| Message ID | 20210201100509.27351-3-borisp@mellanox.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | nvme-tcp receive offloads | expand |
On Mon, Feb 01, 2021 at 12:04:50 +0200, Boris Pismenny wrote: > This commit introduces direct data placement offload for TCP. > This capability is accompanied by new net_device operations that > configure hardware contexts. There is a context per socket, and a context per DDP > opreation. Additionally, a resynchronization routine is used to assist > hardware handle TCP OOO, and continue the offload. > Furthermore, we let the offloading driver advertise what is the max hw > sectors/segments. > > Using this interface, the NIC hardware will scatter TCP payload directly > to the BIO pages according to the command_id. > To maintain the correctness of the network stack, the driver is expected > to construct SKBs that point to the BIO pages. > > The SKB passed to the network stack from the driver > represents data as it is on the wire, while it is pointing > directly to data in destination buffers. > As a result, data from page frags should not be copied out to > the linear part. To avoid needless copies, such as when using > skb_condense, we mark the skb->ddp_crc bit. This bit will be > used to indicate both ddp and crc offload (next patch in series). > > A follow-up patch will use this interface for DDP in NVMe-TCP. > > Signed-off-by: Boris Pismenny <borisp@mellanox.com> > Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com> > Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> > Signed-off-by: Yoray Zack <yorayz@mellanox.com> > --- > include/linux/netdev_features.h | 2 + > include/linux/netdevice.h | 5 ++ > include/linux/skbuff.h | 4 + > include/net/inet_connection_sock.h | 4 + > include/net/tcp_ddp.h | 136 +++++++++++++++++++++++++++++ > net/Kconfig | 9 ++ > net/core/skbuff.c | 8 +- > net/ethtool/common.c | 1 + > net/ipv4/tcp_input.c | 8 ++ > net/ipv4/tcp_ipv4.c | 3 + > net/ipv4/tcp_offload.c | 3 + > 11 files changed, 182 insertions(+), 1 deletion(-) > create mode 100644 include/net/tcp_ddp.h > > diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h > index c06d6aaba9df..7977371d2dd1 100644 > --- a/include/linux/netdev_features.h > +++ b/include/linux/netdev_features.h > @@ -85,6 +85,7 @@ enum { > > NETIF_F_HW_MACSEC_BIT, /* Offload MACsec operations */ > NETIF_F_GRO_UDP_FWD_BIT, /* Allow UDP GRO for forwarding */ > + NETIF_F_HW_TCP_DDP_BIT, /* TCP direct data placement offload */ > > /* > * Add your fresh new feature above and remember to update > @@ -159,6 +160,7 @@ enum { > #define NETIF_F_GSO_FRAGLIST __NETIF_F(GSO_FRAGLIST) > #define NETIF_F_HW_MACSEC __NETIF_F(HW_MACSEC) > #define NETIF_F_GRO_UDP_FWD __NETIF_F(GRO_UDP_FWD) > +#define NETIF_F_HW_TCP_DDP __NETIF_F(HW_TCP_DDP) > > /* Finds the next feature with the highest number of the range of start till 0. > */ > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index e9e7ada07ea1..bd28520e30f2 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -941,6 +941,7 @@ struct dev_ifalias { > > struct devlink; > struct tlsdev_ops; > +struct tcp_ddp_dev_ops; > > struct netdev_name_node { > struct hlist_node hlist; > @@ -1942,6 +1943,10 @@ struct net_device { > const struct tlsdev_ops *tlsdev_ops; > #endif > > +#ifdef CONFIG_TCP_DDP > + const struct tcp_ddp_dev_ops *tcp_ddp_ops; > +#endif > + > const struct header_ops *header_ops; > > unsigned char operstate; > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 9313b5aaf45b..6d00d62628c8 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -684,6 +684,7 @@ typedef unsigned char *sk_buff_data_t; > * CHECKSUM_UNNECESSARY (max 3) > * @dst_pending_confirm: need to confirm neighbour > * @decrypted: Decrypted SKB > + * @ddp_crc: DDP or CRC offloaded > * @napi_id: id of the NAPI struct this skb came from > * @sender_cpu: (aka @napi_id) source CPU in XPS > * @secmark: security marking > @@ -860,6 +861,9 @@ struct sk_buff { > #ifdef CONFIG_TLS_DEVICE > __u8 decrypted:1; > #endif > +#ifdef CONFIG_TCP_DDP > + __u8 ddp_crc:1; > +#endif > > #ifdef CONFIG_NET_SCHED > __u16 tc_index; /* traffic control index */ > diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h > index c11f80f328f1..f9eb28f14d43 100644 > --- a/include/net/inet_connection_sock.h > +++ b/include/net/inet_connection_sock.h > @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops { > * @icsk_ulp_ops Pluggable ULP control hook > * @icsk_ulp_data ULP private data > * @icsk_clean_acked Clean acked data hook > + * @icsk_ulp_ddp_ops Pluggable ULP direct data placement control hook > + * @icsk_ulp_ddp_data ULP direct data placement private data > * @icsk_listen_portaddr_node hash to the portaddr listener hashtable > * @icsk_ca_state: Congestion control state > * @icsk_retransmits: Number of unrecovered [RTO] timeouts > @@ -96,6 +98,8 @@ struct inet_connection_sock { > const struct tcp_ulp_ops *icsk_ulp_ops; > void __rcu *icsk_ulp_data; > void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); > + const struct tcp_ddp_ulp_ops *icsk_ulp_ddp_ops; > + void __rcu *icsk_ulp_ddp_data; > struct hlist_node icsk_listen_portaddr_node; > unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); > __u8 icsk_ca_state:5, > diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h > new file mode 100644 > index 000000000000..31e5b1a16d0f > --- /dev/null > +++ b/include/net/tcp_ddp.h > @@ -0,0 +1,136 @@ > +/* SPDX-License-Identifier: GPL-2.0 > + * > + * tcp_ddp.h > + * Author: Boris Pismenny <borisp@mellanox.com> > + * Copyright (C) 2021 Mellanox Technologies. > + */ > +#ifndef _TCP_DDP_H > +#define _TCP_DDP_H > + > +#include <linux/netdevice.h> > +#include <net/inet_connection_sock.h> > +#include <net/sock.h> > + > +/* limits returned by the offload driver, zero means don't care */ > +struct tcp_ddp_limits { > + int max_ddp_sgl_len; > +}; > + > +enum tcp_ddp_type { > + TCP_DDP_NVME = 1, > +}; > + > +/** > + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue > + * config implementations must use this as the first member. > + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.). > + */ > +struct tcp_ddp_config { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +/** > + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue > + * > + * @pfv: pdu version (e.g., NVME_TCP_PFV_1_0) > + * @cpda: controller pdu data alignmend (dwords, 0's based) > + * @dgst: digest types enabled. > + * The netdev will offload crc if ddp_crc is supported. > + * @queue_size: number of nvme-tcp IO queue elements > + * @queue_id: queue identifier > + * @cpu_io: cpu core running the IO thread for this queue > + */ > +struct nvme_tcp_ddp_config { > + struct tcp_ddp_config cfg; > + > + u16 pfv; > + u8 cpda; > + u8 dgst; > + int queue_size; > + int queue_id; > + int io_cpu; > +}; > + > +/** > + * struct tcp_ddp_io - tcp ddp configuration for an IO request. > + * > + * @command_id: identifier on the wire associated with these buffers > + * @nents: number of entries in the sg_table > + * @sg_table: describing the buffers for this IO request > + * @first_sgl: first SGL in sg_table > + */ > +struct tcp_ddp_io { > + u32 command_id; > + int nents; > + struct sg_table sg_table; > + struct scatterlist first_sgl[SG_CHUNK_SIZE]; > +}; > + > +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload > + * > + * @tcp_ddp_limits: limit the number of scatter gather entries per IO. > + * the device driver can use this to limit the resources allocated per queue. > + * @tcp_ddp_sk_add: add offload for the queue represennted by the socket+config pair. > + * this function is used to configure either copy, crc or both offloads. > + * @tcp_ddp_sk_del: remove offload from the