NN packet handling for SC&MP. More...

#include <stdlib.h>
#include "spinnaker.h"
#include "sark.h"
#include "scamp.h"

Data Structures
struct	nn_desc_t
	Nearest neighbour protocol state. More...

Macros
#define	BC_TABLE_SIZE 16
	Number of packets to allocate for the nearest neighbour protocols.

#define	PART_ID (CHIP_ID_CODE & 0xfff00000)
	Device identifier (`0x591 << 28`, for SpiNNaker)

#define	P2PB_STOP_BIT 0x400
	Set to stop propagation.

Enumerations
enum	ff_states { FF_ST_IDLE = 0 , FF_ST_EXBLK = 1 , FF_ST_INBLK = 2 }
	Flood fill states. More...

enum	sig0_operations { SIG0_FWD_RTRY , SIG0_LEDS , SIG0_GTP , SIG0_ID , SIG0_LEVEL , SIG0_APP , SIG0_TP , SIG0_RST , SIG0_DOWN , SIG0_UP }
	Operation codes for nn_cmd_sig0() More...

enum	sig1_operations { SIG1_WRITE }
	Operation codes for nn_cmd_sig1() More...

Functions
void	send_nn_links (uint)

void	nn_init (void)
	Initialise the nearest-neighbour data structures.

void	compute_eth (void)
	Computes where our board's ethernet chip is.

void	peek_ack_pkt (uint link, uint data, uint key)
	Initialises peek_pkt to contain the given arguments (presumably an acknowledge)

void	poke_ack_pkt (uint link, uint data, uint key)
	Initialises poke_pkt to contain the given arguments (presumably an acknowledge)

uint	link_read_word (uint addr, uint link, uint *buf, uint timeout)
	Read a word from the chip (or device) over a link.

uint	link_write_word (uint addr, uint link, uint *buf, uint timeout)
	Write a word to the chip (or device) over a link.

pkt_buf_t *	pkt_buf_get (void)
	Allocate a packet (getting one from the free list, pkt_buf_list).

void	pkt_buf_free (pkt_buf_t *pkt)
	Add packet to free list (pkt_buf_list), "freeing" it.

void	nn_mark (uint key)
	Mark an ID as discovered.

static void	nn_cmd_rtrc (uint data)
	Write the Router Control Register.

uint	nn_cmd_sig0 (uint data)
	SIG0 does simple commands whose data fits into 28 bits.

static void	nn_cmd_mem (uint data, uint key)
	Memory write operations.

void	nn_cmd_sig1 (uint data, uint key)
	SIG1 does simple commands with a payload whose control fits in 20 bits.

static uint	nn_cmd_p2pb (uint id, uint data, uint link)
	P2P Broadcast, used to propagate P2P addresses and maintain the P2P routing table.

static void	proc_pkt_bc (uint i_pkt, uint count)
	Nearest neighbour packet broadcast handler.

void	nn_rcv_pkt (uint link, uint data, uint key)
	Nearest-neighbour packet received handler.

Flood fill
uint	next_id (void)
	Get the next flood-fill identifier we should use.

void	ff_nn_send (uint key, uint data, uint fwd_rty, uint add_id)
	Flood fill NN packet sender.

static void	nn_cmd_ffs (uint data, uint key)
	Flood fill start.

static uint	nn_cmd_ffcs (uint data, uint key)
	Flood fill core select.

static uint	nn_cmd_fbs (uint id, uint data, uint key)
	Flood fill block start.

static uint	nn_cmd_fbd (uint id, uint data, uint key)
	Flood fill block data.

static uint	nn_cmd_fbe (uint id, uint data, uint key)
	Flood fill block end.

static uint	nn_cmd_ffe (uint id, uint data, uint key)
	Flood fill end.

