cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
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rocker.txt (36775B)


      1Rocker Network Switch Register Programming Guide
      2Copyright (c) Scott Feldman <sfeldma@gmail.com>
      3Copyright (c) Neil Horman <nhorman@tuxdriver.com>
      4Version 0.11, 12/29/2014
      5
      6LICENSE
      7=======
      8
      9This program is free software; you can redistribute it and/or modify
     10it under the terms of the GNU General Public License as published by
     11the Free Software Foundation; either version 2 of the License, or
     12(at your option) any later version.
     13
     14This program is distributed in the hope that it will be useful,
     15but WITHOUT ANY WARRANTY; without even the implied warranty of
     16MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     17GNU General Public License for more details.
     18
     19SECTION 1: Introduction
     20=======================
     21
     22Overview
     23--------
     24
     25This document describes the hardware/software interface for the Rocker switch
     26device.  The intended audience is authors of OS drivers and device emulation
     27software.
     28
     29Notations and Conventions
     30-------------------------
     31
     32o In register descriptions, [n:m] indicates a range from bit n to bit m,
     33inclusive.
     34o Use of leading 0x indicates a hexadecimal number.
     35o Use of leading 0b indicates a binary number.
     36o The use of RSVD or Reserved indicates that a bit or field is reserved for
     37future use.
     38o Field width is in bytes, unless otherwise noted.
     39o Register are (R) read-only, (R/W) read/write, (W) write-only, or (COR) clear
     40on read
     41o TLV values in network-byte-order are designated with (N).
     42
     43
     44SECTION 2: PCI Configuration Registers
     45======================================
     46
     47PCI Configuration Space
     48-----------------------
     49
     50Each switch instance registers as a PCI device with PCI configuration space:
     51
     52	offset	width	description		value
     53	---------------------------------------------
     54	0x0	2	Vendor ID		0x1b36
     55	0x2	2	Device ID		0x0006
     56	0x4	4	Command/Status
     57	0x8	1	Revision ID		0x01
     58	0x9	3	Class code		0x2800
     59	0xC	1	Cache line size
     60	0xD	1	Latency timer
     61	0xE	1	Header type
     62	0xF	1	Built-in self test
     63	0x10	4	Base address low
     64	0x14	4	Base address high
     65	0x18-28		Reserved
     66	0x2C	2	Subsystem vendor ID	*
     67	0x2E	2	Subsystem ID		*
     68	0x30-38		Reserved
     69	0x3C	1	Interrupt line
     70	0x3D	1	Interrupt pin		0x00
     71	0x3E	1	Min grant		0x00
     72	0x3D	1	Max latency		0x00
     73	0x40	1	TRDY timeout
     74	0x41	1	Retry count
     75	0x42	2	Reserved
     76
     77
     78* Assigned by sub-system implementation
     79
     80SECTION 3: Memory-Mapped Register Space
     81=======================================
     82
     83There are two memory-mapped BARs.  BAR0 maps device register space and is
     840x2000 in size.  BAR1 maps MSI-X vector and PBA tables and is also 0x2000 in
     85size, allowing for 256 MSI-X vectors.
     86
     87All registers are 4 or 8 bytes long.  It is assumed host software will access 4
     88byte registers with one 4-byte access, and 8 byte registers with either two
     894-byte accesses or a single 8-byte access.  In the case of two 4-byte accesses,
     90access must be lower and then upper 4-bytes, in that order.
     91
     92BAR0 device register space is organized as follows:
     93
     94	offset		description
     95	------------------------------------------------------
     96	0x0000-0x000f	Bogus registers to catch misbehaving
     97			drivers.  Writes do nothing.  Reads
     98			back as 0xDEADBABE.
     99	0x0010-0x00ff	Test registers
    100	0x0300-0x03ff	General purpose registers
    101	0x1000-0x1fff	Descriptor control
    102
    103Holes in register space are reserved.  Writes to reserved registers do nothing.
    104Reads to reserved registers read back as 0.
    105
    106No fancy stuff like write-combining is enabled on any of the registers.
    107
    108BAR1 MSI-X register space is organized as follows:
    109
    110	offset		description
    111	------------------------------------------------------
    112	0x0000-0x0fff	MSI-X vector table (256 vectors total)
    113	0x1000-0x1fff	MSI-X PBA table
    114
    115
    116SECTION 4: Interrupts, DMA, and Endianness
    117==========================================
    118
    119PCI Interrupts
    120--------------
    121
    122The device supports only MSI-X interrupts.  BAR1 memory-mapped region contains
    123the MSI-X vector and PBA tables, with support for up to 256 MSI-X vectors.
    124
    125The vector assignment is:
    126
    127	vector		description
    128	-----------------------------------------------------
    129	0		Command descriptor ring completion
    130	1		Event descriptor ring completion
    131	2		Test operation completion
    132	3		RSVD
    133	4-255		Tx and Rx descriptor ring completion
    134			  Tx vector is even
    135			  Rx vector is odd
    136
    137A MSI-X vector table entry is 16 bytes:
    138
    139	field		offset	width	description
    140	-------------------------------------------------------------
    141	lower_addr	0x0	4	[31:2] message address[31:2]
    142					[1:0] Rsvd (4 byte alignment
    143						    required)
    144	upper_addr	0x4	4	[31:19] Rsvd
    145					[14:0] message address[46:32]
    146	data		0x8	4	message data[31:0]
    147	control		0xc	4	[31:1] Rsvd
    148					[0] mask (0 = enable,
    149						  1 = masked)
    150
    151Software should install the Interrupt Service Routine (ISR) before any ports
    152are enabled or any commands are issued on the command ring.
