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| author | Björn Töpel <bjorn.topel@intel.com> | 2020-05-20 21:20:53 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-21 17:31:26 -0700 |
| commit | 2b43470add8c8ff1e1ee28dffc5c5df97e955d09 (patch) | |
| tree | f2e61f5891abf48c657365a324d091cdf3922ff0 /net/xdp/xdp_umem.c | |
| parent | 89e4a376e3a3dab639a3947a6c7cf5d461d1aa4c (diff) | |
| download | linux-2b43470add8c8ff1e1ee28dffc5c5df97e955d09.tar.bz2 | |
xsk: Introduce AF_XDP buffer allocation API
In order to simplify AF_XDP zero-copy enablement for NIC driver
developers, a new AF_XDP buffer allocation API is added. The
implementation is based on a single core (single producer/consumer)
buffer pool for the AF_XDP UMEM.
A buffer is allocated using the xsk_buff_alloc() function, and
returned using xsk_buff_free(). If a buffer is disassociated with the
pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is
said to be released. Currently, the release function is only used by
the AF_XDP internals and not visible to the driver.
Drivers using this API should register the XDP memory model with the
new MEM_TYPE_XSK_BUFF_POOL type.
The API is defined in net/xdp_sock_drv.h.
The buffer type is struct xdp_buff, and follows the lifetime of
regular xdp_buffs, i.e. the lifetime of an xdp_buff is restricted to
a NAPI context. In other words, the API is not replacing xdp_frames.
In addition to introducing the API and implementations, the AF_XDP
core is migrated to use the new APIs.
rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test
robot)
Added headroom/chunk size getter. (Maxim/Björn)
v1->v2: Swapped SoBs. (Maxim)
v2->v3: Initialize struct xdp_buff member frame_sz. (Björn)
Add API to query the DMA address of a frame. (Maxim)
Do DMA sync for CPU till the end of the frame to handle
possible growth (frame_sz). (Maxim)
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
Diffstat (limited to 'net/xdp/xdp_umem.c')
| -rw-r--r-- | net/xdp/xdp_umem.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 37ace3bc0d48..7f04688045d5 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -245,7 +245,7 @@ static void xdp_umem_release(struct xdp_umem *umem) } xsk_reuseq_destroy(umem); - + xp_destroy(umem->pool); xdp_umem_unmap_pages(umem); xdp_umem_unpin_pages(umem); @@ -390,6 +390,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) umem->size = size; umem->headroom = headroom; umem->chunk_size_nohr = chunk_size - headroom; + umem->chunk_size = chunk_size; umem->npgs = size / PAGE_SIZE; umem->pgs = NULL; umem->user = NULL; @@ -415,11 +416,21 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) } err = xdp_umem_map_pages(umem); - if (!err) - return 0; + if (err) + goto out_pages; - kvfree(umem->pages); + umem->pool = xp_create(umem->pgs, umem->npgs, chunks, chunk_size, + headroom, size, unaligned_chunks); + if (!umem->pool) { + err = -ENOMEM; + goto out_unmap; + } + return 0; +out_unmap: + xdp_umem_unmap_pages(umem); +out_pages: + kvfree(umem->pages); out_pin: xdp_umem_unpin_pages(umem); out_account: |