1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2006 Mike Kravetz IBM Corporation
4 *
5 * Hypervisor Call Instrumentation
6 */
7
8#include <linux/kernel.h>
9#include <linux/percpu.h>
10#include <linux/debugfs.h>
11#include <linux/seq_file.h>
12#include <linux/cpumask.h>
13#include <asm/hvcall.h>
14#include <asm/firmware.h>
15#include <asm/cputable.h>
16#include <asm/trace.h>
17#include <asm/machdep.h>
18
19/* For hcall instrumentation. One structure per-hcall, per-CPU */
20struct hcall_stats {
21	unsigned long	num_calls;	/* number of calls (on this CPU) */
22	unsigned long	tb_total;	/* total wall time (mftb) of calls. */
23	unsigned long	purr_total;	/* total cpu time (PURR) of calls. */
24	unsigned long	tb_start;
25	unsigned long	purr_start;
26};
27#define HCALL_STAT_ARRAY_SIZE	((MAX_HCALL_OPCODE >> 2) + 1)
28
29static DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
30
31/*
32 * Routines for displaying the statistics in debugfs
33 */
34static void *hc_start(struct seq_file *m, loff_t *pos)
35{
36	if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
37		return (void *)(unsigned long)(*pos + 1);
38
39	return NULL;
40}
41
42static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
43{
44	++*pos;
45
46	return hc_start(m, pos);
47}
48
49static void hc_stop(struct seq_file *m, void *p)
50{
51}
52
53static int hc_show(struct seq_file *m, void *p)
54{
55	unsigned long h_num = (unsigned long)p;
56	struct hcall_stats *hs = m->private;
57
58	if (hs[h_num].num_calls) {
59		if (cpu_has_feature(CPU_FTR_PURR))
60			seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
61				   hs[h_num].num_calls,
62				   hs[h_num].tb_total,
63				   hs[h_num].purr_total);
64		else
65			seq_printf(m, "%lu %lu %lu\n", h_num<<2,
66				   hs[h_num].num_calls,
67				   hs[h_num].tb_total);
68	}
69
70	return 0;
71}
72
73static const struct seq_operations hcall_inst_sops = {
74        .start = hc_start,
75        .next  = hc_next,
76        .stop  = hc_stop,
77        .show  = hc_show
78};
79
80DEFINE_SEQ_ATTRIBUTE(hcall_inst);
81
82#define	HCALL_ROOT_DIR		"hcall_inst"
83#define CPU_NAME_BUF_SIZE	32
84
85
86static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
87{
88	struct hcall_stats *h;
89
90	if (opcode > MAX_HCALL_OPCODE)
91		return;
92
93	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
94	h->tb_start = mftb();
95	h->purr_start = mfspr(SPRN_PURR);
96}
97
98static void probe_hcall_exit(void *ignored, unsigned long opcode, long retval,
99			     unsigned long *retbuf)
100{
101	struct hcall_stats *h;
102
103	if (opcode > MAX_HCALL_OPCODE)
104		return;
105
106	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
107	h->num_calls++;
108	h->tb_total += mftb() - h->tb_start;
109	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
110}
111
112static int __init hcall_inst_init(void)
113{
114	struct dentry *hcall_root;
115	char cpu_name_buf[CPU_NAME_BUF_SIZE];
116	int cpu;
117
118	if (!firmware_has_feature(FW_FEATURE_LPAR))
119		return 0;
120
121	if (register_trace_hcall_entry(probe_hcall_entry, NULL))
122		return -EINVAL;
123
124	if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
125		unregister_trace_hcall_entry(probe_hcall_entry, NULL);
126		return -EINVAL;
127	}
128
129	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
130
131	for_each_possible_cpu(cpu) {
132		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
133		debugfs_create_file(cpu_name_buf, 0444, hcall_root,
134				    per_cpu(hcall_stats, cpu),
135				    &hcall_inst_fops);
136	}
137
138	return 0;
139}
140machine_device_initcall(pseries, hcall_inst_init);
141