Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add the ability to use unaligned chunks in the AF_XDP umem. By
   relaxing where the chunks can be placed, it allows to use an
   arbitrary buffer size and place whenever there is a free
   address in the umem. Helps more seamless DPDK AF_XDP driver
   integration. Support for i40e, ixgbe and mlx5e, from Kevin and
   Maxim.

2) Addition of a wakeup flag for AF_XDP tx and fill rings so the
   application can wake up the kernel for rx/tx processing which
   avoids busy-spinning of the latter, useful when app and driver
   is located on the same core. Support for i40e, ixgbe and mlx5e,
   from Magnus and Maxim.

3) bpftool fixes for printf()-like functions so compiler can actually
   enforce checks, bpftool build system improvements for custom output
   directories, and addition of 'bpftool map freeze' command, from Quentin.

4) Support attaching/detaching XDP programs from 'bpftool net' command,
   from Daniel.

5) Automatic xskmap cleanup when AF_XDP socket is released, and several
   barrier/{read,write}_once fixes in AF_XDP code, from Björn.

6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf
   inclusion as well as libbpf versioning improvements, from Andrii.

7) Several new BPF kselftests for verifier precision tracking, from Alexei.

8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya.

9) And more BPF kselftest improvements all over the place, from Stanislav.

10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub.

11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan.

12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni.

13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin.

14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar.

15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari,
    Peter, Wei, Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 4 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
index 79301d116667..eb2e1f2138e4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
@@ -25,18 +25,33 @@ u16 mlx5e_get_linear_rq_headroom(struct mlx5e_params *params,
 	return headroom;
 }
 
-u32 mlx5e_rx_get_linear_frag_sz(struct mlx5e_params *params,
-				struct mlx5e_xsk_param *xsk)
+u32 mlx5e_rx_get_min_frag_sz(struct mlx5e_params *params,
+			     struct mlx5e_xsk_param *xsk)
 {
 	u32 hw_mtu = MLX5E_SW2HW_MTU(params, params->sw_mtu);
 	u16 linear_rq_headroom = mlx5e_get_linear_rq_headroom(params, xsk);
-	u32 frag_sz = linear_rq_headroom + hw_mtu;
+
+	return linear_rq_headroom + hw_mtu;
+}
+
+u32 mlx5e_rx_get_linear_frag_sz(struct mlx5e_params *params,
+				struct mlx5e_xsk_param *xsk)
+{
+	u32 frag_sz = mlx5e_rx_get_min_frag_sz(params, xsk);
 
 	/* AF_XDP doesn't build SKBs in place. */
 	if (!xsk)
 		frag_sz = MLX5_SKB_FRAG_SZ(frag_sz);
 
-	/* XDP in mlx5e doesn't support multiple packets per page. */
+	/* XDP in mlx5e doesn't support multiple packets per page. AF_XDP is a
+	 * special case. It can run with frames smaller than a page, as it
+	 * doesn't allocate pages dynamically. However, here we pretend that
+	 * fragments are page-sized: it allows to treat XSK frames like pages
+	 * by redirecting alloc and free operations to XSK rings and by using
+	 * the fact there are no multiple packets per "page" (which is a frame).
+	 * The latter is important, because frames may come in a random order,
+	 * and we will have trouble assemblying a real page of multiple frames.
+	 */
 	if (mlx5e_rx_is_xdp(params, xsk))
 		frag_sz = max_t(u32, frag_sz, PAGE_SIZE);