socket, and release any device related resources. > + * @tcp_ddp_setup: request copy offload for buffers associated with a command_id in tcp_ddp_io. > + * @tcp_ddp_teardown: release offload resources association between buffers and command_id in > + * tcp_ddp_io. > + * @tcp_ddp_resync: respond to the driver's resync_request. Called only if resync is successful. > + */ > +struct tcp_ddp_dev_ops { > + int (*tcp_ddp_limits)(struct net_device *netdev, > + struct tcp_ddp_limits *limits); > + int (*tcp_ddp_sk_add)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_config *config); > + void (*tcp_ddp_sk_del)(struct net_device *netdev, > + struct sock *sk); > + int (*tcp_ddp_setup)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io); > + int (*tcp_ddp_teardown)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io, > + void *ddp_ctx); > + void (*tcp_ddp_resync)(struct net_device *netdev, > + struct sock *sk, u32 seq); > +}; > + > +#define TCP_DDP_RESYNC_REQ BIT(0) > + > +/** > + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload > + */ Super trivial (my mail filter just happened to pick up on it), but if you happen to respin: s/uppper/upper/ > +struct tcp_ddp_ulp_ops { > + /* NIC requests ulp to indicate if @seq is the start of a message */ > + bool (*resync_request)(struct sock *sk, u32 seq, u32 flags); > + /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/ > + void (*ddp_teardown_done)(void *ddp_ctx); > +}; > + > +/** > + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must > + * use this as the first member. > + */ > +struct tcp_ddp_ctx { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk) > +{ > + struct inet_connection_sock *icsk = inet_csk(sk); > + > + return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data; > +} > + > +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx) > +{ > + struct inet_connection_sock *icsk = inet_csk(sk); > + > + rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx); > +} > + > +#endif //_TCP_DDP_H > diff --git a/net/Kconfig b/net/Kconfig > index f4c32d982af6..3876861cdc90 100644 > --- a/net/Kconfig > +++ b/net/Kconfig > @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK > netlink. It provides better extensibility and some new features, > e.g. notification messages. > > +config TCP_DDP > + bool "TCP direct data placement offload" > + default n > + help > + Direct Data Placement (DDP) offload for TCP enables ULP, such as > + NVMe-TCP/iSCSI, to request the NIC to place TCP payload data > + of a command response directly into kernel pages. > + > + > endif # if NET > > # Used by archs to tell that they support BPF JIT compiler plus which flavour. > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 2af12f7e170c..ef3f2714994d 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -69,6 +69,7 @@ > #include <net/xfrm.h> > #include <net/mpls.h> > #include <net/mptcp.h> > +#include <net/tcp_ddp.h> > > #include <linux/uaccess.h> > #include <trace/events/skb.h> > @@ -6185,9 +6186,14 @@ EXPORT_SYMBOL(pskb_extract); > */ > void skb_condense(struct sk_buff *skb) > { > + bool is_ddp = false; > + > +#ifdef CONFIG_TCP_DDP > + is_ddp = skb->ddp_crc; > +#endif > if (skb->data_len) { > if (skb->data_len > skb->end - skb->tail || > - skb_cloned(skb)) > + skb_cloned(skb) || is_ddp) > return; > > /* Nice, we can free page frag(s) right now */ > diff --git a/net/ethtool/common.c b/net/ethtool/common.c > index 181220101a6e..bbf83cd01106 100644 > --- a/net/ethtool/common.c > +++ b/net/ethtool/common.c > @@ -69,6 +69,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = { > [NETIF_F_GRO_FRAGLIST_BIT] = "rx-gro-list", > [NETIF_F_HW_MACSEC_BIT] = "macsec-hw-offload", > [NETIF_F_GRO_UDP_FWD_BIT] = "rx-udp-gro-forwarding", > + [NETIF_F_HW_TCP_DDP_BIT] = "tcp-ddp-offload", > }; > > const char > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index