| Jesper Dangaard Brouer | aecd67b | 2018-01-03 11:25:13 +0100 | [diff] [blame] | 1 | /* include/net/xdp.h |
| 2 | * |
| 3 | * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. |
| 4 | * Released under terms in GPL version 2. See COPYING. |
| 5 | */ |
| 6 | #ifndef __LINUX_NET_XDP_H__ |
| 7 | #define __LINUX_NET_XDP_H__ |
| 8 | |
| 9 | /** |
| 10 | * DOC: XDP RX-queue information |
| 11 | * |
| 12 | * The XDP RX-queue info (xdp_rxq_info) is associated with the driver |
| 13 | * level RX-ring queues. It is information that is specific to how |
| 14 | * the driver have configured a given RX-ring queue. |
| 15 | * |
| 16 | * Each xdp_buff frame received in the driver carry a (pointer) |
| 17 | * reference to this xdp_rxq_info structure. This provides the XDP |
| 18 | * data-path read-access to RX-info for both kernel and bpf-side |
| 19 | * (limited subset). |
| 20 | * |
| 21 | * For now, direct access is only safe while running in NAPI/softirq |
| 22 | * context. Contents is read-mostly and must not be updated during |
| 23 | * driver NAPI/softirq poll. |
| 24 | * |
| 25 | * The driver usage API is a register and unregister API. |
| 26 | * |
| 27 | * The struct is not directly tied to the XDP prog. A new XDP prog |
| 28 | * can be attached as long as it doesn't change the underlying |
| 29 | * RX-ring. If the RX-ring does change significantly, the NIC driver |
| 30 | * naturally need to stop the RX-ring before purging and reallocating |
| 31 | * memory. In that process the driver MUST call unregistor (which |
| 32 | * also apply for driver shutdown and unload). The register API is |
| 33 | * also mandatory during RX-ring setup. |
| 34 | */ |
| 35 | |
| 36 | struct xdp_rxq_info { |
| 37 | struct net_device *dev; |
| 38 | u32 queue_index; |
| 39 | u32 reg_state; |
| 40 | } ____cacheline_aligned; /* perf critical, avoid false-sharing */ |
| 41 | |
| 42 | int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, |
| 43 | struct net_device *dev, u32 queue_index); |
| 44 | void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq); |
| 45 | void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq); |
| 46 | |
| 47 | #endif /* __LINUX_NET_XDP_H__ */ |