| 1 | /* |
| 2 | * ltt-ring-buffer-client.h |
| 3 | * |
| 4 | * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * LTTng lib ring buffer client template. |
| 7 | * |
| 8 | * Dual LGPL v2.1/GPL v2 license. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include "ltt-tracer.h" |
| 13 | |
| 14 | struct ring_buffer_priv { |
| 15 | struct dentry *dentry; |
| 16 | } |
| 17 | |
| 18 | struct channel_priv { |
| 19 | struct ltt_trace *trace; |
| 20 | struct ring_buffer_priv *buf; |
| 21 | }; |
| 22 | |
| 23 | static const struct lib_ring_buffer_config client_config; |
| 24 | |
| 25 | static u64 client_ring_buffer_clock_read(struct channel *chan) |
| 26 | { |
| 27 | return lib_ring_buffer_clock_read(chan); |
| 28 | } |
| 29 | |
| 30 | static |
| 31 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, |
| 32 | struct channel *chan, size_t offset, |
| 33 | size_t data_size, |
| 34 | size_t *pre_header_padding, |
| 35 | unsigned int rflags, |
| 36 | struct lib_ring_buffer_ctx *ctx) |
| 37 | { |
| 38 | return record_header_size(config, chan, offset, data_size, |
| 39 | pre_header_padding, rflags, ctx); |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * client_subbuffer_header_size - called on buffer-switch to a new sub-buffer |
| 44 | * |
| 45 | * Return header size without padding after the structure. Don't use packed |
| 46 | * structure because gcc generates inefficient code on some architectures |
| 47 | * (powerpc, mips..) |
| 48 | */ |
| 49 | static size_t client_subbuffer_header_size(void) |
| 50 | { |
| 51 | return offsetof(struct subbuffer_header, header_end); |
| 52 | } |
| 53 | |
| 54 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, |
| 55 | unsigned int subbuf_idx) |
| 56 | { |
| 57 | struct channel *chan = buf->backend.chan; |
| 58 | struct subbuffer_header *header = |
| 59 | (struct subbuffer_header *) |
| 60 | lib_ring_buffer_offset_address(&buf->backend, |
| 61 | subbuf_idx * chan->backend.subbuf_size); |
| 62 | |
| 63 | header->cycle_count_begin = tsc; |
| 64 | header->data_size = 0xFFFFFFFF; /* for debugging */ |
| 65 | write_trace_header(chan->backend.priv, header); |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * offset is assumed to never be 0 here : never deliver a completely empty |
| 70 | * subbuffer. data_size is between 1 and subbuf_size. |
| 71 | */ |
| 72 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, |
| 73 | unsigned int subbuf_idx, unsigned long data_size) |
| 74 | { |
| 75 | struct channel *chan = buf->backend.chan; |
| 76 | struct subbuffer_header *header = |
| 77 | (struct subbuffer_header *) |
| 78 | lib_ring_buffer_offset_address(&buf->backend, |
| 79 | subbuf_idx * chan->backend.subbuf_size); |
| 80 | unsigned long records_lost = 0; |
| 81 | |
| 82 | header->data_size = data_size; |
| 83 | header->subbuf_size = PAGE_ALIGN(data_size); |
| 84 | header->cycle_count_end = tsc; |
| 85 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); |
| 86 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); |
| 87 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); |
| 88 | header->events_lost = records_lost; |
| 89 | header->subbuf_corrupt = 0; /* deprecated */ |
| 90 | } |
| 91 | |
| 92 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, |
| 93 | int cpu, const char *name) |
| 94 | { |
| 95 | struct channel_priv *chan_priv = priv; |
| 96 | struct ring_buffer_priv *buf_priv; |
| 97 | struct dentry *trace_dentry; |
| 98 | char *tmpname; |
| 99 | int ret = 0; |
| 100 | |
| 101 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) |
| 102 | buf_priv = per_cpu_ptr(chan_priv->buf, cpu); |
| 103 | else |
| 104 | buf_priv = chan_priv->buf; |
| 105 | |
| 106 | tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); |
| 107 | if (!tmpname) { |
| 108 | ret = -ENOMEM; |
| 109 | goto end; |
| 110 | } |
| 111 | |
| 112 | snprintf(tmpname, NAME_MAX, "%s%s_%d", |
| 113 | (client_config.mode == RING_BUFFER_OVERWRITE) ? "flight-" : "", |
| 114 | name, cpu); |
| 115 | |
| 116 | trace_dentry = chan_priv->trace->dentry.trace_root; |
| 117 | buf_priv->dentry = debugfs_create_file(tmpname, S_IRUSR, trace_dentry, |
| 118 | buf, |
| 119 | &lib_ring_buffer_file_operations); |
| 120 | if (!buf_priv->dentry) { |
| 121 | ret = -ENOMEM; |
| 122 | goto free_name; |
| 123 | } |
| 124 | free_name: |
| 125 | kfree(tmpname); |
| 126 | end: |
| 127 | return ret; |
| 128 | } |
| 129 | |
| 130 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) |
| 131 | { |
| 132 | struct channel_priv *chan_priv = priv; |
| 133 | struct lib_ring_buffer_priv *buf_priv; |
| 134 | |
| 135 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) |
| 136 | buf_priv = per_cpu_ptr(chan_priv->buf, cpu); |
| 137 | else |
| 138 | buf_priv = chan_priv->buf; |
| 139 | |
