Hi! This series adds support for large io_uring zero-copy RX buffers to fbnic.
fbnic hardware consumes receive memory in 4 KiB device pages, while io_uring may expose a larger software buffer, such as 256 KiB. Track the device-page geometry per BDQ, represent each large buffer with consecutive descriptors, and decode completions to the corresponding offset within the buffer. HPQ keeps its existing PAGE_SIZE geometry. Larger buffers also reduce pressure on the memory provider. One provider allocation supplies multiple 4 KiB device pages, so the same amount of receive memory needs fewer net_iov objects and fewer allocation, refill, and recycle operations. Hardware descriptor use remains unchanged. Ring depth and buffer size must be validated together. An ethtool ring change can otherwise make an active memory-provider configuration invalid. Store accepted ring depths in netdev_config, stage proposed values in cfg_pending, and validate the default and each RX queue before committing the change. Both netlink and ioctl use the same transaction helpers. The selftest requests a power-of-two buffer larger than twice the MTU, checks the reported buffer length, and verifies received data. It does not assume how packets are placed within the buffer. Sashiko found, as usual, a number of bugs. I've sent the relevant ones to net. Changes in v3 ============= - Carry Breno's Reviewed-by on the netdev_config helper patch. - Clarify that the fbnic ring-depth consumer follows the core patch. - Document initialization, override, normalization, and stored ring depth semantics. - Drop the CQE placement assertion from the large-buffer test. - Reject a zero RX-jumbo depth before validating large RX pages. - Rebase on net-next. Changes in v2 ============= - Add generic netdev_config lifecycle helpers for the netlink and ioctl paths. - Store ring parameters in netdev_config and revalidate RX queues before committing a ring change. - Preserve the distinction between accepted and applied HDS state. - Track fbnic device-page geometry per BDQ. - Validate the fbnic RX page size, fragment count, and PPQ depth. - Add automated large-buffer test coverage. v2: https://lore.kernel.org/netdev/[email protected]/ v1: https://lore.kernel.org/netdev/[email protected]/ Björn Töpel (4): fbnic: Track BDQ device-page geometry per ring net: Revalidate queue config for ringparam changes fbnic: Support larger memory-provider RX pages selftests: drv-net: Request larger zcrx buffers Jakub Kicinski (1): net: Add netdev_config helpers drivers/net/ethernet/meta/fbnic/fbnic_csr.h | 34 +--- .../net/ethernet/meta/fbnic/fbnic_debugfs.c | 5 +- .../net/ethernet/meta/fbnic/fbnic_netdev.c | 5 + drivers/net/ethernet/meta/fbnic/fbnic_txrx.c | 173 ++++++++++++++---- drivers/net/ethernet/meta/fbnic/fbnic_txrx.h | 7 + include/net/netdev_queues.h | 49 ++++- net/core/dev.c | 7 +- net/core/dev.h | 7 + net/core/netdev_config.c | 75 +++++++- net/ethtool/common.c | 9 + net/ethtool/common.h | 2 + net/ethtool/ioctl.c | 24 ++- net/ethtool/netlink.c | 15 +- net/ethtool/rings.c | 13 +- .../selftests/drivers/net/hw/iou-zcrx.py | 6 +- 15 files changed, 345 insertions(+), 86 deletions(-) base-commit: b8e9e7d82e7eefd5d2d528469d94ec20e96b38c3 -- 2.55.0
