xref: /linux/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 intel_display *display)
23 {
24 	return DISPLAY_VER(display) >= 14;
25 }
26 
27 bool intel_hdcp_gsc_check_status(struct intel_display *display)
28 {
29 	struct drm_i915_private *i915 = to_i915(display->drm);
30 	struct intel_gt *gt = i915->media_gt;
31 	struct intel_gsc_uc *gsc = gt ? &gt->uc.gsc : NULL;
32 
33 	if (!gsc || !intel_uc_fw_is_running(&gsc->fw)) {
34 		drm_dbg_kms(display->drm,
35 			    "GSC components required for HDCP2.2 are not ready\n");
36 		return false;
37 	}
38 
39 	return true;
40 }
41 
42 /*This function helps allocate memory for the command that we will send to gsc cs */
43 static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
44 					     struct intel_hdcp_gsc_message *hdcp_message)
45 {
46 	struct intel_gt *gt = i915->media_gt;
47 	struct drm_i915_gem_object *obj = NULL;
48 	struct i915_vma *vma = NULL;
49 	void *cmd_in, *cmd_out;
50 	int err;
51 
52 	/* allocate object of two page for HDCP command memory and store it */
53 	obj = i915_gem_object_create_shmem(i915, 2 * PAGE_SIZE);
54 
55 	if (IS_ERR(obj)) {
56 		drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
57 		return PTR_ERR(obj);
58 	}
59 
60 	cmd_in = i915_gem_object_pin_map_unlocked(obj, intel_gt_coherent_map_type(gt, obj, true));
61 	if (IS_ERR(cmd_in)) {
62 		drm_err(&i915->drm, "Failed to map gsc message page!\n");
63 		err = PTR_ERR(cmd_in);
64 		goto out_unpin;
65 	}
66 
67 	cmd_out = cmd_in + PAGE_SIZE;
68 
69 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
70 	if (IS_ERR(vma)) {
71 		err = PTR_ERR(vma);
72 		goto out_unmap;
73 	}
74 
75 	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
76 	if (err)
77 		goto out_unmap;
78 
79 	memset(cmd_in, 0, obj->base.size);
80 
81 	hdcp_message->hdcp_cmd_in = cmd_in;
82 	hdcp_message->hdcp_cmd_out = cmd_out;
83 	hdcp_message->vma = vma;
84 
85 	return 0;
86 
87 out_unmap:
88 	i915_gem_object_unpin_map(obj);
89 out_unpin:
90 	i915_gem_object_put(obj);
91 	return err;
92 }
93 
94 static const struct i915_hdcp_ops gsc_hdcp_ops = {
95 	.initiate_hdcp2_session = intel_hdcp_gsc_initiate_session,
96 	.verify_receiver_cert_prepare_km =
97 				intel_hdcp_gsc_verify_receiver_cert_prepare_km,
98 	.verify_hprime = intel_hdcp_gsc_verify_hprime,
99 	.store_pairing_info = intel_hdcp_gsc_store_pairing_info,
100 	.initiate_locality_check = intel_hdcp_gsc_initiate_locality_check,
101 	.verify_lprime = intel_hdcp_gsc_verify_lprime,
102 	.get_session_key = intel_hdcp_gsc_get_session_key,
103 	.repeater_check_flow_prepare_ack =
104 				intel_hdcp_gsc_repeater_check_flow_prepare_ack,
105 	.verify_mprime = intel_hdcp_gsc_verify_mprime,
106 	.enable_hdcp_authentication = intel_hdcp_gsc_enable_authentication,
107 	.close_hdcp_session = intel_hdcp_gsc_close_session,
108 };
109 
110 static int intel_hdcp_gsc_hdcp2_init(struct intel_display *display)
111 {
112 	struct drm_i915_private *i915 = to_i915(display->drm);
113 	struct intel_hdcp_gsc_message *hdcp_message;
114 	int ret;
115 
116 	hdcp_message = kzalloc(sizeof(*hdcp_message), GFP_KERNEL);
117 
118 	if (!hdcp_message)
119 		return -ENOMEM;
120 
121 	/*
122 	 * NOTE: No need to lock the comp mutex here as it is already
123 	 * going to be taken before this function called
124 	 */
125 	display->hdcp.hdcp_message = hdcp_message;
126 	ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
127 
128 	if (ret)
129 		drm_err(display->drm, "Could not initialize hdcp_message\n");
130 
131 	return ret;
132 }
133 
134 static void intel_hdcp_gsc_free_message(struct intel_display *display)
135 {
136 	struct intel_hdcp_gsc_message *hdcp_message =
137 					display->hdcp.hdcp_message;
138 
139 	hdcp_message->hdcp_cmd_in = NULL;
140 	hdcp_message->hdcp_cmd_out = NULL;
141 	i915_vma_unpin_and_release(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
142 	kfree(hdcp_message);
143 }
144 
145 int intel_hdcp_gsc_init(struct intel_display *display)
146 {
147 	struct i915_hdcp_arbiter *data;
148 	int ret;
149 
150 	data = kzalloc(sizeof(struct i915_hdcp_arbiter), GFP_KERNEL);
151 	if (!data)
152 		return -ENOMEM;
153 
154 	mutex_lock(&display->hdcp.hdcp_mutex);
155 	display->hdcp.arbiter = data;
156 	display->hdcp.arbiter->hdcp_dev = display->drm->dev;
157 	display->hdcp.arbiter->ops = &gsc_hdcp_ops;
158 	ret = intel_hdcp_gsc_hdcp2_init(display);