    153
    154DMA Operations
    155--------------
    156
    157DMA operations are used for packet DMA to/from the CPU, command and event
    158processing.  Command processing includes statistical counters and table dumps,
    159table insertion/deletion, and more.  Event processing provides an async
    160notification method for device-originating events.  Each DMA operation has a
    161set of control registers to manage a descriptor ring.  The descriptor rings are
    162allocated from contiguous host DMA-able memory and registers specify the rings
    163base address, size and current head and tail indices.  Software always writes
    164the head, and hardware always writes the tail.
    165
    166The higher-order bit of DMA_DESC_COMP_ERR is used to mark hardware completion
    167of a descriptor.  Software will clear this bit when posting a descriptor to the
    168ring, and hardware will set this bit when the descriptor is complete.
    169
    170Descriptor ring sizes must be a power of 2 and range from 2 to 64K entries.
    171Descriptor rings' base address must be 8-byte aligned.  Descriptors must be
    172packed within ring.  Each descriptor in each ring must also be aligned on an 8
    173byte boundary.  Each descriptor ring will have these registers:
    174
    175	DMA_DESC_xxx_BASE_ADDR, offset 0x1000 + (x * 32), 64-bit, (R/W)
    176	DMA_DESC_xxx_SIZE, offset 0x1008 + (x * 32), 32-bit, (R/W)
    177	DMA_DESC_xxx_HEAD, offset 0x100c + (x * 32), 32-bit, (R/W)
    178	DMA_DESC_xxx_TAIL, offset 0x1010 + (x * 32), 32-bit, (R)
    179	DMA_DESC_xxx_CTRL, offset 0x1014 + (x * 32), 32-bit, (W)
    180	DMA_DESC_xxx_CREDITS, offset 0x1018 + (x * 32), 32-bit, (R/W)
    181	DMA_DESC_xxx_RSVD1, offset 0x101c + (x * 32), 32-bit, (R/W)
    182
    183Where x is descriptor ring index:
    184
    185	index		ring
    186	--------------------
    187	0		CMD
    188	1		EVENT
    189	2		TX (port 0)
    190	3		RX (port 0)
    191	4		TX (port 1)
    192	5		RX (port 1)
    193	.
    194	.
    195	.
    196	124		TX (port 61)
    197	125		RX (port 61)
    198	126		Resv
    199	127		Resv
    200
    201Writing BASE_ADDR or SIZE will reset HEAD and TAIL to zero.  HEAD cannot be
    202written past TAIL.  To do so would wrap the ring.  An empty ring is when HEAD
    203== TAIL.  A full ring is when HEAD is one position behind TAIL.  Both HEAD and
    204TAIL increment and modulo wrap at the ring size.
    205
    206CTRL register bits:
    207
    208	bit	name		description
    209	------------------------------------------------------------------------
    210	[0]	CTRL_RESET	Reset the descriptor ring
    211	[1:31]	Reserved
    212
    213All descriptor types share some common fields:
    214
    215	field			width	description
    216	-------------------------------------------------------------------
    217	DMA_DESC_BUF_ADDR	8	Phys addr of desc payload, 8-byte
    218					aligned
    219	DMA_DESC_COOKIE		8	Desc cookie for completion matching,
    220					upper-most bit is reserved
    221	DMA_DESC_BUF_SIZE	2	Desc payload size in bytes
    222	DMA_DESC_TLV_SIZE	2	Desc payload total size in bytes
    223					used for TLVs.  Must be <=
    224					DMA_DESC_BUF_SIZE.
    225	DMA_DESC_COMP_ERR	2	Completion status of associated
    226					desc payload.  High order bit is
    227					clear on new descs, toggled by
    228					hw for completed items.
    229
    230To support forward- and backward-compatibility, descriptor and completion
    231payloads are specified in TLV format.  Fields are packed with Type=field name,
    232Length=field length, and Value=field value.  Software will ignore unknown fields
    233filled in by the switch.  Likewise, the switch will ignore unknown fields
    234filled in by software.
    235
    236Descriptor payload buffer is 8-byte aligned and TLVs are 8-byte aligned.  The
    237value within a TLV is also 8-byte aligned.  The (packed, 8 byte) TLV header is:
    238
    239	field	width	description
    240	-----------------------------
    241	type	4	TLV type
    242	len	2	TLV value length
    243	pad	2	Reserved
    244
    245The alignment requirements for descriptors and TLVs are to avoid unaligned
    246access exceptions in software.  Note that the payload for each TLV is also
    2478 byte aligned.
    248
    249Figure 1 shows an example descriptor buffer with two TLVs.
    250
    251                  <------- 8 bytes ------->
    252
    253  8-byte  +––––+  +–––––––––––+–––––+–––––+                     +–+
    254  align           |   type    | len | pad |    TLV#1 hdr          |
    255                  +–––––––––––+–––––+–––––+    (len=22)           |
    256                  |                       |                       |
    257                  |  value                |    TVL#1 value        |
    258                  |                       |    (padded to 8-byte  |
    259                  |                 +–––––+     alignment)        |
    260                  |                 |/////|                       |
    261   8-byte +––––+  +–––––––––––+–––––––––––+                       |
    262   align          |   type    | len | pad |    TLV#2 hdr    DESC_BUF_SIZE
    263                  +–––––+–––––+–––––+–––––+    (len=2)            |
    264                  |value|/////////////////|    TLV#2 value        |
    265                  +–––––+/////////////////|                       |
    266                  |///////////////////////|                       |
    267                  |///////////////////////|                       |
    268                  |///////////////////////|                       |
    269                  |////////unused/////////|                       |
    270                  |////////space//////////|                       |
    271                  |///////////////////////|                       |
    272                  |///////////////////////|                       |
    273                  |///////////////////////|                       |
    274                  +–––––––––––––––––––––––+                     +–+
    275
    276				fig. 1
    277
    278TLVs can be nested within the NEST TLV type.