Board information flood fill
uint	next_biff_id (void)
	Get the next board info flood-fill identifier we should use.

void	biff_nn_send (uint data)
	Board information flood fill packet sender.

void	nn_cmd_biff (uint x, uint y, uint data)
	Board information flood fill command handler.

void	nn_rcv_biff_pct (uint link, uint data, uint key)

void	send_nn_netinit (uint netinit_level)

P2PC
void	p2pc_addr_nn_send (uint arg1, uint arg2)
	Transmit our current best guess of coordinates to all neighbouring chips.

void	p2pc_new_nn_send (uint x, uint y)
	Broadcast the existence of a new P2P coordinate having been discovered.

void	p2pc_dims_nn_send (uint arg1, uint arg2)
	Transmit our current best guess of coordinates to all neighbouring chips.

void	p2pc_reth_nn_send (uint eth, uint arg2)
	Transmit our address back to an Ethernet.

void	p2pb_nn_send (uint arg1, uint arg2)
	Transmit "P2PB" table generating packets.

static void	nn_rcv_p2pc_addr_pct (uint link, uint data, uint key)
	Update our current best guess of our coordinates based on a packet from a neighbour.

static void	nn_rcv_p2pc_new_pct (uint link, uint data, uint key)
	A new P2P coordinate has been broadcast to us.

static void	nn_rcv_p2pc_dims_pct (uint link, uint data, uint key)
	A neighbour has reported their P2P coordinates to us.

static void	nn_rcv_p2pc_reth_pct (uint link, uint data, uint key)
	A P2P address to link back to Ethernet has been sent.

void	nn_rcv_p2pc_pct (uint link, uint data, uint key)
	Handle P2PC packet.

Variables
pkt_buf_t	pkt_buf_table [BC_TABLE_SIZE]
	Storage for packets used in pkt_buf_list.

pkt_buf_t *	pkt_buf_list
	Free list of packets.

uint	pkt_buf_count
	Number of packets (in pkt_buf_table) not on free list (pkt_buf_list)

uint	pkt_buf_max
	Statistics: maximum value of pkt_buf_count.

uint *	hop_table
	Table "hop_table" has entries of type `(id << 24, hops)` for each possible P2P address.

uchar	core_app [MAX_CPUS]
	What application (or at least AppID) is running on each core.

uint	app_mask [256]
	Unused?

static nn_desc_t	nn_desc
	Nearest neighbour protocol state.

pkt_buf_t	peek_pkt
	Packet reserved for performing P2P peeks.

pkt_buf_t	poke_pkt
	Packet reserved for performing P2P pokes.

uint	mon_del = 0
	delegate blacklisted monitor

volatile uint	neighbour_netinit_level [NUM_LINKS]
	neighbour over link netinit level

volatile uint	neighbour_links_enabled [NUM_LINKS]
	neighbour over link links enabled

uint	pp_ping_count [NUM_LINKS]

uint	mc_ping_count [NUM_LINKS]
	Reserved for performing MC and P2P pings.

char	eth_map [12][12]
	Local ethernet chip locator map.

Level deltas
Given a packet arriving from a given direction which is labelled with an X and Y coordinate, gives the dx, dy to get the current chip's coordinate.
const signed char	lx [6] = {-1, -1, 0, +1, +1, 0}
	X deltas, by link ID.

const signed char	ly [6] = { 0, -1, -1, 0, +1, +1}
	Y deltas, by link ID.

Detailed Description

NN packet handling for SC&MP.

Copyright: © The University of Manchester - 2009-2011

Author: Steve Temple, APT Group, School of Computer Science

Data Structure Documentation

◆ nn_desc_t

struct nn_desc_t

Nearest neighbour protocol state.

