Add event logger.

Add a log event tool with a single interface for the user to
add/collect the event log data.

Change-Id: Ia4b78836748c5d7e44ba1bdd50c28434e8a55d65
Signed-off-by: Yonattan Louise <yonattan.a.louise.mendoza@intel.com>

arch/arc/defconfig

@@ -13,6 +13,7 @@ CONFIG_SYS_CLOCK_EXISTS=y
 # CONFIG_INIT_STACKS is not set
 CONFIG_XIP=y
 # CONFIG_ENHANCED_SECURITY is not set
+# CONFIG_EVENT_LOGGER is not set
 
 #
 # Nanokernel Options

arch/arm/defconfig

@@ -14,6 +14,7 @@ CONFIG_SYS_CLOCK_EXISTS=y
 # CONFIG_INIT_STACKS is not set
 CONFIG_XIP=y
 # CONFIG_ENHANCED_SECURITY is not set
+# CONFIG_EVENT_LOGGER is not set
 
 #
 # Nanokernel Options

arch/x86/defconfig

@@ -16,6 +16,7 @@ CONFIG_SYS_CLOCK_EXISTS=y
 # CONFIG_INIT_STACKS is not set
 # CONFIG_XIP is not set
 CONFIG_ENHANCED_SECURITY=y
+# CONFIG_EVENT_LOGGER is not set
 
 #
 # Security Options

include/misc/event_logger.h

@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * 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.
+ *
+ * 3) Neither the name of Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * 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 HOLDER 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.
+ */
+
+/*
+ * @file
+ * @brief Event logger support.
+ */
+
+
+#include <nanokernel.h>
+#include <errno.h>
+
+#ifndef __EVENT_LOGGER_H__
+#define __EVENT_LOGGER_H__
+
+#define EVENT_HEADER_SIZE        1
+
+
+struct event_header_bits {
+	/* length in 32-bit words */
+	uint32_t  data_length   :4;
+	uint32_t  dropped_count :4;
+	uint32_t  event_id      :16;
+	uint32_t  reserved      :8;
+};
+
+union event_header {
+	uint32_t block;
+	struct event_header_bits bits;
+};
+
+struct event_logger {
+	uint32_t head;
+	uint32_t tail;
+	uint16_t dropped_event_count;
+	struct nano_sem sync_sema;
+	uint32_t *buffer;
+	uint32_t buffer_size;
+};
+
+
+/**
+ * @brief Initialize the event logger.
+ *
+ * @details Initialize the ring buffer.
+ *
+ * @param logger        Logger to be initialized.
+ * @param logger_buffer Pointer to the buffer to be used by the logger.
+ * @param buffer_size   Size of the buffer in 32-bit words.
+ *
+ * @return No return value.
+ */
+void sys_event_logger_init(struct event_logger *logger,
+	uint32_t *logger_buffer, uint32_t buffer_size);
+
+
+/**
+ * @brief Send an event message to the logger.
+ *
+ * @details Add an event message to the ring buffer and signal the sync
+ * semaphore to inform that there are event messages available.
+ *
+ * @param logger     Pointer to the event logger used.
+ * @param event_id   The identification of the profiler event.
+ * @param data       Pointer to the data of the message.
+ * @param data_size  Size of the buffer in 32-bit words.
+ *
+ * @return No return value.
+ */
+void sys_event_logger_put(struct event_logger *logger, uint16_t event_id,
+	uint32_t *event_data, uint8_t data_size);
+
+
+/**
+ * @brief Retrieve an event message from the logger.
+ *
+ * @details Retrieve an event message from the ring buffer and copy it to the
+ * provided buffer. If the provided buffer is smaller than the message
+ * size the function returns -EMSGSIZE. Otherwise return the number of 32-bit
+ * words copied. The functon retrieves messages in FIFO order. If there is no
+ * message in the buffer the fuction returns immediately. It can only be called
+ * from a fiber context.
+ *
+ * @param logger       Pointer to the event logger used.
+ * @param buffer       Pointer to the buffer where the message will be copied.
+ * @param buffer_size  Size of the buffer in 32-bit words.
+ *
+ * @return -EMSGSIZE if the buffer size is smaller than the message size, or
+ * the amount of 32-bit words copied. 0 (zero) if there was no message already
+ * available.
+ */
+int sys_event_logger_get(struct event_logger *logger, uint32_t *buffer,
+	uint8_t buffer_size);
+
+
+/**
+ * @brief Retrieve an event message from the logger, wait if empty.
+ *
+ * @details Retrieve an event message from the ring buffer and copy it to the
+ * provided buffer. If the provided buffer is smaller than the message
+ * size the function returns -EMSGSIZE. Otherwise return the number of 32-bit
+ * words copied. The functon retrieves messages in FIFO order. The caller pends
+ * if there is no message available in the buffer. It can only be called from a
+ * fiber context.
+ *
+ * @param logger       Pointer to the event logger used.
+ * @param buffer       Pointer to the buffer where the message will be copied.
+ * @param buffer_size  Size of the buffer in 32-bit words.
+ *
+ * @return -EMSGSIZE if the buffer size is smaller than the message size. Or
+ * the amount of DWORDs copied.
+ */
+int sys_event_logger_get_wait(struct event_logger *logger, uint32_t *buffer,
+	uint8_t buffer_size);
+
+#ifdef CONFIG_NANO_TIMEOUTS
+/**
+ * @brief Retrieve an event message from the logger, wait with a timeout if
+ * empty.
+ *
+ * @details Retrieve an event message from the ring buffer and copy it to the
+ * provided buffer. If the provided buffer is smaller than the message
+ * size the function returns -EMSGSIZE. Otherwise return the number of dwords
+ * copied. The functon retrieves messages in FIFO order. The caller pends if
+ * there is no message available in the buffer until a new message is added or
+ * the timeout expires. It can only be called from a fiber context.
+ *
+ * @param logger       Pointer to the event logger used.
+ * @param buffer       Pointer to the buffer where the message will be copied.
+ * @param buffer_size  Size of the buffer.
+ * @param timeout      Timeout in ticks.
+ *
+ * @return -EMSGSIZE if the buffer size is smaller than the message size. Or
+ * the amount of 32-bit words copied. 0 (zero) if the timeout expired and there
+ * was no message already available.
+ */
+int sys_event_logger_get_wait_timeout(struct event_logger *logger,
+	uint32_t *buffer, uint8_t buffer_size, uint32_t timeout);
+#endif /* CONFIG_NANO_TIMEOUTS */
+
+#endif /* __EVENT_LOGGER_H__ */

