ONL NP Router
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Transcript ONL NP Router
ONL NP Router
xScale
xScale
Assoc. Data
ZBT-SRAM
SRAM
xScale
NN
NN
HdrFmt
(1 ME)
Tx
(1 ME)
64KW
Each
NN
NN
NN
NN
SRAM
Plugin4
SRAM
Ring
Scratch
Ring
QM
(1 ME)
Plugin3
64KW
Parse,
Lookup,
Copy
(3 MEs)
Plugin1
Mux
(1 ME)
Plugin0
Rx
(2 ME)
64KW
SRAM
Plugin2
TCAM
NN
Ring
QM
Copy
Plugins
‹#› - John DeHart, Jing Lu - 5/23/2016
Stats
(1 ME)
SRAM
Tx, QM
Parse
Plugin
XScale
FreeList Mgr
(1 ME)
MUX -> PLC
Rsv Out
Port
(4b) (4b)
Buffer Handle(24b)
L3 (IP, ARP, …) Pkt
Length (16b)
Plugin In
Tag Port
(5b) (3b)
Mux
Flags
(8b)
QID(16b)
Stats Index (16b)
Flags:
Src: Source (2b):
00: Rx
01: XScale
10: Plugin
11: Undefined
PT(1b): PassThrough(1)/Classify(0)
Reserved (5b)
Reserved (5b)
7
‹#› - John DeHart, Jing Lu - 5/23/2016
3
Src
(2b)
PT
(1b)
2 1
0
PLC
PLC -> XScale
XScale
Rsv
(8b)
Buffer Handle(24b)
SRAM
L3 (IP, ARP, …)
Pkt Length (16b)
Plugin In
Tag Port
(5b) (3b)
Flags
(8b)
QID(16b)
Stats Index (16b)
NH MAC DA[47:16] (32b)
xScale
NH MAC DA[15:0]
(16b)
EtherType (16b)
Reserved (16b)
Unicast/MCast bits
(16b)
Flags(8b):
Why pkt is being sent to XScale
TTL(1b): TTL expired
Options(1b): IP Options present
NoRoute(1b): No matching route or filter
NonIP(1b): Non IP Packet received
ARP_Needed(1b): NH_IP valid, but no MAC
NH_Invalid(1b): NH_IP AND NH_MAC both
invalid
Reserved(2b): currently unused
PLC
Reserved
(2b)
7
‹#› - John DeHart, Jing Lu - 5/23/2016
NH
INV
(1b)
5
Same as ring_in
ARP NI
(1b) (1b)
4 3
NR
(1b)
Opt
(1b)
2 1
TTL
(1b)
0
Based on Parse &
Lookup results
PLC -> Plugins
Rsv
(8b)
Buffer Handle(24b)
L3 (IP, ARP, …)
Pkt Length (16b)
Plugin In
Tag Port
(5b) (3b)
Flags
(8b)
SRAM
Same as ring_in
QID(16b)
Based on Parse &
Lookup results
Stats Index (16b)
NH MAC DA[47:16] (32b)
PLC
xScale
NH MAC DA[15:0]
(16b)
EtherType (16b)
Reserved (16b)
Unicast/MCast bits
(16b)
Flags(8b):
Why pkt is being sent to XScale
TTL(1b): TTL expired
Options(1b): IP Options present
NoRoute(1b): No matching route or filter
NonIP(1b): Non IP Packet received
ARP_Needed(1b): NH_IP valid, but no MAC
NH_Invalid(1b): NH_IP AND NH_MAC both
invalid
Reserved(2b): currently unused
Reserved
(2b)
7
NH
INV
(1b)
5
ARP NI
(1b) (1b)
4 3
NR
(1b)
2 1
Plugins 0-4
‹#› - John DeHart, Jing Lu - 5/23/2016
Opt
(1b)
TTL
(1b)
0
PLC -> QM
Rsv
(8b)
PLC
Rsv
(4b)
Out
Port
(4b)
Buffer Handle(24b)
Rsv
(8b)
L3 (IP, ARP, …)
Pkt Length (16b)
Same as ring_in
Based on Parse & Lookup results
Maybe the added hdr buffer handle
‹#› - John DeHart, Jing Lu - 5/23/2016
QID(16b)
Reserved(16b)
QM
Types of Pkts Arriving at PLC
From
Rx:
»Only have a payload buf, ref_cnt == 1.