Data Fields
uchar	state	FF state (see ff_states enum)
uchar	error	Error flag.
uchar	forward	Rebroadcast code.
uchar	retry	Rebroadcast retry.
uchar	id	ID of current FF.
uchar	block_len	Block length.
uchar	block_count	Block count.
uchar	block_num	Block number.
uchar	app_id	AppID.
uchar	load	Whether to load locally.
ushort	srce_addr	P2P of sender.
ushort	word_len	Number of words in block.
ushort	word_count	Count of received words.
uint	gidr_id	GIDR ID.
uint	sum	Checksum.
uint	cores	Selected cores to load.
uint *	aplx_addr	APLX block addr.
uint	load_addr	Block load base.
uint	id_set[4]	ID bitmap (128 bits)
uint	biff_id_set[4]	Board-level flood-fill ID bitmap (128 bits)
uint	fbs_set[8]	Block bitmap for FBS (must be >= 8 words)
uint	fbd_set[8]	Word bitmap for FBD (must be >= 8 words)
uint	fbe_set[8]	Block bitmap for FBE (must be >= 8 words)
uint	stats[16]	Counters for each packet type.
uint	errors	Counter for bad checksums.
uint	buf[SDP_BUF_SIZE/4]	Holding buffer.
uint64	last_ffcs	Index of the last FFCS packet.

Enumeration Type Documentation

◆ ff_states

enum ff_states

Flood fill states.

Enumerator
FF_ST_IDLE	Doing nothing.
FF_ST_EXBLK	Rcvd FFS or FBE, awaiting FBS, FFE.
FF_ST_INBLK	Rcvd FBS, awaiting FBD, FBE.

◆ sig0_operations

enum sig0_operations

Operation codes for nn_cmd_sig0()

Enumerator
SIG0_FWD_RTRY	Set forward and retry.
SIG0_LEDS	Set LEDs (call sark_led_set())
SIG0_GTP	Global Time Phase.
SIG0_ID	ID set/reset.
SIG0_LEVEL	Trigger level_config() _(unimplemented)_.
SIG0_APP	Signal application (call signal_app())
SIG0_TP	Router time phase period _(unimplemented)_.
SIG0_RST	Shut down APs _(unimplemented)_.
SIG0_DOWN	Minimum power mode _(unimplemented)_.
SIG0_UP	Operational mode _(unimplemented)_.

◆ sig1_operations

enum sig1_operations

Operation codes for nn_cmd_sig1()

Enumerator
SIG1_WRITE	Memory write.

Function Documentation

◆ peek_ack_pkt()

void peek_ack_pkt	(	uint	link,
		uint	data,
		uint	key
	)

Initialises peek_pkt to contain the given arguments (presumably an acknowledge)

Parameters

[in]	link	Which link to send the packet on
[in]	data	The payload of the packet
[in]	key	The key of the packet

◆ poke_ack_pkt()

void poke_ack_pkt	(	uint	link,
		uint	data,
		uint	key
	)

Initialises poke_pkt to contain the given arguments (presumably an acknowledge)

Parameters

[in]	link	Which link to send the packet on
[in]	data	The payload of the packet
[in]	key	The key of the packet

◆ link_read_word()

uint link_read_word	(	uint	addr,
		uint	link,
		uint *	buf,
		uint	timeout
	)

Read a word from the chip (or device) over a link.

Parameters

[in]	addr	The address to read from
[in]	link	The link to use
[out]	buf	The data that has been read (4 byte buffer)
[in]	timeout	How long to wait for the other side to respond

Returns: result code

◆ link_write_word()

uint link_write_word	(	uint	addr,
		uint	link,
		uint *	buf,
		uint	timeout
	)

Write a word to the chip (or device) over a link.

Parameters

[in]	addr	The address to write to
[in]	link	The link to use
[in]	buf	The data that is to be written (buffer containing 4 bytes)
[in]	timeout	How long to wait for the other side to respond

Returns: result code

◆ pkt_buf_get()

pkt_buf_t * pkt_buf_get ( void )

Allocate a packet (getting one from the free list, pkt_buf_list).

Returns: The allocated packet, or NULL if none available

◆ pkt_buf_free()

void pkt_buf_free ( pkt_buf_t * pkt )

Add packet to free list (pkt_buf_list), "freeing" it.

Parameters

[in] pkt Packet to free.

◆ next_id()

uint next_id ( void )

Get the next flood-fill identifier we should use.