kernel/Kconfig

@@ -103,6 +103,14 @@ config ENHANCED_SECURITY
 	Users can customize these settings using the CUSTOM_SECURITY option
 	in the "Security Options" menu.
 
+config EVENT_LOGGER
+	bool
+	prompt "Enable event logger"
+	default n
+	help
+	Enable event logging feature. Allow the usage of a ring buffer to
+	transmit event messages with a single interface to collect them.
+
 menu "Security Options"
 	depends on ENHANCED_SECURITY
 

kernel/nanokernel/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_STACK_CANARIES) += compiler_stack_protect.o
 obj-$(CONFIG_INT_LATENCY_BENCHMARK) += int_latency_bench.o
 obj-$(CONFIG_ADVANCED_POWER_MANAGEMENT) += idle.o
 obj-$(CONFIG_NANO_TIMERS) += nano_timer.o
+obj-$(CONFIG_EVENT_LOGGER) += event_logger.o

kernel/nanokernel/event_logger.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * 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.
+ *
+ * 3) Neither the name of Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * 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 HOLDER 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.
+ */
+
+/*
+ * @file
+ * @brief Event logger support.
+ */
+
+#include <misc/event_logger.h>
+
+
+void sys_event_logger_init(struct event_logger *logger,
+	uint32_t *logger_buffer, uint32_t buffer_size)
+{
+	logger->head = logger->tail = 0;
+	logger->dropped_event_count = 0;
+	logger->buffer = logger_buffer;
+	logger->buffer_size = buffer_size;
+	nano_sem_init(&(logger->sync_sema));
+}
+
+
+static void event_logger_put(struct event_logger *logger, uint16_t event_id,
+	uint32_t *event_data, uint8_t data_size,
+	void(*sem_give_fn)(struct nano_sem *))
+{
+	unsigned int key;
+	unsigned int buffer_capacity_used;
+	union event_header header;
+	int i;
+
+	/* Lock interrupt to be sure this function will be atomic */
+	key = irq_lock_inline();
+
+	buffer_capacity_used = (logger->head - logger->tail +
+		logger->buffer_size) % logger->buffer_size;
+
+	/* check if there is space to the new event */
+	if (buffer_capacity_used + EVENT_HEADER_SIZE + data_size >=
+		logger->buffer_size) {
+		(logger->dropped_event_count)++;
+	} else {
+		/* build the header */
+		header.bits.data_length = data_size;
+		header.bits.event_id = event_id;
+		header.bits.dropped_count = logger->dropped_event_count;
+		logger->dropped_event_count = 0;
+
+		/* copy the header to the buffer */
+		logger->buffer[logger->head] = header.block;
+		logger->head = (logger->head + EVENT_HEADER_SIZE) %
+			logger->buffer_size;
+
+		/* copy the extra data to the buffer */
+		for (i=0; i < header.bits.data_length; ++i) {
+			logger->buffer[(logger->head + i) %
+				logger->buffer_size] = event_data[i];
+		}
+		logger->head = (logger->head + header.bits.data_length) %
+			logger->buffer_size;
+
+		/* inform that there is event data available on the buffer */
+		sem_give_fn(&(logger->sync_sema));
+	}
+
+	irq_unlock_inline(key);
+}
+
