xref: /linux/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2023, Intel Corporation.
4  */
5 
6 #include <drm/intel/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 
16 struct intel_hdcp_gsc_message {
17 	struct i915_vma *vma;
18 	void *hdcp_cmd_in;
19 	void *hdcp_cmd_out;
20 };
21 
22 bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
23 {
24 	return DISPLAY_VER(i915) >= 14;
25 }
26 
27 bool intel_hdcp_gsc_check_status(struct drm_i915_private *i915)
28 {
29 	struct intel_gt *gt = i915->media_gt;
30 	struct intel_gsc_uc *gsc = gt ? &gt->uc.gsc : NULL;
31 
32 	if (!gsc || !intel_uc_fw_is_running(&gsc->fw)) {
33 		drm_dbg_kms(&i915->drm,
34 			    "GSC components required for HDCP2.2 are not ready\n");
35 		return false;
36 	}
37 
38 	return true;
39 }
40 
41 /*This function helps allocate memory for the command that we will send to gsc cs */
42 static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
43 					     struct intel_hdcp_gsc_message *hdcp_message)
44 {
45 	struct intel_gt *gt = i915->media_gt;
46 	struct drm_i915_gem_object *obj = NULL;
47 	struct i915_vma *vma = NULL;
48 	void *cmd_in, *cmd_out;
49 	int err;
50 
51 	/* allocate object of two page for HDCP command memory and store it */
52 	obj = i915_gem_object_create_shmem(i915, 2 * PAGE_SIZE);
53 
54 	if (IS_ERR(obj)) {
55 		drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
56 		return PTR_ERR(obj);
57 	}
58 
59 	cmd_in = i915_gem_object_pin_map_unlocked(obj, intel_gt_coherent_map_type(gt, obj, true));
60 	if (IS_ERR(cmd_in)) {
61 		drm_err(&i915->drm, "Failed to map gsc message page!\n");
62 		err = PTR_ERR(cmd_in);
63 		goto out_unpin;
64 	}
65 
66 	cmd_out = cmd_in + PAGE_SIZE;
67 
68 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
69 	if (IS_ERR(vma)) {
70 		err = PTR_ERR(vma);
71 		goto out_unmap;
72 	}
73 
74 	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
75 	if (err)
76 		goto out_unmap;
77 
78 	memset(cmd_in, 0, obj->base.size);
79 
80 	hdcp_message->hdcp_cmd_in = cmd_in;
81 	hdcp_message->hdcp_cmd_out = cmd_out;
82 	hdcp_message->vma = vma;
83 
84 	return 0;
85 
86 out_unmap:
87 	i915_gem_object_unpin_map(obj);
88 out_unpin:
89 	i915_gem_object_put(obj);
90 	return err;
91 }
92 
93 static const struct i915_hdcp_ops gsc_hdcp_ops = {
94 	.initiate_hdcp2_session = intel_hdcp_gsc_initiate_session,
95 	.verify_receiver_cert_prepare_km =
96 				intel_hdcp_gsc_verify_receiver_cert_prepare_km,
97 	.verify_hprime = intel_hdcp_gsc_verify_hprime,
98 	.store_pairing_info = intel_hdcp_gsc_store_pairing_info,
99 	.initiate_locality_check = intel_hdcp_gsc_initiate_locality_check,
100 	.verify_lprime = intel_hdcp_gsc_verify_lprime,
101 	.get_session_key = intel_hdcp_gsc_get_session_key,
102 	.repeater_check_flow_prepare_ack =
103 				intel_hdcp_gsc_repeater_check_flow_prepare_ack,
104 	.verify_mprime = intel_hdcp_gsc_verify_mprime,
105 	.enable_hdcp_authentication = intel_hdcp_gsc_enable_authentication,
106 	.close_hdcp_session = intel_hdcp_gsc_close_session,
107 };
108 
109 static int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915)
110 {
111 	struct intel_hdcp_gsc_message *hdcp_message;
112 	int ret;
113 
114 	hdcp_message = kzalloc(sizeof(*hdcp_message), GFP_KERNEL);
115 
116 	if (!hdcp_message)
117 		return -ENOMEM;
118 
119 	/*
120 	 * NOTE: No need to lock the comp mutex here as it is already
121 	 * going to be taken before this function called
122 	 */
123 	i915->display.hdcp.hdcp_message = hdcp_message;
124 	ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
125 
126 	if (ret)
127 		drm_err(&i915->drm, "Could not initialize hdcp_message\n");
128 
129 	return ret;
130 }
131 
132 static void intel_hdcp_gsc_free_message(struct drm_i915_private *i915)
133 {
134 	struct intel_hdcp_gsc_message *hdcp_message =
135 					i915->display.hdcp.hdcp_message;
136 
137 	hdcp_message->hdcp_cmd_in = NULL;
138 	hdcp_message->hdcp_cmd_out = NULL;
139 	i915_vma_unpin_and_release(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
140 	kfree(hdcp_message);
141 }
142 
143 int intel_hdcp_gsc_init(struct drm_i915_private *i915)
144 {
145 	struct i915_hdcp_arbiter *data;
146 	int ret;
147 
148 	data = kzalloc(sizeof(struct i915_hdcp_arbiter), GFP_KERNEL);
149 	if (!data)
150 		return -ENOMEM;
151 
152 	mutex_lock(&i915->display.hdcp.hdcp_mutex);
153 	i915->display.hdcp.arbiter = data;
154 	i915->display.hdcp.arbiter->hdcp_dev = i915->drm.dev;
155 	i915->display.hdcp.arbiter->ops = &gsc_hdcp_ops;
