1// SPDX-License-Identifier: MIT
2/*
3 * Copyright 2023, Intel Corporation.
4 */
5
6#include <drm/i915_hdcp_interface.h>
7
8#include "gem/i915_gem_region.h"
9#include "gt/intel_gt.h"
10#include "gt/uc/intel_gsc_uc_heci_cmd_submit.h"
11#include "i915_drv.h"
12#include "i915_utils.h"
13#include "intel_hdcp_gsc.h"
14#include "intel_hdcp_gsc_message.h"
15
16bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
17{
18 return DISPLAY_VER(i915) >= 14;
19}
20
21bool intel_hdcp_gsc_check_status(struct drm_i915_private *i915)
22{
23 struct intel_gt *gt = i915->media_gt;
24 struct intel_gsc_uc *gsc = gt ? &gt->uc.gsc : NULL;
25
26 if (!gsc || !intel_uc_fw_is_running(uc_fw: &gsc->fw)) {
27 drm_dbg_kms(&i915->drm,
28 "GSC components required for HDCP2.2 are not ready\n");
29 return false;
30 }
31
32 return true;
33}
34
35/*This function helps allocate memory for the command that we will send to gsc cs */
36static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
37 struct intel_hdcp_gsc_message *hdcp_message)
38{
39 struct intel_gt *gt = i915->media_gt;
40 struct drm_i915_gem_object *obj = NULL;
41 struct i915_vma *vma = NULL;
42 void *cmd_in, *cmd_out;
43 int err;
44
45 /* allocate object of two page for HDCP command memory and store it */
46 obj = i915_gem_object_create_shmem(i915, size: 2 * PAGE_SIZE);
47
48 if (IS_ERR(ptr: obj)) {
49 drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
50 return PTR_ERR(ptr: obj);
51 }
52
53 cmd_in = i915_gem_object_pin_map_unlocked(obj, type: intel_gt_coherent_map_type(gt, obj, always_coherent: true));
54 if (IS_ERR(ptr: cmd_in)) {
55 drm_err(&i915->drm, "Failed to map gsc message page!\n");
56 err = PTR_ERR(ptr: cmd_in);
57 goto out_unpin;
58 }
59
60 cmd_out = cmd_in + PAGE_SIZE;
61
62 vma = i915_vma_instance(obj, vm: &gt->ggtt->vm, NULL);
63 if (IS_ERR(ptr: vma)) {
64 err = PTR_ERR(ptr: vma);
65 goto out_unmap;
66 }
67
68 err = i915_vma_pin(vma, size: 0, alignment: 0, PIN_GLOBAL | PIN_HIGH);
69 if (err)
70 goto out_unmap;
71
72 memset(cmd_in, 0, obj->base.size);
73
74 hdcp_message->hdcp_cmd_in = cmd_in;
75 hdcp_message->hdcp_cmd_out = cmd_out;
76 hdcp_message->vma = vma;
77
78 return 0;
79
80out_unmap:
81 i915_gem_object_unpin_map(obj);
82out_unpin:
83 i915_gem_object_put(obj);
84 return err;
85}
86
87static const struct i915_hdcp_ops gsc_hdcp_ops = {
88 .initiate_hdcp2_session = intel_hdcp_gsc_initiate_session,
89 .verify_receiver_cert_prepare_km =
90 intel_hdcp_gsc_verify_receiver_cert_prepare_km,
91 .verify_hprime = intel_hdcp_gsc_verify_hprime,
92 .store_pairing_info = intel_hdcp_gsc_store_pairing_info,
93 .initiate_locality_check = intel_hdcp_gsc_initiate_locality_check,
94 .verify_lprime = intel_hdcp_gsc_verify_lprime,
95 .get_session_key = intel_hdcp_gsc_get_session_key,
96 .repeater_check_flow_prepare_ack =
97 intel_hdcp_gsc_repeater_check_flow_prepare_ack,
98 .verify_mprime = intel_hdcp_gsc_verify_mprime,
99 .enable_hdcp_authentication = intel_hdcp_gsc_enable_authentication,
100 .close_hdcp_session = intel_hdcp_gsc_close_session,
101};
102
103static int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915)
104{
105 struct intel_hdcp_gsc_message *hdcp_message;
106 int ret;
107
108 hdcp_message = kzalloc(size: sizeof(*hdcp_message), GFP_KERNEL);
109
110 if (!hdcp_message)
111 return -ENOMEM;
112
113 /*
114 * NOTE: No need to lock the comp mutex here as it is already
115 * going to be taken before this function called
116 */
117 i915->display.hdcp.hdcp_message = hdcp_message;
118 ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
119
120 if (ret)
121 drm_err(&i915->drm, "Could not initialize hdcp_message\n");
122
123 return ret;
124}
125
126static void intel_hdcp_gsc_free_message(struct drm_i915_private *i915)
127{
128 struct intel_hdcp_gsc_message *hdcp_message =
129 i915->display.hdcp.hdcp_message;
130
131 hdcp_message->hdcp_cmd_in = NULL;
132 hdcp_message->hdcp_cmd_out = NULL;
133 i915_vma_unpin_and_release(p_vma: &hdcp_message->vma, I915_VMA_RELEASE_MAP);
134 kfree(objp: hdcp_message);
135}
136
137int intel_hdcp_gsc_init(struct drm_i915_private *i915)
138{
139 struct i915_hdcp_arbiter *data;
140 int ret;
141
142 data = kzalloc(size: sizeof(struct i915_hdcp_arbiter), GFP_KERNEL);
143 if (!data)
144 return -ENOMEM;
145
146 mutex_lock(&i915->display.hdcp.hdcp_mutex);
147 i915->display.hdcp.arbiter = data;
148 i915->display.hdcp.arbiter->hdcp_dev = i915->drm.dev;