159 	mutex_unlock(&display->hdcp.hdcp_mutex);
160 
161 	return ret;
162 }
163 
164 void intel_hdcp_gsc_fini(struct intel_display *display)
165 {
166 	intel_hdcp_gsc_free_message(display);
167 	kfree(display->hdcp.arbiter);
168 }
169 
170 static int intel_gsc_send_sync(struct drm_i915_private *i915,
171 			       struct intel_gsc_mtl_header *header_in,
172 			       struct intel_gsc_mtl_header *header_out,
173 			       u64 addr_in, u64 addr_out,
174 			       size_t msg_out_len)
175 {
176 	struct intel_gt *gt = i915->media_gt;
177 	int ret;
178 
179 	ret = intel_gsc_uc_heci_cmd_submit_packet(&gt->uc.gsc, addr_in,
180 						  header_in->message_size,
181 						  addr_out,
182 						  msg_out_len + sizeof(*header_out));
183 	if (ret) {
184 		drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
185 		return ret;
186 	}
187 
188 	/*
189 	 * Checking validity marker and header status to see if some error has
190 	 * blocked us from sending message to gsc cs
191 	 */
192 	if (header_out->validity_marker != GSC_HECI_VALIDITY_MARKER) {
193 		drm_err(&i915->drm, "invalid validity marker\n");
194 		return -EINVAL;
195 	}
196 
197 	if (header_out->status != 0) {
198 		drm_err(&i915->drm, "header status indicates error %d\n",
199 			header_out->status);
200 		return -EINVAL;
201 	}
202 
203 	if (header_out->flags & GSC_OUTFLAG_MSG_PENDING) {
204 		header_in->gsc_message_handle = header_out->gsc_message_handle;
205 		return -EAGAIN;
206 	}
207 
208 	return 0;
209 }
210 
211 /*
212  * This function can now be used for sending requests and will also handle
213  * receipt of reply messages hence no different function of message retrieval
214  * is required. We will initialize intel_hdcp_gsc_message structure then add
215  * gsc cs memory header as stated in specs after which the normal HDCP payload
216  * will follow
217  */
218 ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
219 				size_t msg_in_len, u8 *msg_out,
220 				size_t msg_out_len)
221 {
222 	struct intel_gt *gt = i915->media_gt;
223 	struct intel_gsc_mtl_header *header_in, *header_out;
224 	const size_t max_msg_size = PAGE_SIZE - sizeof(*header_in);
225 	struct intel_hdcp_gsc_message *hdcp_message;
226 	u64 addr_in, addr_out, host_session_id;
227 	u32 reply_size, msg_size_in, msg_size_out;
228 	int ret, tries = 0;
229 
230 	if (!intel_uc_uses_gsc_uc(&gt->uc))
231 		return -ENODEV;
232 
233 	if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
234 		return -ENOSPC;
235 
236 	msg_size_in = msg_in_len + sizeof(*header_in);
237 	msg_size_out = msg_out_len + sizeof(*header_out);
238 	hdcp_message = i915->display.hdcp.hdcp_message;
239 	header_in = hdcp_message->hdcp_cmd_in;
240 	header_out = hdcp_message->hdcp_cmd_out;
241 	addr_in = i915_ggtt_offset(hdcp_message->vma);
242 	addr_out = addr_in + PAGE_SIZE;
243 
244 	memset(header_in, 0, msg_size_in);
245 	memset(header_out, 0, msg_size_out);
246 	get_random_bytes(&host_session_id, sizeof(u64));
247 	intel_gsc_uc_heci_cmd_emit_mtl_header(header_in, HECI_MEADDRESS_HDCP,
248 					      msg_size_in, host_session_id);
249 	memcpy(hdcp_message->hdcp_cmd_in + sizeof(*header_in), msg_in, msg_in_len);
250 
251 	/*
252 	 * Keep sending request in case the pending bit is set no need to add
253 	 * message handle as we are using same address hence loc. of header is
254 	 * same and it will contain the message handle. we will send the message
255 	 * 20 times each message 50 ms apart
256 	 */
257 	do {
258 		ret = intel_gsc_send_sync(i915, header_in, header_out, addr_in,
259 					  addr_out, msg_out_len);
260 
261 		/* Only try again if gsc says so */
262 		if (ret != -EAGAIN)
263 			break;
264 
265 		msleep(50);
266 
267 	} while (++tries < 20);
268 
269 	if (ret)
270 		goto err;
271 
272 	/* we use the same mem for the reply, so header is in the same loc */
273 	reply_size = header_out->message_size - sizeof(*header_out);
274 	if (reply_size > msg_out_len) {
275 		drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u (%d)\n",
276 			 reply_size, (u32)msg_out_len);
277 		reply_size = msg_out_len;
278 	} else if (reply_size != msg_out_len) {
279 		drm_dbg_kms(&i915->drm, "caller unexpected HCDP reply size %u (%d)\n",
280 			    reply_size, (u32)msg_out_len);
281 	}
282 
283 	memcpy(msg_out, hdcp_message->hdcp_cmd_out + sizeof(*header_out), msg_out_len);
284 
285 err:
286 	return ret;
287 }
288