156 	ret = intel_hdcp_gsc_hdcp2_init(i915);
157 	mutex_unlock(&i915->display.hdcp.hdcp_mutex);
158 
159 	return ret;
160 }
161 
162 void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
163 {
164 	intel_hdcp_gsc_free_message(i915);
165 	kfree(i915->display.hdcp.arbiter);
166 }
167 
168 static int intel_gsc_send_sync(struct drm_i915_private *i915,
169 			       struct intel_gsc_mtl_header *header_in,
170 			       struct intel_gsc_mtl_header *header_out,
171 			       u64 addr_in, u64 addr_out,
172 			       size_t msg_out_len)
173 {
174 	struct intel_gt *gt = i915->media_gt;
175 	int ret;
176 
177 	ret = intel_gsc_uc_heci_cmd_submit_packet(&gt->uc.gsc, addr_in,
178 						  header_in->message_size,
179 						  addr_out,
180 						  msg_out_len + sizeof(*header_out));
181 	if (ret) {
182 		drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
183 		return ret;
184 	}
185 
186 	/*
187 	 * Checking validity marker and header status to see if some error has
188 	 * blocked us from sending message to gsc cs
189 	 */
190 	if (header_out->validity_marker != GSC_HECI_VALIDITY_MARKER) {
191 		drm_err(&i915->drm, "invalid validity marker\n");
192 		return -EINVAL;
193 	}
194 
195 	if (header_out->status != 0) {
196 		drm_err(&i915->drm, "header status indicates error %d\n",
197 			header_out->status);
198 		return -EINVAL;
199 	}
200 
201 	if (header_out->flags & GSC_OUTFLAG_MSG_PENDING) {
202 		header_in->gsc_message_handle = header_out->gsc_message_handle;
203 		return -EAGAIN;
204 	}
205 
206 	return 0;
207 }
208 
209 /*
210  * This function can now be used for sending requests and will also handle
211  * receipt of reply messages hence no different function of message retrieval
212  * is required. We will initialize intel_hdcp_gsc_message structure then add
213  * gsc cs memory header as stated in specs after which the normal HDCP payload
214  * will follow
215  */
216 ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
217 				size_t msg_in_len, u8 *msg_out,
218 				size_t msg_out_len)
219 {
220 	struct intel_gt *gt = i915->media_gt;
221 	struct intel_gsc_mtl_header *header_in, *header_out;
222 	const size_t max_msg_size = PAGE_SIZE - sizeof(*header_in);
223 	struct intel_hdcp_gsc_message *hdcp_message;
224 	u64 addr_in, addr_out, host_session_id;
225 	u32 reply_size, msg_size_in, msg_size_out;
226 	int ret, tries = 0;
227 
228 	if (!intel_uc_uses_gsc_uc(&gt->uc))
229 		return -ENODEV;
230 
231 	if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
232 		return -ENOSPC;
233 
234 	msg_size_in = msg_in_len + sizeof(*header_in);
235 	msg_size_out = msg_out_len + sizeof(*header_out);
236 	hdcp_message = i915->display.hdcp.hdcp_message;
237 	header_in = hdcp_message->hdcp_cmd_in;
238 	header_out = hdcp_message->hdcp_cmd_out;
239 	addr_in = i915_ggtt_offset(hdcp_message->vma);
240 	addr_out = addr_in + PAGE_SIZE;
241 
242 	memset(header_in, 0, msg_size_in);
243 	memset(header_out, 0, msg_size_out);
244 	get_random_bytes(&host_session_id, sizeof(u64));
245 	intel_gsc_uc_heci_cmd_emit_mtl_header(header_in, HECI_MEADDRESS_HDCP,
246 					      msg_size_in, host_session_id);
247 	memcpy(hdcp_message->hdcp_cmd_in + sizeof(*header_in), msg_in, msg_in_len);
248 
249 	/*
250 	 * Keep sending request in case the pending bit is set no need to add
251 	 * message handle as we are using same address hence loc. of header is
252 	 * same and it will contain the message handle. we will send the message
253 	 * 20 times each message 50 ms apart
254 	 */
255 	do {
256 		ret = intel_gsc_send_sync(i915, header_in, header_out, addr_in,
257 					  addr_out, msg_out_len);
258 
259 		/* Only try again if gsc says so */
260 		if (ret != -EAGAIN)
261 			break;
262 
263 		msleep(50);
264 
265 	} while (++tries < 20);
266 
267 	if (ret)
268 		goto err;
269 
270 	/* we use the same mem for the reply, so header is in the same loc */
271 	reply_size = header_out->message_size - sizeof(*header_out);
272 	if (reply_size > msg_out_len) {
273 		drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u (%d)\n",
274 			 reply_size, (u32)msg_out_len);
275 		reply_size = msg_out_len;
276 	} else if (reply_size != msg_out_len) {
277 		drm_dbg_kms(&i915->drm, "caller unexpected HCDP reply size %u (%d)\n",
278 			    reply_size, (u32)msg_out_len);
279 	}
280 
281 	memcpy(msg_out, hdcp_message->hdcp_cmd_out + sizeof(*header_out), msg_out_len);
282 
283 err:
284 	return ret;
285 }
286