arch/powerpc/platforms/pseries/hvCall_inst.c

   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 /* For hcall instrumentation. One structure per-hcall, per-CPU */
  33 struct hcall_stats {
  34         unsigned long   num_calls;      /* number of calls (on this CPU) */
  35         unsigned long   tb_total;       /* total wall time (mftb) of calls. */
  36         unsigned long   purr_total;     /* total cpu time (PURR) of calls. */
  37         unsigned long   tb_start;
  38         unsigned long   purr_start;
  39 };
  40 #define HCALL_STAT_ARRAY_SIZE   ((MAX_HCALL_OPCODE >> 2) + 1)
  41
  42 DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
  43
  44 /*
  45  * Routines for displaying the statistics in debugfs
  46  */
  47 static void *hc_start(struct seq_file *m, loff_t *pos)
  48 {
  49         if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
  50                 return (void *)(unsigned long)(*pos + 1);
  51
  52         return NULL;
  53 }
  54
  55 static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
  56 {
  57         ++*pos;
  58
  59         return hc_start(m, pos);
  60 }
  61
  62 static void hc_stop(struct seq_file *m, void *p)
  63 {
  64 }
  65
  66 static int hc_show(struct seq_file *m, void *p)
  67 {
  68         unsigned long h_num = (unsigned long)p;
  69         struct hcall_stats *hs = m->private;
  70
  71         if (hs[h_num].num_calls) {
  72                 if (cpu_has_feature(CPU_FTR_PURR))
  73                         seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
  74                                    hs[h_num].num_calls,
  75                                    hs[h_num].tb_total,
  76                                    hs[h_num].purr_total);
  77                 else
  78                         seq_printf(m, "%lu %lu %lu\n", h_num<<2,
  79                                    hs[h_num].num_calls,
  80                                    hs[h_num].tb_total);
  81         }
  82
  83         return 0;
  84 }
  85
  86 static const struct seq_operations hcall_inst_seq_ops = {
  87         .start = hc_start,
  88         .next  = hc_next,
  89         .stop  = hc_stop,
  90         .show  = hc_show
  91 };
  92
  93 static int hcall_inst_seq_open(struct inode *inode, struct file *file)
  94 {
  95         int rc;
  96         struct seq_file *seq;
  97
  98         rc = seq_open(file, &hcall_inst_seq_ops);
  99         seq = file->private_data;
 100         seq->private = file_inode(file)->i_private;
 101
 102         return rc;
 103 }
 104
 105 static const struct file_operations hcall_inst_seq_fops = {
 106         .open = hcall_inst_seq_open,
 107         .read = seq_read,
 108         .llseek = seq_lseek,
 109         .release = seq_release,
 110 };
 111
 112 #define HCALL_ROOT_DIR          "hcall_inst"
 113 #define CPU_NAME_BUF_SIZE       32
 114
 115
 116 static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
 117 {
 118         struct hcall_stats *h;
 119
 120         if (opcode > MAX_HCALL_OPCODE)
 121                 return;
 122
 123         h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 124         h->tb_start = mftb();
 125         h->purr_start = mfspr(SPRN_PURR);
 126 }
 127
 128 static void probe_hcall_exit(void *ignored, unsigned long opcode, unsigned long retval,
 129                              unsigned long *retbuf)
 130 {
 131         struct hcall_stats *h;
 132
 133         if (opcode > MAX_HCALL_OPCODE)
 134                 return;
 135
 136         h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 137         h->num_calls++;
 138         h->tb_total += mftb() - h->tb_start;
 139         h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
 140 }
 141
 142 static int __init hcall_inst_init(void)
 143 {
 144         struct dentry *hcall_root;
 145         struct dentry *hcall_file;
 146         char cpu_name_buf[CPU_NAME_BUF_SIZE];
 147         int cpu;
 148
 149         if (!firmware_has_feature(FW_FEATURE_LPAR))
 150                 return 0;
 151
 152         if (register_trace_hcall_entry(probe_hcall_entry, NULL))
 153                 return -EINVAL;
 154
 155         if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
 156                 unregister_trace_hcall_entry(probe_hcall_entry, NULL);
 157                 return -EINVAL;
 158         }
 159
 160         hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
 161         if (!hcall_root)
 162                 return -ENOMEM;
 163
 164         for_each_possible_cpu(cpu) {
 165                 snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
 166                 hcall_file = debugfs_create_file(cpu_name_buf, S_IRUGO,
 167                                                  hcall_root,
 168                                                  per_cpu(hcall_stats, cpu),
 169                                                  &hcall_inst_seq_fops);
 170                 if (!hcall_file)
 171                         return -ENOMEM;
 172         }
 173
 174         return 0;
 175 }
 176 machine_device_initcall(pseries, hcall_inst_init);