rte_trace_point.h

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/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(C) 2020 Marvell International Ltd.
 */

#ifndef _RTE_TRACE_POINT_H_
#define _RTE_TRACE_POINT_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <stdbool.h>
#include <stdio.h>

#include <rte_branch_prediction.h>
#include <rte_common.h>
#include <rte_compat.h>
#include <rte_cycles.h>
#include <rte_per_lcore.h>
#include <rte_string_fns.h>
#include <rte_uuid.h>

typedef uint64_t rte_trace_point_t;

#define RTE_TRACE_POINT_DEFINE(tp) \
rte_trace_point_t __attribute__((section("__rte_trace_point"))) __##tp

#define RTE_TRACE_POINT_ARGS

#define __RTE_TRACE_POINT(_mode, _tp, _args, ...) \
extern rte_trace_point_t __##_tp; \
static __rte_always_inline void \
_tp _args \
{ \
    __rte_trace_point_emit_header_##_mode(&__##_tp); \
    __VA_ARGS__ \
}

#define RTE_TRACE_POINT(tp, args, ...) \
    __RTE_TRACE_POINT(generic, tp, args, __VA_ARGS__)

#define RTE_TRACE_POINT_FP(tp, args, ...) \
    __RTE_TRACE_POINT(fp, tp, args, __VA_ARGS__)

#ifdef __DOXYGEN__

#define RTE_TRACE_POINT_REGISTER(trace, name)

#define rte_trace_point_emit_u64(val)

#define rte_trace_point_emit_i64(val)

#define rte_trace_point_emit_u32(val)

#define rte_trace_point_emit_i32(val)

#define rte_trace_point_emit_u16(val)

#define rte_trace_point_emit_i16(val)

#define rte_trace_point_emit_u8(val)

#define rte_trace_point_emit_i8(val)

#define rte_trace_point_emit_int(val)

#define rte_trace_point_emit_long(val)

#define rte_trace_point_emit_float(val)

#define rte_trace_point_emit_double(val)

#define rte_trace_point_emit_ptr(val)

#define rte_trace_point_emit_string(val)

#endif /* __DOXYGEN__ */

#define __RTE_TRACE_EMIT_STRING_LEN_MAX 32

#define __RTE_TRACE_EVENT_HEADER_SZ sizeof(uint64_t)

__rte_experimental
int rte_trace_point_enable(rte_trace_point_t *tp);

__rte_experimental
int rte_trace_point_disable(rte_trace_point_t *tp);

__rte_experimental
bool rte_trace_point_is_enabled(rte_trace_point_t *tp);

__rte_experimental
rte_trace_point_t *rte_trace_point_lookup(const char *name);

__rte_experimental
static __rte_always_inline bool
__rte_trace_point_fp_is_enabled(void)
{
#ifdef RTE_ENABLE_TRACE_FP
    return true;
#else
    return false;
#endif
}

__rte_experimental
void __rte_trace_mem_per_thread_alloc(void);

__rte_experimental
void __rte_trace_point_emit_field(size_t sz, const char *field,
    const char *type);

__rte_experimental
int __rte_trace_point_register(rte_trace_point_t *trace, const char *name,
    void (*register_fn)(void));

#ifndef __DOXYGEN__

#ifndef _RTE_TRACE_POINT_REGISTER_H_
#ifdef ALLOW_EXPERIMENTAL_API

#define __RTE_TRACE_EVENT_HEADER_ID_SHIFT (48)

#define __RTE_TRACE_FIELD_SIZE_SHIFT 0
#define __RTE_TRACE_FIELD_SIZE_MASK (0xffffULL << __RTE_TRACE_FIELD_SIZE_SHIFT)
#define __RTE_TRACE_FIELD_ID_SHIFT (16)
#define __RTE_TRACE_FIELD_ID_MASK (0xffffULL << __RTE_TRACE_FIELD_ID_SHIFT)
#define __RTE_TRACE_FIELD_ENABLE_MASK (1ULL << 63)
#define __RTE_TRACE_FIELD_ENABLE_DISCARD (1ULL << 62)

struct __rte_trace_stream_header {
    uint32_t magic;
    rte_uuid_t uuid;
    uint32_t lcore_id;
    char thread_name[__RTE_TRACE_EMIT_STRING_LEN_MAX];
} __rte_packed;

struct __rte_trace_header {
    uint32_t offset;
    uint32_t len;
    struct __rte_trace_stream_header stream_header;
    uint8_t mem[];
};

RTE_DECLARE_PER_LCORE(void *, trace_mem);

static __rte_always_inline void *
__rte_trace_mem_get(uint64_t in)
{
    struct __rte_trace_header *trace = RTE_PER_LCORE(trace_mem);
    const uint16_t sz = in & __RTE_TRACE_FIELD_SIZE_MASK;