    279
    280Interrupt credits
    281^^^^^^^^^^^^^^^^^
    282
    283MSI-X vectors used for descriptor ring completions use a credit mechanism for
    284efficient device, PCIe bus, OS and driver operations.  Each descriptor ring has
    285a credit count which represents the number of outstanding descriptors to be
    286processed by the driver.  As the device marks descriptors complete, the credit
    287count is incremented.  As the driver processes those outstanding descriptors,
    288it returns credits back to the device.  This way, the device knows the driver's
    289progress and can make decisions about when to fire the next interrupt or not.
    290When the credit count is zero, and the first descriptors are posted for the
    291driver, a single interrupt is fired.  Once the interrupt is fired, the
    292interrupt is disabled (auto-masked*).  In response to the interrupt, the driver
    293will process descriptors and PIO write a returned credit value for that
    294descriptor ring.  If the driver returns all credits (the driver caught up with
    295the device and there is no outstanding work), then the interrupt is unmasked,
    296but not fired.  If only partial credits are returned, the interrupt remains
    297masked but the device generates an interrupt, signaling the driver that more
    298outstanding work is available.
    299
    300(* this masking is unrelated to the MSI-X interrupt mask register)
    301
    302Endianness
    303----------
    304
    305Device registers are hard-coded to little-endian (LE).  The driver should
    306convert to/from host endianness to LE for device register accesses.
    307
    308Descriptors are LE.  Descriptor buffer TLVs will have LE type and length
    309fields, but the value field can either be LE or network-byte-order, depending
    310on context.  TLV values containing network packet data will be in network-byte
    311order.  A TLV value containing a field or mask used to compare against network
    312packet data is network-byte order.  For example, flow match fields (and masks)
    313are network-byte-order since they're matched directly, byte-by-byte, against
    314network packet data.  All non-network-packet TLV multi-byte values will be LE.
    315
    316TLV values in network-byte-order are designated with (N).
    317
    318
    319SECTION 5: Test Registers
    320=========================
    321
    322Rocker has several test registers to support troubleshooting register access,
    323interrupt generation, and DMA operations:
    324
    325	TEST_REG, offset 0x0010, 32-bit (R/W)
    326	TEST_REG64, offset 0x0018, 64-bit (R/W)
    327	TEST_IRQ, offset 0x0020, 32-bit (R/W)
    328	TEST_DMA_ADDR, offset 0x0028, 64-bit (R/W)
    329	TEST_DMA_SIZE, offset 0x0030, 32-bit (R/W)
    330	TEST_DMA_CTRL, offset 0x0034, 32-bit (R/W)
    331
    332Reads to TEST_REG and TEST_REG64 will read a value equal to twice the last
    333value written to the register.  The 32-bit and 64-bit versions are for testing
    33432-bit and 64-bit host accesses.
    335
    336A vector can be written to TEST_IRQ and the device will generate an interrupt
    337for that vector.
    338
    339To test basic DMA operations, allocate a DMA-able host buffer and put the
    340buffer address into TEST_DMA_ADDR and size into TEST_DMA_SIZE.  Then, write to
    341TEST_DMA_CTRL to manipulate the buffer contents.  TEST_DMA_CTRL operations are:
    342
    343	operation		value	description
    344	-----------------------------------------------------------
    345	TEST_DMA_CTRL_CLEAR	1	clear buffer
    346	TEST_DMA_CTRL_FILL	2	fill buffer bytes with 0x96
    347	TEST_DMA_CTRL_INVERT	4	invert bytes in buffer
    348
    349Various buffer address and sizes should be tested to verify no address boundary
    350issue exists.  In particular, buffers that start on odd-8-byte boundary and/or
    351span multiple PAGE sizes should be tested.
    352
    353
    354SECTION 6: Ports
    355================
    356
    357Physical and Logical Ports
    358------------------------------------
    359
    360The switch supports up to 62 physical (front-panel) ports.  Register
    361PORT_PHYS_COUNT returns the actual number of physical ports available:
    362
    363	PORT_PHYS_COUNT, offset 0x0304, 32-bit, (R)
    364
    365In addition to front-panel ports, the switch supports logical ports for
    366tunnels.
    367
    368Front-panel ports and logical tunnel ports are mapped into a single 32-bit port
    369space.  A special CPU port is assigned port 0.  The front-panel ports are
    370mapped to ports 1-62.  A special loopback port is assigned port 63.  Logical
    371tunnel ports are assigned ports 0x0001000-0x0001ffff.
    372To summarize the port assignments:
    373
    374	port			mapping
    375	-------------------------------------------------------
    376	0			CPU port (for packets to/from host CPU)
    377	1-62			front-panel physical ports
    378	63			loopback port
    379	64-0x0000ffff		RSVD
    380	0x00010000-0x0001ffff	logical tunnel ports
    381	0x00020000-0xffffffff	RSVD
    382
    383Physical Port Mode
    384------------------
    385
    386Switch front-panel ports operate in a mode.  Currently, the only mode is
    387OF-DPA.  OF-DPA[1] mode is based on OpenFlow Data Plane Abstraction (OF-DPA)
    388Abstract Switch Specification, Version 1.0, from Broadcom Corporation.  To
    389set/get the mode for front-panel ports, see port settings, below.
