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
15struct intel_hdcp_gsc_context {
16 struct drm_i915_private *i915;
17 struct i915_vma *vma;
18 void *hdcp_cmd_in;
19 void *hdcp_cmd_out;
20};
21
22bool intel_hdcp_gsc_check_status(struct drm_device *drm)
23{
24 struct drm_i915_private *i915 = to_i915(dev: drm);
25 struct intel_gt *gt = i915->media_gt;
26 struct intel_gsc_uc *gsc = gt ? &gt->uc.gsc : NULL;
27
28 if (!gsc || !intel_uc_fw_is_running(uc_fw: &gsc->fw)) {
29 drm_dbg_kms(&i915->drm,
30 "GSC components required for HDCP2.2 are not ready\n");
31 return false;
32 }
33
34 return true;
35}
36
37/*This function helps allocate memory for the command that we will send to gsc cs */
38static int intel_hdcp_gsc_initialize_message(struct drm_i915_private *i915,
39 struct intel_hdcp_gsc_context *gsc_context)
40{
41 struct intel_gt *gt = i915->media_gt;
42 struct drm_i915_gem_object *obj = NULL;
43 struct i915_vma *vma = NULL;
44 void *cmd_in, *cmd_out;
45 int err;
46
47 /* allocate object of two page for HDCP command memory and store it */
48 obj = i915_gem_object_create_shmem(i915, size: 2 * PAGE_SIZE);
49
50 if (IS_ERR(ptr: obj)) {
51 drm_err(&i915->drm, "Failed to allocate HDCP streaming command!\n");
52 return PTR_ERR(ptr: obj);
53 }
54
55 cmd_in = i915_gem_object_pin_map_unlocked(obj, type: intel_gt_coherent_map_type(gt, obj, always_coherent: true));
56 if (IS_ERR(ptr: cmd_in)) {
57 drm_err(&i915->drm, "Failed to map gsc message page!\n");
58 err = PTR_ERR(ptr: cmd_in);
59 goto out_unpin;
60 }
61
62 cmd_out = cmd_in + PAGE_SIZE;
63
64 vma = i915_vma_instance(obj, vm: &gt->ggtt->vm, NULL);
65 if (IS_ERR(ptr: vma)) {
66 err = PTR_ERR(ptr: vma);
67 goto out_unmap;
68 }
69
70 err = i915_vma_pin(vma, size: 0, alignment: 0, PIN_GLOBAL | PIN_HIGH);
71 if (err)
72 goto out_unmap;
73
74 memset(s: cmd_in, c: 0, n: obj->base.size);
75
76 gsc_context->hdcp_cmd_in = cmd_in;
77 gsc_context->hdcp_cmd_out = cmd_out;
78 gsc_context->vma = vma;
79 gsc_context->i915 = i915;
80
81 return 0;
82
83out_unmap:
84 i915_gem_object_unpin_map(obj);
85out_unpin:
86 i915_gem_object_put(obj);
87 return err;
88}
89
90struct intel_hdcp_gsc_context *intel_hdcp_gsc_context_alloc(struct drm_device *drm)
91{
92 struct drm_i915_private *i915 = to_i915(dev: drm);
93 struct intel_hdcp_gsc_context *gsc_context;
94 int ret;
95
96 gsc_context = kzalloc(sizeof(*gsc_context), GFP_KERNEL);
97 if (!gsc_context)
98 return ERR_PTR(error: -ENOMEM);
99
100 /*
101 * NOTE: No need to lock the comp mutex here as it is already
102 * going to be taken before this function called
103 */
104 ret = intel_hdcp_gsc_initialize_message(i915, gsc_context);
105 if (ret) {
106 drm_err(&i915->drm, "Could not initialize gsc_context\n");
107 kfree(objp: gsc_context);
108 gsc_context = ERR_PTR(error: ret);
109 }
110
111 return gsc_context;
112}
113
114void intel_hdcp_gsc_context_free(struct intel_hdcp_gsc_context *gsc_context)
115{
116 if (!gsc_context)
117 return;
118
119 i915_vma_unpin_and_release(p_vma: &gsc_context->vma, I915_VMA_RELEASE_MAP);
120 kfree(objp: gsc_context);
121}
122
123static int intel_gsc_send_sync(struct drm_i915_private *i915,
124 struct intel_gsc_mtl_header *header_in,
125 struct intel_gsc_mtl_header *header_out,
126 u64 addr_in, u64 addr_out,
127 size_t msg_out_len)
128{
129 struct intel_gt *gt = i915->media_gt;
130 int ret;
131
132 ret = intel_gsc_uc_heci_cmd_submit_packet(gsc: &gt->uc.gsc, addr_in,
133 size_in: header_in->message_size,
134 addr_out,
135 size_out: msg_out_len + sizeof(*header_out));
136 if (ret) {
