1 // SPDX-License-Identifier: GPL-2.0 2 #ifdef HAVE_BPF_SKEL 3 #include "timerlat.h" 4 #include "timerlat_bpf.h" 5 #include "timerlat.skel.h" 6 7 static struct timerlat_bpf *bpf; 8 9 /* 10 * timerlat_bpf_init - load and initialize BPF program to collect timerlat data 11 */ 12 int timerlat_bpf_init(struct timerlat_params *params) 13 { 14 int err; 15 16 debug_msg("Loading BPF program\n"); 17 18 bpf = timerlat_bpf__open(); 19 if (!bpf) 20 return 1; 21 22 /* Pass common options */ 23 bpf->rodata->output_divisor = params->output_divisor; 24 bpf->rodata->entries = params->entries; 25 bpf->rodata->irq_threshold = params->stop_us; 26 bpf->rodata->thread_threshold = params->stop_total_us; 27 bpf->rodata->aa_only = params->aa_only; 28 29 if (params->entries != 0) { 30 /* Pass histogram options */ 31 bpf->rodata->bucket_size = params->bucket_size; 32 33 /* Set histogram array sizes */ 34 bpf_map__set_max_entries(bpf->maps.hist_irq, params->entries); 35 bpf_map__set_max_entries(bpf->maps.hist_thread, params->entries); 36 bpf_map__set_max_entries(bpf->maps.hist_user, params->entries); 37 } else { 38 /* No entries, disable histogram */ 39 bpf_map__set_autocreate(bpf->maps.hist_irq, false); 40 bpf_map__set_autocreate(bpf->maps.hist_thread, false); 41 bpf_map__set_autocreate(bpf->maps.hist_user, false); 42 } 43 44 if (params->aa_only) { 45 /* Auto-analysis only, disable summary */ 46 bpf_map__set_autocreate(bpf->maps.summary_irq, false); 47 bpf_map__set_autocreate(bpf->maps.summary_thread, false); 48 bpf_map__set_autocreate(bpf->maps.summary_user, false); 49 } 50 51 /* Load and verify BPF program */ 52 err = timerlat_bpf__load(bpf); 53 if (err) { 54 timerlat_bpf__destroy(bpf); 55 return err; 56 } 57 58 return 0; 59 } 60 61 /* 62 * timerlat_bpf_attach - attach BPF program to collect timerlat data 63 */ 64 int timerlat_bpf_attach(void) 65 { 66 debug_msg("Attaching BPF program\n"); 67 68 return timerlat_bpf__attach(bpf); 69 } 70 71 /* 72 * timerlat_bpf_detach - detach BPF program to collect timerlat data 73 */ 74 void timerlat_bpf_detach(void) 75 { 76 timerlat_bpf__detach(bpf); 77 } 78 79 /* 80 * timerlat_bpf_detach - destroy BPF program to collect timerlat data 81 */ 82 void timerlat_bpf_destroy(void) 83 { 84 timerlat_bpf__destroy(bpf); 85 } 86 87 static int handle_rb_event(void *ctx, void *data, size_t data_sz) 88 { 89 return 0; 90 } 91 92 /* 93 * timerlat_bpf_wait - wait until tracing is stopped or signal 94 */ 95 int timerlat_bpf_wait(int timeout) 96 { 97 struct ring_buffer *rb; 98 int retval; 99 100 rb = ring_buffer__new(bpf_map__fd(bpf->maps.signal_stop_tracing), 101 handle_rb_event, NULL, NULL); 102 retval = ring_buffer__poll(rb, timeout * 1000); 103 ring_buffer__free(rb); 104 105 return retval; 106 } 107 108 static int get_value(struct bpf_map *map_irq, 109 struct bpf_map *map_thread, 110 struct bpf_map *map_user, 111 int key, 112 long long *value_irq, 113 long long *value_thread, 114 long long *value_user, 115 int cpus) 116 { 117 int err; 118 119 err = bpf_map__lookup_elem(map_irq, &key, 120 sizeof(unsigned int), value_irq, 121 sizeof(long long) * cpus, 0); 122 if (err) 123 return err; 124 err = bpf_map__lookup_elem(map_thread, &key, 125 sizeof(unsigned int), value_thread, 126 sizeof(long long) * cpus, 0); 127 if (err) 128 return err; 129 err = bpf_map__lookup_elem(map_user, &key, 130 sizeof(unsigned int), value_user, 131 sizeof(long long) * cpus, 0); 132 if (err) 133 return err; 134 return 0; 135 } 136 137 /* 138 * timerlat_bpf_get_hist_value - get value from BPF hist map 139 */ 140 int timerlat_bpf_get_hist_value(int key, 141 long long *value_irq, 142 long long *value_thread, 143 long long *value_user, 144 int cpus) 145 { 146 return get_value(bpf->maps.hist_irq, 147 bpf->maps.hist_thread, 148 bpf->maps.hist_user, 149 key, value_irq, value_thread, value_user, cpus); 150 } 151 152 /* 153 * timerlat_bpf_get_summary_value - get value from BPF summary map 154 */ 155 int timerlat_bpf_get_summary_value(enum summary_field key, 156 long long *value_irq, 157 long long *value_thread, 158 long long *value_user, 159 int cpus) 160 { 161 return get_value(bpf->maps.summary_irq, 162 bpf->maps.summary_thread, 163 bpf->maps.summary_user, 164 key, value_irq, value_thread, value_user, cpus); 165 } 166 #endif /* HAVE_BPF_SKEL */ 167