--- /dev/null +++ b/include/linux/ltt-core.h @@ -0,0 +1,630 @@ +/* + * linux/include/linux/ltt-core.h + * + * Copyright (C) 2005,2006 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) + * + * This contains the core definitions for the Linux Trace Toolkit. + */ + +#ifndef _LTT_CORE_H +#define _LTT_CORE_H + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* Number of bytes to log with a read/write event */ +#define LTT_LOG_RW_SIZE 32 + +#ifdef CONFIG_LTT_ALIGNMENT + +/* Calculate the offset needed to align the type */ +static inline unsigned int ltt_align(size_t align_drift, + size_t size_of_type) +{ + size_t alignment = min(sizeof(void*), size_of_type); + return ((alignment - align_drift) & (alignment-1)); +} +/* Default arch alignment */ +#define LTT_ALIGN + +#else +static inline unsigned int ltt_align(size_t align_drift, + size_t size_of_type) +{ + return 0; +} + +#define LTT_ALIGN __attribute__((packed)) + +#endif //CONFIG_LTT_ALIGNMENT + +#ifdef CONFIG_LTT + + +extern void ltt_init(void); + +/* All modifications of ltt_traces must be done by ltt-core.c, while holding the + * semaphore. Only reading of this information can be done elsewhere, with the + * RCU mechanism : the preemption must be disabled while reading the list. */ +struct ltt_traces { + struct list_head head; /* Traces list */ + unsigned int num_active_traces; /* Number of active traces */ +} ____cacheline_aligned; + +extern struct ltt_traces ltt_traces; +/* Keep track of traps nesting inside LTT */ +extern volatile unsigned int ltt_nesting[]; +struct ltt_trace_struct; + +/* LTTng lockless logging buffer info */ +struct ltt_channel_buf_struct { + /* Use the relay void *start as buffer start pointer */ + atomic_t offset; /* Current offset in the buffer */ + atomic_t consumed; /* Current offset in the buffer */ + atomic_t active_readers; /* Active readers count */ + atomic_t wakeup_readers; /* Boolean : wakeup readers waiting ? */ + atomic_t *reserve_count; /* Final per sub-buffer reserve count */ + atomic_t *commit_count; /* Commit count per sub-buffer */ + spinlock_t full_lock; /* buffer full condition spinlock, only + * for userspace tracing blocking mode + * synchronisation with reader. */ + atomic_t events_lost; + atomic_t corrupted_subbuffers; + struct timeval current_subbuffer_start_time; + wait_queue_head_t write_wait; /* Wait queue for blocking user space + * writers */ + struct work_struct wake_writers;/* Writers wake-up work struct */ +} ____cacheline_aligned; + +struct ltt_channel_struct { + char channel_name[PATH_MAX]; + struct ltt_trace_struct *trace; + struct ltt_channel_buf_struct buf[NR_CPUS]; + int overwrite; + struct kref kref; + + void *trans_channel_data; + + /* + * buffer_begin - called on buffer-switch to a new sub-buffer + * @buf: the channel buffer containing the new sub-buffer + */ + void (*buffer_begin) (struct rchan_buf *buf, + u64 tsc, unsigned int subbuf_idx); + /* + * buffer_end - called on buffer-switch to a new sub-buffer + * @buf: the channel buffer containing the previous sub-buffer + */ + void (*buffer_end) (struct rchan_buf *buf, + u64 tsc, unsigned int offset, unsigned int subbuf_idx); +}; + +struct user_dbg_data { + unsigned long avail_size; + unsigned long write; + unsigned long read; +}; + +struct ltt_trace_ops { + int (*create_dirs) (struct ltt_trace_struct *new_trace); + void (*remove_dirs) (struct ltt_trace_struct *new_trace); + int (*create_channel) (char *trace_name, struct ltt_trace_struct *trace, + struct dentry *dir, char *channel_name, + struct ltt_channel_struct **ltt_chan, + unsigned int subbuf_size, + unsigned int n_subbufs, int overwrite); + void (*wakeup_channel) (struct ltt_channel_struct *ltt_channel); + void (*finish_channel) (struct ltt_channel_struct *channel); + void (*remove_channel) (struct ltt_channel_struct *channel); + void *(*reserve_slot) (struct ltt_trace_struct *trace, + struct ltt_channel_struct *channel, + void **transport_data, unsigned int data_size, + size_t *slot_size, u64 *tsc, + size_t *before_hdr_pad, size_t *after_hdr_pad, + size_t *header_size); + void (*commit_slot) (struct ltt_channel_struct *channel, + void **transport_data, void *reserved, + size_t slot_size); + void (*print_errors)(struct ltt_trace_struct *trace, + struct ltt_channel_struct *ltt_chan, int cpu); + int (*user_blocking) (struct ltt_trace_struct *trace, + unsigned int index, size_t data_size, + struct user_dbg_data *dbg); + void (*user_errors) (struct ltt_trace_struct *trace, + unsigned int index, size_t data_size, + struct user_dbg_data *dbg); +}; + +struct ltt_transport { + char *name; + struct module *owner; + struct list_head node; + struct ltt_trace_ops ops; +}; + + +enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID }; + +/* Per-trace information - each trace/flight recorder represented by one */ +struct ltt_trace_struct { + struct list_head list; + int active; + char trace_name[NAME_MAX]; + int paused; + enum trace_mode mode; + struct ltt_transport *transport; + struct ltt_trace_ops *ops; + struct kref ltt_transport_kref; + u32 freq_scale; + u64 start_freq; + u64 start_tsc; + unsigned long long start_monotonic; + struct timeval start_time; + struct { + struct dentry *trace_root; + struct dentry *control_root; + } dentry; + struct { + struct ltt_channel_struct *facilities; + struct ltt_channel_struct *interrupts; + struct ltt_channel_struct *processes; + struct ltt_channel_struct *modules; + struct ltt_channel_struct *cpu; + struct ltt_channel_struct *network; + } channel; + struct rchan_callbacks callbacks; + struct kref kref; /* Each channel has a kref of the trace struct */ +} ____cacheline_aligned; + +enum ltt_channels { LTT_CHANNEL_FACILITIES, LTT_CHANNEL_INTERRUPTS, + LTT_CHANNEL_PROCESSES, LTT_CHANNEL_MODULES, LTT_CHANNEL_CPU, + LTT_CHANNEL_NETWORK }; + +/* Hardcoded event headers */ + +/* event header for a trace with active heartbeat : 32 bits timestamps */ + +/* headers are 8 bytes aligned : that means members are aligned on memory + * boundaries *if* structure starts on a 8 bytes boundary. In order to insure + * such alignment, a dynamic per trace alignment value must be set. + * + * Remeber that the C compiler does align each member on the boundary equivalent + * to their own size. + * + * As relay subbuffers are aligned on pages, we are sure that they are 8 bytes + * aligned, so the buffer header and trace header are aligned. + * + * Event headers are aligned depending on the trace alignment option. */ + +struct ltt_event_header_hb { + uint32_t timestamp; + unsigned char facility_id; + unsigned char event_id; + uint16_t event_size; +} __attribute((packed)); + +struct ltt_event_header_nohb { + uint64_t timestamp; + unsigned char facility_id; + unsigned char event_id; + uint16_t event_size; +} __attribute((packed)); + +struct ltt_trace_header { + uint32_t magic_number; + uint32_t arch_type; + uint32_t arch_variant; + uint32_t float_word_order; /* Only useful for user space traces */ + uint8_t arch_size; + uint8_t major_version; + uint8_t minor_version; + uint8_t flight_recorder; + uint8_t has_heartbeat; + uint8_t has_alignment; /* Event header alignment */ + uint32_t freq_scale; + uint64_t start_freq; + uint64_t start_tsc; + uint64_t start_monotonic; + uint64_t start_time_sec; + uint64_t start_time_usec; +} __attribute((packed)); + + +/* We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal + * specifically with CPU frequency scaling someday, so using an interpolation + * between the start and end of buffer values is not flexible enough. Using an + * immediate frequency value permits to calculate directly the times for parts + * of a buffer that would