diff options
Diffstat (limited to 'Documentation/networking/altera_tse.txt')
| -rw-r--r-- | Documentation/networking/altera_tse.txt | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/Documentation/networking/altera_tse.txt b/Documentation/networking/altera_tse.txt new file mode 100644 index 000000000000..3f24df8c6e65 --- /dev/null +++ b/Documentation/networking/altera_tse.txt @@ -0,0 +1,263 @@ + Altera Triple-Speed Ethernet MAC driver + +Copyright (C) 2008-2014 Altera Corporation + +This is the driver for the Altera Triple-Speed Ethernet (TSE) controllers +using the SGDMA and MSGDMA soft DMA IP components. The driver uses the +platform bus to obtain component resources. The designs used to test this +driver were built for a Cyclone(R) V SOC FPGA board, a Cyclone(R) V FPGA board, +and tested with ARM and NIOS processor hosts seperately. The anticipated use +cases are simple communications between an embedded system and an external peer +for status and simple configuration of the embedded system. + +For more information visit www.altera.com and www.rocketboards.org. Support +forums for the driver may be found on www.rocketboards.org, and a design used +to test this driver may be found there as well. Support is also available from +the maintainer of this driver, found in MAINTAINERS. + +The Triple-Speed Ethernet, SGDMA, and MSGDMA components are all soft IP +components that can be assembled and built into an FPGA using the Altera +Quartus toolchain. Quartus 13.1 and 14.0 were used to build the design that +this driver was tested against. The sopc2dts tool is used to create the +device tree for the driver, and may be found at rocketboards.org. + +The driver probe function examines the device tree and determines if the +Triple-Speed Ethernet instance is using an SGDMA or MSGDMA component. The +probe function then installs the appropriate set of DMA routines to +initialize, setup transmits, receives, and interrupt handling primitives for +the respective configurations. + +The SGDMA component is to be deprecated in the near future (over the next 1-2 +years as of this writing in early 2014) in favor of the MSGDMA component. +SGDMA support is included for existing designs and reference in case a +developer wishes to support their own soft DMA logic and driver support. Any +new designs should not use the SGDMA. + +The SGDMA supports only a single transmit or receive operation at a time, and +therefore will not perform as well compared to the MSGDMA soft IP. Please +visit www.altera.com for known, documented SGDMA errata. + +Scatter-gather DMA is not supported by the SGDMA or MSGDMA at this time. +Scatter-gather DMA will be added to a future maintenance update to this +driver. + +Jumbo frames are not supported at this time. + +The driver limits PHY operations to 10/100Mbps, and has not yet been fully +tested for 1Gbps. This support will be added in a future maintenance update. + +1) Kernel Configuration +The kernel configuration option is ALTERA_TSE: + Device Drivers ---> Network device support ---> Ethernet driver support ---> + Altera Triple-Speed Ethernet MAC support (ALTERA_TSE) + +2) Driver parameters list: + debug: message level (0: no output, 16: all); + dma_rx_num: Number of descriptors in the RX list (default is 64); + dma_tx_num: Number of descriptors in the TX list (default is 64). + +3) Command line options +Driver parameters can be also passed in command line by using: + altera_tse=dma_rx_num:128,dma_tx_num:512 + +4) Driver information and notes + +4.1) Transmit process +When the driver's transmit routine is called by the kernel, it sets up a +transmit descriptor by calling the underlying DMA transmit routine (SGDMA or +MSGDMA), and initites a transmit operation. Once the transmit is complete, an +interrupt is driven by the transmit DMA logic. The driver handles the transmit +completion in the context of the interrupt handling chain by recycling +resource required to send and track the requested transmit operation. + +4.2) Receive process +The driver will post receive buffers to the receive DMA logic during driver +intialization. Receive buffers may or may not be queued depending upon the +underlying DMA logic (MSGDMA is able queue receive buffers, SGDMA is not able +to queue receive buffers to the SGDMA receive logic). When a packet is +received, the DMA logic generates an interrupt. The driver handles a receive +interrupt