    390
    391Port Settings
    392-------------
    393
    394Link status for all front-panel ports is available via PORT_PHYS_LINK_STATUS:
    395
    396	PORT_PHYS_LINK_STATUS, offset 0x0310, 64-bit, (R)
    397
    398	Value is port bitmap.  Bits 0 and 63 always read 0.  Bits 1-62
    399	read 1 for link UP and 0 for link DOWN for respective front-panel ports.
    400
    401Other properties for front-panel ports are available via DMA CMD descriptors:
    402
    403	Get PORT_SETTINGS descriptor:
    404
    405		field		width	description
    406		----------------------------------------------
    407		PORT_SETTINGS	2	CMD_GET
    408		PPORT		4	Physical port #
    409
    410	Get PORT_SETTINGS completion:
    411
    412		field		width	description
    413		----------------------------------------------
    414		PPORT		4	Physical port #
    415		SPEED		4	Current port interface speed, in Mbps
    416		DUPLEX		1	1 = Full, 0 = Half
    417		AUTONEG		1	1 = enabled, 0 = disabled
    418		MACADDR		6	Port MAC address
    419		MODE		1	0 = OF-DPA
    420		LEARNING	1	MAC address learning on port
    421						1 = enabled
    422						0 = disabled
    423		PHYS_NAME	<var>	Physical port name (string)
    424
    425	Set PORT_SETTINGS descriptor:
    426
    427		field		width	description
    428		----------------------------------------------
    429		PORT_SETTINGS	2	CMD_SET
    430		PPORT		4	Physical port #
    431		SPEED		4	Port interface speed, in Mbps
    432		DUPLEX		1	1 = Full, 0 = Half
    433		AUTONEG		1	1 = enabled, 0 = disabled
    434		MACADDR		6	Port MAC address
    435		MODE		1	0 = OF-DPA
    436
    437Port Enable
    438-----------
    439
    440Front-panel ports are initially disabled, which means port ingress and egress
    441packets will be dropped.  To enable or disable a port, use PORT_PHYS_ENABLE:
    442
    443	PORT_PHYS_ENABLE: offset 0x0318, 64-bit, (R/W)
    444
    445	Value is bitmap of first 64 ports.  Bits 0 and 63 are ignored
    446	and always read as 0.  Write 1 to enable port; write 0 to disable it.
    447	Default is 0.
    448
    449
    450SECTION 7: Switch Control
    451=========================
    452
    453This section covers switch-wide register settings.
    454
    455Control
    456-------
    457
    458This register is used for low level control of the switch.
    459
    460	CONTROL: offset 0x0300, 32-bit, (W)
    461
    462	bit	name		description
    463	------------------------------------------------------------------------
    464	[0]	CONTROL_RESET	If set, device will perform reset
    465	[1:31]	Reserved
    466
    467Switch ID
    468---------
    469
    470The switch has a SWITCH_ID to be used by software to uniquely identify the
    471switch:
    472
    473	SWITCH_ID: offset 0x0320, 64-bit, (R)
    474
    475	Value is opaque to switch software and no special encoding is implied.
    476
    477
    478SECTION 8: Events
    479=================
    480
    481Non-I/O asynchronous events from the device are notified to the host using the
    482event ring.  The TLV structure for events is:
    483
    484	field		width	description
    485	---------------------------------------------------
    486	TYPE		4	Event type, one of:
    487					1: LINK_CHANGED
    488					2: MAC_VLAN_SEEN
    489	INFO		<nest>	Event info (details below)
    490
    491Link Changed Event
    492------------------
    493
    494When link status changes on a physical port, this event is generated.
    495
    496	field		width	description
    497	---------------------------------------------------
    498	INFO		<nest>
    499	  PPORT		4	Physical port
    500	  LINKUP	1	Link status:
    501					0: down
    502					1: up
    503
    504MAC VLAN Seen Event
    505-------------------
    506
    507When a packet ingresses on a port and the source MAC/VLAN isn't known to the
    508device, the device will generate this event.  In response to the event, the
    509driver should install to the device the MAC/VLAN on the port into the bridge
    510table.  Once installed, the MAC/VLAN is known on the port and this event will
    511no longer be generated.
    512
    513	field		width	description
    514	---------------------------------------------------
    515	INFO		<nest>
    516	  PPORT		4	Physical port
    517	  MAC		6	MAC address
    518	  VLAN		2	VLAN ID
    519
    520
    521SECTION 9: CPU Packet Processing
    522================================
    523
    524Ingress packets directed to the host CPU for further processing are delivered
    525in the DMA RX ring.  Likewise, host CPU originating packets destined to egress
    526on switch ports are scheduled by software using the DMA TX ring.
    527
    528Tx Packet Processing
    529--------------------
    530
    531Software schedules packets for egress on switch ports using the DMA TX ring.  A
    532TX descriptor buffer describes the packet location and size in host DMA-able
    533memory, the destination port, and any hardware-offload functions (such as L3
    534payload checksum offload).  Software then bumps the descriptor head to signal
    535hardware of new Tx work.  In response, hardware will DMA read Tx descriptors up
    536to head, DMA read descriptor buffer and packet data, perform offloading
    537functions, and finally frame packet on wire (network).  Once packet processing
    538is complete, hardware will writeback status to descriptor(s) to signal to
    539software that Tx is complete and software resources (e.g. skb) backing packet
    540can be released.
    541
    542Figure 2 shows an example 3-fragment packet queued with one Tx descriptor.  A
    543TLV is used for each packet fragment.