Returns: A new flood fill ID (range: 2–254)

◆ next_biff_id()

uint next_biff_id ( void )

Get the next board info flood-fill identifier we should use.

Returns: A new flood fill ID (range: 2–254)

◆ nn_mark()

void nn_mark ( uint key )

Mark an ID as discovered.

Parameters

[in] key The key from the NN packet

◆ ff_nn_send()

void ff_nn_send	(	uint	key,
		uint	data,
		uint	fwd_rty,
		uint	add_id
	)

Flood fill NN packet sender.

Parameters

[in]	key	The key to use
[in]	data	The data to use
[in]	fwd_rty	Forward/delay/retry configuration
[in]	add_id	Whether to merge the next_id() result into the key

◆ biff_nn_send()

void biff_nn_send ( uint data )

Board information flood fill packet sender.

Note: Should only be called on chips which are at position (0, 0) on their board.

Parameters

[in] data The payload of the packet to send.

◆ p2pc_addr_nn_send()

void p2pc_addr_nn_send	(	uint	arg1,
		uint	arg2
	)

Transmit our current best guess of coordinates to all neighbouring chips.

Parameters

arg1	unused
arg2	unused

◆ p2pc_new_nn_send()

void p2pc_new_nn_send	(	uint	x,
		uint	y
	)

Broadcast the existence of a new P2P coordinate having been discovered.

Parameters

[in]	x	X coordinate
[in]	y	Y coordinate

◆ p2pc_dims_nn_send()

void p2pc_dims_nn_send	(	uint	arg1,
		uint	arg2
	)

Transmit our current best guess of coordinates to all neighbouring chips.

Parameters

arg1	unused
arg2	unused

◆ p2pc_reth_nn_send()

void p2pc_reth_nn_send	(	uint	eth,
		uint	arg2
	)

Transmit our address back to an Ethernet.

Parameters

eth	The Ethernet address to send to
arg2	unused

◆ p2pb_nn_send()

void p2pb_nn_send	(	uint	arg1,
		uint	arg2
	)

Transmit "P2PB" table generating packets.

Parameters

arg1	unused
arg2	unused

◆ nn_rcv_p2pc_addr_pct()

static void nn_rcv_p2pc_addr_pct	(	uint	link,
		uint	data,
		uint	key
	)

static

Update our current best guess of our coordinates based on a packet from a neighbour.

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_rcv_p2pc_new_pct()

static void nn_rcv_p2pc_new_pct	(	uint	link,
		uint	data,
		uint	key
	)

static

A new P2P coordinate has been broadcast to us.

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_rcv_p2pc_dims_pct()

static void nn_rcv_p2pc_dims_pct	(	uint	link,
		uint	data,
		uint	key
	)

static

A neighbour has reported their P2P coordinates to us.

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_rcv_p2pc_reth_pct()

static void nn_rcv_p2pc_reth_pct	(	uint	link,
		uint	data,
		uint	key
	)

static

A P2P address to link back to Ethernet has been sent.

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_rcv_p2pc_pct()

void nn_rcv_p2pc_pct	(	uint	link,
		uint	data,
		uint	key
	)

Handle P2PC packet.

Delegates to:

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_cmd_rtrc()

static void nn_cmd_rtrc ( uint data )

static

Write the Router Control Register.

Parameters

[in] data payload from the NN packet. Various fields may be selected using 'spare' bits in the word. The field is updated if the bit is set.
bit 5 — Wait2
bit 4 — Wait1
bit 3 — W bit
bit 2 — MP field
bit 1 — TP field

◆ nn_cmd_sig0()

uint nn_cmd_sig0 ( uint data )

SIG0 does simple commands whose data fits into 28 bits.

Delegates to:

sark_led_set()
level_config()
signal_app()
Parameters

[in] data The message payload

Returns
0 if packet should not be propagated, 1 otherwise.

◆ nn_cmd_mem()

static void nn_cmd_mem	(	uint	data,
		uint	key
	)

static

Memory write operations.

