+/*
+ * ltt-ring-buffer-client.h
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client template.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
+#include "ltt-events.h"
+#include "ltt-tracer.h"
+
+#ifndef CHAR_BIT
+#define CHAR_BIT 8
+#endif
+
+struct metadata_packet_header {
+ uint32_t magic; /* 0x75D11D57 */
+ uint8_t trace_uuid[16]; /* Unique Universal Identifier */
+ uint32_t checksum; /* 0 if unused */
+ uint32_t content_size; /* in bits */
+ uint32_t packet_size; /* in bits */
+ uint8_t compression_scheme; /* 0 if unused */
+ uint8_t encryption_scheme; /* 0 if unused */
+ uint8_t checksum_scheme; /* 0 if unused */
+ uint8_t header_end[0];
+};
+
+struct metadata_record_header {
+ uint8_t header_end[0]; /* End of header */
+};
+
+static const struct lib_ring_buffer_config client_config;
+
+static inline
+u64 lib_ring_buffer_clock_read(struct channel *chan)
+{
+ return 0;
+}
+
+static inline
+unsigned char record_header_size(const struct lib_ring_buffer_config *config,
+ struct channel *chan, size_t offset,
+ size_t data_size, size_t *pre_header_padding,
+ unsigned int rflags,
+ struct lib_ring_buffer_ctx *ctx)
+{
+ return 0;
+}
+
+#include "wrapper/ringbuffer/api.h"
+
+static u64 client_ring_buffer_clock_read(struct channel *chan)
+{
+ return 0;
+}
+
+static
+size_t client_record_header_size(const struct lib_ring_buffer_config *config,
+ struct channel *chan, size_t offset,
+ size_t data_size,
+ size_t *pre_header_padding,
+ unsigned int rflags,
+ struct lib_ring_buffer_ctx *ctx)
+{
+ return 0;
+}
+
+/**
+ * client_packet_header_size - called on buffer-switch to a new sub-buffer
+ *
+ * Return header size without padding after the structure. Don't use packed
+ * structure because gcc generates inefficient code on some architectures
+ * (powerpc, mips..)
+ */
+static size_t client_packet_header_size(void)
+{
+ return offsetof(struct metadata_packet_header, header_end);
+}
+
+static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
+ unsigned int subbuf_idx)
+{
+ struct channel *chan = buf->backend.chan;
+ struct metadata_packet_header *header =
+ (struct metadata_packet_header *)
+ lib_ring_buffer_offset_address(&buf->backend,
+ subbuf_idx * chan->backend.subbuf_size);
+
+ header->magic = TSDL_MAGIC_NUMBER;
+ /* TODO */
+ //header->trace_uuid = ; /* Unique Universal Identifier */
+ header->checksum = 0; /* 0 if unused */
+ header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
+ header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
+ header->compression_scheme = 0; /* 0 if unused */
+ header->encryption_scheme = 0; /* 0 if unused */
+ header->checksum_scheme = 0; /* 0 if unused */
+}
+
+/*
+ * offset is assumed to never be 0 here : never deliver a completely empty
+ * subbuffer. data_size is between 1 and subbuf_size.
+ */
+static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
+ unsigned int subbuf_idx, unsigned long data_size)
+{
+ struct channel *chan = buf->backend.chan;
+ struct packet_header *header =
+ (struct packet_header *)
+ lib_ring_buffer_offset_address(&buf->backend,
+ subbuf_idx * chan->backend.subbuf_size);
+ unsigned long records_lost = 0;
+
+ header->content_size = data_size * CHAR_BIT; /* in bits */
+ header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
+ records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
+ records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
+ records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
+ WARN_ON_ONCE(records_lost != 0);
+}
+
+static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
+ int cpu, const char *name)
+{
+ return 0;
+}
+
+static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
+{
+}
+
+static const struct lib_ring_buffer_config client_config = {
+ .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
+ .cb.record_header_size = client_record_header_size,
+ .cb.subbuffer_header_size = client_packet_header_size,
+ .cb.buffer_begin = client_buffer_begin,
+ .cb.buffer_end = client_buffer_end,
+ .cb.buffer_create = client_buffer_create,
+ .cb.buffer_finalize = client_buffer_finalize,
+
+ .tsc_bits = 0,
+ .alloc = RING_BUFFER_ALLOC_GLOBAL,
+ .sync = RING_BUFFER_SYNC_GLOBAL,
+ .mode = RING_BUFFER_MODE_TEMPLATE,
+ .backend = RING_BUFFER_PAGE,
+ .output = RING_BUFFER_SPLICE,
+ .oops = RING_BUFFER_OOPS_CONSISTENCY,
+ .ipi = RING_BUFFER_IPI_BARRIER,
+ .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
+};
+
+static
+struct channel *_channel_create(const char *name,
+ struct ltt_session *session, void *buf_addr,
+ size_t subbuf_size, size_t num_subbuf,
+ unsigned int switch_timer_interval,
+ unsigned int read_timer_interval)
+{
+ return channel_create(&client_config, name, session, buf_addr,
+ subbuf_size, num_subbuf, switch_timer_interval,
+ read_timer_interval);
+}
+
+static
+void ltt_channel_destroy(struct channel *chan)
+{
+ channel_destroy(chan);
+}
+
+static
+struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan)
+{
+ struct lib_ring_buffer *buf;
+ int cpu;
+
+ for_each_channel_cpu(cpu, chan) {
+ buf = channel_get_ring_buffer(&client_config, chan, cpu);
+ if (!lib_ring_buffer_open_read(buf))
+ return buf;
+ }
+ return NULL;
+}
+
+static
+void ltt_buffer_read_close(struct lib_ring_buffer *buf)
+{
+ lib_ring_buffer_release_read(buf);
+
+}
+
+int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx)
+{
+ return lib_ring_buffer_reserve(&client_config, ctx);
+}
+
+void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
+{
+ lib_ring_buffer_commit(&client_config, ctx);
+}
+
+void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
+ size_t len)
+{
+ lib_ring_buffer_write(&client_config, ctx, src, len);
+}
+
+static struct ltt_transport ltt_relay_transport = {
+ .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
+ .owner = THIS_MODULE,
+ .ops = {
+ .channel_create = _channel_create,
+ .channel_destroy = ltt_channel_destroy,
+ .buffer_read_open = ltt_buffer_read_open,
+ .buffer_read_close = ltt_buffer_read_close,
+ .event_reserve = ltt_event_reserve,
+ .event_commit = ltt_event_commit,
+ .event_write = ltt_event_write,
+ },
+};
+
+static int __init ltt_ring_buffer_client_init(void)
+{
+ /*
+ * This vmalloc sync all also takes care of the lib ring buffer
+ * vmalloc'd module pages when it is built as a module into LTTng.
+ */
+ wrapper_vmalloc_sync_all();
+ printk(KERN_INFO "LTT : ltt ring buffer metadata client init\n");
+ ltt_transport_register(<t_relay_transport);
+ return 0;
+}
+
+module_init(ltt_ring_buffer_client_init);
+
+static void __exit ltt_ring_buffer_client_exit(void)
+{
+ printk(KERN_INFO "LTT : ltt ring buffer metadata client exit\n");
+ ltt_transport_unregister(<t_relay_transport);
+}
+
+module_exit(ltt_ring_buffer_client_exit);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
+ " client");