1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #ifndef __INTEL_ENGINE_STATS_H__
7 #define __INTEL_ENGINE_STATS_H__
8 
9 #include <linux/atomic.h>
10 #include <linux/ktime.h>
11 #include <linux/seqlock.h>
12 
13 #include "i915_gem.h" /* GEM_BUG_ON */
14 #include "intel_engine.h"
15 
16 static inline void intel_engine_context_in(struct intel_engine_cs *engine)
17 {
18 	struct intel_engine_execlists_stats *stats = &engine->stats.execlists;
19 	unsigned long flags;
20 
21 	if (stats->active) {
22 		stats->active++;
23 		return;
24 	}
25 
26 	/* The writer is serialised; but the pmu reader may be from hardirq */
27 	local_irq_save(flags);
28 	write_seqcount_begin(&stats->lock);
29 
30 	stats->start = ktime_get();
31 	stats->active++;
32 
33 	write_seqcount_end(&stats->lock);
34 	local_irq_restore(flags);
35 
36 	GEM_BUG_ON(!stats->active);
37 }
38 
39 static inline void intel_engine_context_out(struct intel_engine_cs *engine)
40 {
41 	struct intel_engine_execlists_stats *stats = &engine->stats.execlists;
42 	unsigned long flags;
43 
44 	GEM_BUG_ON(!stats->active);
45 	if (stats->active > 1) {
46 		stats->active--;
47 		return;
48 	}
49 
50 	local_irq_save(flags);
51 	write_seqcount_begin(&stats->lock);
52 
53 	stats->active--;
54 	stats->total = ktime_add(stats->total,
55 				 ktime_sub(ktime_get(), stats->start));
56 
57 	write_seqcount_end(&stats->lock);
58 	local_irq_restore(flags);
59 }
60 
61 #endif /* __INTEL_ENGINE_STATS_H__ */
62