»Subject to classification except mal-formed IP pkts detected by
Parse.
From
XScale/Plugins:
»Passthrough (PT) pkt
May/May not have a hdr buf, ref_cnt >= 1.
Not processed by PLC.
Copy sends it to QM.
»Non-PT pkt
Only have a payload buf at arrival, ref_cnt >= 1.
Is IP pkt.
Will be classified if it passes IP hdr validation done by Parse.
‹#› - John DeHart, Jing Lu - 5/23/2016
PLC()
PLC()
{
if (!ring_in.PT) {
Parse();
if (dlNextBlock != BID_FREELISTMGR)
Lookup();
}
Copy();
}
Inside Copy(), dl_sink() is called to enqueue pkts to downstream
blocks.
‹#› - John DeHart, Jing Lu - 5/23/2016
dl_sink
Special design of dl_sink(first, last, try_action)
» “first” == TRUE, means current pkt is the first one of a sequence of pkts
to be sunk.
» “last” == TRUE, means current pkt is the last one of a sequence of pkts
to be sunk.
» “try_action” == 1, drop the pkt if ring is full; otherwise try till succeeds.
» dl_sink() has a return value to indicate if enqueue is successful or not.
» If DL_ORDERED is defined and “first” == TRUE, thread waits for signal
from previous context before enqueuing the first pkt.
» If DL_ORDERED is defined and “last” == TRUE, thread passes signal to
next context after euqueuing the last pkt.
‹#› - John DeHart, Jing Lu - 5/23/2016
Parse
Functions:
» Do IP Router checks (wrong ver, Hlen, Plen, cksum), count error pkts.
» Decrement TTL on pkts from Rx and recompute IP cksum
» Detect exceptions (expired TTL, IP option, Non-IP)
» Extract lookup key
Input:
» ring_in data
Output:
» lookup key, dlNextBlock, eth_type, DG QID.
140 Bit Key:
IP DAddr (32b)
IP SAddr (32b)
P
Exceptions
P Proto
Tag(3b) (8b) DPort (16b) SPort (16b)
(16b)
(5b)
RL
PF and AF
‹#› - John DeHart, Jing Lu - 5/23/2016
TCP
Flags
(12b)
Parse
Operations:
» If pkt is from Rx:
Read eth_type in Ethernet hdr
If eth_type != 0x0800, set NIP in exception bits.
– If eth_type == 0x0806, set ARP in exception bits.
Return.
» eth_type <= 0x0800.
» For pkt from Rx, offset <= 0x18E; for pkt from XScale/plugins, get
offset from payload buf desc.
» Read 20B IP hdr.
Check for ver, Hlen, Plen. If fails, count and dlNextBlock <=
BID_FREELISTMGR. Return.
If Hlen > 5, set OPT in exception bits, read IP option.
Verify cksum. If fails, count and dlNextBlock <= BID_FREELISTMGR. Return.
If pkt is from Rx and TTL <= 1, or pkt is from plugins/XScale and TTL < 1, set
TTL in exception bits.
If pkt is from Rx and TTL > 1, decrement TTL, recompute cksum and write
them back to dram.
Form Datagram QID using DG QID = SA[9:8] SA[6:5] DA[6:5] (Used by Copy
in case of a zero QID).
Extract key from IP hdr.
If IP protocol is TCP/UDP, read 14B, and extract key from TCP/UDP hdr.
Copy Plugin Tag and In Port to lookup key.
