ebdfae0d - gve: adopt page pool for DQ RDA mode

Mon, 14 Oct 2024 20:21:07 +0000

gve: adopt page pool for DQ RDA modeFor DQ queue format in raw DMA addressing(RDA) mode,implement page pool recycling of buffers by leveraginga few helper functions.DQ QPL mode will continue to use the exisiting recyclinglogic. This is because in QPL mode, the pages come from aconstant set of pages that the driver pre-allocates andregisters with the device.Reviewed-by: Praveen Kaligineedi Reviewed-by: Shailend Chand Reviewed-by: Willem de Bruijn Signed-off-by: Harshitha Ramamurthy Reviewed-by: Jacob Keller Link: https://patch.msgid.link/20241014202108.1051963-3-pkaligineedi@google.comSigned-off-by: Jakub Kicinski List of files: /linux-6.15/drivers/net/ethernet/google/Kconfig

22319818 - gve: Add dqo descriptors

Thu, 24 Jun 2021 18:06:25 +0000

gve: Add dqo descriptorsGeneral description of rings and descriptors:TX ring is used for sending TX packet buffers to the NIC. It has thefollowing descriptors:- `gve_tx_pkt_desc_dqo` - Data buffer descriptor- `gve_tx_tso_context_desc_dqo` - TSO context descriptor- `gve_tx_general_context_desc_dqo` - Generic metadata descriptorMetadata is a collection of 12 bytes. We define `gve_tx_metadata_dqo`which represents the logical interpetation of the metadata bytes. It'shelpful to define this structure because the metadata bytes exist inmultiple descriptor types (including `gve_tx_tso_context_desc_dqo`),and the device requires same field has the same value in alldescriptors.The TX completion ring is used to receive completions from the NIC.Having a separate ring allows for completions to be out of order. Thecompletion descriptor `gve_tx_compl_desc` has several different types,most important are packet and descriptor completions. Descriptorcompletions are used to notify the driver when descriptors sent on theTX ring are done being consumed. The descriptor completion is only usedto signal that space is cleared in the TX ring. A packet completion willbe received when a packet transmitted on the TX queue is done beingtransmitted.In addition there are "miss" and "reinjection" completions. The deviceimplements a "flow-miss model". Most packets will simply receive apacket completion. The flow-miss system may choose to process a packetbased on its contents. A TX packet which experiences a flow miss wouldreceive a miss completion followed by a later reinjection completion.The miss-completion is received when the packet starts to be processedby the flow-miss system and the reinjection completion is received whenthe flow-miss system completes processing the packet and sends it on thewire.The RX buffer ring is used to send buffers to HW via the`gve_rx_desc_dqo` descriptor.Received packets are put into the RX queue by the device, whichpopulates the `gve_rx_compl_desc_dqo` descriptor. The RX descriptorsrefer to buffers posted by the buffer queue. Received buffers may bereturned out of order, such as when HW LRO is enabled.Important concepts:- "TX" and "RX buffer" queues, which send descriptors to the device, use MMIO doorbells to notify the device of new descriptors.- "RX" and "TX completion" queues, which receive descriptors from the device, use a "generation bit" to know when a descriptor was populated by the device. The driver initializes all bits with the "current generation". The device will populate received descriptors with the "next generation" which is inverted from the current generation. When the ring wraps, the current/next generation are swapped.- It's the driver's responsibility to ensure that the RX and TX completion queues are not overrun. This can be accomplished by limiting the number of descriptors posted to HW.- TX packets have a 16 bit completion_tag and RX buffers have a 16 bit buffer_id. These will be returned on the TX completion and RX queues respectively to let the driver know which packet/buffer was completed.Bitfields are used to describe descriptor fields. This notation is moreconcise and readable than shift-and-mask. It is possible because thedriver is restricted to little endian platforms.Signed-off-by: Bailey Forrest Reviewed-by: Willem de Bruijn Reviewed-by: Catherine Sullivan Signed-off-by: David S. Miller List of files: /linux-6.15/drivers/net/ethernet/google/Kconfig

893ce44d - gve: Add basic driver framework for Compute Engine Virtual NIC

Mon, 01 Jul 2019 22:57:52 +0000

gve: Add basic driver framework for Compute Engine Virtual NICAdd a driver framework for the Compute Engine Virtual NIC that will beavailable in the future.At this point the only functionality is loading the driver.Signed-off-by: Catherine Sullivan Signed-off-by: Sagi Shahar Signed-off-by: Jon Olson Acked-by: Willem de Bruijn Reviewed-by: Luigi Rizzo Signed-off-by: David S. Miller List of files: /linux-6.15/drivers/net/ethernet/google/Kconfig

Changes in Kconfig

ebdfae0d - gve: adopt page pool for DQ RDA mode

22319818 - gve: Add dqo descriptors

893ce44d - gve: Add basic driver framework for Compute Engine Virtual NIC