be before a frequency change. */ +struct ltt_block_start_header { + struct { + uint64_t cycle_count; + uint64_t freq; /* khz */ + } begin; + struct { + uint64_t cycle_count; + uint64_t freq; /* khz */ + } end; + uint32_t lost_size; /* Size unused at the end of the buffer */ + uint32_t buf_size; /* The size of this sub-buffer */ + struct ltt_trace_header trace; +} __attribute((packed)); + +/* + * ltt_subbuf_header_len - called on buffer-switch to a new sub-buffer + * + * returns the client header size at the beginning of the buffer. + */ +static inline unsigned int ltt_subbuf_header_len(void) +{ + return sizeof(struct ltt_block_start_header); +} + +/* Get the offset of the channel in the ltt_trace_struct */ +#define GET_CHANNEL_INDEX(chan) \ + (unsigned int)&((struct ltt_trace_struct*)NULL)->channel.chan + +/* ltt_get_index_from_facility + * + * Get channel index from facility and event id. + * + * @fID : facility ID + * @eID : event number + * + * Get the channel index into which events must be written for the given + * facility and event number. We get this structure offset as soon as possible + * and remember it so we pass through this logic only once per trace call (not + * for every trace). + */ +static inline unsigned int ltt_get_index_from_facility(ltt_facility_t fID, + u8 eID) +{ + if(fID == ltt_facility_core) { + switch(eID) { + case event_core_facility_load: + case event_core_facility_unload: + case event_core_state_dump_facility_load: + return GET_CHANNEL_INDEX(facilities); + default: + return GET_CHANNEL_INDEX(cpu); + } + } + + /* Default channel */ + return GET_CHANNEL_INDEX(cpu); +} + +static inline struct ltt_channel_struct *ltt_get_channel_from_index( + struct ltt_trace_struct *trace, unsigned int index) +{ + return *(struct ltt_channel_struct **)((void*)trace+index); +} + + +/* + * ltt_get_header_size + * + * Calculate alignment offset for arch size void*. This is the + * alignment offset of the event header. + * + * Important note : + * The event header must be a size multiple of the void* size. This is necessary + * to be able to calculate statically the alignment offset of the variable + * length data fields that follows. The total offset calculated here : + * + * Alignment of header struct on arch size + * + sizeof(header struct) + * + padding added to end of struct to align on arch size. + * */ +static inline unsigned char ltt_get_header_size(struct ltt_trace_struct *trace, + void *address, + size_t *before_hdr_pad, + size_t *after_hdr_pad, + size_t *header_size) +{ + unsigned int padding; + unsigned int header; + +#ifdef CONFIG_LTT_HEARTBEAT_EVENT + header = sizeof(struct ltt_event_header_hb); +#else + header = sizeof(struct ltt_event_header_nohb); +#endif // CONFIG_LTT_HEARTBEAT_EVENT + + /* Padding before the header. Calculated dynamically */ + *before_hdr_pad = ltt_align((unsigned long)address, header); + padding = *before_hdr_pad; + + /* Padding after header, considering header aligned on ltt_align. + * Calculated statically if header size if known. */ + *after_hdr_pad = ltt_align(header, sizeof(void*)); + padding += *after_hdr_pad; + + *header_size = header; + + return header+padding; +} + + +/* ltt_write_event_header + * + * Writes the event header to the pointer. + * + * @channel : pointer to the channel structure + * @ptr : buffer pointer + * @fID : facility ID + * @eID : event ID + * @event_size : size of the event, excluding the event header. + * @offset : offset of the beginning of the header, for alignment. + * Calculated by ltt_get_event_header_size. + * @tsc : time stamp counter. + */ +static inline void ltt_write_event_header(struct ltt_trace_struct *trace, + struct ltt_channel_struct *channel, + void *ptr, ltt_facility_t fID, + uint32_t eID, size_t event_size, + size_t offset, u64 tsc) +{ +#ifdef CONFIG_LTT_HEARTBEAT_EVENT + struct ltt_event_header_hb *hb; + + event_size = min(event_size, (size_t)0xFFFFU); + hb = (struct ltt_event_header_hb *)(ptr+offset); + hb->timestamp = (u32)tsc; + hb->facility_id = fID; + hb->event_id = eID; + hb->event_size = (uint16_t)event_size; +#else + struct ltt_event_header_nohb *nohb; + + event_size = min(event_size, (size_t)0xFFFFU); + nohb = (struct ltt_event_header_nohb *)(ptr+offset); + nohb->timestamp = (u64)tsc; + nohb->facility_id = fID; + nohb->event_id = eID; + nohb->event_size = (uint16_t)event_size; +#endif //CONFIG_LTT_HEARTBEAT_EVENT +} + +/* for flight recording. must be called after relay_commit. + * This function does not protect from corruption resulting from writing non + * sequentially in the buffer (and trying to read this buffer after a crash + * which occured at the wrong moment). + * That's why sequential writes are good! + * + * This function does nothing if trace is in normal mode. */ +#if 0 +static inline void ltt_write_commit_counter(struct rchan_buf *buf, + void *reserved) +{ + struct ltt_channel_struct *channel = + (struct ltt_channel_struct*)buf->chan->client_data; + struct ltt_block_start_header *header = + (struct ltt_block_start_header*)buf->data; + unsigned offset, subbuf_idx; + + offset = reserved - buf->start; + subbuf_idx = offset / buf->chan->subbuf_size; + + if(channel->trace->mode == LTT_TRACE_FLIGHT) + header->lost_size = buf->chan->subbuf_size - + buf->commit[subbuf_idx]; + +} +#endif //0 + +/* Lockless LTTng */ + +/* Buffer offset macros */ + +#define BUFFER_OFFSET(offset, chan) (offset & (chan->alloc_size-1)) +#define SUBBUF_OFFSET(offset, chan) (offset & (chan->subbuf_size-1)) +#define SUBBUF_ALIGN(offset, chan) \ + (((offset) + chan->subbuf_size) & (~(chan->subbuf_size-1))) +#define SUBBUF_TRUNC(offset, chan) \ + ((offset) & (~(chan->subbuf_size-1))) +#define SUBBUF_INDEX(offset, chan) \ + (BUFFER_OFFSET(offset,chan)/chan->subbuf_size) + +/* ltt_reserve_slot + * + * Atomic slot reservation in a LTTng buffer. It will take care of + * sub-buffer switching. + * + * Parameters: + * + * @trace : the trace structure to log to. + * @buf : the buffer to reserve space into. + * @data_size : size of the variable length data to log. + * @slot_size : pointer to total size of the slot (out) + * @tsc : pointer to the tsc at the slot reservation (out) + * @before_hdr_pad : dynamic padding before the event header. + * @after_hdr_pad : dynamic padding after the event header. + * + * Return : NULL if not enough space, else returns the pointer + * to the beginning of the reserved slot. */ +static inline void *ltt_reserve_slot( + struct ltt_trace_struct *trace, + struct ltt_channel_struct *channel, + void **transport_data, + size_t data_size, + size_t *slot_size, + u64 *tsc, + size_t *before_hdr_pad, + size_t *after_hdr_pad, + size_t *header_size) +{ + return trace->ops->reserve_slot(trace, channel, transport_data, + data_size, slot_size, tsc, before_hdr_pad, + after_hdr_pad, header_size); +} + + +/* ltt_commit_slot + * + * Atomic unordered slot commit. Increments the commit count in the + * specified sub-buffer, and delivers it if necessary. + * + * Parameters: + * + * @buf : the buffer to commit to. + * @reserved : address of the beginnig of the reserved slot. + * @slot_size : size of the reserved slot. + * + */ +static inline void ltt_commit_slot( + struct ltt_channel_struct *channel, + void **transport_data, + void *reserved, + size_t slot_size) +{ + struct ltt_trace_struct *trace = channel->trace; + + trace->ops->commit_slot(channel, transport_data, reserved, slot_size); +} + +#endif //CONFIG_LTT + +/* Is kernel tracer enabled */ +#if defined(CONFIG_LTT_TRACER) || defined(CONFIG_LTT_TRACER_MODULE) + +/* 4 control channels : + * ltt/control/facilities + * ltt/control/interrupts + * ltt/control/processes + * ltt/control/network + * + * 1 cpu channel : + * ltt/cpu + */ +#define LTT_RELAY_ROOT "ltt" +#define LTT_CONTROL_ROOT "control" +#define LTT_FACILITIES_CHANNEL "facilities_" +#define LTT_INTERRUPTS_CHANNEL "interrupts_" +#define LTT_PROCESSES_CHANNEL "processes_" +#define LTT_MODULES_CHANNEL "modules_" +#define LTT_NETWORK_CHANNEL "network_" +#define LTT_CPU_CHANNEL "cpu_" +#define LTT_FLIGHT_PREFIX "flight-" + +/* System types */ +#define LTT_SYS_TYPE_VANILLA_LINUX 1 + +/* Architecture types */ +#define LTT_ARCH_TYPE_I386 1 +#define LTT_ARCH_TYPE_PPC 2 +#define LTT_ARCH_TYPE_SH 3 +#define LTT_ARCH_TYPE_S390 4 +#define LTT_ARCH_TYPE_MIPS 5 +#define LTT_ARCH_TYPE_ARM 6 +#define LTT_ARCH_TYPE_PPC64 7 +#define LTT_ARCH_TYPE_X86_64 8 +#define LTT_ARCH_TYPE_C2 9 +#define LTT_ARCH_TYPE_POWERPC 10 + +/* Standard definitions for variants */ +#define LTT_ARCH_VARIANT_NONE 0 + +/* Tracer properties */ +#define LTT_DEFAULT_SUBBUF_SIZE_LOW 65536 +#define LTT_DEFAULT_N_SUBBUFS_LOW 2 +#define LTT_DEFAULT_SUBBUF_SIZE_MED 262144 +#define LTT_DEFAULT_N_SUBBUFS_MED 2 +#define LTT_DEFAULT_SUBBUF_SIZE_HIGH 1048576 +#define LTT_DEFAULT_N_SUBBUFS_HIGH 2 +#define LTT_TRACER_MAGIC_NUMBER 0x00D6B7ED +#define LTT_TRACER_VERSION_MAJOR 0 +#define LTT_TRACER_VERSION_MINOR 7 + +/* Size reserved for high priority events (interrupts, NMI, BH) at the end of a + * nearly full buffer. User space won't use this last amount of space when in + * blocking mode. This space also includes the event header that would be + * written by this user space event. */ +#define LTT_RESERVE_CRITICAL 4096 + +/* Register and unregister function pointers */ + +enum ltt_module_function { + LTT_FUNCTION_RUN_FILTER, + LTT_FUNCTION_FILTER_CONTROL, + LTT_FUNCTION_STATEDUMP +}; + +extern int ltt_module_register(enum ltt_module_function name, void *function, + struct module *owner); +extern void ltt_module_unregister(enum ltt_module_function name); + +void ltt_transport_register(struct ltt_transport *transport); +void ltt_transport_unregister(struct ltt_transport *transport); + +/* Exported control function */ + +enum ltt_heartbeat_functor_msg { LTT_HEARTBEAT_START, LTT_HEARTBEAT_STOP }; + +enum ltt_control_msg { + LTT_CONTROL_START, + LTT_CONTROL_STOP, + LTT_CONTROL_CREATE_TRACE, + LTT_CONTROL_DESTROY_TRACE +}; + +union ltt_control_args { + struct { + enum trace_mode mode; + unsigned subbuf_size_low; + unsigned n_subbufs_low; + unsigned subbuf_size_med; + unsigned n_subbufs_med; + unsigned subbuf_size_high; + unsigned n_subbufs_high; + } new_trace; +}; + +extern int ltt_control(enum ltt_control_msg msg, char *trace_name, + char *trace_type, union ltt_control_args args); + +enum ltt_filter_control_msg { + LTT_FILTER_DEFAULT_ACCEPT, + LTT_FILTER_DEFAULT_REJECT }; + +extern int ltt_filter_control(enum ltt_filter_control_msg msg, + char *trace_name); + +void ltt_write_trace_header(struct ltt_trace_struct *trace, + struct ltt_trace_header *header); +extern void ltt_buffer_destroy(struct ltt_channel_struct *ltt_chan); +extern void ltt_wakeup_writers(void *private); + +void ltt_core_register(int (*function)(u8, void*)); + +void ltt_core_unregister(void); + +#ifdef CONFIG_LTT_HEARTBEAT +int ltt_heartbeat_trigger(enum ltt_heartbeat_functor_msg msg); +#endif //CONFIG_LTT_HEARTBEAT + +/* Relay IOCTL */ + +/* Get the next sub buffer that can be read. */ +#define RELAY_GET_SUBBUF _IOR(0xF4, 0x00,__u32) +/* Release the oldest reserved (by "get") sub buffer. */ +#define RELAY_PUT_SUBBUF _IOW(0xF4, 0x01,__u32) +/* returns the number of sub buffers in the per cpu channel. */ +#define RELAY_GET_N_SUBBUFS _IOR(0xF4, 0x02,__u32) +/* returns the size of the sub buffers. */ +#define RELAY_GET_SUBBUF_SIZE _IOR(0xF4, 0x03,__u32) + +#endif /* defined(CONFIG_LTT_TRACER) || defined(CONFIG_LTT_TRACER_MODULE) */ +#endif /* _LTT_CORE_H */