[RFC PATCH net-next v3 6/9] net/smc: Introudce interfaces for DMB attach and detach

Wen Gu
2023-02-15T16:19:20Z

This patch extends smcd_ops, adding two more semantic for SMC-D DMB:

- attach_dmb:
Attach an already registered DMB to a specific buf_desc, so that we
can refer to the DMB through this buf_desc.

- detach_dmb:
Reverse operation of attach_dmb. detach the DMB from the buf_desc.

This interface extension is to prepare for the avoidance of memory
copy from sndbuf to DMB with SMC-D device whose DMBs has ISM_DMB_MAPPABLE
attribute.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
include/net/smc.h | 2 ++
net/smc/smc_ism.c | 31 +++++++++++++++++++++++++++++++
net/smc/smc_ism.h | 2 ++
3 files changed, 35 insertions(+)

diff --git a/include/net/smc.h b/include/net/smc.h
index 256d600..0790e64 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -67,6 +67,8 @@ struct smcd_ops {
int (*register_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb,
void *client_priv);
int (*unregister_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb);
+ int (*attach_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb);
+ int (*detach_dmb)(struct smcd_dev *dev, u64 token);
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);
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index e085c48..e2670e3 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -243,6 +243,37 @@ int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
return rc;
}

+int smc_ism_attach_dmb(struct smcd_dev *dev, u64 token,
+ struct smc_buf_desc *dmb_desc)
+{
+ struct smcd_dmb dmb;
+ int rc = 0;
+
+ memset(&dmb, 0, sizeof(dmb));
+ dmb.dmb_tok = token;
+
+ if (!dev->ops->attach_dmb)
+ return -EINVAL;
+
+ rc = dev->ops->attach_dmb(dev, &dmb);
+ if (!rc) {
+ dmb_desc->sba_idx = dmb.sba_idx;
+ dmb_desc->token = dmb.dmb_tok;
+ dmb_desc->cpu_addr = dmb.cpu_addr;
+ dmb_desc->dma_addr = dmb.dma_addr;
+ dmb_desc->len = dmb.dmb_len;
+ }
+ return rc;
+}
+
+int smc_ism_detach_dmb(struct smcd_dev *dev, u64 token)
+{
+ if (!dev->ops->detach_dmb)
+ return -EINVAL;
+
+ return dev->ops->detach_dmb(dev, token);
+}
+
static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
struct sk_buff *skb,
struct netlink_callback *cb)
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index aabea35..fc16dc2 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -39,6 +39,8 @@ int smc_ism_register_dmb(struct smc_link_group *lgr, int buf_size,
struct smc_buf_desc *dmb_desc);
int smc_ism_unregister_dmb(struct smcd_dev *dev, struct smc_buf_desc *dmb_desc);
bool smc_ism_dmb_mappable(struct smcd_dev *smcd);
+int smc_ism_attach_dmb(struct smcd_dev *dev, u64 token, struct smc_buf_desc *dmb_desc);
+int smc_ism_detach_dmb(struct smcd_dev *dev, u64 token);
int smc_ism_signal_shutdown(struct smc_link_group *lgr);
void smc_ism_get_system_eid(u8 **eid);
u16 smc_ism_get_chid(struct smcd_dev *dev);
--
1.8.3.1