xref: /linux/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c (revision a23e1966932464e1c5226cb9ac4ce1d5fc10ba22)
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 
16 bool intel_hdcp_gsc_cs_required(struct drm_i915_private *i915)
17 {
18 	return DISPLAY_VER(i915) >= 14;
19 }
20 
21 bool 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(&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 */
36 static 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, 2 * PAGE_SIZE);
47 
48 	if (IS_ERR(obj)) {
49 		drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
50 		return PTR_ERR(obj);
51 	}
52 
53 	cmd_in = i915_gem_object_pin_map_unlocked(obj, intel_gt_coherent_map_type(gt, obj, true));
54 	if (IS_ERR(cmd_in)) {
55 		drm_err(&i915->drm, "Failed to map gsc message page!\n");
56 		err = PTR_ERR(cmd_in);
57 		goto out_unpin;
58 	}
59 
60 	cmd_out = cmd_in + PAGE_SIZE;
61 
62 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
63 	if (IS_ERR(vma)) {
64 		err = PTR_ERR(vma);
65 		goto out_unmap;
66 	}
67 
68 	err = i915_vma_pin(vma, 0, 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 
80 out_unmap:
81 	i915_gem_object_unpin_map(obj);
82 out_unpin:
83 	i915_gem_object_put(obj);
84 	return err;
85 }
86 
87 static 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 
103 static 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(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 
126 static 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(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
134 	kfree(hdcp_message);
135 }
136 
137 int intel_hdcp_gsc_init(struct drm_i915_private *i915)
138 {
139 	struct i915_hdcp_arbiter *data;
140 	int ret;
141 
142 	data = kzalloc(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(&i915->display.hdcp.hdcp_mutex);
152 
153 	return ret;
154 }
155 
156 void intel_hdcp_gsc_fini(struct drm_i915_private *i915)
157 {
158 	intel_hdcp_gsc_free_message(i915);
159 	kfree(i915->display.hdcp.arbiter);
160 }
161 
162 static 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(&gt->uc.gsc, addr_in,
172 						  header_in->message_size,
173 						  addr_out,
174 						  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  */
210 ssize_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(&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(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(&host_session_id, sizeof(u64));
239 	intel_gsc_uc_heci_cmd_emit_mtl_header(header_in, HECI_MEADDRESS_HDCP,
240 					      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(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 
277 err:
278 	return ret;
279 }
280