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 	unsigned long flags;
19 
20 	if (engine->stats.active) {
21 		engine->stats.active++;
22 		return;
23 	}
24 
25 	/* The writer is serialised; but the pmu reader may be from hardirq */
26 	local_irq_save(flags);
27 	write_seqcount_begin(&engine->stats.lock);
28 
29 	engine->stats.start = ktime_get();
30 	engine->stats.active++;
31 
32 	write_seqcount_end(&engine->stats.lock);
33 	local_irq_restore(flags);
34 
35 	GEM_BUG_ON(!engine->stats.active);
36 }
37 
38 static inline void intel_engine_context_out(struct intel_engine_cs *engine)
39 {
40 	unsigned long flags;
41 
42 	GEM_BUG_ON(!engine->stats.active);
43 	if (engine->stats.active > 1) {
44 		engine->stats.active--;
45 		return;
46 	}
47 
48 	local_irq_save(flags);
49 	write_seqcount_begin(&engine->stats.lock);
50 
51 	engine->stats.active--;
52 	engine->stats.total =
53 		ktime_add(engine->stats.total,
54 			  ktime_sub(ktime_get(), engine->stats.start));
55 
56 	write_seqcount_end(&engine->stats.lock);
57 	local_irq_restore(flags);
58 }
59 
60 #endif /* __INTEL_ENGINE_STATS_H__ */
61