1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/percpu.h>
 3#include <linux/jump_label.h>
 4#include <asm/trace.h>
 5#include <asm/asm-prototypes.h>
 6
 7#ifdef CONFIG_JUMP_LABEL
 8struct static_key opal_tracepoint_key = STATIC_KEY_INIT;
 9
10int opal_tracepoint_regfunc(void)
11{
12	static_key_slow_inc(&opal_tracepoint_key);
13	return 0;
14}
15
16void opal_tracepoint_unregfunc(void)
17{
18	static_key_slow_dec(&opal_tracepoint_key);
19}
20#else
21/*
22 * We optimise OPAL calls by placing opal_tracepoint_refcount
23 * directly in the TOC so we can check if the opal tracepoints are
24 * enabled via a single load.
25 */
26
27/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
28extern long opal_tracepoint_refcount;
29
30int opal_tracepoint_regfunc(void)
31{
32	opal_tracepoint_refcount++;
33	return 0;
34}
35
36void opal_tracepoint_unregfunc(void)
37{
38	opal_tracepoint_refcount--;
39}
40#endif
41
42/*
43 * Since the tracing code might execute OPAL calls we need to guard against
44 * recursion.
45 */
46static DEFINE_PER_CPU(unsigned int, opal_trace_depth);
47
48void __trace_opal_entry(unsigned long opcode, unsigned long *args)
49{
50	unsigned long flags;
51	unsigned int *depth;
52
53	local_irq_save(flags);
54
55	depth = this_cpu_ptr(&opal_trace_depth);
56
57	if (*depth)
58		goto out;
59
60	(*depth)++;
61	preempt_disable();
62	trace_opal_entry(opcode, args);
63	(*depth)--;
64
65out:
66	local_irq_restore(flags);
67}
68
69void __trace_opal_exit(long opcode, unsigned long retval)
70{
71	unsigned long flags;
72	unsigned int *depth;
73
74	local_irq_save(flags);
75
76	depth = this_cpu_ptr(&opal_trace_depth);
77
78	if (*depth)
79		goto out;
80
81	(*depth)++;
82	trace_opal_exit(opcode, retval);
83	preempt_enable();
84	(*depth)--;
85
86out:
87	local_irq_restore(flags);
88}

 
 1#include <linux/percpu.h>
 2#include <linux/jump_label.h>
 3#include <asm/trace.h>
 
 4
 5#ifdef HAVE_JUMP_LABEL
 6struct static_key opal_tracepoint_key = STATIC_KEY_INIT;
 7
 8void opal_tracepoint_regfunc(void)
 9{
10	static_key_slow_inc(&opal_tracepoint_key);
 
11}
12
13void opal_tracepoint_unregfunc(void)
14{
15	static_key_slow_dec(&opal_tracepoint_key);
16}
17#else
18/*
19 * We optimise OPAL calls by placing opal_tracepoint_refcount
20 * directly in the TOC so we can check if the opal tracepoints are
21 * enabled via a single load.
22 */
23
24/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
25extern long opal_tracepoint_refcount;
26
27void opal_tracepoint_regfunc(void)
28{
29	opal_tracepoint_refcount++;
 
30}
31
32void opal_tracepoint_unregfunc(void)
33{
34	opal_tracepoint_refcount--;
35}
36#endif
37
38/*
39 * Since the tracing code might execute OPAL calls we need to guard against
40 * recursion.
41 */
42static DEFINE_PER_CPU(unsigned int, opal_trace_depth);
43
44void __trace_opal_entry(unsigned long opcode, unsigned long *args)
45{
46	unsigned long flags;
47	unsigned int *depth;
48
49	local_irq_save(flags);
50
51	depth = this_cpu_ptr(&opal_trace_depth);
52
53	if (*depth)
54		goto out;
55
56	(*depth)++;
57	preempt_disable();
58	trace_opal_entry(opcode, args);
59	(*depth)--;
60
61out:
62	local_irq_restore(flags);
63}
64
65void __trace_opal_exit(long opcode, unsigned long retval)
66{
67	unsigned long flags;
68	unsigned int *depth;
69
70	local_irq_save(flags);
71
72	depth = this_cpu_ptr(&opal_trace_depth);
73
74	if (*depth)
75		goto out;
76
77	(*depth)++;
78	trace_opal_exit(opcode, retval);
79	preempt_enable();
80	(*depth)--;
81
82out:
83	local_irq_restore(flags);
84}