
 365         hdcp_work = container_of(to_delayed_work(work),
 366                                       struct hdcp_workqueue,
 367                                       watchdog_timer_dwork);
 368
 369         mutex_lock(&hdcp_work->mutex);
 370
 371         cancel_delayed_work(&hdcp_work->watchdog_timer_dwork);
 372
 373         mod_hdcp_process_event(&hdcp_work->hdcp,
 374                                MOD_HDCP_EVENT_WATCHDOG_TIMEOUT,
 375                                &hdcp_work->output);
 376
 377         process_output(hdcp_work);
 378
 379         mutex_unlock(&hdcp_work->mutex);
 380
 381 }
 382
 383 static void event_cpirq(struct work_struct *work)
 384 {
 385         struct hdcp_workqueue *hdcp_work;
 386
 387         hdcp_work = container_of(work, struct hdcp_workqueue, cpirq_work);
 388
 389         mutex_lock(&hdcp_work->mutex);
 390
 391         mod_hdcp_process_event(&hdcp_work->hdcp, MOD_HDCP_EVENT_CPIRQ, &hdcp_work->output);
 392
 393         process_output(hdcp_work);
 394
 395         mutex_unlock(&hdcp_work->mutex);
 396
 397 }
 398
 399
 400 void hdcp_destroy(struct kobject *kobj, struct hdcp_workqueue *hdcp_work)
 401 {
 402         int i = 0;
 403
 404         for (i = 0; i < hdcp_work->max_link; i++) {
 405                 cancel_delayed_work_sync(&hdcp_work[i].callback_dwork);
 406                 cancel_delayed_work_sync(&hdcp_work[i].watchdog_timer_dwork);
 407         }
 408
 409         sysfs_remove_bin_file(kobj, &hdcp_work[0].attr);
 410         kfree(hdcp_work->srm);
 411         kfree(hdcp_work->srm_temp);
 412         kfree(hdcp_work);
 413 }
 414
 415
 416 static bool enable_assr(void *handle, struct dc_link *link)
 417 {
 418
 419         struct hdcp_workqueue *hdcp_work = handle;
 420         struct mod_hdcp hdcp = hdcp_work->hdcp;
 421         struct psp_context *psp = hdcp.config.psp.handle;
 422         struct ta_dtm_shared_memory *dtm_cmd;
 423         bool res = true;
 424
 425         if (!psp->dtm_context.context.initialized) {
 426                 DRM_INFO("Failed to enable ASSR, DTM TA is not initialized.");
 427                 return false;
 428         }
 429
 430         dtm_cmd = (struct ta_dtm_shared_memory *)psp->dtm_context.context.mem_context.shared_buf;
 431
 432         mutex_lock(&psp->dtm_context.mutex);
 433         memset(dtm_cmd, 0, sizeof(struct ta_dtm_shared_memory));
 434
 435         dtm_cmd->cmd_id = TA_DTM_COMMAND__TOPOLOGY_ASSR_ENABLE;
 436         dtm_cmd->dtm_in_message.topology_assr_enable.display_topology_dig_be_index = link->link_enc_hw_inst;
 437         dtm_cmd->dtm_status = TA_DTM_STATUS__GENERIC_FAILURE;
 438
 439         psp_dtm_invoke(psp, dtm_cmd->cmd_id);
 440
 441         if (dtm_cmd->dtm_status != TA_DTM_STATUS__SUCCESS) {
 442                 DRM_INFO("Failed to enable ASSR");
 443                 res = false;
 444         }
 445
 446         mutex_unlock(&psp->dtm_context.mutex);
 447
 448         return res;
 449 }
 450
 451 static void update_config(void *handle, struct cp_psp_stream_config *config)
 452 {
 453         struct hdcp_workqueue *hdcp_work = handle;
 454         struct amdgpu_dm_connector *aconnector = config->dm_stream_ctx;
 455         int link_index = aconnector->dc_link->link_index;
 456         struct mod_hdcp_display *display = &hdcp_work[link_index].display;
 457         struct mod_hdcp_link *link = &hdcp_work[link_index].link;
 458         struct drm_connector_state *conn_state;
 459         struct dc_sink *sink = NULL;
 460         bool link_is_hdcp14 = false;
 461
 462         if (config->dpms_off) {
 463                 hdcp_remove_display(hdcp_work, link_index, aconnector);
 464                 return;
 465         }