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup Key and Results Formats
140 Bit Key:
IP DAddr (32b)
P
Exceptions
P Proto
Tag(3b) (8b) DPort (16b) SPort (16b)
(16b)
(5b)
IP SAddr (32b)
TCP
Flags
(12b)
RL
PF and AF
32 Bit Result in TCAM
Assoc. Data SRAM:
M Prio
(1b) (1b) H (8b)
(1b)
Address (21b)
AF
D H
M Res
(1b) (1b) H (8b)
(1b)
Address (21b)
RL
M Res
(1b) (1b) H (8b)
(1b)
Address (21b)
PF
D H
D H
TCAM Ctrl
Bits:
D:Done
H:HIT
MH:Multi-Hit
‹#› - John DeHart, Jing Lu - 5/23/2016
NH
Entry
IP
Valid
Valid
(1b)
(1b)
96 Bit Result in
QDR SRAM Bank0:
V
(4b)
UCast
MCast
R
Uni
e
s Cast
(2b)(2b) (8b)
V
(4b)
NH
IP
MAC MC
Valid Valid
(1b) (1b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
(12b)
S
B
(4b)
V
QID (16b)
UCast
MCast
(12b)
Reserved D PPS
(4b)
(1b) (1b)
PPS
(1b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
Multicast Copy Vector (11b)
•If IP MC Valid = 0
•If IP MC Valid = 1
Lookup Overview
Initialization
» Control Plane initializes TCAM and Route and Filter DBs
Runtime Updates
» Control Plane updates to Route and Filter DBs
Design – in upcoming slides
Processing – in upcoming slides
Lookup will be written in C
» There are many things about writing IXP code in “C” that I
need to learn. Here are some of them:
Performing multiple memory operations in parallel and waiting on a
set of signals (If needed for performance reasons)
Performing timestamp waits
Calling IDT microcode macros
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup: Design -- Databases
Three Databases:
» Route Lookup:
Unicast
Multicast
Sorted by DAddr Prefix Length
Exact match on DAddr and prefix of SAddr
» Primary Filter
Filters should be sorted in the DB with higher priority filters first
Filters should be sorted in the DB with higher priority filters first
» Auxiliary Filter
Priority between Primary Filter and Route Lookup
» A priority will be stored with each Primary Filter
» A priority will be assigned to RLs (all routes have same priority)
» PF priority and RL priority compared after result is retrieved.
One of them will be selected based on this priority comparison.
Auxiliary Filters:
» If matched, cause a copy of packet to be sent out according to the Aux Filter’s result.
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup: Design -- Results
Use SRAM Bank 0 (2 MB per NPU) for Results
» B0 Byte Address Range: 0x000000 – 0x1FFFFF
21 bits
» B0 Word Address Range: 0x000000 – 0x1FFFFC
19 significant bits
2 trailing 0’s
Store result in two parts:
» 32-bit Associated Data SRAM result for Address of actual Result:
TCAM Control Bits (3b)
Priority: 8b
Done: 1b
Hit: 1b
MHit: 1b
Present for Primary Filters, for RL and Aux Filters should be 0
SRAM B0 Word Address: 21b
2 spare bitS if needed for anything else
» 3 Words (<= 96 bits) of Result in SRAM Bank0
Use Multi-Database Lookup (MDL) Indirect for searching all 3 DBs
» Order of fields in Key is important.
Each thread will need one TCAM context
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup Processing
write KEY to TCAM
use timestamp delay to wait appropriate time
make delay long enough that we are as sure as possible that we will
have to read the 1st word of the Results MB only once
while !DoneBit
// DONE Bit BUG Fix requires reading just first word
read 1 word from Results Mailbox and check DoneBit
done
read words 2 and 3 from Results Mailbox
If (PrimaryFilter AND RouteLookup results HIT) {
PrimaryResult.Valid TRUE
compare priorities
store higher priority result as Primary Result (read result from SRAM Bank0)
} else if (PrimaryFilter results HIT) {
PrimaryResult.Valid TRUE
PrimaryResults.* PrimaryFilter.* (read result from SRAM Bank0)
} else if (RouterLookup results HIT) {
PrimaryResult.Valid TRUE
