ipmb.c File Reference

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"
#include "string.h"
#include "utils.h"
#include "ipmb.h"
#include "ipmi.h"
#include "led.h"
#include "port.h"
#include "task_priorities.h"

Include dependency graph for ipmb.c:

Functions
ipmb_error	ipmb_encode (uint8_t *buffer, ipmi_msg *msg)
	Encode IPMI msg struct to a byte formatted buffer.
ipmb_error	ipmb_decode (ipmi_msg *msg, uint8_t *buffer, uint8_t len)
	Decodes a buffer and copies to its specific fields in a ipmi_msg struct.
ipmb_error	ipmb_notify_client (ipmi_msg_cfg *msg_cfg)
	Notifies the client that a new request has arrived and copies the message to its queue. This function receives a message wrapped in a ipmi_msg_cfg struct and copies only the ipmi_msg field to the client queue. Also, if a task has registered its handle in the caller_task field, notify it.
void	IPMB_TXTask (void *pvParameters)
	IPMB Transmitter Task.
void	IPMB_RXTask (void *pvParameters)
	IPMB Receiver Task.
void	ipmb_init (void)
	Initializes the IPMB Layer.
ipmb_error	ipmb_send_request (ipmi_msg *req)
	Format and send a request via IPMB channel.
ipmb_error	ipmb_send_response (ipmi_msg *req, ipmi_msg *resp)
	Format and send a response via IPMB channel.
ipmb_error	ipmb_register_rxqueue (QueueHandle_t *queue)
	Creates and returns a queue in which the client can block to receive the incoming requests.
ipmb_error	ipmb_assert_chksum (uint8_t *buffer, uint8_t buffer_len)
	Asserts the input message checksums by comparing them with our calculated ones.

Variables
uint8_t	ipmb_addr = 0xFF
	AMC IPMB Address.
QueueHandle_t	ipmb_txqueue = NULL
QueueHandle_t	client_queue = NULL

Function Documentation

ipmb_assert_chksum()

ipmb_error ipmb_assert_chksum	(	uint8_t *	buffer,
		uint8_t	buffer_len )

Asserts the input message checksums by comparing them with our calculated ones.

Parameters

buffer	Pointer to the message bytes.
buffer_len	Size of the message.

Return values

ipmb_error_success	The message's checksum bytes are correct, therefore the message is valid.
ipmb_error_hdr_chksum	The header checksum byte is invalid.
ipmb_error_hdr_chksum	The final checksum byte is invalid.

ipmb_decode()

ipmb_error ipmb_decode	(	ipmi_msg *	msg,
		uint8_t *	buffer,
		uint8_t	len )

Decodes a buffer and copies to its specific fields in a ipmi_msg struct.

Parameters

[out]	msg	Pointer to a ipmi_msg struct which will hold the decoded message
[in]	buffer	Pointer to a byte array that will be decoded
[in]	len	Length of buffer

Return values

ipmb_error_success

The message was successfully decoded

ipmb_encode()

ipmb_error ipmb_encode	(	uint8_t *	buffer,
		ipmi_msg *	msg )

Encode IPMI msg struct to a byte formatted buffer.

This function formats the ipmi_msg struct fields into a byte array, following the specification:

IPMB Messages

	REQUEST	RESPONSE	Bit Len	Byte #
Connection	rsSA	rqSA	8	1
Header	NetFN	NetFN	6	2
	rsLUN	rqLUN	2	2
Header Chksum	Chksum	Chksum	8	3
	rqSA	rsSA	8	4
Callback Info	rqSeq	rqSeq	6	5
	rqLUN	rsLUN	2	5
Command	CMD	CMD	8	6
Data		CC	8	7
	Data	Data	8*N	7+N
Message Chksum	Chksum	Checksum	8	7+N+1

Parameters

[out]	buffer	Byte buffer which will hold the formatted message
[in]	msg	The message struct to be formatted

Return values

ipmb_error_success

The message was successfully formatted

ipmb_init()

void ipmb_init

(

void

)

Initializes the IPMB Layer.

