Add low level event recording support

Add low level event recording infrastructure for system and user
defined events.  The infrastructure is able to record high frequency
events such as

 * SMP lock acquire/release,
 * interrupt entry/exit,
 * thread switches,
 * UMA zone allocate/free, and
 * Ethernet packet input/output, etc.

It allows post-mortem analysis in fatal error handlers, e.g. the last
events are in the record buffer, the newest event overwrites the oldest
event.  It is possible to detect record buffer overflows for consumers
that expect a continuous stream of events, e.g. to display the system
state in real-time.

The implementation supports high-end SMP machines (more than 1GHz
processor frequency, more than four processors).

Add a new API instead. The implementation uses per-processor data
structures and no atomic read-modify-write operations.  It is uses
per-processor ring buffers to record the events.

The CPU counter is used to get the time of events. It is combined with
periodic uptime events to synchronize it with CLOCK_REALTIME.

The existing capture engine tries to solve this problem also, but its
performance is not good enough for high-end production systems.  The
main issues are the variable-size buffers and the use of SMP locks for
synchronization.  To fix this, the API would change significantly.

Update #3665.

1 files changed, 139 insertions, 0 deletions

diff --git a/cpukit/include/rtems/recordclient.h b/cpukit/include/rtems/recordclient.h
new file mode 100644
index 0000000000..61ef96791c
--- /dev/null
+++ b/cpukit/include/rtems/recordclient.h
@@ -0,0 +1,139 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (C) 2018, 2019 embedded brains GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * This file must be compatible to general purpose POSIX system, e.g. Linux,
+ * FreeBSD.  It may be used for utility programs.
+ */
+
+#ifndef _RTEMS_RECORDCLIENT_H
+#define _RTEMS_RECORDCLIENT_H
+
+#include "recorddata.h"
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @addtogroup RTEMSRecord
+ *
+ * @{
+ */
+
+#define RTEMS_RECORD_CLIENT_MAXIMUM_CPU_COUNT 32
+
+typedef enum {
+  RTEMS_RECORD_CLIENT_SUCCESS,
+  RTEMS_RECORD_CLIENT_ERROR_INVALID_MAGIC,
+  RTEMS_RECORD_CLIENT_ERROR_UNKNOWN_FORMAT,
+  RTEMS_RECORD_CLIENT_ERROR_UNSUPPORTED_VERSION,
+  RTEMS_RECORD_CLIENT_ERROR_UNSUPPORTED_CPU
+} rtems_record_client_status;
+
+typedef rtems_record_client_status ( *rtems_record_client_handler )(
+  uint32_t            seconds,
+  uint32_t            nanoseconds,
+  uint32_t            cpu,
+  rtems_record_event  event,
+  uint64_t            data,
+  void               *arg
+);
+
+typedef struct {
+  struct {
+    uint64_t bt;
+    uint32_t time_at_bt;
+    uint32_t time_last;
+    uint32_t time_accumulated;
+  } uptime;
+  uint32_t tail[ 2 ];
+  uint32_t head[ 2 ];
+  size_t index;
+} rtems_record_client_per_cpu;
+
+typedef struct rtems_record_client_context {
+  uint64_t to_bt_scaler;
+  rtems_record_client_per_cpu per_cpu[ RTEMS_RECORD_CLIENT_MAXIMUM_CPU_COUNT ];
+  uint64_t data;
+  uint32_t cpu;
+  uint32_t event;
+  uint32_t count;
+  union {
+    rtems_record_item_32 format_32;
+    rtems_record_item_64 format_64;
+  } item;
+  size_t todo;
+  void *pos;
+  rtems_record_client_status ( *consume )(
+    struct rtems_record_client_context *,
+    const void *,
+    size_t
+  );
+  rtems_record_client_handler handler;
+  void *handler_arg;
+  uint32_t header[ 2 ];
+} rtems_record_client_context;
+
+/**
+ * @brief Initializes a record client.
+ *
+ * The record client consumes a record item stream produces by the record
+ * server.
+ *
+ * @param ctx The record client context to initialize.
+ * @param handler The handler is invoked for each received record item.
+ * @param arg The handler argument.
+ */
+void rtems_record_client_init(
+  rtems_record_client_context *ctx,
+  rtems_record_client_handler  handler,
+  void                        *arg
+);
+
+/**
+ * @brief Runs the record client to consume new stream data.
+ *
+ * @param ctx The record client context.
+ * @param buf The buffer with new stream data.
+ * @param n The size of the buffer.
+ */
+rtems_record_client_status rtems_record_client_run(
+  rtems_record_client_context *ctx,
+  const void                  *buf,
+  size_t                       n
+);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _RTEMS_RECORDCLIENT_H */