PrimaryResults.* RouteLookup.* (read result from SRAM Bank0)
} else PrimaryResult.Valid False
if (AuxiliaryFilter result HIT) {
AuxiliaryResult.Valid TRUE
AuxiliaryResults.* (read result from SRAM Bank0)
} else AuxiliaryResult.Valid FALSE
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup Key and Results Formats
140 Bit Key:
IP DAddr (32b)
P
Exceptions
P Proto
Tag(3b) (8b) DPort (16b) SPort (16b)
(16b)
(5b)
IP SAddr (32b)
TCP
Flags
(12b)
RL
PF and AF
32 Bit Result in TCAM
Assoc. Data SRAM:
M Prio
(1b) (1b) H (8b)
(1b)
Address (21b)
AF
D H
M Res
(1b) (1b) H (8b)
(1b)
Address (21b)
RL
M Res
(1b) (1b) H (8b)
(1b)
Address (21b)
PF
D H
D H
TCAM Ctrl
Bits:
D:Done
H:HIT
MH:Multi-Hit
‹#› - John DeHart, Jing Lu - 5/23/2016
NH
Entry
IP
Valid
Valid
(1b)
(1b)
96 Bit Result in
QDR SRAM Bank0:
V
(4b)
UCast
MCast
R
Uni
e
s Cast
(2b)(2b) (8b)
V
(4b)
NH
IP
MAC MC
Valid Valid
(1b) (1b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
(12b)
S
B
(4b)
V
QID (16b)
UCast
MCast
(12b)
Reserved D PPS
(4b)
(1b) (1b)
PPS
(1b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
Multicast Copy Vector (11b)
•If IP MC Valid = 0
•If IP MC Valid = 1
Exception Bits in Lookup Key
140 Bit Key:
IP DAddr (32b)
IP SAddr (32b)
P
Exceptions
P Proto
Tag(3b) (8b) DPort (16b) SPort (16b)
(16b)
(5b)
TCP
Flags
(12b)
RL
PF and AF
Reserved (12b)
Exception
Non-IP ARP
(1b)
(1b)
Bits:
»TTL: TTL has expired. It was 0 or 1 on arriving packet
»IP Opt: IP Packet contained Options
»ARP: Ethertype field in ethernet header was ARP
»Non-IP: Ethertype field in ethernet header was NOT IP
NOTE: An ARP packet will have ARP bit and Non-IP bit set
‹#› - John DeHart, Jing Lu - 5/23/2016
IP Opt
(1b)
TTL
(1b)
Lookup Block Diagram
mem access
Latency
Setup Lookup Key
Write Lookup Key to TCAM
SRAM Write: 5W
TimeStamp Delay
315 cycles
ctx_swap
Read 1W Result from AD
SRAM Read: 1W
150 cycles
SRAM Read: 2W
150 cycles
SRAM Read: 3W
SRAM Read: 3W
150 cycles
150 cycles
ctx_swap
Check Done Bit
Read 2W Result from AD
ctx_swap
Read 2 Full Results from QDR
ctx_swap
Setup Results for Copy
TOTAL (No optimization) 915 cycles
‹#› - John DeHart, Jing Lu - 5/23/2016
Lookup File locations
Code
» src/applications/ONL_Router/src/plc/ONL/lookup.c
Include Paths
» src/applications/ONL_Router/src/dispatch_loop/ONL/
dl_source.h and dl_source.c
dl_source() and dl_sink() functions
» src/IDT_NSE/data_place_IXP2XXX/include
IDT IIPC defines and macros
» others?
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy
Functions:
» Drop error pkts detected by Parse.
» Count and send PT pkts to QM.
» Process lookup results:
When “control error” (NH_IP and NH_MAC both invalid or both valid), or “ARP
request needed” (Uncast pkt with valid NH_IP but invalid NH_MAC), or “no
route” (invalid PR and AR) is detected, pkt should be sent to XScale, or one of
five plugins, or dropped based on user preference (dynamically configurable).
Compute MAC DAddr for IP multicast pkts.
Update total ref_cnt in paylod buf desc for each classified pkt.
If total ref_cnt == 1 and pkt goes to QM, fill in payload buf desc with NH_MAC,
Stats index and EtherType.
If total ref_cnt > 1, add hdr buf to each pkt going to QM, and fill in hdr buf
desc with buffer_next, packet_size, ref_cnt (=1), NH_MAC, Stats index,
EtherType.
For each copy, form ring_out data and enqueue it to the outgoing ring.
Input:
» ring_in data, exception bits, dlNextBlock, eth_type, DG QID, lookup
results
Output:
» Ring_out data
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy
Operations:
» Error pkt detected by Parse (to freelist_mgr):
Construct ring_out data to Freelist_mgr
Call dl_sink(TRUE, TRUE, 0). Return.
» PT pkt (to QM):
dlNextBlock <= BID_QM
Construct ring_out data to QM from ring_in data
Call dl_sink(TRUE, TRUE, 0). Return.