 466
 467         memset(display, 0, sizeof(*display));
 468         memset(link, 0, sizeof(*link));
 469
 470         display->index = aconnector->base.index;
 471         display->state = MOD_HDCP_DISPLAY_ACTIVE;
 472
 473         if (aconnector->dc_sink)
 474                 sink = aconnector->dc_sink;
 475         else if (aconnector->dc_em_sink)
 476                 sink = aconnector->dc_em_sink;
 477
 478         if (sink != NULL)
 479                 link->mode = mod_hdcp_signal_type_to_operation_mode(sink->sink_signal);
 480
 481         display->controller = CONTROLLER_ID_D0 + config->otg_inst;
 482         display->dig_fe = config->dig_fe;
 483         link->dig_be = config->dig_be;
 484         link->ddc_line = aconnector->dc_link->ddc_hw_inst + 1;
 485         display->stream_enc_idx = config->stream_enc_idx;
 486         link->link_enc_idx = config->link_enc_idx;
 487         link->dio_output_id = config->dio_output_idx;
 488         link->phy_idx = config->phy_idx;
 489
 490         if (sink)
 491                 link_is_hdcp14 = dc_link_is_hdcp14(aconnector->dc_link, sink->sink_signal);
 492         link->hdcp_supported_informational = link_is_hdcp14;
 493         link->dp.rev = aconnector->dc_link->dpcd_caps.dpcd_rev.raw;
 494         link->dp.assr_enabled = config->assr_enabled;
 495         link->dp.mst_enabled = config->mst_enabled;
 496         link->dp.usb4_enabled = config->usb4_enabled;
 497         display->adjust.disable = MOD_HDCP_DISPLAY_DISABLE_AUTHENTICATION;
 498         link->adjust.auth_delay = 3;
 499         link->adjust.hdcp1.disable = 0;
 500         conn_state = aconnector->base.state;
 501
 502         DRM_DEBUG_DRIVER("[HDCP_DM] display %d, CP %d, type %d\n", aconnector->base.index,
 503                         (!!aconnector->base.state) ? aconnector->base.state->content_protection : -1,
 504                         (!!aconnector->base.state) ? aconnector->base.state->hdcp_content_type : -1);
 505
 506         if (conn_state)
 507                 hdcp_update_display(hdcp_work, link_index, aconnector,
 508                         conn_state->hdcp_content_type, false);
 509 }
 510
 511
 512 /* NOTE: From the usermodes prospective you only need to call write *ONCE*, the kernel
 513  *      will automatically call once or twice depending on the size
 514  *
 515  * call: "cat file > /sys/class/drm/card0/device/hdcp_srm" from usermode no matter what the size is
 516  *
 517  * The kernel can only send PAGE_SIZE at once and since MAX_SRM_FILE(5120) > PAGE_SIZE(4096),
 518  * srm_data_write can be called multiple times.
 519  *
 520  * sysfs interface doesn't tell us the size we will get so we are sending partial SRMs to psp and on
 521  * the last call we will send the full SRM. PSP will fail on every call before the last.
 522  *
 523  * This means we don't know if the SRM is good until the last call. And because of this limitation we
 524  * cannot throw errors early as it will stop the kernel from writing to sysfs
 525  *
 526  * Example 1:
 527  *      Good SRM size = 5096
 528  *      first call to write 4096 -> PSP fails
 529  *      Second call to write 1000 -> PSP Pass -> SRM is set
 530  *
 531  * Example 2:
 532  *      Bad SRM size = 4096
 533  *      first call to write 4096 -> PSP fails (This is the same as above, but we don't know if this
 534  *      is the last call)
 535  *
 536  * Solution?:
 537  *      1: Parse the SRM? -> It is signed so we don't know the EOF
 538  *      2: We can have another sysfs that passes the size before calling set. -> simpler solution
 539  *      below
 540  *
 541  * Easy Solution:
 542  * Always call get after Set to verify if set was successful.
