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); 164