a8f8f9815953..0ae1ffca090d 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -5149,6 +5149,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, > memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); > #ifdef CONFIG_TLS_DEVICE > nskb->decrypted = skb->decrypted; > +#endif > +#ifdef CONFIG_TCP_DDP > + nskb->ddp_crc = skb->ddp_crc; > #endif > TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start; > if (list) > @@ -5182,6 +5185,11 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, > #ifdef CONFIG_TLS_DEVICE > if (skb->decrypted != nskb->decrypted) > goto end; > +#endif > +#ifdef CONFIG_TCP_DDP > + > + if (skb->ddp_crc != nskb->ddp_crc) > + goto end; > #endif > } > } > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 777306b5bc22..b114fc870513 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1810,6 +1810,9 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb) > TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || > #ifdef CONFIG_TLS_DEVICE > tail->decrypted != skb->decrypted || > +#endif > +#ifdef CONFIG_TCP_DDP > + tail->ddp_crc != skb->ddp_crc || > #endif > thtail->doff != th->doff || > memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) > diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c > index e09147ac9a99..3ce196375d94 100644 > --- a/net/ipv4/tcp_offload.c > +++ b/net/ipv4/tcp_offload.c > @@ -262,6 +262,9 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) > #ifdef CONFIG_TLS_DEVICE > flush |= p->decrypted ^ skb->decrypted; > #endif > +#ifdef CONFIG_TCP_DDP > + flush |= p->ddp_crc ^ skb->ddp_crc; > +#endif > > if (flush || skb_gro_receive(p, skb)) { > mss = 1; > -- > 2.24.1 >
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index c06d6aaba9df..7977371d2dd1 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -85,6 +85,7 @@ enum { NETIF_F_HW_MACSEC_BIT, /* Offload MACsec operations */ NETIF_F_GRO_UDP_FWD_BIT, /* Allow UDP GRO for forwarding */ + NETIF_F_HW_TCP_DDP_BIT, /* TCP direct data placement offload */ /* * Add your fresh new feature above and remember to update @@ -159,6 +160,7 @@ enum { #define NETIF_F_GSO_FRAGLIST __NETIF_F(GSO_FRAGLIST) #define NETIF_F_HW_MACSEC __NETIF_F(HW_MACSEC) #define NETIF_F_GRO_UDP_FWD __NETIF_F(GRO_UDP_FWD) +#define NETIF_F_HW_TCP_DDP __NETIF_F(HW_TCP_DDP) /* Finds the next feature with the highest number of the range of start till 0. */ diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e9e7ada07ea1..bd28520e30f2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -941,6 +941,7 @@ struct dev_ifalias { struct devlink; struct tlsdev_ops; +struct tcp_ddp_dev_ops; struct netdev_name_node { struct hlist_node hlist; @@ -1942,6 +1943,10 @@ struct net_device { const struct tlsdev_ops *tlsdev_ops; #endif +#ifdef CONFIG_TCP_DDP + const struct tcp_ddp_dev_ops *tcp_ddp_ops; +#endif + const struct header_ops *header_ops; unsigned char operstate; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 9313b5aaf45b..6d00d62628c8 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -684,6 +684,7 @@ typedef unsigned char *sk_buff_data_t; * CHECKSUM_UNNECESSARY (max 3) * @dst_pending_confirm: need to confirm neighbour * @decrypted: Decrypted SKB + * @ddp_crc: DDP or CRC offloaded * @napi_id: id of the NAPI struct this skb came from * @sender_cpu: (aka @napi_id) source CPU in XPS * @secmark: security marking @@ -860,6 +861,9 @@ struct sk_buff { #ifdef CONFIG_TLS_DEVICE __u8 decrypted:1; #endif +#ifdef CONFIG_TCP_DDP + __u8 ddp_crc:1; +#endif #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index c11f80f328f1..f9eb28f14d43 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops { * @icsk_ulp_ops Pluggable ULP control hook * @icsk_ulp_data ULP private data * @icsk_clean_acked Clean acked data hook + * @icsk_ulp_ddp_ops Pluggable ULP direct data placement control hook + * @icsk_ulp_ddp_data ULP direct data placement private data * @icsk_listen_portaddr_node hash to the portaddr listener hashtable * @icsk_ca_state: Congestion control state * @icsk_retransmits: Number of unrecovered [RTO] timeouts @@ -96,6 +98,8 @@ struct inet_connection_sock { const struct tcp_ulp_ops *icsk_ulp_ops; void __rcu *icsk_ulp_data; void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); + const struct tcp_ddp_ulp_ops *icsk_ulp_ddp_ops; + void __rcu *icsk_ulp_ddp_data; struct hlist_node icsk_listen_portaddr_node; unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); __u8 icsk_ca_state:5, diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h new file mode 100644 index 000000000000..31e5b1a16d0f --- /dev/null +++ b/include/net/tcp_ddp.h @@ -0,0 +1,136 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * tcp_ddp.h + * Author: Boris Pismenny <borisp@mellanox.com> + * Copyright (C) 2021 Mellanox Technologies. + */ +#ifndef _TCP_DDP_H +#define _TCP_DDP_H + +#include <linux/netdevice.h> +#include <net/inet_connection_sock.h> +#include <net/sock.h> + +/* limits returned by the offload driver, zero means don't care */ +struct tcp_ddp_limits { + int max_ddp_sgl_len; +}; + +enum tcp_ddp_type { + TCP_DDP_NVME = 1, +}; + +/** + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue + * config implementations must use this as the first member. + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.). + */ +struct tcp_ddp_config { + enum tcp_ddp_type type; + unsigned char buf[]; +}; + +/** + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue + * + * @pfv: pdu version (e.g., NVME_TCP_PFV_1_0) + * @cpda: controller pdu data alignmend (dwords, 0's based) + * @dgst: digest types enabled. + * The netdev will offload crc if ddp_crc is supported. + * @queue_size: number of nvme-tcp IO queue elements + * @queue_id: queue identifier + * @cpu_io: cpu core running the IO thread for this queue + */ +struct nvme_tcp_ddp_config { + struct tcp_ddp_config cfg; + + u16 pfv; + u8 cpda; + u8 dgst; + int queue_size; + int queue_id; + int io_cpu; +}; + +/** + * struct tcp_ddp_io - tcp ddp configuration for an IO request. + * + * @command_id: identifier on the wire associated with these buffers + * @nents: number of entries in the sg_table + * @sg_table: describing the buffers for this IO request + * @first_sgl: first SGL in sg_table + */ +struct tcp_ddp_io { + u32 command_id; + int nents; + struct sg_table sg_table; + struct scatterlist first_sgl[SG_CHUNK_SIZE]; +}; + +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload + * + * @tcp_ddp_limits: limit the number of scatter gather entries per IO. + * the device driver can use this to limit the resources allocated per queue. + * @tcp_ddp_sk_add: add offload for the queue represennted by the socket+config pair. + * this function is used to configure either copy, crc or both offloads. + * @tcp_ddp_sk_del: remove offload from the socket, and release any device related resources. + * @tcp_ddp_setup: request copy offload for buffers associated with a command_id in tcp_ddp_io. + * @tcp_ddp_teardown: release offload resources association between buffers and command_id in + * tcp_ddp_io. + * @tcp_ddp_resync: respond to the driver's resync_request. Called only if resync is successful. + */ +struct tcp_ddp_dev_ops { + int (*tcp_ddp_limits)(struct net_device *netdev, + struct tcp_ddp_limits *limits); + int (*tcp_ddp_sk_add)(struct net_device *netdev, + struct sock *sk, + struct tcp_ddp_config *config); + void (*tcp_ddp_sk_del)(struct net_device *netdev, + struct sock *sk); + int (*tcp_ddp_setup)(struct net_device *netdev, + struct sock *sk, + struct tcp_ddp_io *io); + int (*tcp_ddp_teardown)(struct net_device *netdev, + struct sock *sk, + struct tcp_ddp_io *io, + void *ddp_ctx); + void (*tcp_ddp_resync)(struct net_device *netdev, + struct