drivers/gpu/drm/i915/pxp/intel_pxp_tee.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright(c) 2020 Intel Corporation.
   4  */
   5
   6 #include <linux/component.h>
   7
   8 #include <drm/i915_pxp_tee_interface.h>
   9 #include <drm/i915_component.h>
  10
  11 #include "i915_drv.h"
  12 #include "intel_pxp.h"
  13 #include "intel_pxp_session.h"
  14 #include "intel_pxp_tee.h"
  15 #include "intel_pxp_tee_interface.h"
  16
  17 static inline struct intel_pxp *i915_dev_to_pxp(struct device *i915_kdev)
  18 {
  19         struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
  20
  21         return &to_gt(i915)->pxp;
  22 }
  23
  24 static int intel_pxp_tee_io_message(struct intel_pxp *pxp,
  25                                     void *msg_in, u32 msg_in_size,
  26                                     void *msg_out, u32 msg_out_max_size,
  27                                     u32 *msg_out_rcv_size)
  28 {
  29         struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
  30         struct i915_pxp_component *pxp_component = pxp->pxp_component;
  31         int ret = 0;
  32
  33         mutex_lock(&pxp->tee_mutex);
  34
  35         /*
  36          * The binding of the component is asynchronous from i915 probe, so we
  37          * can't be sure it has happened.
  38          */
  39         if (!pxp_component) {
  40                 ret = -ENODEV;
  41                 goto unlock;
  42         }
  43
  44         ret = pxp_component->ops->send(pxp_component->tee_dev, msg_in, msg_in_size);
  45         if (ret) {
  46                 drm_err(&i915->drm, "Failed to send PXP TEE message\n");
  47                 goto unlock;
  48         }
  49
  50         ret = pxp_component->ops->recv(pxp_component->tee_dev, msg_out, msg_out_max_size);
  51         if (ret < 0) {
  52                 drm_err(&i915->drm, "Failed to receive PXP TEE message\n");
  53                 goto unlock;
  54         }
  55
  56         if (ret > msg_out_max_size) {
  57                 drm_err(&i915->drm,
  58                         "Failed to receive PXP TEE message due to unexpected output size\n");
  59                 ret = -ENOSPC;
  60                 goto unlock;
  61         }
  62
  63         if (msg_out_rcv_size)
  64                 *msg_out_rcv_size = ret;
  65
  66         ret = 0;
  67 unlock:
  68         mutex_unlock(&pxp->tee_mutex);
  69         return ret;
  70 }
  71
  72 /**
  73  * i915_pxp_tee_component_bind - bind function to pass the function pointers to pxp_tee
  74  * @i915_kdev: pointer to i915 kernel device
  75  * @tee_kdev: pointer to tee kernel device
  76  * @data: pointer to pxp_tee_master containing the function pointers
  77  *
  78  * This bind function is called during the system boot or resume from system sleep.
  79  *
  80  * Return: return 0 if successful.
  81  */
  82 static int i915_pxp_tee_component_bind(struct device *i915_kdev,
  83                                        struct device *tee_kdev, void *data)
  84 {
  85         struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
  86         struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
  87         intel_wakeref_t wakeref;
  88
  89         mutex_lock(&pxp->tee_mutex);
  90         pxp->pxp_component = data;
  91         pxp->pxp_component->tee_dev = tee_kdev;
  92         mutex_unlock(&pxp->tee_mutex);
  93
  94         /* if we are suspended, the HW will be re-initialized on resume */
  95         wakeref = intel_runtime_pm_get_if_in_use(&i915->runtime_pm);
  96         if (!wakeref)
  97                 return 0;
  98
  99         /* the component is required to fully start the PXP HW */
 100         intel_pxp_init_hw(pxp);
 101
 102         intel_runtime_pm_put(&i915->runtime_pm, wakeref);
 103
 104         return 0;
 105 }
 106
 107 static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
 108                                           struct device *tee_kdev, void *data)
 109 {
 110         struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
 111         struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
 112         intel_wakeref_t wakeref;
 113
 114         with_intel_runtime_pm_if_in_use(&i915->runtime_pm, wakeref)
 115                 intel_pxp_fini_hw(pxp);
 116
 117         mutex_lock(&pxp->tee_mutex);
 118         pxp->pxp_component = NULL;
 119         mutex_unlock(&pxp->tee_mutex);
 120 }
 121
 122 static const struct component_ops i915_pxp_tee_component_ops = {
 123         .bind   = i915_pxp_tee_component_bind,
 124         .unbind = i915_pxp_tee_component_unbind,
 125 };
 126
 127 int intel_pxp_tee_component_init(struct intel_pxp *pxp)
 128 {
 129         int ret;
 130         struct intel_gt *gt = pxp_to_gt(pxp);
 131         struct drm_i915_private *i915 = gt->i915;
 132
 133         ret = component_add_typed(i915->drm.dev, &i915_pxp_tee_component_ops,
 134                                   I915_COMPONENT_PXP);
 135         if (ret < 0) {
 136                 drm_err(&i915->drm, "Failed to add PXP component (%d)\n", ret);
 137                 return ret;
 138         }
 139
 140         pxp->pxp_component_added = true;
 141
 142         return 0;
 143 }
 144
 145 void intel_pxp_tee_component_fini(struct intel_pxp *pxp)
 146 {
 147         struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
 148
 149         if (!pxp->pxp_component_added)
 150                 return;
 151
 152         component_del(i915->drm.dev, &i915_pxp_tee_component_ops);
 153         pxp->pxp_component_added = false;
 154 }
 155
 156 int intel_pxp_tee_cmd_create_arb_session(struct intel_pxp *pxp,
 157                                          int arb_session_id)
 158 {
 159         struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
 160         struct pxp_tee_create_arb_in msg_in = {0};
 161         struct pxp_tee_create_arb_out msg_out = {0};
 162         int ret;
 163
 164         msg_in.header.api_version = PXP_TEE_APIVER;
 165         msg_in.header.command_id = PXP_TEE_ARB_CMDID;
 166         msg_in.header.buffer_len = sizeof(msg_in) - sizeof(msg_in.header);
 167         msg_in.protection_mode = PXP_TEE_ARB_PROTECTION_MODE;
 168         msg_in.session_id = arb_session_id;
 169
 170         ret = intel_pxp_tee_io_message(pxp,
 171                                        &msg_in, sizeof(msg_in),
 172                                        &msg_out, sizeof(msg_out),
 173                                        NULL);
 174
 175         if (ret)
 176                 drm_err(&i915->drm, "Failed to send tee msg ret=[%d]\n", ret);
 177
 178         return ret;
 179 }