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  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/drm_hdcp.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
 39static bool
 40lp_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
 50static bool
 51lp_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
 61static bool
 62lp_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
 69static bool
 70lp_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
 77static 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.hdcp_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.hdcp_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
103static 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.hdcp_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.hdcp_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
130static 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
151static 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}
163void 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 = 0;
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 = 1;
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
220static 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
226	mutex_lock(&hdcp_w->mutex);
227	hdcp_w->aconnector = aconnector;
228
229	mod_hdcp_remove_display(&hdcp_w->hdcp, aconnector->base.index, &hdcp_w->output);
230
231	process_output(hdcp_w);
232	mutex_unlock(&hdcp_w->mutex);
233}
234void hdcp_reset_display(struct hdcp_workqueue *hdcp_work, unsigned int link_index)
235{
236	struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
237
238	mutex_lock(&hdcp_w->mutex);
239
240	mod_hdcp_reset_connection(&hdcp_w->hdcp,  &hdcp_w->output);
241
242	cancel_delayed_work(&hdcp_w->property_validate_dwork);
243	hdcp_w->encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
244
245	process_output(hdcp_w);
246
247	mutex_unlock(&hdcp_w->mutex);
248}
249
250void hdcp_handle_cpirq(struct hdcp_workqueue *hdcp_work, unsigned int link_index)
251{
252	struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
253
254	schedule_work(&hdcp_w->cpirq_work);
255}
256
257
258
259
260static void event_callback(struct work_struct *work)
261{
262	struct hdcp_workqueue *hdcp_work;
263
264	hdcp_work = container_of(to_delayed_work(work), struct hdcp_workqueue,
265				      callback_dwork);
266
267	mutex_lock(&hdcp_work->mutex);
268
269	cancel_delayed_work(&hdcp_work->callback_dwork);
270
271	mod_hdcp_process_event(&hdcp_work->hdcp, MOD_HDCP_EVENT_CALLBACK,
272			       &hdcp_work->output);
273
274	process_output(hdcp_work);
275
276	mutex_unlock(&hdcp_work->mutex);
277
278
279}
280static void event_property_update(struct work_struct *work)
281{
282
283	struct hdcp_workqueue *hdcp_work = container_of(work, struct hdcp_workqueue, property_update_work);
284	struct amdgpu_dm_connector *aconnector = hdcp_work->aconnector;
285	struct drm_device *dev = hdcp_work->aconnector->base.dev;
286	long ret;
287
288	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
289	mutex_lock(&hdcp_work->mutex);
290
291
292	if (aconnector->base.state->commit) {
293		ret = wait_for_completion_interruptible_timeout(&aconnector->base.state->commit->hw_done, 10 * HZ);
294
295		if (ret == 0) {
296			DRM_ERROR("HDCP state unknown! Setting it to DESIRED");
297			hdcp_work->encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
298		}
299	}
300
301	if (hdcp_work->encryption_status != MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF) {
302		if (aconnector->base.state->hdcp_content_type == DRM_MODE_HDCP_CONTENT_TYPE0 &&
303		    hdcp_work->encryption_status <= MOD_HDCP_ENCRYPTION_STATUS_HDCP2_TYPE0_ON)
304			drm_hdcp_update_content_protection(&aconnector->base, DRM_MODE_CONTENT_PROTECTION_ENABLED);
305		else if (aconnector->base.state->hdcp_content_type == DRM_MODE_HDCP_CONTENT_TYPE1 &&
306			 hdcp_work->encryption_status == MOD_HDCP_ENCRYPTION_STATUS_HDCP2_TYPE1_ON)
307			drm_hdcp_update_content_protection(&aconnector->base, DRM_MODE_CONTENT_PROTECTION_ENABLED);
308	} else {
309		drm_hdcp_update_content_protection(&aconnector->base, DRM_MODE_CONTENT_PROTECTION_DESIRED);
310	}
311
312
313	mutex_unlock(&hdcp_work->mutex);
314	drm_modeset_unlock(&dev->mode_config.connection_mutex);
315}
316
317static void event_property_validate(struct work_struct *work)
318{
319	struct hdcp_workqueue *hdcp_work =
320		container_of(to_delayed_work(work), struct hdcp_workqueue, property_validate_dwork);
321	struct mod_hdcp_display_query query;
322	struct amdgpu_dm_connector *aconnector = hdcp_work->aconnector;
323
324	if (!aconnector)
325		return;
326