 543  * +----------------------+
 544  * |   Why it works:      |
 545  * +----------------------+
 546  * PSP will only update its srm if its older than the one we are trying to load.
 547  * Always do set first than get.
 548  *      -if we try to "1. SET" a older version PSP will reject it and we can "2. GET" the newer
 549  *      version and save it
 550  *
 551  *      -if we try to "1. SET" a newer version PSP will accept it and we can "2. GET" the
 552  *      same(newer) version back and save it
 553  *
 554  *      -if we try to "1. SET" a newer version and PSP rejects it. That means the format is
 555  *      incorrect/corrupted and we should correct our SRM by getting it from PSP
 556  */
 557 static ssize_t srm_data_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer,
 558                               loff_t pos, size_t count)
 559 {
 560         struct hdcp_workqueue *work;
 561         uint32_t srm_version = 0;
 562
 563         work = container_of(bin_attr, struct hdcp_workqueue, attr);
 564         link_lock(work, true);
 565
 566         memcpy(work->srm_temp + pos, buffer, count);
 567
 568         if (!psp_set_srm(work->hdcp.config.psp.handle, work->srm_temp, pos + count, &srm_version)) {
 569                 DRM_DEBUG_DRIVER("HDCP SRM SET version 0x%X", srm_version);
 570                 memcpy(work->srm, work->srm_temp, pos + count);
 571                 work->srm_size = pos + count;
 572                 work->srm_version = srm_version;
 573         }
 574
 575
 576         link_lock(work, false);
 577
 578         return count;
 579 }
 580
 581 static ssize_t srm_data_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer,
 582                              loff_t pos, size_t count)
 583 {
 584         struct hdcp_workqueue *work;
 585         uint8_t *srm = NULL;
 586         uint32_t srm_version;
 587         uint32_t srm_size;
 588         size_t ret = count;
 589
 590         work = container_of(bin_attr, struct hdcp_workqueue, attr);
 591
 592         link_lock(work, true);
 593
 594         srm = psp_get_srm(work->hdcp.config.psp.handle, &srm_version, &srm_size);
 595
 596         if (!srm) {
 597                 ret = -EINVAL;
 598                 goto ret;
 599         }
 600
 601         if (pos >= srm_size)
 602                 ret = 0;
 603
 604         if (srm_size - pos < count) {
 605                 memcpy(buffer, srm + pos, srm_size - pos);
 606                 ret = srm_size - pos;
 607                 goto ret;
 608         }
 609
 610         memcpy(buffer, srm + pos, count);
 611
 612 ret:
 613         link_lock(work, false);
 614         return ret;
 615 }
 616
 617 /* From the hdcp spec (5.Renewability) SRM needs to be stored in a non-volatile memory.
 618  *
 619  * For example,
 620  *      if Application "A" sets the SRM (ver 2) and we reboot/suspend and later when Application "B"
 621  *      needs to use HDCP, the version in PSP should be SRM(ver 2). So SRM should be persistent
 622  *      across boot/reboots/suspend/resume/shutdown
 623  *
 624  * Currently when the system goes down (suspend/shutdown) the SRM is cleared from PSP. For HDCP we need
 625  * to make the SRM persistent.
 626  *
 627  * -PSP owns the checking of SRM but doesn't have the ability to store it in a non-volatile memory.
 628  * -The kernel cannot write to the file systems.
