xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_tlb.c (revision 1539adf7) 
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_perf_oa_regs.h"
8 #include "intel_engine_pm.h"
9 #include "intel_gt.h"
10 #include "intel_gt_mcr.h"
11 #include "intel_gt_pm.h"
12 #include "intel_gt_print.h"
13 #include "intel_gt_regs.h"
14 #include "intel_tlb.h"
15 
16 /*
17  * HW architecture suggest typical invalidation time at 40us,
18  * with pessimistic cases up to 100us and a recommendation to
19  * cap at 1ms. We go a bit higher just in case.
20  */
21 #define TLB_INVAL_TIMEOUT_US 100
22 #define TLB_INVAL_TIMEOUT_MS 4
23 
24 /*
25  * On Xe_HP the TLB invalidation registers are located at the same MMIO offsets
26  * but are now considered MCR registers.  Since they exist within a GAM range,
27  * the primary instance of the register rolls up the status from each unit.
28  */
29 static int wait_for_invalidate(struct intel_engine_cs *engine)
30 {
31 	if (engine->tlb_inv.mcr)
32 		return intel_gt_mcr_wait_for_reg(engine->gt,
33 						 engine->tlb_inv.reg.mcr_reg,
34 						 engine->tlb_inv.done,
35 						 0,
36 						 TLB_INVAL_TIMEOUT_US,
37 						 TLB_INVAL_TIMEOUT_MS);
38 	else
39 		return __intel_wait_for_register_fw(engine->gt->uncore,
40 						    engine->tlb_inv.reg.reg,
41 						    engine->tlb_inv.done,
42 						    0,
43 						    TLB_INVAL_TIMEOUT_US,
44 						    TLB_INVAL_TIMEOUT_MS,
45 						    NULL);
46 }
47 
48 static void mmio_invalidate_full(struct intel_gt *gt)
49 {
50 	struct drm_i915_private *i915 = gt->i915;
51 	struct intel_uncore *uncore = gt->uncore;
52 	struct intel_engine_cs *engine;
53 	intel_engine_mask_t awake, tmp;
54 	enum intel_engine_id id;
55 	unsigned long flags;
56 
57 	if (GRAPHICS_VER(i915) < 8)
58 		return;
59 
60 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
61 
62 	intel_gt_mcr_lock(gt, &flags);
63 	spin_lock(&uncore->lock); /* serialise invalidate with GT reset */
64 
65 	awake = 0;
66 	for_each_engine(engine, gt, id) {
67 		if (!intel_engine_pm_is_awake(engine))
68 			continue;
69 
70 		if (engine->tlb_inv.mcr)
71 			intel_gt_mcr_multicast_write_fw(gt,
72 							engine->tlb_inv.reg.mcr_reg,
73 							engine->tlb_inv.request);
74 		else
75 			intel_uncore_write_fw(uncore,
76 					      engine->tlb_inv.reg.reg,
77 					      engine->tlb_inv.request);
78 
79 		awake |= engine->mask;
80 	}
81 
82 	GT_TRACE(gt, "invalidated engines %08x\n", awake);
83 
84 	/* Wa_2207587034:tgl,dg1,rkl,adl-s,adl-p */
85 	if (awake &&
86 	    (IS_TIGERLAKE(i915) ||
87 	     IS_DG1(i915) ||
88 	     IS_ROCKETLAKE(i915) ||
89 	     IS_ALDERLAKE_S(i915) ||
90 	     IS_ALDERLAKE_P(i915)))
91 		intel_uncore_write_fw(uncore, GEN12_OA_TLB_INV_CR, 1);
92 
93 	spin_unlock(&uncore->lock);
94 	intel_gt_mcr_unlock(gt, flags);
95 
96 	for_each_engine_masked(engine, gt, awake, tmp) {
97 		if (wait_for_invalidate(engine))
98 			gt_err_ratelimited(gt,
99 					   "%s TLB invalidation did not complete in %ums!\n",
100 					   engine->name, TLB_INVAL_TIMEOUT_MS);
101 	}
102 
103 	/*
104 	 * Use delayed put since a) we mostly expect a flurry of TLB
105 	 * invalidations so it is good to avoid paying the forcewake cost and
106 	 * b) it works around a bug in Icelake which cannot cope with too rapid
107 	 * transitions.
108 	 */
109 	intel_uncore_forcewake_put_delayed(uncore, FORCEWAKE_ALL);
110 }
111 
112 static bool tlb_seqno_passed(const struct intel_gt *gt, u32 seqno)
113 {
114 	u32 cur = intel_gt_tlb_seqno(gt);
115 
116 	/* Only skip if a *full* TLB invalidate barrier has passed */
117 	return (s32)(cur - ALIGN(seqno, 2)) > 0;
118 }
119 
120 void intel_gt_invalidate_tlb_full(struct intel_gt *gt, u32 seqno)
121 {
122 	intel_wakeref_t wakeref;
123 
124 	if (I915_SELFTEST_ONLY(gt->awake == -ENODEV))
125 		return;
126 
127 	if (intel_gt_is_wedged(gt))
128 		return;
129 
130 	if (tlb_seqno_passed(gt, seqno))
131 		return;
132 
133 	with_intel_gt_pm_if_awake(gt, wakeref) {
134 		mutex_lock(&gt->tlb.invalidate_lock);
135 		if (tlb_seqno_passed(gt, seqno))
136 			goto unlock;
137 
138 		mmio_invalidate_full(gt);
139 
140 		write_seqcount_invalidate(&gt->tlb.seqno);
141 unlock:
142 		mutex_unlock(&gt->tlb.invalidate_lock);
143 	}
144 }
145 
146 void intel_gt_init_tlb(struct intel_gt *gt)
147 {
148 	mutex_init(&gt->tlb.invalidate_lock);
149 	seqcount_mutex_init(&gt->tlb.seqno, &gt->tlb.invalidate_lock);
150 }
151 
152 void intel_gt_fini_tlb(struct intel_gt *gt)
153 {
154 	mutex_destroy(&gt->tlb.invalidate_lock);
155 }
156 
157 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
158 #include "selftest_tlb.c"
159 #endif
160