by obtaining the DMA receive logic status, reaping receive +completions until no more receive completions are available. + +4.3) Interrupt Mitigation +The driver is able to mitigate the number of its DMA interrupts +using NAPI for receive operations. Interrupt mitigation is not yet supported +for transmit operations, but will be added in a future maintenance release. + +4.4) Ethtool support +Ethtool is supported. Driver statistics and internal errors can be taken using: +ethtool -S ethX command. It is possible to dump registers etc. + +4.5) PHY Support +The driver is compatible with PAL to work with PHY and GPHY devices. + +4.7) List of source files: + o Kconfig + o Makefile + o altera_tse_main.c: main network device driver + o altera_tse_ethtool.c: ethtool support + o altera_tse.h: private driver structure and common definitions + o altera_msgdma.h: MSGDMA implementation function definitions + o altera_sgdma.h: SGDMA implementation function definitions + o altera_msgdma.c: MSGDMA implementation + o altera_sgdma.c: SGDMA implementation + o altera_sgdmahw.h: SGDMA register and descriptor definitions + o altera_msgdmahw.h: MSGDMA register and descriptor definitions + o altera_utils.c: Driver utility functions + o altera_utils.h: Driver utility function definitions + +5) Debug Information + +The driver exports debug information such as internal statistics, +debug information, MAC and DMA registers etc. + +A user may use the ethtool support to get statistics: +e.g. using: ethtool -S ethX (that shows the statistics counters) +or sees the MAC registers: e.g. using: ethtool -d ethX + +The developer can also use the "debug" module parameter to get +further debug information. + +6) Statistics Support + +The controller and driver support a mix of IEEE standard defined statistics, +RFC defined statistics, and driver or Altera defined statistics. The four +specifications containing the standard definitions for these statistics are +as follows: + + o IEEE 802.3-2012 - IEEE Standard for Ethernet. + o RFC 2863 found at http://www.rfc-editor.org/rfc/rfc2863.txt. + o RFC 2819 found at http://www.rfc-editor.org/rfc/rfc2819.txt. + o Altera Triple Speed Ethernet User Guide, found at http://www.altera.com + +The statistics supported by the TSE and the device driver are as follows: + +"tx_packets" is equivalent to aFramesTransmittedOK defined in IEEE 802.3-2012, +Section 5.2.2.1.2. This statistics is the count of frames that are successfully +transmitted. + +"rx_packets" is equivalent to aFramesReceivedOK defined in IEEE 802.3-2012, +Section 5.2.2.1.5. This statistic is the count of frames that are successfully +received. This count does not include any error packets such as CRC errors, +length errors, or alignment errors. + +"rx_crc_errors" is equivalent to aFrameCheckSequenceErrors defined in IEEE +802.3-2012, Section 5.2.2.1.6. This statistic is the count of frames that are +an integral number of bytes in length and do not pass the CRC test as the frame +is received. + +"rx_align_errors" is equivalent to aAlignmentErrors defined in IEEE 802.3-2012, +Section 5.2.2.1.7. This statistic is the count of frames that are not an +integral number of bytes in length and do not pass the CRC test as the frame is +received. + +"tx_bytes" is equivalent to aOctetsTransmittedOK defined in IEEE 802.3-2012, +Section 5.2.2.1.8. This statistic is the count of data and pad bytes +successfully transmitted from the interface. + +"rx_bytes" is equivalent to aOctetsReceivedOK defined in IEEE 802.3-2012, +Section 5.2.2.1.14. This statistic is the count of data and pad bytes +successfully received by the controller. + +"tx_pause" is equivalent to aPAUSEMACCtrlFramesTransmitted defined in IEEE +802.3-2012, Section 30.3.4.2. This statistic is a count of PAUSE frames +transmitted from the network controller. + +"rx_pause" is equivalent to aPAUSEMACCtrlFramesReceived defined in IEEE +802.3-2012, Section 30.3.4.3. This statistic is a count of PAUSE frames +received by the network controller. + +"rx_errors" is equivalent to ifInErrors defined in RFC 2863. This statistic is +a count of the number of packets received containing errors that prevented the +packet from being delivered to a higher level protocol. + +"tx_errors" is equivalent to ifOutErrors defined in RFC 2863. This statistic +is a count of the number of packets that could not be transmitted due to errors. + +"rx_unicast" is