48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
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/* include/net/xdp.h
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*
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* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
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* Released under terms in GPL version 2. See COPYING.
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*/
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#ifndef __LINUX_NET_XDP_H__
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#define __LINUX_NET_XDP_H__
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/**
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* DOC: XDP RX-queue information
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*
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* The XDP RX-queue info (xdp_rxq_info) is associated with the driver
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* level RX-ring queues. It is information that is specific to how
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* the driver have configured a given RX-ring queue.
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*
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* Each xdp_buff frame received in the driver carry a (pointer)
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* reference to this xdp_rxq_info structure. This provides the XDP
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* data-path read-access to RX-info for both kernel and bpf-side
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* (limited subset).
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*
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* For now, direct access is only safe while running in NAPI/softirq
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* context. Contents is read-mostly and must not be updated during
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* driver NAPI/softirq poll.
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*
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* The driver usage API is a register and unregister API.
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*
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* The struct is not directly tied to the XDP prog. A new XDP prog
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* can be attached as long as it doesn't change the underlying
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* RX-ring. If the RX-ring does change significantly, the NIC driver
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* naturally need to stop the RX-ring before purging and reallocating
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* memory. In that process the driver MUST call unregistor (which
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* also apply for driver shutdown and unload). The register API is
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* also mandatory during RX-ring setup.
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*/
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struct xdp_rxq_info {
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struct net_device *dev;
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u32 queue_index;
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u32 reg_state;
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} ____cacheline_aligned; /* perf critical, avoid false-sharing */
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int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
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struct net_device *dev, u32 queue_index);
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void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);
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void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq);
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#endif /* __LINUX_NET_XDP_H__ */
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