Configures the I2C Driver, creates the TX queue for the IPMB Task and both IPMB RX and IPMB TX tasks

ipmb_notify_client()

ipmb_error ipmb_notify_client

(

ipmi_msg_cfg *

msg_cfg

)

Notifies the client that a new request has arrived and copies the message to its queue. This function receives a message wrapped in a ipmi_msg_cfg struct and copies only the ipmi_msg field to the client queue. Also, if a task has registered its handle in the caller_task field, notify it.

Parameters

[in]

msg_cfg

The message that arrived, wrapped in the configuration struct ipmi_msg_cfg.

Return values

ipmb_error_success	The message was successfully copied.
ipmb_error_timeout	The client_queue was full.

ipmb_register_rxqueue()

ipmb_error ipmb_register_rxqueue

(

QueueHandle_t *

queue

)

Creates and returns a queue in which the client can block to receive the incoming requests.

The queue is created and its handler is written at the given pointer (queue). Also keeps a copy of the handler to know where to write the incoming messages.

Parameters

queue

Pointer to a QueueHandle_t variable which will be written by this function.

Return values

ipmb_error_success	The queue was successfully created.
ipmb_error_queue_creation	Queue creation failed due to lack of Heap space.

IPMB_RXTask()

void IPMB_RXTask

(

void *

pvParameters

)

IPMB Receiver Task.

Similarly to IPMB_TXTask, this task remains blocked until a new message is received by the I2C driver. The message passes through checksum checking to assure its integrity.
If the message is a request, we have to check if it's a new one or just a retransmission of the last. In order to do this, the sequential number is tested, since every request has a different one.
Right after that, the arrival time and the message body are stored for future checking and the specified client is notified using ipmb_notify_client.

If we have received a response instead, we match it with the last stored request and also check if the awating request hasn't timed-out yet.

Note

When a malformed message, a response without a request or a repeated request are received, they are just ignored, following the IPMB specifications.

Parameters

pvParameters

Default parameter to FreeRTOS tasks, not used here.

See also

IPMB_TXTask

ipmb_notify_client

ipmb_send_request()

ipmb_error ipmb_send_request

(

ipmi_msg *

req

)

Format and send a request via IPMB channel.

ipmb_send_response()

ipmb_error ipmb_send_response	(	ipmi_msg *	req,
		ipmi_msg *	resp )

Format and send a response via IPMB channel.

IPMB_TXTask()

void IPMB_TXTask

(

void *

pvParameters

)

IPMB Transmitter Task.

When ipmb_send_request or ipmb_send_response put a message in ipmb_txqueue, this task unblocks. First step to send a message is differentiating requests from responses. It does this analyzing the parity of NetFN (even for requests, odd for responses).

When sending a response, this task has to check if it matches with the sequence number from the last known request and the amount of time it took to be built (timeout checking). Last step is checking if it has already tried to send this message more than IPMB_MAX_RETRIES value.
After passing all checking, the message is formatted as the IPMB protocol demands and passed down to the I2C driver, using the function xI2CWrite().
If an error comes out of the I2C driver when sending the message, it increases the retry counter in the ipmi_msg_cfg struct and send the message to the front of ipmb_txqueue.
If no errors occurs, the task that put the message in the queue is notified with a success flag.

The proccess is analog when sending a request, but the only check that is made is the retry number. The task skip all checking because, when sending a request, the message is formatted using it's own functions ipmb_send_request or ipmb_send_response and they are guaranteed to put only valid messages in queue.

Parameters

pvParameters

Default parameter to FreeRTOS tasks, not used here.

See also

IPMB_RXTask

ipmb_send_request

ipmb_send_response

Variable Documentation

client_queue

QueueHandle_t client_queue = NULL

ipmb_addr

uint8_t ipmb_addr = 0xFF

AMC IPMB Address.

This variable saves this module's IPMB address read through the Geographical Address pins

See also

get_ipmb_addr

ipmb_txqueue

QueueHandle_t ipmb_txqueue = NULL