diff options
| -rw-r--r-- | include/linux/filter.h | 2 | ||||
| -rw-r--r-- | include/net/xdp.h | 47 | ||||
| -rw-r--r-- | net/core/Makefile | 2 | ||||
| -rw-r--r-- | net/core/xdp.c | 67 |
4 files changed, 117 insertions, 1 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 2b0df2703671..425056c7f96c 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -20,6 +20,7 @@ #include <linux/set_memory.h> #include <linux/kallsyms.h> +#include <net/xdp.h> #include <net/sch_generic.h> #include <uapi/linux/filter.h> @@ -503,6 +504,7 @@ struct xdp_buff { void *data_end; void *data_meta; void *data_hard_start; + struct xdp_rxq_info *rxq; }; /* Compute the linear packet data range [data, data_end) which diff --git a/include/net/xdp.h b/include/net/xdp.h new file mode 100644 index 000000000000..86c41631a908 --- /dev/null +++ b/include/net/xdp.h @@ -0,0 +1,47 @@ +/* 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); + +#endif /* __LINUX_NET_XDP_H__ */ diff --git a/net/core/Makefile b/net/core/Makefile index 1fd0a9c88b1b..6dbbba8c57ae 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -11,7 +11,7 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.o obj-y += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \ neighbour.o rtnetlink.o utils.o link_watch.o filter.o \ sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \ - fib_notifier.o + fib_notifier.o xdp.o obj-y += net-sysfs.o obj-$(CONFIG_PROC_FS) += net-procfs.o diff --git a/net/core/xdp.c b/net/core/xdp.c new file mode 100644 index 000000000000..229bc5a0ee04 --- /dev/null +++ b/net/core/xdp.c @@ -0,0 +1,67 @@ +/* net/core/xdp.c + * + * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. + * Released under terms in GPL version 2. See COPYING. + */ +#include <linux/types.h> +#include <linux/mm.h> + +#include <net/xdp.h> + +#define REG_STATE_NEW 0x0 +#define REG_STATE_REGISTERED 0x1 +#define REG_STATE_UNREGISTERED 0x2 +#define REG_STATE_UNUSED 0x3 + +void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq) +{ + /* Simplify driver cleanup code paths, allow unreg "unused" */ + if (xdp_rxq->reg_state == REG_STATE_UNUSED) + return; + + WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG"); + + xdp_rxq->reg_state = REG_STATE_UNREGISTERED; + xdp_rxq->dev = NULL; +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg); + +static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq) +{ + memset(xdp_rxq, 0, sizeof(*xdp_rxq)); +} + +/* Returns 0 on success, negative on failure */ +int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, + struct net_device *dev, u32 queue_index) +{ + if (xdp_rxq->reg_state == REG_STATE_UNUSED) { + WARN(1, "Driver promised not to register this"); + return -EINVAL; + } + + if (xdp_rxq->reg_state == REG_STATE_REGISTERED) { + WARN(1, "Missing unregister, handled but fix driver"); + xdp_rxq_info_unreg(xdp_rxq); + } + + if (!dev) { + WARN(1, "Missing net_device from driver"); + return -ENODEV; + } + + /* State either UNREGISTERED or NEW */ + xdp_rxq_info_init(xdp_rxq); + xdp_rxq->dev = dev; + xdp_rxq->queue_index = queue_index; + + xdp_rxq->reg_state = REG_STATE_REGISTERED; + return 0; +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_reg); + +void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq) +{ + xdp_rxq->reg_state = REG_STATE_UNUSED; +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_unused); |