/*
 * Copyright (c) 2020 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __perfmon_perfmon_h
#define __perfmon_perfmon_h

#include <linux/perf_event.h>
#include <vppinfra/clib.h>
#include <vppinfra/format.h>
#include <vppinfra/error.h>
#include <vppinfra/cpu.h>
#include <vlib/vlib.h>

#if defined(__x86_64__)
#define PERF_MAX_EVENTS 12 /* 4 fixed and 8 programable on ICX */
#elif defined(__aarch64__)
#define PERF_MAX_EVENTS 7 /* 6 events + 1 CPU cycle counter */
#endif

typedef enum
{
  PERFMON_EVENT_TYPE_GENERAL,
  PERFMON_EVENT_TYPE_FIXED,
  PERFMON_EVENT_TYPE_PSEUDO,
  PERFMON_EVENT_TYPE_MAX,
} perfmon_event_type_t;

typedef enum
{
  PERFMON_BUNDLE_TYPE_UNKNOWN,
  PERFMON_BUNDLE_TYPE_NODE,
  PERFMON_BUNDLE_TYPE_THREAD,
  PERFMON_BUNDLE_TYPE_SYSTEM,
  PERFMON_BUNDLE_TYPE_MAX,
  PERFMON_BUNDLE_TYPE_NODE_OR_THREAD,
} perfmon_bundle_type_t;

#define foreach_perfmon_bundle_type                                           \
  _ (PERFMON_BUNDLE_TYPE_UNKNOWN, "not supported")                            \
  _ (PERFMON_BUNDLE_TYPE_NODE, "node")                                        \
  _ (PERFMON_BUNDLE_TYPE_THREAD, "thread")                                    \
  _ (PERFMON_BUNDLE_TYPE_SYSTEM, "system")

typedef enum
{
#define _(e, str) e##_FLAG = 1 << e,
  foreach_perfmon_bundle_type
#undef _

} perfmon_bundle_type_flag_t;

typedef struct
{
  u32 type_from_instance : 1;
  u32 exclude_kernel : 1;
  u32 config1 : 2;
  u32 implemented : 1;
  union
  {
    u32 type;
    u32 instance_type;
  };
  u64 config;
  char *name;
  char *description;
} perfmon_event_t;

typedef struct
{
  u32 type;
  int cpu;
  pid_t pid;
  char *name;
} perfmon_instance_t;

typedef struct
{
  char *name;
  perfmon_instance_t *instances;
} perfmon_instance_type_t;

struct perfmon_source;
typedef struct perfmon_bundle perfmon_bundle_t;

typedef clib_error_t *(perfmon_source_init_fn_t) (vlib_main_t *vm,
						  struct perfmon_source *);
typedef perfmon_event_type_t (perfmon_source_get_event_type) (u32 event);
typedef u8 (perfmon_source_bundle_support_t) (perfmon_bundle_t *);
typedef clib_error_t *(perfmon_source_config_dispatch_wrapper_t) (
  perfmon_bundle_t *b, vlib_node_function_t **dispatch_wrapper);

typedef struct perfmon_source
{
  char *name;
  char *description;
  struct perfmon_source *next;
  perfmon_event_t *events;
  u32 n_events;
  perfmon_instance_type_t *instances_by_type;
  format_function_t *format_config;
  perfmon_source_get_event_type *get_event_type;
  perfmon_source_init_fn_t *init_fn;
  perfmon_source_bundle_support_t *bundle_support;
  perfmon_source_config_dispatch_wrapper_t *config_dispatch_wrapper;
} perfmon_source_t;

typedef clib_error_t *(perfmon_bundle_init_fn_t) (vlib_main_t *vm,
						  struct perfmon_bundle *);

typedef struct
{
  clib_cpu_supports_func_t cpu_supports;
  perfmon_bundle_type_t bundle_type;
} perfmon_cpu_supports_t;

typedef struct perfmon_bundle
{
  char *name;
  char *description;
  char *source;
  char *footer;

  union
  {
    perfmon_bundle_type_flag_t type_flags;
    perfmon_bundle_type_t type;
  };
  perfmon_bundle_type_t active_type;

  u32 events[PERF_MAX_EVENTS];
  u32 n_events;
  u32 n_columns;

  uword *event_disabled;
  uword *column_disabled;
  u8 *column_events;

  u16 preserve_samples;

  perfmon_cpu_supports_t *cpu_supports;
  u32 n_cpu_supports;

  perfmon_bundle_init_fn_t *init_fn;

  char **column_headers;
  format_function_t *format_fn;

