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