327	mutex_lock(&hdcp_work->mutex);
328
329	query.encryption_status = MOD_HDCP_ENCRYPTION_STATUS_HDCP_OFF;
330	mod_hdcp_query_display(&hdcp_work->hdcp, aconnector->base.index, &query);
331
332	if (query.encryption_status != hdcp_work->encryption_status) {
333		hdcp_work->encryption_status = query.encryption_status;
334		schedule_work(&hdcp_work->property_update_work);
335	}
336
337	mutex_unlock(&hdcp_work->mutex);
338}
339
340static void event_watchdog_timer(struct work_struct *work)
341{
342	struct hdcp_workqueue *hdcp_work;
343
344	hdcp_work = container_of(to_delayed_work(work),
345				      struct hdcp_workqueue,
346				      watchdog_timer_dwork);
347
348	mutex_lock(&hdcp_work->mutex);
349
350	cancel_delayed_work(&hdcp_work->watchdog_timer_dwork);
351
352	mod_hdcp_process_event(&hdcp_work->hdcp,
353			       MOD_HDCP_EVENT_WATCHDOG_TIMEOUT,
354			       &hdcp_work->output);
355
356	process_output(hdcp_work);
357
358	mutex_unlock(&hdcp_work->mutex);
359
360}
361
362static void event_cpirq(struct work_struct *work)
363{
364	struct hdcp_workqueue *hdcp_work;
365
366	hdcp_work = container_of(work, struct hdcp_workqueue, cpirq_work);
367
368	mutex_lock(&hdcp_work->mutex);
369
370	mod_hdcp_process_event(&hdcp_work->hdcp, MOD_HDCP_EVENT_CPIRQ, &hdcp_work->output);
371
372	process_output(hdcp_work);
373
374	mutex_unlock(&hdcp_work->mutex);
375
376}
377
378
379void hdcp_destroy(struct hdcp_workqueue *hdcp_work)
380{
381	int i = 0;
382
383	for (i = 0; i < hdcp_work->max_link; i++) {
384		cancel_delayed_work_sync(&hdcp_work[i].callback_dwork);
385		cancel_delayed_work_sync(&hdcp_work[i].watchdog_timer_dwork);
386	}
387
388	kfree(hdcp_work->srm);
389	kfree(hdcp_work->srm_temp);
390	kfree(hdcp_work);
391}
392
393
394static bool enable_assr(void *handle, struct dc_link *link)
395{
396
397	struct hdcp_workqueue *hdcp_work = handle;
398	struct mod_hdcp hdcp = hdcp_work->hdcp;
399	struct psp_context *psp = hdcp.config.psp.handle;
400	struct ta_dtm_shared_memory *dtm_cmd;
401	bool res = true;
402
403	if (!psp->dtm_context.dtm_initialized) {
404		DRM_INFO("Failed to enable ASSR, DTM TA is not initialized.");
405		return false;
406	}
407
408	dtm_cmd = (struct ta_dtm_shared_memory *)psp->dtm_context.dtm_shared_buf;
409
410	mutex_lock(&psp->dtm_context.mutex);
411	memset(dtm_cmd, 0, sizeof(struct ta_dtm_shared_memory));
412
413	dtm_cmd->cmd_id = TA_DTM_COMMAND__TOPOLOGY_ASSR_ENABLE;
414	dtm_cmd->dtm_in_message.topology_assr_enable.display_topology_dig_be_index = link->link_enc_hw_inst;
415	dtm_cmd->dtm_status = TA_DTM_STATUS__GENERIC_FAILURE;
416
417	psp_dtm_invoke(psp, dtm_cmd->cmd_id);
418
419	if (dtm_cmd->dtm_status != TA_DTM_STATUS__SUCCESS) {
420		DRM_INFO("Failed to enable ASSR");
421		res = false;
422	}
423
424	mutex_unlock(&psp->dtm_context.mutex);
425
426	return res;
427}
428
429static void update_config(void *handle, struct cp_psp_stream_config *config)
430{
431	struct hdcp_workqueue *hdcp_work = handle;
432	struct amdgpu_dm_connector *aconnector = config->dm_stream_ctx;
433	int link_index = aconnector->dc_link->link_index;
434	struct mod_hdcp_display *display = &hdcp_work[link_index].display;
435	struct mod_hdcp_link *link = &hdcp_work[link_index].link;
436
437	if (config->dpms_off) {
438		hdcp_remove_display(hdcp_work, link_index, aconnector);
439		return;
440	}
441
442	memset(display, 0, sizeof(*display));
443	memset(link, 0, sizeof(*link));
444
445	display->index = aconnector->base.index;
446	display->state = MOD_HDCP_DISPLAY_ACTIVE;
447
448	if (aconnector->dc_sink != NULL)
449		link->mode = mod_hdcp_signal_type_to_operation_mode(aconnector->dc_sink->sink_signal);
450
451	display->controller = CONTROLLER_ID_D0 + config->otg_inst;
452	display->dig_fe = config->stream_enc_inst;
453	link->dig_be = config->link_enc_inst;
454	link->ddc_line = aconnector->dc_link->ddc_hw_inst + 1;
455	link->dp.rev = aconnector->dc_link->dpcd_caps.dpcd_rev.raw;
456	link->dp.mst_supported = config->mst_supported;
457	display->adjust.disable = 1;
458	link->adjust.auth_delay = 3;
459	link->adjust.hdcp1.disable = 0;
460
461	hdcp_update_display(hdcp_work, link_index, aconnector, DRM_MODE_HDCP_CONTENT_TYPE0, false);
462}
463
464
465/* NOTE: From the usermodes prospective you only need to call write *ONCE*, the kernel
466 *      will automatically call once or twice depending on the size
467 *
468 * call: "cat file > /sys/class/drm/card0/device/hdcp_srm" from usermode no matter what the size is
469 *
470 * The kernel can only send PAGE_SIZE at once and since MAX_SRM_FILE(5120) > PAGE_SIZE(4096),
471 * srm_data_write can be called multiple times.