137 drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
138 return ret;
139 }
140
141 /*
142 * Checking validity marker and header status to see if some error has
143 * blocked us from sending message to gsc cs
144 */
145 if (header_out->validity_marker != GSC_HECI_VALIDITY_MARKER) {
146 drm_err(&i915->drm, "invalid validity marker\n");
147 return -EINVAL;
148 }
149
150 if (header_out->status != 0) {
151 drm_err(&i915->drm, "header status indicates error %d\n",
152 header_out->status);
153 return -EINVAL;
154 }
155
156 if (header_out->flags & GSC_OUTFLAG_MSG_PENDING) {
157 header_in->gsc_message_handle = header_out->gsc_message_handle;
158 return -EAGAIN;
159 }
160
161 return 0;
162}
163
164/*
165 * This function can now be used for sending requests and will also handle
166 * receipt of reply messages hence no different function of message retrieval
167 * is required. We will initialize intel_hdcp_gsc_context structure then add
168 * gsc cs memory header as stated in specs after which the normal HDCP payload
169 * will follow
170 */
171ssize_t intel_hdcp_gsc_msg_send(struct intel_hdcp_gsc_context *gsc_context,
172 void *msg_in, size_t msg_in_len,
173 void *msg_out, size_t msg_out_len)
174{
175 struct drm_i915_private *i915 = gsc_context->i915;
176 struct intel_gt *gt = i915->media_gt;
177 struct intel_gsc_mtl_header *header_in, *header_out;
178 const size_t max_msg_size = PAGE_SIZE - sizeof(*header_in);
179 u64 addr_in, addr_out, host_session_id;
180 u32 reply_size, msg_size_in, msg_size_out;
181 int ret, tries = 0;
182
183 if (!intel_uc_uses_gsc_uc(uc: &gt->uc))
184 return -ENODEV;
185
186 if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
187 return -ENOSPC;
188
189 msg_size_in = msg_in_len + sizeof(*header_in);
190 msg_size_out = msg_out_len + sizeof(*header_out);
191 header_in = gsc_context->hdcp_cmd_in;
192 header_out = gsc_context->hdcp_cmd_out;
193 addr_in = i915_ggtt_offset(vma: gsc_context->vma);
194 addr_out = addr_in + PAGE_SIZE;
195
196 memset(s: header_in, c: 0, n: msg_size_in);
197 memset(s: header_out, c: 0, n: msg_size_out);
198 get_random_bytes(buf: &host_session_id, len: sizeof(u64));
199 intel_gsc_uc_heci_cmd_emit_mtl_header(header: header_in, HECI_MEADDRESS_HDCP,
200 msg_size: msg_size_in, host_session_id);
201 memcpy(to: gsc_context->hdcp_cmd_in + sizeof(*header_in), from: msg_in, len: msg_in_len);
202
203 /*
204 * Keep sending request in case the pending bit is set no need to add
205 * message handle as we are using same address hence loc. of header is
206 * same and it will contain the message handle. we will send the message
207 * 20 times each message 50 ms apart
208 */
209 do {
210 ret = intel_gsc_send_sync(i915, header_in, header_out, addr_in,
211 addr_out, msg_out_len);
212
213 /* Only try again if gsc says so */
214 if (ret != -EAGAIN)
215 break;
216
217 msleep(msecs: 50);
218
219 } while (++tries < 20);
220
221 if (ret)
222 goto err;
223
224 /* we use the same mem for the reply, so header is in the same loc */
225 reply_size = header_out->message_size - sizeof(*header_out);
226 if (reply_size > msg_out_len) {
227 drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u (%d)\n",
228 reply_size, (u32)msg_out_len);
229 reply_size = msg_out_len;
230 } else if (reply_size != msg_out_len) {
231 drm_dbg_kms(&i915->drm, "caller unexpected HCDP reply size %u (%d)\n",
232 reply_size, (u32)msg_out_len);
233 }
234
235 memcpy(to: msg_out, from: gsc_context->hdcp_cmd_out + sizeof(*header_out), len: msg_out_len);
236
237err:
238 return ret;
239}
240