net/smc/smc_llc.c

File Facts

System

Linux kernel

Corpus path

net/smc/smc_llc.c

Extension

.c

Size

67088 bytes

Lines

2377

Domain

Networking Core

Bucket

Sockets, Protocols, Packet Path, And Network Policy

Inferred role

Networking Core: implementation source

Status

source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

• Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• net/tcp.h
• rdma/ib_verbs.h
• smc.h
• smc_core.h
• smc_clc.h
• smc_llc.h
• smc_pnet.h

Detected Declarations

• struct smc_llc_hdr
• struct smc_llc_msg_confirm_link
• struct smc_llc_msg_add_link
• struct smc_llc_msg_add_link_cont_rt
• struct smc_llc_msg_add_link_v2_ext
• struct smc_llc_msg_req_add_link_v2
• struct smc_llc_msg_add_link_cont
• struct smc_llc_msg_del_link
• struct smc_llc_msg_test_link
• struct smc_rmb_rtoken
• struct smc_llc_msg_confirm_rkey
• struct smc_llc_msg_delete_rkey
• struct smc_llc_msg_delete_rkey_v2
• struct smc_llc_qentry
• struct smc_llc_tx_pend
• function smc_llc_flow_qentry_del
• function smc_llc_flow_qentry_set
• function smc_llc_flow_parallel
• function smc_llc_flow_start
• function smc_llc_flow_initiate
• function smc_llc_flow_stop
• function smc_llc_tx_handler
• function smc_llc_add_pending_send_v2
• function smc_llc_init_msg_hdr
• function smc_llc_send_confirm_link
• function smc_llc_send_confirm_rkey
• function smc_llc_send_delete_rkey
• function smc_llc_fill_ext_v2
• function smc_llc_send_add_link
• function smc_llc_send_delete_link
• function smc_llc_send_test_link
• function smc_llc_send_message
• function smc_llc_send_message_wait
• function smc_llc_alloc_alt_link
• function smc_llc_add_link_cont
• function smc_llc_cli_rkey_exchange
• function smc_llc_cli_add_link_reject
• function smc_llc_cli_conf_link
• function smc_llc_save_add_link_rkeys
• function smc_llc_save_add_link_info
• function smc_llc_cli_add_link
• function smc_llc_send_request_add_link
• function smc_llc_cli_add_link_invite
• function smc_llc_is_empty_llc_message
• function smc_llc_is_local_add_link
• function smc_llc_process_cli_add_link
• function smc_llc_active_link_count
• function smc_llc_delete_asym_link

Annotated Snippet

struct smc_llc_hdr {
	struct smc_wr_rx_hdr common;
	union {
		struct {
			u8 length;	/* 44 */
	#if defined(__BIG_ENDIAN_BITFIELD)
			u8 reserved:4,
			   add_link_rej_rsn:4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
			u8 add_link_rej_rsn:4,
			   reserved:4;
#endif
		};
		u16 length_v2;	/* 44 - 8192*/
	};
	u8 flags;
} __packed;		/* format defined in
			 * IBM Shared Memory Communications Version 2
			 * (https://www.ibm.com/support/pages/node/6326337)
			 */

#define SMC_LLC_FLAG_NO_RMBE_EYEC	0x03

struct smc_llc_msg_confirm_link {	/* type 0x01 */
	struct smc_llc_hdr hd;
	u8 sender_mac[ETH_ALEN];
	u8 sender_gid[SMC_GID_SIZE];
	u8 sender_qp_num[3];
	u8 link_num;
	u8 link_uid[SMC_LGR_ID_SIZE];
	u8 max_links;
	u8 max_conns;
	u8 reserved[8];
};

#define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
#define SMC_LLC_REJ_RSN_NO_ALT_PATH	1

struct smc_llc_msg_add_link {		/* type 0x02 */
	struct smc_llc_hdr hd;
	u8 sender_mac[ETH_ALEN];
	u8 reserved2[2];
	u8 sender_gid[SMC_GID_SIZE];
	u8 sender_qp_num[3];
	u8 link_num;
#if defined(__BIG_ENDIAN_BITFIELD)
	u8 reserved3 : 4,
	   qp_mtu   : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
	u8 qp_mtu   : 4,
	   reserved3 : 4;
#endif
	u8 initial_psn[3];
	u8 reserved[8];
};

struct smc_llc_msg_add_link_cont_rt {
	__be32 rmb_key;
	__be32 rmb_key_new;
	__be64 rmb_vaddr_new;
};

struct smc_llc_msg_add_link_v2_ext {
#if defined(__BIG_ENDIAN_BITFIELD)
	u8 v2_direct : 1,
	   reserved  : 7;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
	u8 reserved  : 7,
	   v2_direct : 1;
#endif
	u8 reserved2;
	u8 client_target_gid[SMC_GID_SIZE];
	u8 reserved3[8];
	u16 num_rkeys;
	struct smc_llc_msg_add_link_cont_rt rt[];
} __packed;		/* format defined in
			 * IBM Shared Memory Communications Version 2
			 * (https://www.ibm.com/support/pages/node/6326337)
			 */

struct smc_llc_msg_req_add_link_v2 {
	struct smc_llc_hdr hd;
	u8 reserved[20];
	u8 gid_cnt;
	u8 reserved2[3];
	u8 gid[][SMC_GID_SIZE];
};

#define SMC_LLC_RKEYS_PER_CONT_MSG	2

Annotation

• Immediate include surface: `net/tcp.h`, `rdma/ib_verbs.h`, `smc.h`, `smc_core.h`, `smc_clc.h`, `smc_llc.h`, `smc_pnet.h`.
• Detected declarations: `struct smc_llc_hdr`, `struct smc_llc_msg_confirm_link`, `struct smc_llc_msg_add_link`, `struct smc_llc_msg_add_link_cont_rt`, `struct smc_llc_msg_add_link_v2_ext`, `struct smc_llc_msg_req_add_link_v2`, `struct smc_llc_msg_add_link_cont`, `struct smc_llc_msg_del_link`, `struct smc_llc_msg_test_link`, `struct smc_rmb_rtoken`.
• Atlas domain: Networking Core / Sockets, Protocols, Packet Path, And Network Policy.
• Implementation status: source implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.