472 *
473 * sysfs interface doesn't tell us the size we will get so we are sending partial SRMs to psp and on
474 * the last call we will send the full SRM. PSP will fail on every call before the last.
475 *
476 * This means we don't know if the SRM is good until the last call. And because of this limitation we
477 * cannot throw errors early as it will stop the kernel from writing to sysfs
478 *
479 * Example 1:
480 * 	Good SRM size = 5096
481 * 	first call to write 4096 -> PSP fails
482 * 	Second call to write 1000 -> PSP Pass -> SRM is set
483 *
484 * Example 2:
485 * 	Bad SRM size = 4096
486 * 	first call to write 4096 -> PSP fails (This is the same as above, but we don't know if this
487 * 	is the last call)
488 *
489 * Solution?:
490 * 	1: Parse the SRM? -> It is signed so we don't know the EOF
491 * 	2: We can have another sysfs that passes the size before calling set. -> simpler solution
492 * 	below
493 *
494 * Easy Solution:
495 * Always call get after Set to verify if set was successful.
496 * +----------------------+
497 * |   Why it works:      |
498 * +----------------------+
499 * PSP will only update its srm if its older than the one we are trying to load.
500 * Always do set first than get.
501 * 	-if we try to "1. SET" a older version PSP will reject it and we can "2. GET" the newer
502 * 	version and save it
503 *
504 * 	-if we try to "1. SET" a newer version PSP will accept it and we can "2. GET" the
505 * 	same(newer) version back and save it
506 *
507 * 	-if we try to "1. SET" a newer version and PSP rejects it. That means the format is
508 * 	incorrect/corrupted and we should correct our SRM by getting it from PSP
509 */
510static ssize_t srm_data_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer,
511			      loff_t pos, size_t count)
512{
513	struct hdcp_workqueue *work;
514	uint32_t srm_version = 0;
515
516	work = container_of(bin_attr, struct hdcp_workqueue, attr);
517	link_lock(work, true);
518
519	memcpy(work->srm_temp + pos, buffer, count);
520
521	if (!psp_set_srm(work->hdcp.config.psp.handle, work->srm_temp, pos + count, &srm_version)) {
522		DRM_DEBUG_DRIVER("HDCP SRM SET version 0x%X", srm_version);
523		memcpy(work->srm, work->srm_temp, pos + count);
524		work->srm_size = pos + count;
525		work->srm_version = srm_version;
526	}
527
528
529	link_lock(work, false);
530
531	return count;
532}
533
534static ssize_t srm_data_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer,
535			     loff_t pos, size_t count)
536{
537	struct hdcp_workqueue *work;
538	uint8_t *srm = NULL;
539	uint32_t srm_version;
540	uint32_t srm_size;
541	size_t ret = count;
542
543	work = container_of(bin_attr, struct hdcp_workqueue, attr);
544
545	link_lock(work, true);
546
547	srm = psp_get_srm(work->hdcp.config.psp.handle, &srm_version, &srm_size);
548
549	if (!srm) {
550		ret = -EINVAL;
551		goto ret;
552	}
553
554	if (pos >= srm_size)
555		ret = 0;
556
557	if (srm_size - pos < count) {
558		memcpy(buffer, srm + pos, srm_size - pos);
559		ret = srm_size - pos;
560		goto ret;
561	}
562
563	memcpy(buffer, srm + pos, count);
564
565ret:
566	link_lock(work, false);
567	return ret;
568}
569
570/* From the hdcp spec (5.Renewability) SRM needs to be stored in a non-volatile memory.