Pre-check:
» Classified pkt:
Pre-process lookup results, because:
Copy exception bits to flags.
If PR and AR are both invalid, this pkt has no route.
– Set NR bit in flags.
– Set dlNextBlock to user preference.
– Construct ring_out data.
– Call dl_sink(TRUE, TRUE, 1). Return.
Both PR and AR can generate pkt copies to QM and XScale/plugins.
Need to know total num of copies to
– Decide whether hdr buffer decs should be added to copy going to QM.
– Set “last” bit in dl_sink().
– Update total ref_cnt in payload buf desc using one atomic addition.
Post-process lookup results, copy and send pkts to proper rings.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy
Pre-processing
data structure:
struct copy_qm_prep{
unsigned int pkt_cnt;
bool pr_ucast;
bool pr_mcast;
bool ar_ucast;
} qm;
struct copy_plugins_prep{
unsigned int pkt_cnt;
bool pr_arp;
bool pr_nh_inv;
bool pr_ucast;
bool pr_mcast;
bool ar_arp;
bool ar_nh_inv;
bool ar_ucast;
} plugins;
‹#› - John DeHart, Jing Lu - 5/23/2016
PR:
AR:
V
(4b)
UCast
MCast
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
(12b)
S
B
(4b)
V
QID (16b)
R
Uni
e
s Cast
(2b)(2b) (8b)
Pre-process fields
Post-process fields
Only one can be TRUE
Copy (pre-process PR)
V
(4b)
NH
Entry
IP
Valid
Valid
(1b)
(1b)
NH
IP
MAC MC
Valid Valid
(1b) (1b)
UCast
MCast
(12b)
Reserved D PPS
(4b)
(1b) (1b)
PPS
(1b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
Multicast Copy Vector (11b)
•If IP MC Valid = 0
•If IP MC Valid = 1
If PR is valid,
» If NH_IP is valid and NH_MAC is invalid and IP_MC is invalid, this pkt
needs ARP.
Set ARP bit in flags.
If pkt should be sent to XScale/plugins,
plugins.pkt_cnt ++; plugins.pr_arp <= TRUE.
» Else if NH_IP and NH_MAC are both invalid or both valid, lookup entry is
mis-configured.
Set NH_INV bit in flags.
If pkt should be sent to XScale/plugins,
plugins.pkt_cnt ++; plugins.pr_nh_inv <= TRUE.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy (pre-process PR)
»Else,
If MC_valid == 0 (unicast),
If Drop == 0,
Reserved D PPS
(4b)
(1b) (1b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
– If PPS == 0, qm.pkt_cnt ++, qm.pr_ucast <= TRUE.
– Else (PPS == 1), plugins.pkt_cnt ++, plugins.pr_ucast <= TRUE.
Else (MC_valid == 1 (Multicast)),
Multicast Copy Vector (11b)
If PPS == 0,
–
–
–
–
PPS
(1b)
qm.pkt_cnt <= total 1’s in high 5 bits in MCast_copyVector;
plugins.pkt_cnt <= total 1’s in low 6 bits in MCAST_copyVector.
If qm.pkt_cnt > 0, qm.pr_mcast <= TRUE.
If plugins.pkt_cnt > 0, plugins.pr_mcast <= TRUE.
Else (PPS == 1),
– plugins.pkt_cnt <= total 1’s in low 6 bits in Mcast_copyVector;
– If plugins.pkt_cnt > 0, plugins.pr_mcast <= TURE.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy (pre-process AR)
S
B
(4b)
V
NH
Entry
IP
Valid
Valid
(1b)
(1b)
If
NH
IP
MAC MC
Valid Valid
(1b) (1b)
R
Uni
e
s Cast
(2b)(2b) (8b)
QID (16b)
D PPS
(1b) (1b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
AR is valid,
»If NH_IP is valid and NH_MAC is invalid, this pkt needs ARP.
Set ARP bit in flags.
If pkt should be sent to XScale/plugins,
plugins.pkt_cnt ++; plugins.pr_arp <= TRUE.
»Else if NH_IP and NH_MAC are both invalid or both valid, lookup
entry is mis-configured.
