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* xsk: wire upp Tx zero-copy functionsMagnus Karlsson2018-06-051-2/+27
| | | | | | | | Here we add the functionality required to support zero-copy Tx, and also exposes various zero-copy related functions for the netdevs. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: add zero-copy support for RxBjörn Töpel2018-06-051-0/+77
| | | | | | | | Extend the xsk_rcv to support the new MEM_TYPE_ZERO_COPY memory, and wireup ndo_bpf call in bind. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: introduce xdp_umem_pageBjörn Töpel2018-06-051-1/+14
| | | | | | | | The xdp_umem_page holds the address for a page. Trade memory for faster lookup. Later, we'll add DMA address here as well. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: moved struct xdp_umem definitionBjörn Töpel2018-06-051-0/+1
| | | | | | | | Moved struct xdp_umem to xdp_sock.h, in order to prepare for zero-copy support. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: new descriptor addressing schemeBjörn Töpel2018-06-041-18/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, AF_XDP only supports a fixed frame-size memory scheme where each frame is referenced via an index (idx). A user passes the frame index to the kernel, and the kernel acts upon the data. Some NICs, however, do not have a fixed frame-size model, instead they have a model where a memory window is passed to the hardware and multiple frames are filled into that window (referred to as the "type-writer" model). By changing the descriptor format from the current frame index addressing scheme, AF_XDP can in the future be extended to support these kinds of NICs. In the index-based model, an idx refers to a frame of size frame_size. Addressing a frame in the UMEM is done by offseting the UMEM starting address by a global offset, idx * frame_size + offset. Communicating via the fill- and completion-rings are done by means of idx. In this commit, the idx is removed in favor of an address (addr), which is a relative address ranging over the UMEM. To convert an idx-based address to the new addr is simply: addr = idx * frame_size + offset. We also stop referring to the UMEM "frame" as a frame. Instead it is simply called a chunk. To transfer ownership of a chunk to the kernel, the addr of the chunk is passed in the fill-ring. Note, that the kernel will mask addr to make it chunk aligned, so there is no need for userspace to do that. E.g., for a chunk size of 2k, passing an addr of 2048, 2050 or 3000 to the fill-ring will refer to the same chunk. On the completion-ring, the addr will match that of the Tx descriptor, passed to the kernel. Changing the descriptor format to use chunks/addr will allow for future changes to move to a type-writer based model, where multiple frames can reside in one chunk. In this model passing one single chunk into the fill-ring, would potentially result in multiple Rx descriptors. This commit changes the uapi of AF_XDP sockets, and updates the documentation. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: convert atomic_t to refcount_tBjörn Töpel2018-05-221-3/+3
| | | | | | | Introduce refcount_t, in favor of atomic_t. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: simplified umem setupBjörn Töpel2018-05-221-41/+38
| | | | | | | | | | As suggested by Daniel Borkmann, the umem setup code was a too defensive and complex. Here, we reduce the number of checks. Also, the memory pinning is now folded into the umem creation, and we do correct locking. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: fixed some cases of unnecessary parenthesesBjörn Töpel2018-05-181-2/+2
| | | | | | | Removed some cases of unnecessary parentheses. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: clean up SPDX headersBjörn Töpel2018-05-181-9/+0
| | | | | | | Clean up SPDX-License-Identifier and removing licensing leftovers. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: fix 64-bit divisionBjörn Töpel2018-05-091-1/+1
| | | | | | | | | | | | | | i386 builds report: net/xdp/xdp_umem.o: In function `xdp_umem_reg': xdp_umem.c:(.text+0x47e): undefined reference to `__udivdi3' This fix uses div_u64 instead of the GCC built-in. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: add umem completion queue support and mmapMagnus Karlsson2018-05-031-1/+6
| | | | | | | | | | | | | | | Here, we add another setsockopt for registered user memory (umem) called XDP_UMEM_COMPLETION_QUEUE. Using this socket option, the process can ask the kernel to allocate a queue (ring buffer) and also mmap it (XDP_UMEM_PGOFF_COMPLETION_QUEUE) into the process. The queue is used to explicitly pass ownership of umem frames from the kernel to user process. This will be used by the TX path to tell user space that a certain frame has been transmitted and user space can use it for something else, if it wishes. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: add support for bind for RxMagnus Karlsson2018-05-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | Here, the bind syscall is added. Binding an AF_XDP socket, means associating the socket to an umem, a netdev and a queue index. This can be done in two ways. The first way, creating a "socket from scratch". Create the umem using the XDP_UMEM_REG setsockopt and an associated fill queue with XDP_UMEM_FILL_QUEUE. Create the Rx queue using the XDP_RX_QUEUE setsockopt. Call bind passing ifindex and queue index ("channel" in ethtool speak). The second way to bind a socket, is simply skipping the umem/netdev/queue index, and passing another already setup AF_XDP socket. The new socket will then have the same umem/netdev/queue index as the parent so it will share the same umem. You must also set the flags field in the socket address to XDP_SHARED_UMEM. v2: Use PTR_ERR instead of passing error variable explicitly. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: add umem fill queue support and mmapMagnus Karlsson2018-05-031-0/+5
| | | | | | | | | | | | | | | | Here, we add another setsockopt for registered user memory (umem) called XDP_UMEM_FILL_QUEUE. Using this socket option, the process can ask the kernel to allocate a queue (ring buffer) and also mmap it (XDP_UMEM_PGOFF_FILL_QUEUE) into the process. The queue is used to explicitly pass ownership of umem frames from the user process to the kernel. These frames will in a later patch be filled in with Rx packet data by the kernel. v2: Fixed potential crash in xsk_mmap. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: add user memory registration support sockoptBjörn Töpel2018-05-031-0/+245
In this commit the base structure of the AF_XDP address family is set up. Further, we introduce the abilty register a window of user memory to the kernel via the XDP_UMEM_REG setsockopt syscall. The memory window is viewed by an AF_XDP socket as a set of equally large frames. After a user memory registration all frames are "owned" by the user application, and not the kernel. v2: More robust checks on umem creation and unaccount on error. Call set_page_dirty_lock on cleanup. Simplified xdp_umem_reg. Co-authored-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>