    /* Trace memory is not initialized for this thread */
    if (unlikely(trace == NULL)) {
        __rte_trace_mem_per_thread_alloc();
        trace = RTE_PER_LCORE(trace_mem);
        if (unlikely(trace == NULL))
            return NULL;
    }
    /* Check the wrap around case */
    uint32_t offset = trace->offset;
    if (unlikely((offset + sz) >= trace->len)) {
        /* Disable the trace event if it in DISCARD mode */
        if (unlikely(in & __RTE_TRACE_FIELD_ENABLE_DISCARD))
            return NULL;

        offset = 0;
    }
    /* Align to event header size */
    offset = RTE_ALIGN_CEIL(offset, __RTE_TRACE_EVENT_HEADER_SZ);
    void *mem = RTE_PTR_ADD(&trace->mem[0], offset);
    offset += sz;
    trace->offset = offset;

    return mem;
}

static __rte_always_inline void *
__rte_trace_point_emit_ev_header(void *mem, uint64_t in)
{
    uint64_t val;

    /* Event header [63:0] = id [63:48] | timestamp [47:0] */
    val = rte_get_tsc_cycles() &
        ~(0xffffULL << __RTE_TRACE_EVENT_HEADER_ID_SHIFT);
    val |= ((in & __RTE_TRACE_FIELD_ID_MASK) <<
        (__RTE_TRACE_EVENT_HEADER_ID_SHIFT -
         __RTE_TRACE_FIELD_ID_SHIFT));

    *(uint64_t *)mem = val;
    return RTE_PTR_ADD(mem, __RTE_TRACE_EVENT_HEADER_SZ);
}

#define __rte_trace_point_emit_header_generic(t) \
void *mem; \
do { \
    const uint64_t val = __atomic_load_n(t, __ATOMIC_ACQUIRE); \
    if (likely(!(val & __RTE_TRACE_FIELD_ENABLE_MASK))) \
        return; \
    mem = __rte_trace_mem_get(val); \
    if (unlikely(mem == NULL)) \
        return; \
    mem = __rte_trace_point_emit_ev_header(mem, val); \
} while (0)

#define __rte_trace_point_emit_header_fp(t) \
    if (!__rte_trace_point_fp_is_enabled()) \
        return; \
    __rte_trace_point_emit_header_generic(t)

#define __rte_trace_point_emit(in, type) \
do { \
    memcpy(mem, &(in), sizeof(in)); \
    mem = RTE_PTR_ADD(mem, sizeof(in)); \
} while (0)

#define rte_trace_point_emit_string(in) \
do { \
    if (unlikely(in == NULL)) \
        return; \
    rte_strscpy(mem, in, __RTE_TRACE_EMIT_STRING_LEN_MAX); \
    mem = RTE_PTR_ADD(mem, __RTE_TRACE_EMIT_STRING_LEN_MAX); \
} while (0)

#else

#define __rte_trace_point_emit_header_generic(t) RTE_SET_USED(t)
#define __rte_trace_point_emit_header_fp(t) RTE_SET_USED(t)
#define __rte_trace_point_emit(in, type) RTE_SET_USED(in)
#define rte_trace_point_emit_string(in) RTE_SET_USED(in)

#endif /* ALLOW_EXPERIMENTAL_API */
#endif /* _RTE_TRACE_POINT_REGISTER_H_ */

#define rte_trace_point_emit_u64(in) __rte_trace_point_emit(in, uint64_t)
#define rte_trace_point_emit_i64(in) __rte_trace_point_emit(in, int64_t)
#define rte_trace_point_emit_u32(in) __rte_trace_point_emit(in, uint32_t)
#define rte_trace_point_emit_i32(in) __rte_trace_point_emit(in, int32_t)
#define rte_trace_point_emit_u16(in) __rte_trace_point_emit(in, uint16_t)
#define rte_trace_point_emit_i16(in) __rte_trace_point_emit(in, int16_t)
#define rte_trace_point_emit_u8(in) __rte_trace_point_emit(in, uint8_t)
#define rte_trace_point_emit_i8(in) __rte_trace_point_emit(in, int8_t)
#define rte_trace_point_emit_int(in) __rte_trace_point_emit(in, int32_t)
#define rte_trace_point_emit_long(in) __rte_trace_point_emit(in, long)
#define rte_trace_point_emit_float(in) __rte_trace_point_emit(in, float)
#define rte_trace_point_emit_double(in) __rte_trace_point_emit(in, double)
#define rte_trace_point_emit_ptr(in) __rte_trace_point_emit(in, uintptr_t)

#endif /* __DOXYGEN__ */

#ifdef __cplusplus
}
#endif

#endif /* _RTE_TRACE_POINT_H_ */