arch/powerpc/platforms/pseries/hvCall_inst.c

   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 DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
  30
  31 /*
  32  * Routines for displaying the statistics in debugfs
  33  */
  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
  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
  49 static void hc_stop(struct seq_file *m, void *p)
  50 {
  51 }
  52
  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_seq_ops = {
  74         .start = hc_start,
  75         .next  = hc_next,
  76         .stop  = hc_stop,
  77         .show  = hc_show
  78 };
  79
  80 static int hcall_inst_seq_open(struct inode *inode, struct file *file)
  81 {
  82         int rc;
  83         struct seq_file *seq;
  84
  85         rc = seq_open(file, &hcall_inst_seq_ops);
  86         seq = file->private_data;
  87         seq->private = file_inode(file)->i_private;
  88
  89         return rc;
  90 }
  91
  92 static const struct file_operations hcall_inst_seq_fops = {
  93         .open = hcall_inst_seq_open,
  94         .read = seq_read,
  95         .llseek = seq_lseek,
  96         .release = seq_release,
  97 };
  98
  99 #define HCALL_ROOT_DIR          "hcall_inst"
 100 #define CPU_NAME_BUF_SIZE       32
 101
 102
 103 static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
 104 {
 105         struct hcall_stats *h;
 106
 107         if (opcode > MAX_HCALL_OPCODE)
 108                 return;
 109
 110         h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 111         h->tb_start = mftb();
 112         h->purr_start = mfspr(SPRN_PURR);
 113 }
 114
 115 static void probe_hcall_exit(void *ignored, unsigned long opcode, long retval,
 116                              unsigned long *retbuf)
 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->num_calls++;
 125         h->tb_total += mftb() - h->tb_start;
 126         h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
 127 }
 128
 129 static int __init hcall_inst_init(void)
 130 {
 131         struct dentry *hcall_root;
 132         struct dentry *hcall_file;
 133         char cpu_name_buf[CPU_NAME_BUF_SIZE];
 134         int cpu;
 135
 136         if (!firmware_has_feature(FW_FEATURE_LPAR))
 137                 return 0;
 138
 139         if (register_trace_hcall_entry(probe_hcall_entry, NULL))
 140                 return -EINVAL;
 141
 142         if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
 143                 unregister_trace_hcall_entry(probe_hcall_entry, NULL);
 144                 return -EINVAL;
 145         }
 146
 147         hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
 148         if (!hcall_root)
 149                 return -ENOMEM;
 150
 151         for_each_possible_cpu(cpu) {
 152                 snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
 153                 hcall_file = debugfs_create_file(cpu_name_buf, 0444,
 154                                                  hcall_root,
 155                                                  per_cpu(hcall_stats, cpu),
 156                                                  &hcall_inst_seq_fops);
 157                 if (!hcall_file)
 158                         return -ENOMEM;
 159         }
 160
 161         return 0;
 162 }
 163 machine_device_initcall(pseries, hcall_inst_init);