Parameters

[in]	data	The data to write
[in]	key	The key from the NN packet. Encodes where to write relative to (sv, sysram, sc, or sv_t::mem_ptr), what the offset should be, and how much to write (1, 2 or 4 bytes).

◆ nn_cmd_sig1()

void nn_cmd_sig1	(	uint	data,
		uint	key
	)

SIG1 does simple commands with a payload whose control fits in 20 bits.

Delegates to:

nn_cmd_mem()
Parameters

[in] data The payload from the NN packet

[in] key The key from the NN packet

◆ nn_cmd_p2pb()

static uint nn_cmd_p2pb	(	uint	id,
		uint	data,
		uint	link
	)

static

P2P Broadcast, used to propagate P2P addresses and maintain the P2P routing table.

Table "hop_table" has entries of type (id << 24, hops) for each possible P2P address. Field "hops" contains the number of hops to the address (initialised to 65535) and "id" contains the ID of the last packet used to update the table (initialised to 128).

An update occurs when a packet with a lower hop count than the current one arrives via an enabled link. The link on which the packet arrived is used to update the P2P routing table.

Parameters

[in]	id	The ID from the key of the packet
[in]	data	The payload of the packet
[in]	link	What route the packet came from

Returns: data, with P2P_STOP_BIT set if the packet should not be propagated

◆ nn_cmd_ffs()

static void nn_cmd_ffs	(	uint	data,
		uint	key
	)

static

Flood fill start.

Parameters

[in]	data	The payload of the packet
[in]	key	The key of the packet

◆ nn_cmd_ffcs()

static uint nn_cmd_ffcs	(	uint	data,
		uint	key
	)

static

Flood fill core select.

Parameters

[in]	data	The payload of the packet
[in]	key	The key of the packet

Returns: 1 if the packet should not be propagated further

◆ nn_cmd_fbs()

static uint nn_cmd_fbs	(	uint	id,
		uint	data,
		uint	key
	)

static

Flood fill block start.

Parameters

[in]	id	The ID from the key of the packet
[in]	data	The payload of the packet
[in]	key	The key of the packet

Returns: 1 if the packet should not be propagated further

◆ nn_cmd_fbd()

static uint nn_cmd_fbd	(	uint	id,
		uint	data,
		uint	key
	)

static

Flood fill block data.

Parameters

[in]	id	The ID from the key of the packet
[in]	data	The payload of the packet
[in]	key	The key of the packet

Returns: 1 if the packet should not be propagated further

◆ nn_cmd_fbe()

static uint nn_cmd_fbe	(	uint	id,
		uint	data,
		uint	key
	)

static

Flood fill block end.

Parameters

[in]	id	The ID from the key of the packet
[in]	data	The payload of the packet
[in]	key	The key of the packet

Returns: 1 if the packet should not be propagated further

◆ nn_cmd_ffe()

static uint nn_cmd_ffe	(	uint	id,
		uint	data,
		uint	key
	)

static

Flood fill end.

Parameters

[in]	id	The ID from the key of the packet
[in]	data	The payload of the packet
[in]	key	The key of the packet

Returns: 1 if the packet should not be propagated further

◆ proc_pkt_bc()

static void proc_pkt_bc	(	uint	i_pkt,
		uint	count
	)

static

Nearest neighbour packet broadcast handler.

Parameters

[in]	i_pkt	(Type-punned) pkt_buf_t pointer
[in]	count	Number of times to try; should be at least 1

◆ nn_cmd_biff()

void nn_cmd_biff	(	uint	x,
		uint	y,
		uint	data
	)

Board information flood fill command handler.

Can be invoked directly during setup, or in response to a BIFF message.

Parameters

[in]	x	The believed X coordinate
[in]	y	The believed Y coordinate
[in]	data	The payload word from the message

◆ nn_rcv_biff_pct()

void nn_rcv_biff_pct	(	uint	link,
		uint	data,
		uint	key
	)

Board info flood fill packet receiver

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

◆ nn_rcv_pkt()

void nn_rcv_pkt	(	uint	link,
		uint	data,
		uint	key
	)

Nearest-neighbour packet received handler.

