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Diffstat (limited to 'include/net/xdp.h')
| -rw-r--r-- | include/net/xdp.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/include/net/xdp.h b/include/net/xdp.h new file mode 100644 index 000000000000..b2362ddfa694 --- /dev/null +++ b/include/net/xdp.h @@ -0,0 +1,48 @@ +/* include/net/xdp.h + * + * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. + * Released under terms in GPL version 2. See COPYING. + */ +#ifndef __LINUX_NET_XDP_H__ +#define __LINUX_NET_XDP_H__ + +/** + * DOC: XDP RX-queue information + * + * The XDP RX-queue info (xdp_rxq_info) is associated with the driver + * level RX-ring queues. It is information that is specific to how + * the driver have configured a given RX-ring queue. + * + * Each xdp_buff frame received in the driver carry a (pointer) + * reference to this xdp_rxq_info structure. This provides the XDP + * data-path read-access to RX-info for both kernel and bpf-side + * (limited subset). + * + * For now, direct access is only safe while running in NAPI/softirq + * context. Contents is read-mostly and must not be updated during + * driver NAPI/softirq poll. + * + * The driver usage API is a register and unregister API. + * + * The struct is not directly tied to the XDP prog. A new XDP prog + * can be attached as long as it doesn't change the underlying + * RX-ring. If the RX-ring does change significantly, the NIC driver + * naturally need to stop the RX-ring before purging and reallocating + * memory. In that process the driver MUST call unregistor (which + * also apply for driver shutdown and unload). The register API is + * also mandatory during RX-ring setup. + */ + +struct xdp_rxq_info { + struct net_device *dev; + u32 queue_index; + u32 reg_state; +} ____cacheline_aligned; /* perf critical, avoid false-sharing */ + +int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, + struct net_device *dev, u32 queue_index); +void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq); +void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq); +bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq); + +#endif /* __LINUX_NET_XDP_H__ */ |