+
+void sys_event_logger_put(struct event_logger *logger, uint16_t event_id,
+	uint32_t *event_data, uint8_t data_size)
+{
+	event_logger_put(logger, event_id, event_data, data_size, nano_sem_give);
+}
+
+
+/**
+ * @brief Send an event message to the logger with a non preemptible
+ * behaviour.
+ *
+ * @details Add an event message to the ring buffer and signal the sync
+ * semaphore using the internal function _sem_give_non_preemptible to inform
+ * that there are event messages available, avoiding the preemptible
+ * behaviour when the function is called from a task context. This function
+ * should be only used for special cases where the sys_event_logger_put
+ * does not satisfy the needs.
+ *
+ * @param logger     Pointer to the event logger used.
+ * @param event_id   The identification of the profiler event.
+ * @param data       Pointer to the data of the message.
+ * @param data_size  Size of the buffer in 32-bit words.
+ *
+ * @return No return value.
+ */
+void _sys_event_logger_put_non_preemptible(struct event_logger *logger,
+	uint16_t event_id, uint32_t *event_data, uint8_t data_size)
+{
+	extern void _sem_give_non_preemptible(struct nano_sem *sem);
+
+	event_logger_put(logger, event_id, event_data, data_size,
+		_sem_give_non_preemptible);
+}
+
+
+static inline int event_logger_get(struct event_logger *logger,
+	uint32_t *buffer, uint8_t buffer_size)
+{
+	int i;
+	union event_header *header;
+
+	/* obtain the header */
+	header = (union event_header *) &(logger->buffer[logger->tail]);
+	if (buffer_size < EVENT_HEADER_SIZE + header->bits.data_length) {
+		/* if the user can not retrieve the message, we increase the semaphore
+		 * to indicate that the message remains in the buffer */
+		nano_fiber_sem_give(&(logger->sync_sema));
+		return -EMSGSIZE;
+	}
+
+	for (i=0; i < header->bits.data_length + EVENT_HEADER_SIZE; i++) {
+		buffer[i] = logger->buffer[(logger->tail + i) %
+			logger->buffer_size];
+	}
+	logger->tail = (logger->tail + header->bits.data_length +
+		EVENT_HEADER_SIZE) % logger->buffer_size;
+
+	return header->bits.data_length + EVENT_HEADER_SIZE;
+}
+
+
+int sys_event_logger_get(struct event_logger *logger, uint32_t *buffer,
+	uint8_t buffer_size)
+{
+	if (nano_fiber_sem_take(&(logger->sync_sema))) {
+		return sys_event_logger_get(logger, buffer, buffer_size);
+	}
+	return 0;
+}
+
+
+int sys_event_logger_get_wait(struct event_logger *logger, uint32_t *buffer,
+	uint8_t buffer_size)
+{
+	nano_fiber_sem_take_wait(&(logger->sync_sema));
+
+	return event_logger_get(logger, buffer, buffer_size);
+}
+
+
+#ifdef CONFIG_NANO_TIMEOUTS
+int sys_event_logger_get_wait_timeout(struct event_logger *logger,
+	uint32_t *buffer, uint8_t buffer_size, uint32_t timeout)
+{
+	if (nano_fiber_sem_take_wait_timeout(&(logger->sync_sema), timeout)) {
+		return event_logger_get(logger, buffer, buffer_size);
+	}
+	return 0;
+}
+#endif /* CONFIG_NANO_TIMEOUTS */