Parameters

[in]	link	What link was the packet received on
[in]	data	The payload from the packet
[in]	key	The key from the packet

Variable Documentation

◆ hop_table

uint* hop_table

Table "hop_table" has entries of type (id << 24, hops) for each possible P2P address.

Field "hops" contains the number of hops to the address (initialised to 65535) and "id" contains the ID of the last packet used to update the table (initialised to 128). These are packed into a word.

Stored in SYSRAM so visible to all cores. Should only be updated by SCAMP

◆ eth_map

char eth_map[12][12]

Initial value:

= {
    {0x00, 0x10, 0x20, 0x30, 0x40, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74},
    {0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75},
    {0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x36, 0x46, 0x56, 0x66, 0x76},
    {0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, 0x47, 0x57, 0x67, 0x77},
 
    {0x40, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, 0x00, 0x10, 0x20, 0x30},
    {0x41, 0x51, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, 0x01, 0x11, 0x21, 0x31},
    {0x42, 0x52, 0x62, 0x36, 0x46, 0x56, 0x66, 0x76, 0x02, 0x12, 0x22, 0x32},
    {0x43, 0x53, 0x63, 0x73, 0x47, 0x57, 0x67, 0x77, 0x03, 0x13, 0x23, 0x33},
 
    {0x44, 0x54, 0x64, 0x74, 0x00, 0x10, 0x20, 0x30, 0x40, 0x14, 0x24, 0x34},
    {0x45, 0x55, 0x65, 0x75, 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x25, 0x35},
    {0x46, 0x56, 0x66, 0x76, 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x36},
    {0x47, 0x57, 0x67, 0x77, 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73}
}

Local ethernet chip locator map.

Given a P2P address, compute P2P address of chip with Ethernet interface on same PCB. Table is for standard 48-chip boards only. Will work with 4-chip boards - may not work for more exotic combinations! Also computes the position of the chip on the PCB as offset from (0,0)

Each byte in this table is a pair of X,Y values which are subtracted from a P2P address to give the address of the Ethernet-attached chip on the same 48-chip PCB.

[in]	data	The payload from the NN packet
[in]	key	The key from the NN packet

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Data Structure Documentation

◆ nn_desc_t

Enumeration Type Documentation

◆ ff_states

◆ sig0_operations

◆ sig1_operations

Function Documentation

◆ peek_ack_pkt()

◆ poke_ack_pkt()

◆ link_read_word()

◆ link_write_word()

◆ pkt_buf_get()

◆ pkt_buf_free()

◆ next_id()

◆ next_biff_id()

◆ nn_mark()

◆ ff_nn_send()

◆ biff_nn_send()

◆ p2pc_addr_nn_send()

◆ p2pc_new_nn_send()

◆ p2pc_dims_nn_send()

◆ p2pc_reth_nn_send()

◆ p2pb_nn_send()

◆ nn_rcv_p2pc_addr_pct()

◆ nn_rcv_p2pc_new_pct()

◆ nn_rcv_p2pc_dims_pct()

◆ nn_rcv_p2pc_reth_pct()

◆ nn_rcv_p2pc_pct()

◆ nn_cmd_rtrc()

◆ nn_cmd_sig0()

◆ nn_cmd_mem()

◆ nn_cmd_sig1()

◆ nn_cmd_p2pb()

◆ nn_cmd_ffs()

◆ nn_cmd_ffcs()

◆ nn_cmd_fbs()

◆ nn_cmd_fbd()

◆ nn_cmd_fbe()

◆ nn_cmd_ffe()

◆ proc_pkt_bc()

◆ nn_cmd_biff()

◆ nn_rcv_biff_pct()

◆ nn_rcv_pkt()

Variable Documentation

◆ hop_table

◆ eth_map