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