equivalent to ifInUcastPkts defined in RFC 2863. This +statistic is a count of the number of packets received that were not addressed +to the broadcast address or a multicast group. + +"rx_multicast" is equivalent to ifInMulticastPkts defined in RFC 2863. This +statistic is a count of the number of packets received that were addressed to +a multicast address group. + +"rx_broadcast" is equivalent to ifInBroadcastPkts defined in RFC 2863. This +statistic is a count of the number of packets received that were addressed to +the broadcast address. + +"tx_discards" is equivalent to ifOutDiscards defined in RFC 2863. This +statistic is the number of outbound packets not transmitted even though an +error was not detected. An example of a reason this might occur is to free up +internal buffer space. + +"tx_unicast" is equivalent to ifOutUcastPkts defined in RFC 2863. This +statistic counts the number of packets transmitted that were not addressed to +a multicast group or broadcast address. + +"tx_multicast" is equivalent to ifOutMulticastPkts defined in RFC 2863. This +statistic counts the number of packets transmitted that were addressed to a +multicast group. + +"tx_broadcast" is equivalent to ifOutBroadcastPkts defined in RFC 2863. This +statistic counts the number of packets transmitted that were addressed to a +broadcast address. + +"ether_drops" is equivalent to etherStatsDropEvents defined in RFC 2819. +This statistic counts the number of packets dropped due to lack of internal +controller resources. + +"rx_total_bytes" is equivalent to etherStatsOctets defined in RFC 2819. +This statistic counts the total number of bytes received by the controller, +including error and discarded packets. + +"rx_total_packets" is equivalent to etherStatsPkts defined in RFC 2819. +This statistic counts the total number of packets received by the controller, +including error, discarded, unicast, multicast, and broadcast packets. + +"rx_undersize" is equivalent to etherStatsUndersizePkts defined in RFC 2819. +This statistic counts the number of correctly formed packets received less +than 64 bytes long. + +"rx_oversize" is equivalent to etherStatsOversizePkts defined in RFC 2819. +This statistic counts the number of correctly formed packets greater than 1518 +bytes long. + +"rx_64_bytes" is equivalent to etherStatsPkts64Octets defined in RFC 2819. +This statistic counts the total number of packets received that were 64 octets +in length. + +"rx_65_127_bytes" is equivalent to etherStatsPkts65to127Octets defined in RFC +2819. This statistic counts the total number of packets received that were +between 65 and 127 octets in length inclusive. + +"rx_128_255_bytes" is equivalent to etherStatsPkts128to255Octets defined in +RFC 2819. This statistic is the total number of packets received that were +between 128 and 255 octets in length inclusive. + +"rx_256_511_bytes" is equivalent to etherStatsPkts256to511Octets defined in +RFC 2819. This statistic is the total number of packets received that were +between 256 and 511 octets in length inclusive. + +"rx_512_1023_bytes" is equivalent to etherStatsPkts512to1023Octets defined in +RFC 2819. This statistic is the total number of packets received that were +between 512 and 1023 octets in length inclusive. + +"rx_1024_1518_bytes" is equivalent to etherStatsPkts1024to1518Octets define +in RFC 2819. This statistic is the total number of packets received that were +between 1024 and 1518 octets in length inclusive. + +"rx_gte_1519_bytes" is a statistic defined specific to the behavior of the +Altera TSE. This statistics counts the number of received good and errored +frames between the length of 1519 and the maximum frame length configured +in the frm_length register. See the Altera TSE User Guide for More details. + +"rx_jabbers" is equivalent to etherStatsJabbers defined in RFC 2819. This +statistic is the total number of packets received that were longer than 1518 +octets, and had either a bad CRC with an integral number of octets (CRC Error) +or a bad CRC with a non-integral number of octets (Alignment Error). + +"rx_runts" is equivalent to etherStatsFragments defined in RFC 2819. This +statistic is the total number of packets received that were less than 64 octets +in length and had either a bad CRC with an integral number of octets (CRC +error) or a bad CRC with a non-integral number of octets (Alignment Error). |