linux/include/net/smc.h
Wen Gu 4398888268 net/smc: add operations to merge sndbuf with peer DMB
In some scenarios using Emulated-ISM device, sndbuf can share the same
physical memory region with peer DMB to avoid data copy from one side
to the other. In such case the sndbuf is only a descriptor that
describes the shared memory and does not actually occupy memory, it's
more like a ghost buffer.

      +----------+                     +----------+
      | socket A |                     | socket B |
      +----------+                     +----------+
            |                               |
       +--------+                       +--------+
       | sndbuf |                       |  DMB   |
       |  desc  |                       |  desc  |
       +--------+                       +--------+
            |                               |
            |                          +----v-----+
            +-------------------------->  memory  |
                                       +----------+

So here introduces three new SMC-D device operations to check if this
feature is supported by device, and to {attach|detach} ghost sndbuf to
peer DMB. For now only loopback-ism supports this.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-30 13:24:48 +02:00

101 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* Definitions for the SMC module (socket related)
*
* Copyright IBM Corp. 2016
*
* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
*/
#ifndef _SMC_H
#define _SMC_H
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>
#include "linux/ism.h"
struct sock;
#define SMC_MAX_PNETID_LEN 16 /* Max. length of PNET id */
struct smc_hashinfo {
rwlock_t lock;
struct hlist_head ht;
};
/* SMCD/ISM device driver interface */
struct smcd_dmb {
u64 dmb_tok;
u64 rgid;
u32 dmb_len;
u32 sba_idx;
u32 vlan_valid;
u32 vlan_id;
void *cpu_addr;
dma_addr_t dma_addr;
};
#define ISM_EVENT_DMB 0
#define ISM_EVENT_GID 1
#define ISM_EVENT_SWR 2
#define ISM_RESERVED_VLANID 0x1FFF
#define ISM_ERROR 0xFFFF
struct smcd_dev;
struct smcd_gid {
u64 gid;
u64 gid_ext;
};
struct smcd_ops {
int (*query_remote_gid)(struct smcd_dev *dev, struct smcd_gid *rgid,
u32 vid_valid, u32 vid);
int (*register_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb,
void *client);
int (*unregister_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb);
int (*move_data)(struct smcd_dev *dev, u64 dmb_tok, unsigned int idx,
bool sf, unsigned int offset, void *data,
unsigned int size);
int (*supports_v2)(void);
void (*get_local_gid)(struct smcd_dev *dev, struct smcd_gid *gid);
u16 (*get_chid)(struct smcd_dev *dev);
struct device* (*get_dev)(struct smcd_dev *dev);
/* optional operations */
int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
int (*del_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
int (*set_vlan_required)(struct smcd_dev *dev);
int (*reset_vlan_required)(struct smcd_dev *dev);
int (*signal_event)(struct smcd_dev *dev, struct smcd_gid *rgid,
u32 trigger_irq, u32 event_code, u64 info);
int (*support_dmb_nocopy)(struct smcd_dev *dev);
int (*attach_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb);
int (*detach_dmb)(struct smcd_dev *dev, u64 token);
};
struct smcd_dev {
const struct smcd_ops *ops;
void *priv;
void *client;
struct list_head list;
spinlock_t lock;
struct smc_connection **conn;
struct list_head vlan;
struct workqueue_struct *event_wq;
u8 pnetid[SMC_MAX_PNETID_LEN];
bool pnetid_by_user;
struct list_head lgr_list;
spinlock_t lgr_lock;
atomic_t lgr_cnt;
wait_queue_head_t lgrs_deleted;
u8 going_away : 1;
};
#endif /* _SMC_H */