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
i915_dev_to_pxp(struct device * i915_kdev)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
intel_pxp_tee_io_message(struct intel_pxp * pxp,void * msg_in,u32 msg_in_size,void * msg_out,u32 msg_out_max_size,u32 * msg_out_rcv_size)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 */
i915_pxp_tee_component_bind(struct device * i915_kdev,struct device * tee_kdev,void * data)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
i915_pxp_tee_component_unbind(struct device * i915_kdev,struct device * tee_kdev,void * data)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
intel_pxp_tee_component_init(struct intel_pxp * pxp)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
intel_pxp_tee_component_fini(struct intel_pxp * pxp)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
intel_pxp_tee_cmd_create_arb_session(struct intel_pxp * pxp,int arb_session_id)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 }
180