1 /*
2  * Copyright (C) 2006 Mike Kravetz IBM Corporation
3  *
4  * Hypervisor Call Instrumentation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/percpu.h>
23 #include <linux/debugfs.h>
24 #include <linux/seq_file.h>
25 #include <linux/cpumask.h>
26 #include <asm/hvcall.h>
27 #include <asm/firmware.h>
28 #include <asm/cputable.h>
29 #include <asm/trace.h>
30 
31 DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
32 
33 /*
34  * Routines for displaying the statistics in debugfs
35  */
36 static void *hc_start(struct seq_file *m, loff_t *pos)
37 {
38 	if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
39 		return (void *)(unsigned long)(*pos + 1);
40 
41 	return NULL;
42 }
43 
44 static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
45 {
46 	++*pos;
47 
48 	return hc_start(m, pos);
49 }
50 
51 static void hc_stop(struct seq_file *m, void *p)
52 {
53 }
54 
55 static int hc_show(struct seq_file *m, void *p)
56 {
57 	unsigned long h_num = (unsigned long)p;
58 	struct hcall_stats *hs = (struct hcall_stats *)m->private;
59 
60 	if (hs[h_num].num_calls) {
61 		if (cpu_has_feature(CPU_FTR_PURR))
62 			seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
63 				   hs[h_num].num_calls,
64 				   hs[h_num].tb_total,
65 				   hs[h_num].purr_total);
66 		else
67 			seq_printf(m, "%lu %lu %lu\n", h_num<<2,
68 				   hs[h_num].num_calls,
69 				   hs[h_num].tb_total);
70 	}
71 
72 	return 0;
73 }
74 
75 static const struct seq_operations hcall_inst_seq_ops = {
76         .start = hc_start,
77         .next  = hc_next,
78         .stop  = hc_stop,
79         .show  = hc_show
80 };
81 
82 static int hcall_inst_seq_open(struct inode *inode, struct file *file)
83 {
84 	int rc;
85 	struct seq_file *seq;
86 
87 	rc = seq_open(file, &hcall_inst_seq_ops);
88 	seq = file->private_data;
89 	seq->private = file->f_path.dentry->d_inode->i_private;
90 
91 	return rc;
92 }
93 
94 static const struct file_operations hcall_inst_seq_fops = {
95 	.open = hcall_inst_seq_open,
96 	.read = seq_read,
97 	.llseek = seq_lseek,
98 	.release = seq_release,
99 };
100 
101 #define	HCALL_ROOT_DIR		"hcall_inst"
102 #define CPU_NAME_BUF_SIZE	32
103 
104 
105 static void probe_hcall_entry(unsigned long opcode, unsigned long *args)
106 {
107 	struct hcall_stats *h;
108 
109 	if (opcode > MAX_HCALL_OPCODE)
110 		return;
111 
112 	h = &get_cpu_var(hcall_stats)[opcode / 4];
113 	h->tb_start = mftb();
114 	h->purr_start = mfspr(SPRN_PURR);
115 }
116 
117 static void probe_hcall_exit(unsigned long opcode, unsigned long retval,
118 			     unsigned long *retbuf)
119 {
120 	struct hcall_stats *h;
121 
122 	if (opcode > MAX_HCALL_OPCODE)
123 		return;
124 
125 	h = &__get_cpu_var(hcall_stats)[opcode / 4];
126 	h->num_calls++;
127 	h->tb_total = mftb() - h->tb_start;
128 	h->purr_total = mfspr(SPRN_PURR) - h->purr_start;
129 
130 	put_cpu_var(hcall_stats);
131 }
132 
133 static int __init hcall_inst_init(void)
134 {
135 	struct dentry *hcall_root;
136 	struct dentry *hcall_file;
137 	char cpu_name_buf[CPU_NAME_BUF_SIZE];
138 	int cpu;
139 
140 	if (!firmware_has_feature(FW_FEATURE_LPAR))
141 		return 0;
142 
143 	if (register_trace_hcall_entry(probe_hcall_entry))
144 		return -EINVAL;
145 
146 	if (register_trace_hcall_exit(probe_hcall_exit)) {
147 		unregister_trace_hcall_entry(probe_hcall_entry);
148 		return -EINVAL;
149 	}
150 
151 	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
152 	if (!hcall_root)
153 		return -ENOMEM;
154 
155 	for_each_possible_cpu(cpu) {
156 		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
157 		hcall_file = debugfs_create_file(cpu_name_buf, S_IRUGO,
158 						 hcall_root,
159 						 per_cpu(hcall_stats, cpu),
160 						 &hcall_inst_seq_fops);
161 		if (!hcall_file)
162 			return -ENOMEM;
163 	}
164 
165 	return 0;
166 }
167 __initcall(hcall_inst_init);
168