Set NH_INV bit in flags.
If pkt should be sent to XScale/plugins,
plugins.pkt_cnt ++; plugins.pr_nh_inv <= TRUE.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy (pre-process AR)
SB Rsv D PPS
(2b) (2b) (1b) (1b)
UCast
Out Port
UCast
Out Plugin
(3b)
(3b)
»Else,
Each SB value is associated with a sampling rate rt(SB) that is
dynamically configurable by users.
Generate a random number rd.
If rd <= rt(SB),
If PPS == 0,
– qm.ar_ucast <= TRUE, qm.pkt_cnt ++.
Else (PPS == 1),
– plugins.ar_ucast <= TRUE, plugins.pkt_cnt ++.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy (post-process)
struct copy_qm_prep{
unsigned int pkt_cnt;
bool pr_ucast;
bool pr_mcast;
bool ar_ucast;
} qm;
struct copy_plugins_prep{
unsigned int pkt_cnt;
bool pr_arp;
bool pr_nh_inv;
bool pr_ucast;
bool pr_mcast;
bool ar_arp;
bool ar_nh_inv;
bool ar_ucast;
} plugins;
PR:
V
(4b)
UCast
MCast
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
QID (16b)
NH_MAC (48b)
Stats Index
(16b)
Res (16b)
NH_IP (32b)
(12b)
AR:
S
(4b) B
V
R
Uni
e
s Cast
(2b)(2b) (8b)
If qm.pkt_cnt + plugins.pkt_cnt == 0, dlNextBlock <= BID_FREELISTMGR,
dl_sink(TRUE, TRUE, 0). Return.
Read ref_cnt from payload buf desc.
If qm.pkt_cnt + plugins.pkt_cnt + (ref_cnt – 1) == 1,
» If qm.pkt_cnt == 1, DO NOT add hdr buf desc.
Based on qm.pr_ucast, qm.pr_mcast, qm.ar_ucast,
Fill in NH_MAC, stats index, and eth_type in payload buf desc.
Construct QM ring_out data.
dlNextBlock <= BID_QM.
dl_sink(TRUE, TRUE, 0). Return.
» Else (plugins.pkt_cnt == 1),
Based on plugins.*,
construct plugins/XScale ring_out data.
Set dlNextBlock to XScale or one of the five plugins.
dl_sink(TRUE, TRUE, 1). Return.
‹#› - John DeHart, Jing Lu - 5/23/2016
Copy (post-process)
Else (qm.pkt_cnt + plugins.pkt_cnt + (ref_cnt – 1) > 1),
» Add (qm.pkt_cnt + plugins.pkt_cnt – 1) to ref_cnt in payload buf desc.
» If qm.pkt_cnt >0,
for each copy to QM, add hdr buf desc.
Based on qm.pr_ucast, qm.pr_mcast, qm.ar_ucast,
Fill in buffer_next, packet_size, ref_cnt (=1), NH, stats index, and eth_type in hdr buf
desc.
Construct QM ring_out data.
dlNextBlock <= BID_QM.
Call dl_sink() qm.pkt_cnt times.
– If plugins.pkt_cnt == 0, Set “last” bit in dl_sink() for the last copy and return.
» If plugins.pkt_cnt > 0,
Based on plugins.*,
Construct plugins/XScale ring_out data.
Set dlNextBlock to XScale or one of the five plugins.
Call dl_sink() plugins.pkt_cnt times.
– Set “last” bit in dl_sink() for the last copy and return.
‹#› - John DeHart, Jing Lu - 5/23/2016
PLC Typical Case
Valid IP Pkt from Rx, no option, go to one port as a result of PR. AR entry
is invalid.
Operation
dl_source
Memory Access
Cycle Count
Dequeue pkt from MUX
3LW Scratch Ring read
60
Read eth_type, IP, TCP/UDP hdr
Aligned 10LW DRAM read
300
Write TTL, IP cksum
Aligned 4LW DRAM write
300
Parse
Lookup
Lookup
Copy
Write NH MAC, stats index,
eth_type
Aligned 3LW SRAM write
150
dl_sink
Enqueue pkt to QM
3LW Scratch Ring write
60
915
Total: 1785
‹#› - John DeHart, Jing Lu - 5/23/2016