571 *
572 * For example,
573 * 	if Application "A" sets the SRM (ver 2) and we reboot/suspend and later when Application "B"
574 * 	needs to use HDCP, the version in PSP should be SRM(ver 2). So SRM should be persistent
575 * 	across boot/reboots/suspend/resume/shutdown
576 *
577 * Currently when the system goes down (suspend/shutdown) the SRM is cleared from PSP. For HDCP we need
578 * to make the SRM persistent.
579 *
580 * -PSP owns the checking of SRM but doesn't have the ability to store it in a non-volatile memory.
581 * -The kernel cannot write to the file systems.
582 * -So we need usermode to do this for us, which is why an interface for usermode is needed
583 *
584 *
585 *
586 * Usermode can read/write to/from PSP using the sysfs interface
587 * For example:
588 * 	to save SRM from PSP to storage : cat /sys/class/drm/card0/device/hdcp_srm > srmfile
589 * 	to load from storage to PSP: cat srmfile > /sys/class/drm/card0/device/hdcp_srm
590 */
591static const struct bin_attribute data_attr = {
592	.attr = {.name = "hdcp_srm", .mode = 0664},
593	.size = PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, /* Limit SRM size */
594	.write = srm_data_write,
595	.read = srm_data_read,
596};
597
598
599struct hdcp_workqueue *hdcp_create_workqueue(struct amdgpu_device *adev, struct cp_psp *cp_psp, struct dc *dc)
600{
601
602	int max_caps = dc->caps.max_links;
603	struct hdcp_workqueue *hdcp_work;
604	int i = 0;
605
606	hdcp_work = kcalloc(max_caps, sizeof(*hdcp_work), GFP_KERNEL);
607	if (ZERO_OR_NULL_PTR(hdcp_work))
608		return NULL;
609
610	hdcp_work->srm = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm), GFP_KERNEL);
611
612	if (hdcp_work->srm == NULL)
613		goto fail_alloc_context;
614
615	hdcp_work->srm_temp = kcalloc(PSP_HDCP_SRM_FIRST_GEN_MAX_SIZE, sizeof(*hdcp_work->srm_temp), GFP_KERNEL);
616
617	if (hdcp_work->srm_temp == NULL)
618		goto fail_alloc_context;
619
620	hdcp_work->max_link = max_caps;
621
622	for (i = 0; i < max_caps; i++) {
623		mutex_init(&hdcp_work[i].mutex);
624
625		INIT_WORK(&hdcp_work[i].cpirq_work, event_cpirq);
626		INIT_WORK(&hdcp_work[i].property_update_work, event_property_update);
627		INIT_DELAYED_WORK(&hdcp_work[i].callback_dwork, event_callback);
628		INIT_DELAYED_WORK(&hdcp_work[i].watchdog_timer_dwork, event_watchdog_timer);
629		INIT_DELAYED_WORK(&hdcp_work[i].property_validate_dwork, event_property_validate);
630
631		hdcp_work[i].hdcp.config.psp.handle = &adev->psp;
632		hdcp_work[i].hdcp.config.ddc.handle = dc_get_link_at_index(dc, i);
633		hdcp_work[i].hdcp.config.ddc.funcs.write_i2c = lp_write_i2c;
634		hdcp_work[i].hdcp.config.ddc.funcs.read_i2c = lp_read_i2c;
635		hdcp_work[i].hdcp.config.ddc.funcs.write_dpcd = lp_write_dpcd;
636		hdcp_work[i].hdcp.config.ddc.funcs.read_dpcd = lp_read_dpcd;
637	}
638
639	cp_psp->funcs.update_stream_config = update_config;
640	cp_psp->funcs.enable_assr = enable_assr;
641	cp_psp->handle = hdcp_work;
642
643	/* File created at /sys/class/drm/card0/device/hdcp_srm*/
644	hdcp_work[0].attr = data_attr;
645
646	if (sysfs_create_bin_file(&adev->dev->kobj, &hdcp_work[0].attr))
647		DRM_WARN("Failed to create device file hdcp_srm");
648
649	return hdcp_work;
650
651fail_alloc_context:
652	kfree(hdcp_work->srm);
653	kfree(hdcp_work->srm_temp);
654	kfree(hdcp_work);
655
656	return NULL;
657
658
659
660}
661
662
663