    544
    545	                                           pkt frag 1
    546	                                           +–––––––+  +–+
    547	                                       +–––+       |    |
    548	                         desc buf      |   |       |    |
    549	                        +––––––––+     |   |       |    |
    550	        Tx ring     +–––+        +–––––+   |       |    |
    551	      +–––––––––+   |   |  TLVs  |         +–––––––+    |
    552	      |         +–––+   +––––––––+         pkt frag 2   |
    553	      | desc 0  |       |        +–––––+   +–––––––+    |
    554	      +–––––––––+       |  TLVs  |     +–––+       |    |
    555	head+–+         |       +––––––––+         |       |    |
    556	      | desc 1  |       |        +–––––+   +–––––––+    |pkt
    557	      +–––––––––+       |  TLVs  |     |                |
    558	      |         |       +––––––––+     |   pkt frag 3   |
    559	      |         |                      |   +–––––––+    |
    560	      +–––––––––+                      +–––+       |    |
    561	      |         |                          |       |    |
    562	      |         |                          |       |    |
    563	      +–––––––––+                          |       |    |
    564	      |         |                          |       |    |
    565	      |         |                          |       |    |
    566	      +–––––––––+                          |       |    |
    567	      |         |                          +–––––––+  +–+
    568	      |         |
    569	      +–––––––––+
    570
    571				fig 2.
    572
    573The TLVs for Tx descriptor buffer are:
    574
    575	field			width	description
    576	---------------------------------------------------------------------
    577	PPORT			4	Destination physical port #
    578	TX_OFFLOAD		1	Hardware offload modes:
    579					  0: no offload
    580					  1: insert IP csum (ipv4 only)
    581					  2: insert TCP/UDP csum
    582					  3: L3 csum calc and insert
    583                        	             into csum offset (TX_L3_CSUM_OFF)
    584                 	                    16-bit 1's complement csum value.
    585                                	     IPv4 pseudo-header and IP
    586                        	             already calculated by OS
    587                  	                   and inserted.
    588					  4: TSO (TCP Segmentation Offload)
    589	TX_L3_CSUM_OFF		2	For L3 csum offload mode, the offset,
    590					from the beginning of the packet,
    591					of the csum field in the L3 header
    592	TX_TSO_MSS		2	For TSO offload mode, the
    593					Maximum Segment Size in bytes
    594        TX_TSO_HDR_LEN		2	For TSO offload mode, the
    595					length of ethernet, IP, and
    596					TCP/UDP headers, including IP
    597					and TCP options.
    598	TX_FRAGS		<array>	Packet fragments
    599	  TX_FRAG		<nest>	Packet fragment
    600	    TX_FRAG_ADDR	8	DMA address of packet fragment
    601	    TX_FRAG_LEN		2	Packet fragment length
    602
    603Possible status return codes in descriptor on completion are:
    604
    605	DESC_COMP_ERR	reason
    606	--------------------------------------------------------------------
    607	0		OK
    608	-ROCKER_ENXIO	address or data read err on desc buf or packet
    609			fragment
    610	-ROCKER_EINVAL	bad pport or TSO or csum offloading error
    611	-ROCKER_ENOMEM	no memory for internal staging tx fragment
    612
    613Rx Packet Processing
    614--------------------
    615
    616For packets ingressing on switch ports that are not forwarded by the switch but
    617rather directed to the host CPU for further processing are delivered in the DMA
    618RX ring.  Rx descriptor buffers are allocated by software and placed on the
    619ring.  Hardware will fill Rx descriptor buffers with packet data, write the
    620completion, and signal to software that a new packet is ready.  Since Rx packet
    621size is not known a-priori, the Rx descriptor buffer must be allocated for
    622worst-case packet size.  A single Rx descriptor will contain the entire Rx
    623packet data in one RX_FRAG.  Other Rx TLVs describe and hardware offloads
    624performed on the packet, such as checksum validation.
    625
    626The TLVs for Rx descriptor buffer are:
    627
    628	field		width	description
    629	---------------------------------------------------
    630	PPORT		4	Source physical port #
    631	RX_FLAGS	2	Packet parsing flags:
    632				  (1 << 0): IPv4 packet
    633				  (1 << 1): IPv6 packet
    634				  (1 << 2): csum calculated
    635				  (1 << 3): IPv4 csum good
    636				  (1 << 4): IP fragment
    637				  (1 << 5): TCP packet
    638				  (1 << 6): UDP packet
    639				  (1 << 7): TCP/UDP csum good
    640				  (1 << 8): Offload forward
    641	RX_CSUM		2	IP calculated checksum:
    642				  IPv4: IP payload csum
    643				  IPv6: header and payload csum
    644				(Only valid is RX_FLAGS:csum calc is set)
    645	RX_FRAG_ADDR	8	DMA address of packet fragment
    646	RX_FRAG_MAX_LEN	2	Packet maximum fragment length
    647	RX_FRAG_LEN	2	Actual packet fragment length after receive
    648
    649Offload forward RX_FLAG indicates the device has already forwarded the packet
    650so the host CPU should not also forward the packet.
    651
    652Possible status return codes in descriptor on completion are:
    653
    654	DESC_COMP_ERR	reason
    655	--------------------------------------------------------------------
    656	0		OK
    657	-ROCKER_ENXIO	address or data read err on desc buf
    658	-ROCKER_ENOMEM	no memory for internal staging desc buf
    659	-ROCKER_EMSGSIZE Rx descriptor buffer wasn't big enough to contain
    660			packet data TLV and other TLVs.