 629  * -So we need usermode to do this for us, which is why an interface for usermode is needed
 630  *
 631  *
 632  *
 633  * Usermode can read/write to/from PSP using the sysfs interface
 634  * For example:
 635  *      to save SRM from PSP to storage : cat /sys/class/drm/card0/device/hdcp_srm > srmfile
 636  *      to load from storage to PSP: cat srmfile > /sys/class/drm/card0/device/hdcp_srm
 637  */
 638 static const struct bin_attribute data_attr = {
 639         .attr = {.name = "hdcp_srm", .mode = 0664},
 640         .size = PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, /* Limit SRM size */
 641         .write = srm_data_write,
 642         .read = srm_data_read,
 643 };
 644
 645
 646 struct hdcp_workqueue *hdcp_create_workqueue(struct amdgpu_device *adev, struct cp_psp *cp_psp, struct dc *dc)
 647 {
 648
 649         int max_caps = dc->caps.max_links;
 650         struct hdcp_workqueue *hdcp_work;
 651         int i = 0;
 652
 653         hdcp_work = kcalloc(max_caps, sizeof(*hdcp_work), GFP_KERNEL);
 654         if (ZERO_OR_NULL_PTR(hdcp_work))
 655                 return NULL;
 656
 657         hdcp_work->srm = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm), GFP_KERNEL);
 658
 659         if (hdcp_work->srm == NULL)
 660                 goto fail_alloc_context;
 661
 662         hdcp_work->srm_temp = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm_temp), GFP_KERNEL);
 663
 664         if (hdcp_work->srm_temp == NULL)
 665                 goto fail_alloc_context;
 666
 667         hdcp_work->max_link = max_caps;
 668
 669         for (i = 0; i < max_caps; i++) {
 670                 mutex_init(&hdcp_work[i].mutex);
 671
 672                 INIT_WORK(&hdcp_work[i].cpirq_work, event_cpirq);
 673                 INIT_WORK(&hdcp_work[i].property_update_work, event_property_update);
 674                 INIT_DELAYED_WORK(&hdcp_work[i].callback_dwork, event_callback);
 675                 INIT_DELAYED_WORK(&hdcp_work[i].watchdog_timer_dwork, event_watchdog_timer);
 676                 INIT_DELAYED_WORK(&hdcp_work[i].property_validate_dwork, event_property_validate);
 677
 678                 hdcp_work[i].hdcp.config.psp.handle = &adev->psp;
 679                 if (dc->ctx->dce_version == DCN_VERSION_3_1 ||
 680                     dc->ctx->dce_version == DCN_VERSION_3_14 ||
 681                     dc->ctx->dce_version == DCN_VERSION_3_15 ||
 682                     dc->ctx->dce_version == DCN_VERSION_3_16)
 683                         hdcp_work[i].hdcp.config.psp.caps.dtm_v3_supported = 1;
 684                 hdcp_work[i].hdcp.config.ddc.handle = dc_get_link_at_index(dc, i);
 685                 hdcp_work[i].hdcp.config.ddc.funcs.write_i2c = lp_write_i2c;
 686                 hdcp_work[i].hdcp.config.ddc.funcs.read_i2c = lp_read_i2c;
 687                 hdcp_work[i].hdcp.config.ddc.funcs.write_dpcd = lp_write_dpcd;
 688                 hdcp_work[i].hdcp.config.ddc.funcs.read_dpcd = lp_read_dpcd;
 689         }
 690
 691         cp_psp->funcs.update_stream_config = update_config;
 692         cp_psp->funcs.enable_assr = enable_assr;
 693         cp_psp->handle = hdcp_work;
 694
 695         /* File created at /sys/class/drm/card0/device/hdcp_srm*/
 696         hdcp_work[0].attr = data_attr;
 697         sysfs_bin_attr_init(&hdcp_work[0].attr);
 698
 699         if (sysfs_create_bin_file(&adev->dev->kobj, &hdcp_work[0].attr))
 700                 DRM_WARN("Failed to create device file hdcp_srm");
 701
 702         return hdcp_work;
 703
 704 fail_alloc_context:
 705         kfree(hdcp_work->srm);
 706         kfree(hdcp_work->srm_temp);
 707         kfree(hdcp_work);
 708
 709         return NULL;
 710
 711
 712
 713 }
 714
 715
 716