[PATCH net-next 0/7] xdp: a fistful of generic changes pt. III

[Alexander Lobakin <aleksander.lobakin@intel.com>]

XDP for idpf is currently 5.(6) chapters:
* convert Rx to libeth;
* convert Tx and stats to libeth;
* generic XDP and XSk code changes;
* generic XDP and XSk code additions pt. 1;
* generic XDP and XSk code additions pt. 2 (you are here);
* actual XDP for idpf via new libeth_xdp;
* XSk for idpf (via ^).

Part III.3 does the following:
* adds generic functions to build skbs from xdp_buffs (regular and
  XSk) and attach frags to xdp_buffs (regular and XSk);
* adds helper to optimize XSk xmit in drivers;
* add generic loop unroll hint macros.

Everything is prereq for libeth_xdp, but will be useful standalone
as well: less code in drivers, faster XSk XDP_PASS, smaller object
code.

Alexander Lobakin (7):
  page_pool: add page_pool_dev_alloc_netmem()
  xdp: add generic xdp_buff_add_frag()
  xdp: add generic xdp_build_skb_from_buff()
  xsk: make xsk_buff_add_frag() really add the frag via
    __xdp_buff_add_frag()
  xsk: add generic XSk &xdp_buff -> skb conversion
  xsk: add helper to get &xdp_desc's DMA and meta pointer in one go
  unroll: add generic loop unroll helpers

 include/linux/skbuff.h                     |  16 +-
 include/linux/unroll.h                     |  44 +++++
 include/net/page_pool/helpers.h            |   9 ++
 include/net/xdp.h                          |  98 +++++++++++-
 include/net/xdp_sock_drv.h                 |  41 ++++-
 include/net/xsk_buff_pool.h                |   8 +
 drivers/net/ethernet/intel/i40e/i40e_xsk.c |  30 +---
 drivers/net/ethernet/intel/ice/ice_xsk.c   |  32 +---
 net/core/xdp.c                             | 178 +++++++++++++++++++++
 net/xdp/xsk_buff_pool.c                    |  40 +++++
 10 files changed, 431 insertions(+), 65 deletions(-)

---
Each patch except trivial 0001 was on the lists already.

Since the not applied part of Chapter III.2:
* rebase on top of Mina's netmem fixes;
* 0003: remove redundant double CONFIG_PAGE_POOL check (one inside
  and another one outside of skb_mark_for_recycle()) (Jakub);
* 0005: remove !CONFIG_PAGE_POOL code as unreachable (eBPF always
  selects it) (also Jakub);
* 0005: actually check the pfmemalloc flag of newly allocated frags;
* drop exporting static_key_{inc,dec}_cpuslocked() -- were used on
  slowpath in very unlikely case where saving a few cycles looked
  worse and less convienient than the "regular" way.
-- 
2.47.1