    661
    662
    663SECTION 10: OF-DPA Mode
    664======================
    665
    666OF-DPA mode allows the switch to offload flow packet processing functions to
    667hardware.  An OpenFlow controller would communicate with an OpenFlow agent
    668installed on the switch.  The OpenFlow agent would (directly or indirectly)
    669communicate with the Rocker switch driver, which in turn would program switch
    670hardware with flow functionality, as defined in OF-DPA.  The block diagram is:
    671
    672		+–––––––––––––––----–––+
    673		|        OF            |
    674		|  Remote Controller   |
    675		+––––––––+––----–––––––+
    676		         |
    677		         |
    678		+––––––––+–––––––––+
    679		|       OF         |
    680		|   Local Agent    |
    681		+––––––––––––––––––+
    682		|                  |
    683		|   Rocker Driver  |
    684		+––––––––––––––––––+
    685		    <this spec>
    686		+––––––––––––––––––+
    687		|                  |
    688		|   Rocker Switch  |
    689		+––––––––––––––––––+
    690
    691To participate in flow functions, ports must be configure for OF-DPA mode
    692during switch initialization.
    693
    694OF-DPA Flow Table Interface
    695---------------------------
    696
    697There are commands to add, modify, delete, and get stats of flow table entries.
    698The commands are issued using the DMA CMD descriptor ring.  The following
    699commands are defined:
    700
    701	CMD_ADD:		add an entry to flow table
    702	CMD_MOD:		modify an entry in flow table
    703	CMD_DEL:		delete an entry from flow table
    704	CMD_GET_STATS:		get stats for flow entry
    705
    706TLVs for add and modify commands are:
    707
    708	field			width	description
    709	----------------------------------------------------
    710	OF_DPA_CMD		2	CMD_[ADD|MOD]
    711	OF_DPA_TBL		2	Flow table ID
    712					  0: ingress port
    713					  10: vlan
    714					  20: termination mac
    715					  30: unicast routing
    716					  40: multicast routing
    717					  50: bridging
    718					  60: ACL policy
    719	OF_DPA_PRIORITY		4	Flow priority
    720	OF_DPA_HARDTIME		4	Hard timeout for flow
    721	OF_DPA_IDLETIME		4	Idle timeout for flow
    722	OF_DPA_COOKIE		8	Cookie
    723
    724Additional TLVs based on flow table ID:
    725
    726Table ID 0: ingress port
    727
    728	field			width	description
    729	----------------------------------------------------
    730	OF_DPA_IN_PPORT		4	ingress physical port number
    731	OF_DPA_GOTO_TBL		2	goto table ID; zero to drop
    732
    733Table ID 10: vlan
    734
    735	field			width	description
    736	----------------------------------------------------
    737	OF_DPA_IN_PPORT		4	ingress physical port number
    738	OF_DPA_VLAN_ID		2 (N)	vlan ID
    739	OF_DPA_VLAN_ID_MASK	2 (N)	vlan ID mask
    740	OF_DPA_GOTO_TBL		2	goto table ID; zero to drop
    741	OF_DPA_NEW_VLAN_ID	2 (N)	new vlan ID
    742
    743Table ID 20: termination mac
    744
    745	field			width	description
    746	----------------------------------------------------
    747	OF_DPA_IN_PPORT		4	ingress physical port number
    748	OF_DPA_IN_PPORT_MASK	4	ingress physical port number mask
    749	OF_DPA_ETHERTYPE	2 (N)	must be either 0x0800 or 0x86dd
    750	OF_DPA_DST_MAC		6 (N)	destination MAC
    751	OF_DPA_DST_MAC_MASK	6 (N)	destination MAC mask
    752	OF_DPA_VLAN_ID		2 (N)	vlan ID
    753	OF_DPA_VLAN_ID_MASK	2 (N)	vlan ID mask
    754	OF_DPA_GOTO_TBL		2	only acceptable values are
    755					unicast or multicast routing
    756					table IDs
    757	OF_DPA_OUT_PPORT	2	if specified, must be
    758					controller, set zero otherwise
    759
    760Table ID 30: unicast routing
    761
    762	field			width	description
    763	----------------------------------------------------
    764	OF_DPA_ETHERTYPE	2 (N)	must be either 0x0800 or 0x86dd
    765	OF_DPA_DST_IP		4 (N)	destination IPv4 address.
    766					Must be unicast address
    767	OF_DPA_DST_IP_MASK	4 (N)	IP mask.  Must be prefix mask
    768	OF_DPA_DST_IPV6		16 (N)	destination IPv6 address.
    769					Must be unicast address
    770	OF_DPA_DST_IPV6_MASK	16 (N)	IPv6 mask. Must be prefix mask
    771	OF_DPA_GOTO_TBL		2	goto table ID; zero to drop
    772	OF_DPA_GROUP_ID		4	data for GROUP action must
    773					be an L3 Unicast group entry
    774
    775Table ID 40: multicast routing
    776
    777	field			width	description
    778	----------------------------------------------------
    779	OF_DPA_ETHERTYPE	2 (N)	must be either 0x0800 or 0x86dd
    780	OF_DPA_VLAN_ID		2 (N)	vlan ID
    781	OF_DPA_SRC_IP		4 (N)	source IPv4. Optional,
    782					can contain IPv4 address,
    783					must be completely masked
    784					if not used
    785	OF_DPA_SRC_IP_MASK	4 (N)	IP Mask
    786	OF_DPA_DST_IP		4 (N)	destination IPv4 address.
    787					Must be multicast address
    788	OF_DPA_SRC_IPV6		16 (N)	source IPv6 Address. Optional.
    789					Can contain IPv6 address,
    790					must be completely masked
    791					if not used
    792	OF_DPA_SRC_IPV6_MASK	16 (N)	IPv6 mask.
    793	OF_DPA_DST_IPV6		16 (N)	destination IPv6 Address. Must
    794					be multicast address
    795					Must be multicast address
    796	OF_DPA_GOTO_TBL		2	goto table ID; zero to drop
    797	OF_DPA_GROUP_ID		4	data for GROUP action must
    798					be an L3 multicast group entry
    799
    800Table ID 50: bridging
    801
    802	field			width	description
    803	----------------------------------------------------
    804	OF_DPA_VLAN_ID		2 (N)	vlan ID
    805	OF_DPA_TUNNEL_ID	4	tunnel ID
    806	OF_DPA_DST_MAC		6 (N)	destination MAC
    807	OF_DPA_DST_MAC_MASK	6 (N)	destination MAC mask
    808	OF_DPA_GOTO_TBL		2	goto table ID; zero to drop
    809	OF_DPA_GROUP_ID		4	data for GROUP action must
    810					be a L2 Interface, L2
    811					Multicast, L2 Flood,
    812					or L2 Overlay group entry
    813					as appropriate
    814	OF_DPA_TUNNEL_LPORT	4	unicast Tenant Bridging
    815					flows specify a tunnel
    816					logical port ID
    817	OF_DPA_OUT_PPORT	2	data for OUTPUT action,
    818					restricted to CONTROLLER,
    819					set to 0 otherwise
    820
    821Table ID 60: acl policy
    822
    823	field			width	description
    824	----------------------------------------------------
    825	OF_DPA_IN_PPORT		4	ingress physical port number
    826	OF_DPA_IN_PPORT_MASK	4	ingress physical port number mask
    827	OF_DPA_ETHERTYPE	2 (N)	ethertype
    828	OF_DPA_VLAN_ID		2 (N)	vlan ID
    829	OF_DPA_VLAN_ID_MASK	2 (N)	vlan ID mask
    830	OF_DPA_VLAN_PCP		2 (N)	vlan Priority Code Point
    831	OF_DPA_VLAN_PCP_MASK	2 (N)	vlan Priority Code Point mask
    832	OF_DPA_SRC_MAC		6 (N)	source MAC
    833	OF_DPA_SRC_MAC_MASK	6 (N)	source MAC mask
    834	OF_DPA_DST_MAC		6 (N)	destination MAC
    835	OF_DPA_DST_MAC_MASK	6 (N)	destination MAC mask
    836	OF_DPA_TUNNEL_ID	4	tunnel ID
    837	OF_DPA_SRC_IP		4 (N)	source IPv4. Optional,
    838					can contain IPv4 address,
    839					must be completely masked
    840					if not used
    841	OF_DPA_SRC_IP_MASK	4 (N)	IP Mask
    842	OF_DPA_DST_IP		4 (N)	destination IPv4 address.
    843					Must be multicast address
    844	OF_DPA_DST_IP_MASK	4 (N)	IP Mask
    845	OF_DPA_SRC_IPV6		16 (N)	source IPv6 Address. Optional.
    846					Can contain IPv6 address,
    847					must be completely masked
    848					if not used
    849	OF_DPA_SRC_IPV6_MASK	16 (N)	IPv6 mask
    850	OF_DPA_DST_IPV6		16 (N)	destination IPv6 Address. Must
    851					be multicast address.
    852	OF_DPA_DST_IPV6_MASK	16 (N)	IPv6 mask
    853	OF_DPA_SRC_ARP_IP	4 (N)	source IPv4 address in the ARP
    854					payload.  Only used if ethertype
    855					== 0x0806.
    856	OF_DPA_SRC_ARP_IP_MASK	4 (N)	IP Mask
    857	OF_DPA_IP_PROTO		1	IP protocol
    858	OF_DPA_IP_PROTO_MASK	1	IP protocol mask
    859	OF_DPA_IP_DSCP		1	DSCP
    860	OF_DPA_IP_DSCP_MASK	1	DSCP mask
    861	OF_DPA_IP_ECN		1	ECN
    862	OF_DPA_IP_ECN_MASK		1	ECN mask
    863	OF_DPA_L4_SRC_PORT	2 (N)	L4 source port, only for
    864					TCP, UDP, or SCTP
    865	OF_DPA_L4_SRC_PORT_MASK	2 (N)	L4 source port mask
    866	OF_DPA_L4_DST_PORT	2 (N)	L4 source port, only for
    867					TCP, UDP, or SCTP
    868	OF_DPA_L4_DST_PORT_MASK	2 (N)	L4 source port mask
    869	OF_DPA_ICMP_TYPE	1	ICMP type, only if IP
    870					protocol is 1
    871	OF_DPA_ICMP_TYPE_MASK	1	ICMP type mask
    872	OF_DPA_ICMP_CODE	1	ICMP code
    873	OF_DPA_ICMP_CODE_MASK	1	ICMP code mask
    874	OF_DPA_IPV6_LABEL	4 (N)	IPv6 flow label
    875	OF_DPA_IPV6_LABEL_MASK	4 (N)	IPv6 flow label mask
    876	OF_DPA_GROUP_ID		4	data for GROUP action
    877	OF_DPA_QUEUE_ID_ACTION	1	write the queue ID
    878	OF_DPA_NEW_QUEUE_ID	1	queue ID
    879	OF_DPA_VLAN_PCP_ACTION	1	write the VLAN priority
    880	OF_DPA_NEW_VLAN_PCP	1	VLAN priority
    881	OF_DPA_IP_DSCP_ACTION	1	write the DSCP
    882	OF_DPA_NEW_IP_DSCP	1	new DSCP
    883	OF_DPA_TUNNEL_LPORT	4	restrct to valid tunnel
    884					logical port, set to 0
    885					otherwise.
