1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright(c) 2020, Intel Corporation. All rights reserved.
4  */
5 
6 #include <drm/i915_drm.h>
7 
8 #include "i915_drv.h"
9 
10 #include "intel_pxp.h"
11 #include "intel_pxp_cmd.h"
12 #include "intel_pxp_session.h"
13 #include "intel_pxp_tee.h"
14 #include "intel_pxp_types.h"
15 
16 #define ARB_SESSION I915_PROTECTED_CONTENT_DEFAULT_SESSION /* shorter define */
17 
18 #define GEN12_KCR_SIP _MMIO(0x32260) /* KCR hwdrm session in play 0-31 */
19 
20 /* PXP global terminate register for session termination */
21 #define PXP_GLOBAL_TERMINATE _MMIO(0x320f8)
22 
23 static bool intel_pxp_session_is_in_play(struct intel_pxp *pxp, u32 id)
24 {
25 	struct intel_uncore *uncore = pxp_to_gt(pxp)->uncore;
26 	intel_wakeref_t wakeref;
27 	u32 sip = 0;
28 
29 	/* if we're suspended the session is considered off */
30 	with_intel_runtime_pm_if_in_use(uncore->rpm, wakeref)
31 		sip = intel_uncore_read(uncore, GEN12_KCR_SIP);
32 
33 	return sip & BIT(id);
34 }
35 
36 static int pxp_wait_for_session_state(struct intel_pxp *pxp, u32 id, bool in_play)
37 {
38 	struct intel_uncore *uncore = pxp_to_gt(pxp)->uncore;
39 	intel_wakeref_t wakeref;
40 	u32 mask = BIT(id);
41 	int ret;
42 
43 	/* if we're suspended the session is considered off */
44 	wakeref = intel_runtime_pm_get_if_in_use(uncore->rpm);
45 	if (!wakeref)
46 		return in_play ? -ENODEV : 0;
47 
48 	ret = intel_wait_for_register(uncore,
49 				      GEN12_KCR_SIP,
50 				      mask,
51 				      in_play ? mask : 0,
52 				      100);
53 
54 	intel_runtime_pm_put(uncore->rpm, wakeref);
55 
56 	return ret;
57 }
58 
59 static int pxp_create_arb_session(struct intel_pxp *pxp)
60 {
61 	struct intel_gt *gt = pxp_to_gt(pxp);
62 	int ret;
63 
64 	pxp->arb_is_valid = false;
65 
66 	if (intel_pxp_session_is_in_play(pxp, ARB_SESSION)) {
67 		drm_err(&gt->i915->drm, "arb session already in play at creation time\n");
68 		return -EEXIST;
69 	}
70 
71 	ret = intel_pxp_tee_cmd_create_arb_session(pxp, ARB_SESSION);
72 	if (ret) {
73 		drm_err(&gt->i915->drm, "tee cmd for arb session creation failed\n");
74 		return ret;
75 	}
76 
77 	ret = pxp_wait_for_session_state(pxp, ARB_SESSION, true);
78 	if (ret) {
79 		drm_err(&gt->i915->drm, "arb session failed to go in play\n");
80 		return ret;
81 	}
82 
83 	if (!++pxp->key_instance)
84 		++pxp->key_instance;
85 
86 	pxp->arb_is_valid = true;
87 
88 	return 0;
89 }
90 
91 static int pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
92 {
93 	int ret;
94 	struct intel_gt *gt = pxp_to_gt(pxp);
95 
96 	/* must mark termination in progress calling this function */
97 	GEM_WARN_ON(pxp->arb_is_valid);
98 
99 	/* terminate the hw sessions */
100 	ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
101 	if (ret) {
102 		drm_err(&gt->i915->drm, "Failed to submit session termination\n");
103 		return ret;
104 	}
105 
106 	ret = pxp_wait_for_session_state(pxp, ARB_SESSION, false);
107 	if (ret) {
108 		drm_err(&gt->i915->drm, "Session state did not clear\n");
109 		return ret;
110 	}
111 
112 	intel_uncore_write(gt->uncore, PXP_GLOBAL_TERMINATE, 1);
113 
114 	return ret;
115 }
116 
117 static void pxp_terminate(struct intel_pxp *pxp)
118 {
119 	int ret;
120 
121 	pxp->hw_state_invalidated = true;
122 
123 	/*
124 	 * if we fail to submit the termination there is no point in waiting for
125 	 * it to complete. PXP will be marked as non-active until the next
126 	 * termination is issued.
127 	 */
128 	ret = pxp_terminate_arb_session_and_global(pxp);
129 	if (ret)
130 		complete_all(&pxp->termination);
131 }
132 
133 static void pxp_terminate_complete(struct intel_pxp *pxp)
134 {
135 	/* Re-create the arb session after teardown handle complete */
136 	if (fetch_and_zero(&pxp->hw_state_invalidated))
137 		pxp_create_arb_session(pxp);
138 
139 	complete_all(&pxp->termination);
140 }
141 
142 void intel_pxp_session_work(struct work_struct *work)
143 {
144 	struct intel_pxp *pxp = container_of(work, typeof(*pxp), session_work);
145 	struct intel_gt *gt = pxp_to_gt(pxp);
146 	intel_wakeref_t wakeref;
147 	u32 events = 0;
148 
149 	spin_lock_irq(&gt->irq_lock);
150 	events = fetch_and_zero(&pxp->session_events);
151 	spin_unlock_irq(&gt->irq_lock);
152 
153 	if (!events)
154 		return;
155 
156 	if (events & PXP_INVAL_REQUIRED)
157 		intel_pxp_invalidate(pxp);
158 
159 	/*
160 	 * If we're processing an event while suspending then don't bother,
161 	 * we're going to re-init everything on resume anyway.
162 	 */
163 	wakeref = intel_runtime_pm_get_if_in_use(gt->uncore->rpm);
164 	if (!wakeref)
165 		return;
166 
167 	if (events & PXP_TERMINATION_REQUEST) {
168 		events &= ~PXP_TERMINATION_COMPLETE;
169 		pxp_terminate(pxp);
170 	}
171 
172 	if (events & PXP_TERMINATION_COMPLETE)
173 		pxp_terminate_complete(pxp);
174 
175 	intel_runtime_pm_put(gt->uncore->rpm, wakeref);
176 }
177