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 */
20 struct 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
29 static DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
30
31 /*
32 * Routines for displaying the statistics in debugfs
33 */
hc_start(struct seq_file * m,loff_t * pos)34 static 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
hc_next(struct seq_file * m,void * p,loff_t * pos)42 static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
43 {
44 ++*pos;
45
46 return hc_start(m, pos);
47 }
48
hc_stop(struct seq_file * m,void * p)49 static void hc_stop(struct seq_file *m, void *p)
50 {
51 }
52
hc_show(struct seq_file * m,void * p)53 static 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
73 static 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
80 DEFINE_SEQ_ATTRIBUTE(hcall_inst);
81
82 #define HCALL_ROOT_DIR "hcall_inst"
83 #define CPU_NAME_BUF_SIZE 32
84
85
probe_hcall_entry(void * ignored,unsigned long opcode,unsigned long * args)86 static 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
probe_hcall_exit(void * ignored,unsigned long opcode,long retval,unsigned long * retbuf)98 static 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
hcall_inst_init(void)112 static 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 }
140 machine_device_initcall(pseries, hcall_inst_init);
141