    886	OF_DPA_OUT_PPORT	2	data for OUTPUT action,
    887					restricted to CONTROLLER,
    888					set to 0 otherwise
    889	OF_DPA_CLEAR_ACTIONS	4	if 1 packets matching flow are
    890					dropped (all other instructions
    891					ignored)
    892
    893TLVs for flow delete and get stats command are:
    894
    895	field			width	description
    896	---------------------------------------------------
    897	OF_DPA_CMD		2	CMD_[DEL|GET_STATS]
    898	OF_DPA_COOKIE		8	Cookie
    899
    900On completion of get stats command, the descriptor buffer is written back with
    901the following TLVs:
    902
    903	field			width	description
    904	---------------------------------------------------
    905	OF_DPA_STAT_DURATION	4	Flow duration
    906	OF_DPA_STAT_RX_PKTS	8	Received packets
    907	OF_DPA_STAT_TX_PKTS	8	Transmit packets
    908
    909Possible status return codes in descriptor on completion are:
    910
    911	DESC_COMP_ERR	command			reason
    912	--------------------------------------------------------------------
    913	0		all			OK
    914	-ROCKER_EFAULT	all			head or tail index outside
    915						of ring
    916	-ROCKER_ENXIO	all			address or data read err on
    917						desc buf
    918	-ROCKER_EMSGSIZE GET_STATS		cmd descriptor buffer wasn't
    919						big enough to contain write-back
    920						TLVs
    921	-ROCKER_EINVAL	all			invalid parameters passed in
    922	-ROCKER_EEXIST	ADD			entry already exists
    923	-ROCKER_ENOSPC	ADD			no space left in flow table
    924	-ROCKER_ENOENT	MOD|DEL|GET_STATS	cookie invalid
    925
    926Group Table Interface
    927---------------------
    928
    929There are commands to add, modify, delete, and get stats of group table
    930entries.  The commands are issued using the DMA CMD descriptor ring.  The
    931following commands are defined:
    932
    933	CMD_ADD:		add an entry to group table
    934	CMD_MOD:		modify an entry in group table
    935	CMD_DEL:		delete an entry from group table
    936	CMD_GET_STATS:		get stats for group entry
    937
    938TLVs for add and modify commands are:
    939
    940	field			width	description
    941	-----------------------------------------------------------
    942	FLOW_GROUP_CMD		2	CMD_[ADD|MOD]
    943	FLOW_GROUP_ID		2	Flow group ID
    944	FLOW_GROUP_TYPE		1	Group type:
    945					  0: L2 interface
    946					  1: L2 rewrite
    947					  2: L3 unicast
    948					  3: L2 multicast
    949					  4: L2 flood
    950					  5: L3 interface
    951					  6: L3 multicast
    952					  7: L3 ECMP
    953					  8: L2 overlay
    954	FLOW_VLAN_ID		2	Vlan ID (types 0, 3, 4, 6)
    955	FLOW_L2_PORT		2	Port (types 0)
    956	FLOW_INDEX		4	Index (all types but 0)
    957	FLOW_OVERLAY_TYPE	1	Overlay sub-type (type 8):
    958					  0: Flood unicast tunnel
    959					  1: Flood multicast tunnel
    960					  2: Multicast unicast tunnel
    961					  3: Multicast multicast tunnel
    962	FLOW_GROUP_ACTION		nest
    963	  FLOW_GROUP_ID		2	next group ID in chain (all
    964					types except 0)
    965	  FLOW_OUT_PORT		4	egress port (types 0, 8)
    966	  FLOW_POP_VLAN_TAG	1	strip outer VLAN tag (type 1
    967					only)
    968	  FLOW_VLAN_ID		2	(types 1, 5)
    969	  FLOW_SRC_MAC		6	(types 1, 2, 5)
    970	  FLOW_DST_MAC		6	(types 1, 2)
    971
    972TLVs for flow delete and get stats command are:
    973
    974	field			width	description
    975	-----------------------------------------------------------
    976	FLOW_GROUP_CMD		2	CMD_[DEL|GET_STATS]
    977	FLOW_GROUP_ID		2	Flow group ID
    978
    979On completion of get stats command, the descriptor buffer is written back with
    980the following TLVs:
    981
    982	field			width	description
    983	---------------------------------------------------
    984	FLOW_GROUP_ID		2	Flow group ID
    985	FLOW_STAT_DURATION	4	Flow duration
    986	FLOW_STAT_REF_COUNT	4	Flow reference count
    987	FLOW_STAT_BUCKET_COUNT	4	Flow bucket count
    988
    989Possible status return codes in descriptor on completion are:
    990
    991	DESC_COMP_ERR	command			reason
    992	--------------------------------------------------------------------
    993	0		all			OK
    994	-ROCKER_EFAULT	all			head or tail index outside
    995						of ring
    996	-ROCKER_ENXIO	all			address or data read err on
    997						desc buf
    998	-ROCKER_ENOSPC	GET_STATS		cmd descriptor buffer wasn't
    999						big enough to contain write-back
   1000						TLVs
   1001	-ROCKER_EINVAL	ADD|MOD			invalid parameters passed in
   1002	-ROCKER_EEXIST	ADD			entry already exists
   1003	-ROCKER_ENOSPC	ADD			no space left in flow table
   1004	-ROCKER_ENOENT	MOD|DEL|GET_STATS	group ID invalid
   1005	-ROCKER_EBUSY	DEL			group reference count non-zero
   1006	-ROCKER_ENODEV	ADD			next group ID doesn't exist
   1007
   1008
   1009
   1010References
   1011==========
   1012
   1013[1] OpenFlow Data Plane Abstraction (OF-DPA) Abstract Switch Specification,
   1014Version 1.0, from Broadcom Corporation, February 21, 2014.