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(&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, 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
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(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(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
134	kfree(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(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
156void 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
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(&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 */
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(&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
277err:
278	return ret;
279}
280