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 #include <asm/machdep.h>
31 
32 DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
33 
34 /*
35  * Routines for displaying the statistics in debugfs
36  */
37 static void *hc_start(struct seq_file *m, loff_t *pos)
38 {
39 	if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
40 		return (void *)(unsigned long)(*pos + 1);
41 
42 	return NULL;
43 }
44 
45 static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
46 {
47 	++*pos;
48 
49 	return hc_start(m, pos);
50 }
51 
52 static void hc_stop(struct seq_file *m, void *p)
53 {
54 }
55 
56 static int hc_show(struct seq_file *m, void *p)
57 {
58 	unsigned long h_num = (unsigned long)p;
59 	struct hcall_stats *hs = m->private;
60 
61 	if (hs[h_num].num_calls) {
62 		if (cpu_has_feature(CPU_FTR_PURR))
63 			seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
64 				   hs[h_num].num_calls,
65 				   hs[h_num].tb_total,
66 				   hs[h_num].purr_total);
67 		else
68 			seq_printf(m, "%lu %lu %lu\n", h_num<<2,
69 				   hs[h_num].num_calls,
70 				   hs[h_num].tb_total);
71 	}
72 
73 	return 0;
74 }
75 
76 static const struct seq_operations hcall_inst_seq_ops = {
77         .start = hc_start,
78         .next  = hc_next,
79         .stop  = hc_stop,
80         .show  = hc_show
81 };
82 
83 static int hcall_inst_seq_open(struct inode *inode, struct file *file)
84 {
85 	int rc;
86 	struct seq_file *seq;
87 
88 	rc = seq_open(file, &hcall_inst_seq_ops);
89 	seq = file->private_data;
90 	seq->private = file_inode(file)->i_private;
91 
92 	return rc;
93 }
94 
95 static const struct file_operations hcall_inst_seq_fops = {
96 	.open = hcall_inst_seq_open,
97 	.read = seq_read,
98 	.llseek = seq_lseek,
99 	.release = seq_release,
100 };
101 
102 #define	HCALL_ROOT_DIR		"hcall_inst"
103 #define CPU_NAME_BUF_SIZE	32
104 
105 
106 static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
107 {
108 	struct hcall_stats *h;
109 
110 	if (opcode > MAX_HCALL_OPCODE)
111 		return;
112 
113 	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
114 	h->tb_start = mftb();
115 	h->purr_start = mfspr(SPRN_PURR);
116 }
117 
118 static void probe_hcall_exit(void *ignored, unsigned long opcode, unsigned long retval,
119 			     unsigned long *retbuf)
120 {
121 	struct hcall_stats *h;
122 
123 	if (opcode > MAX_HCALL_OPCODE)
124 		return;
125 
126 	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
127 	h->num_calls++;
128 	h->tb_total += mftb() - h->tb_start;
129 	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
130 }
131 
132 static int __init hcall_inst_init(void)
133 {
134 	struct dentry *hcall_root;
135 	struct dentry *hcall_file;
136 	char cpu_name_buf[CPU_NAME_BUF_SIZE];
137 	int cpu;
138 
139 	if (!firmware_has_feature(FW_FEATURE_LPAR))
140 		return 0;
141 
142 	if (register_trace_hcall_entry(probe_hcall_entry, NULL))
143 		return -EINVAL;
144 
145 	if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
146 		unregister_trace_hcall_entry(probe_hcall_entry, NULL);
147 		return -EINVAL;
148 	}
149 
150 	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
151 	if (!hcall_root)
152 		return -ENOMEM;
153 
154 	for_each_possible_cpu(cpu) {
155 		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
156 		hcall_file = debugfs_create_file(cpu_name_buf, S_IRUGO,
157 						 hcall_root,
158 						 per_cpu(hcall_stats, cpu),
159 						 &hcall_inst_seq_fops);
160 		if (!hcall_file)
161 			return -ENOMEM;
162 	}
163 
164 	return 0;
165 }
166 machine_device_initcall(pseries, hcall_inst_init);
167