  /* do not set manually */
  perfmon_source_t *src;
  struct perfmon_bundle *next;
} perfmon_bundle_t;

typedef struct
{
  u64 nr;
  u64 time_enabled;
  u64 time_running;
  u64 value[PERF_MAX_EVENTS];
} perfmon_reading_t;

typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  u64 n_calls;
  u64 n_packets;
  union
  {
    struct
    {
      u64 value[PERF_MAX_EVENTS];
    } t[2];
    u64 value[PERF_MAX_EVENTS * 2];
  };
} perfmon_node_stats_t;

typedef struct
{
  u8 n_events;
  u16 n_nodes;
  perfmon_node_stats_t *node_stats;
  perfmon_bundle_t *bundle;
  u32 indexes[PERF_MAX_EVENTS];
  u16 preserve_samples;
  struct perf_event_mmap_page *mmap_pages[PERF_MAX_EVENTS];
} perfmon_thread_runtime_t;

typedef struct
{
  perfmon_thread_runtime_t *thread_runtimes;
  perfmon_bundle_t *bundles;
  uword *bundle_by_name;
  perfmon_source_t *sources;
  uword *source_by_name;
  perfmon_bundle_t *active_bundle;
  int is_running;
  f64 sample_time;
  int *group_fds;
  int *fds_to_close;
  perfmon_instance_type_t *default_instance_type;
  perfmon_instance_type_t *active_instance_type;
} perfmon_main_t;

extern perfmon_main_t perfmon_main;

#define PERFMON_BUNDLE_TYPE_TO_FLAGS(type)                                    \
  ({                                                                          \
    uword rtype = 0;                                                          \
    if (type == PERFMON_BUNDLE_TYPE_NODE_OR_THREAD)                           \
      rtype =                                                                 \
	1 << PERFMON_BUNDLE_TYPE_THREAD | 1 << PERFMON_BUNDLE_TYPE_NODE;      \
    else                                                                      \
      rtype = 1 << type;                                                      \
    rtype;                                                                    \
  })

always_inline uword
perfmon_cpu_update_bundle_type (perfmon_bundle_t *b)
{
  perfmon_cpu_supports_t *supports = b->cpu_supports;
  uword type = 0;

  /* either supports or b->type should be set, but not both */
  ASSERT (!!supports ^ !!b->type);

  /* if nothing specific for this bundle, go with the defaults */
  if (!supports)
    type = PERFMON_BUNDLE_TYPE_TO_FLAGS (b->type);
  else
    {
      /* more than one type may be supported by a given bundle */
      for (int i = 0; i < b->n_cpu_supports; ++i)
	if (supports[i].cpu_supports ())
	  type |= PERFMON_BUNDLE_TYPE_TO_FLAGS (supports[i].bundle_type);
    }

  return type;
}
#undef PERFMON_BUNDLE_TYPE_TO_FLAGS

#define PERFMON_REGISTER_SOURCE(x)                                            \
  perfmon_source_t __perfmon_source_##x;                                      \
  static void __clib_constructor __perfmon_source_registration_##x (void)     \
  {                                                                           \
    perfmon_main_t *pm = &perfmon_main;                                       \
    __perfmon_source_##x.next = pm->sources;                                  \
    pm->sources = &__perfmon_source_##x;                                      \
  }                                                                           \
  perfmon_source_t __perfmon_source_##x

#define PERFMON_REGISTER_BUNDLE(x)                                            \
  perfmon_bundle_t __perfmon_bundle_##x;                                      \
  static void __clib_constructor __perfmon_bundle_registration_##x (void)     \
  {                                                                           \
    perfmon_main_t *pm = &perfmon_main;                                       \
    __perfmon_bundle_##x.next = pm->bundles;                                  \
    __perfmon_bundle_##x.type_flags =                                         \
      perfmon_cpu_update_bundle_type (&__perfmon_bundle_##x);                 \
    pm->bundles = &__perfmon_bundle_##x;                                      \
  }                                                                           \
  perfmon_bundle_t __perfmon_bundle_##x

void perfmon_reset (vlib_main_t *vm);
clib_error_t *perfmon_start (vlib_main_t *vm, perfmon_bundle_t *);
clib_error_t *perfmon_stop (vlib_main_t *vm);

#define PERFMON_STRINGS(...)                                                  \
  (char *[]) { __VA_ARGS__, 0 }

#define PERFMON_COLUMN_EVENTS(...)                                            \
  (u8[]) { __VA_ARGS__ }

#endif