149 i915->display.hdcp.arbiter->ops = &gsc_hdcp_ops;
150 ret = intel_hdcp_gsc_hdcp2_init(i915);
151 mutex_unlock(lock: &i915->display.hdcp.hdcp_mutex);
152
153 return ret;
154}
155
156void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
157{
158 intel_hdcp_gsc_free_message(i915);
159 kfree(objp: i915->display.hdcp.arbiter);
160}
161
162static int intel_gsc_send_sync(struct drm_i915_private *i915,
163 struct intel_gsc_mtl_header *header_in,
164 struct intel_gsc_mtl_header *header_out,
165 u64 addr_in, u64 addr_out,
166 size_t msg_out_len)
167{
168 struct intel_gt *gt = i915->media_gt;
169 int ret;
170
171 ret = intel_gsc_uc_heci_cmd_submit_packet(gsc: &gt->uc.gsc, addr_in,
172 size_in: header_in->message_size,
173 addr_out,
174 size_out: msg_out_len + sizeof(*header_out));
175 if (ret) {
176 drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
177 return ret;
178 }
179
180 /*
181 * Checking validity marker and header status to see if some error has
182 * blocked us from sending message to gsc cs
183 */
184 if (header_out->validity_marker != GSC_HECI_VALIDITY_MARKER) {
185 drm_err(&i915->drm, "invalid validity marker\n");
186 return -EINVAL;
187 }
188
189 if (header_out->status != 0) {
190 drm_err(&i915->drm, "header status indicates error %d\n",
191 header_out->status);
192 return -EINVAL;
193 }
194
195 if (header_out->flags & GSC_OUTFLAG_MSG_PENDING) {
196 header_in->gsc_message_handle = header_out->gsc_message_handle;
197 return -EAGAIN;
198 }
199
200 return 0;
201}
202
203/*
204 * This function can now be used for sending requests and will also handle
205 * receipt of reply messages hence no different function of message retrieval
206 * is required. We will initialize intel_hdcp_gsc_message structure then add
207 * gsc cs memory header as stated in specs after which the normal HDCP payload
208 * will follow
209 */
210ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
211 size_t msg_in_len, u8 *msg_out,
212 size_t msg_out_len)
213{
214 struct intel_gt *gt = i915->media_gt;
215 struct intel_gsc_mtl_header *header_in, *header_out;
216 const size_t max_msg_size = PAGE_SIZE - sizeof(*header_in);
217 struct intel_hdcp_gsc_message *hdcp_message;
218 u64 addr_in, addr_out, host_session_id;
219 u32 reply_size, msg_size_in, msg_size_out;
220 int ret, tries = 0;
221
222 if (!intel_uc_uses_gsc_uc(uc: &gt->uc))
223 return -ENODEV;
224
225 if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
226 return -ENOSPC;
227
228 msg_size_in = msg_in_len + sizeof(*header_in);
229 msg_size_out = msg_out_len + sizeof(*header_out);
230 hdcp_message = i915->display.hdcp.hdcp_message;
231 header_in = hdcp_message->hdcp_cmd_in;
232 header_out = hdcp_message->hdcp_cmd_out;
233 addr_in = i915_ggtt_offset(vma: hdcp_message->vma);
234 addr_out = addr_in + PAGE_SIZE;
235
236 memset(header_in, 0, msg_size_in);
237 memset(header_out, 0, msg_size_out);
238 get_random_bytes(buf: &host_session_id, len: sizeof(u64));
239 intel_gsc_uc_heci_cmd_emit_mtl_header(header: header_in, HECI_MEADDRESS_HDCP,
240 msg_size: msg_size_in, host_session_id);
241 memcpy(hdcp_message->hdcp_cmd_in + sizeof(*header_in), msg_in, msg_in_len);
242
243 /*
244 * Keep sending request in case the pending bit is set no need to add
245 * message handle as we are using same address hence loc. of header is
246 * same and it will contain the message handle. we will send the message
247 * 20 times each message 50 ms apart
248 */
249 do {
250 ret = intel_gsc_send_sync(i915, header_in, header_out, addr_in,
251 addr_out, msg_out_len);
252
253 /* Only try again if gsc says so */
254 if (ret != -EAGAIN)
255 break;
256
257 msleep(msecs: 50);
258
259 } while (++tries < 20);
260
261 if (ret)
262 goto err;
263
264 /* we use the same mem for the reply, so header is in the same loc */
265 reply_size = header_out->message_size - sizeof(*header_out);
266 if (reply_size > msg_out_len) {
267 drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u (%d)\n",
268 reply_size, (u32)msg_out_len);
269 reply_size = msg_out_len;
270 } else if (reply_size != msg_out_len) {
271 drm_dbg_kms(&i915->drm, "caller unexpected HCDP reply size %u (%d)\n",
272 reply_size, (u32)msg_out_len);
273 }
274
275 memcpy(msg_out, hdcp_message->hdcp_cmd_out + sizeof(*header_out), msg_out_len);
276
277err:
278 return ret;
279}
280

source code of linux/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c