sock *sk, u32 seq); +}; + +#define TCP_DDP_RESYNC_REQ BIT(0) + +/** + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload + */ +struct tcp_ddp_ulp_ops { + /* NIC requests ulp to indicate if @seq is the start of a message */ + bool (*resync_request)(struct sock *sk, u32 seq, u32 flags); + /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/ + void (*ddp_teardown_done)(void *ddp_ctx); +}; + +/** + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must + * use this as the first member. + */ +struct tcp_ddp_ctx { + enum tcp_ddp_type type; + unsigned char buf[]; +}; + +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data; +} + +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx); +} + +#endif //_TCP_DDP_H diff --git a/net/Kconfig b/net/Kconfig index f4c32d982af6..3876861cdc90 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK netlink. It provides better extensibility and some new features, e.g. notification messages. +config TCP_DDP + bool "TCP direct data placement offload" + default n + help + Direct Data Placement (DDP) offload for TCP enables ULP, such as + NVMe-TCP/iSCSI, to request the NIC to place TCP payload data + of a command response directly into kernel pages. + + endif # if NET # Used by archs to tell that they support BPF JIT compiler plus which flavour. diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 2af12f7e170c..ef3f2714994d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -69,6 +69,7 @@ #include <net/xfrm.h> #include <net/mpls.h> #include <net/mptcp.h> +#include <net/tcp_ddp.h> #include <linux/uaccess.h> #include <trace/events/skb.h> @@ -6185,9 +6186,14 @@ EXPORT_SYMBOL(pskb_extract); */ void skb_condense(struct sk_buff *skb) { + bool is_ddp = false; + +#ifdef CONFIG_TCP_DDP + is_ddp = skb->ddp_crc; +#endif if (skb->data_len) { if (skb->data_len > skb->end - skb->tail || - skb_cloned(skb)) + skb_cloned(skb) || is_ddp) return; /* Nice, we can free page frag(s) right now */ diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 181220101a6e..bbf83cd01106 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -69,6 +69,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = { [NETIF_F_GRO_FRAGLIST_BIT] = "rx-gro-list", [NETIF_F_HW_MACSEC_BIT] = "macsec-hw-offload", [NETIF_F_GRO_UDP_FWD_BIT] = "rx-udp-gro-forwarding", + [NETIF_F_HW_TCP_DDP_BIT] = "tcp-ddp-offload", }; const char diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a8f8f9815953..0ae1ffca090d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5149,6 +5149,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); #ifdef CONFIG_TLS_DEVICE nskb->decrypted = skb->decrypted; +#endif +#ifdef CONFIG_TCP_DDP + nskb->ddp_crc = skb->ddp_crc; #endif TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start; if (list) @@ -5182,6 +5185,11 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, #ifdef CONFIG_TLS_DEVICE if (skb->decrypted != nskb->decrypted) goto end; +#endif +#ifdef CONFIG_TCP_DDP + + if (skb->ddp_crc != nskb->ddp_crc) + goto end; #endif } } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 777306b5bc22..b114fc870513 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1810,6 +1810,9 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb) TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || #ifdef CONFIG_TLS_DEVICE tail->decrypted != skb->decrypted || +#endif +#ifdef CONFIG_TCP_DDP + tail->ddp_crc != skb->ddp_crc || #endif thtail->doff != th->doff || memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index e09147ac9a99..3ce196375d94 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -262,6 +262,9 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) #ifdef CONFIG_TLS_DEVICE flush |= p->decrypted ^ skb->decrypted; #endif +#ifdef CONFIG_TCP_DDP + flush |= p->ddp_crc ^ skb->ddp_crc; +#endif if (flush || skb_gro_receive(p, skb)) { mss = 1;