| 140 | debugfs_remove(buf_priv->dentry); |
| 141 | } |
| 142 | |
| 143 | static const struct lib_ring_buffer_config client_config = { |
| 144 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, |
| 145 | .cb.record_header_size = client_record_header_size, |
| 146 | .cb.subbuffer_header_size = client_subbuffer_header_size, |
| 147 | .cb.buffer_begin = client_buffer_begin, |
| 148 | .cb.buffer_end = client_buffer_end, |
| 149 | .cb.buffer_create = client_buffer_create, |
| 150 | .cb.buffer_finalize = client_buffer_finalize, |
| 151 | |
| 152 | .tsc_bits = 32, |
| 153 | .alloc = RING_BUFFER_ALLOC_PER_CPU, |
| 154 | .sync = RING_BUFFER_SYNC_PER_CPU, |
| 155 | .mode = RING_BUFFER_MODE_TEMPLATE, |
| 156 | #ifdef RING_BUFFER_ALIGN |
| 157 | .align = RING_BUFFER_NATURAL, |
| 158 | #else |
| 159 | .align = RING_BUFFER_PACKED, |
| 160 | #endif |
| 161 | .backend = RING_BUFFER_PAGE, |
| 162 | .output = RING_BUFFER_SPLICE, |
| 163 | .oops = RING_BUFFER_OOPS_CONSISTENCY, |
| 164 | .ipi = RING_BUFFER_IPI_BARRIER, |
| 165 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, |
| 166 | }; |
| 167 | |
| 168 | static |
| 169 | struct channel *ltt_channel_create(const char *name, struct ltt_trace *trace, |
| 170 | void *buf_addr, |
| 171 | size_t subbuf_size, size_t num_subbuf, |
| 172 | unsigned int switch_timer_interval, |
| 173 | unsigned int read_timer_interval) |
| 174 | { |
| 175 | struct channel *chan; |
| 176 | struct chan_priv *chan_priv; |
| 177 | |
| 178 | chan_priv = kzalloc(sizeof(struct chan_priv), GFP_KERNEL); |
| 179 | if (!chan_priv) |
| 180 | return NULL; |
| 181 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) { |
| 182 | chan_priv->buf = alloc_percpu(struct lib_ring_buffer_priv); |
| 183 | memset(chan_priv->buf, 0, sizeof(*chan_priv->buf)); |
| 184 | } else |
| 185 | chan_priv->buf = kzalloc(sizeof(*chan_priv->buf), GFP_KERNEL) |
| 186 | if (!channel_priv->buf) |
| 187 | goto free_chan_priv; |
| 188 | chan_priv->trace = trace; |
| 189 | chan = channel_create(&client_config, name, chan_priv, buf_addr, |
| 190 | subbuf_size, num_subbuf, switch_timer_interval, |
| 191 | read_timer_interval); |
| 192 | if (!chan) |
| 193 | goto free_buf_priv; |
| 194 | return chan; |
| 195 | |
| 196 | free_buf_priv: |
| 197 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) |
| 198 | free_percpu(chan_priv->buf); |
| 199 | else |
| 200 | kfree(chan_priv->buf); |
| 201 | free_chan_priv: |
| 202 | kfree(chan_priv); |
| 203 | return NULL; |
| 204 | } |
| 205 | |
| 206 | static |
| 207 | void ltt_channel_destroy(struct channel *chan) |
| 208 | { |
| 209 | struct chan_priv *chan_priv = channel_get_private(chan); |
| 210 | |
| 211 | channel_destroy(chan); |
| 212 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) |
| 213 | free_percpu(chan_priv->buf); |
| 214 | else |
| 215 | kfree(chan_priv->buf); |
| 216 | kfree(chan_priv); |
| 217 | } |
| 218 | |
| 219 | static void ltt_relay_remove_dirs(struct ltt_trace *trace) |
| 220 | { |
| 221 | debugfs_remove(trace->dentry.trace_root); |
| 222 | } |
| 223 | |
| 224 | static int ltt_relay_create_dirs(struct ltt_trace *new_trace) |
| 225 | { |
| 226 | struct dentry *ltt_root_dentry; |
| 227 | int ret; |
| 228 | |
| 229 | ltt_root_dentry = get_ltt_root(); |
| 230 | if (!ltt_root_dentry) |
| 231 | return ENOENT; |
| 232 | |
| 233 | new_trace->dentry.trace_root = debugfs_create_dir(new_trace->trace_name, |
| 234 | ltt_root_dentry); |
| 235 | put_ltt_root(); |
| 236 | if (new_trace->dentry.trace_root == NULL) { |
| 237 | printk(KERN_ERR "LTT : Trace directory name %s already taken\n", |
| 238 | new_trace->trace_name); |
| 239 | return EEXIST; |
| 240 | } |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | static struct ltt_transport ltt_relay_transport = { |
| 245 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
| 246 | .owner = THIS_MODULE, |
| 247 | .ops = { |
| 248 | .create_dirs = ltt_relay_create_dirs, |
| 249 | .remove_dirs = ltt_relay_remove_dirs, |
| 250 | .create_channel = ltt_channel_create, |
| 251 | .destroy_channel = ltt_channel_destroy, |
| 252 | }, |
| 253 | }; |
| 254 | |
| 255 | static int __init ltt_ring_buffer_client_init(void) |
| 256 | { |
| 257 | printk(KERN_INFO "LTT : ltt ring buffer client init\n"); |
| 258 | ltt_transport_register(<t_relay_transport); |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | static void __exit ltt_ring_buffer_client_exit(void) |
| 263 | { |
| 264 | printk(KERN_INFO "LTT : ltt ring buffer client exit\n"); |
| 265 | ltt_transport_unregister(<t_relay_transport); |
| 266 | } |
| 267 | |
| 268 | MODULE_LICENSE("GPL and additional rights"); |
| 269 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 270 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING |
| 271 | " client"); |