net: bnxt: Implement software USO

Browse source

Implement bnxt_sw_udp_gso_xmit() using the core tso_dma_map API and
the pre-allocated TX inline buffer for per-segment headers.

The xmit path:
1. Calls tso_start() to initialize TSO state
2. Stack-allocates a tso_dma_map and calls tso_dma_map_init() to
   DMA-map the linear payload and all frags upfront.
3. For each segment:
   - Copies and patches headers via tso_build_hdr() into the
     pre-allocated tx_inline_buf (DMA-synced per segment)
   - Counts payload BDs via tso_dma_map_count()
   - Emits long BD (header) + ext BD + payload BDs
   - Payload BDs use tso_dma_map_next() which yields (dma_addr,
     chunk_len, mapping_len) tuples.

Header BDs set dma_unmap_len=0 since the inline buffer is pre-allocated
and unmapped only at ring teardown.

Completion state is updated by calling tso_dma_map_completion_save() for
the last segment.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20260408230607.2019402-8-joe@dama.to
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Joe Damato 2026-04-08 16:05:56 -07:00 • committed by Jakub Kicinski

parent 0440e27eed

commit cc5d90667d

3 changed files with 219 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

drivers/net/ethernet/broadcom/bnxt/bnxt.h

View file

210

drivers/net/ethernet/broadcom/bnxt/bnxt_gso.c

View file

6

drivers/net/ethernet/broadcom/bnxt/bnxt_gso.h

View file