drivers/gpu/drm/i915/display/intel_hdcp_gsc.c

   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);
  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 }