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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);