!811 [OLK-5.10] net/smc: patches to optimize rmbs and sndbuff

Merge Pull Request from: @giree2 
 
1. add sysctl interface for SMC and make sndbufs or RMBs tunable
2. add sysctl for setting SMC-R buffer type
3. add virtually contiguous sndbufs or RMBs for SMC-R
4. match unused lgr with buf len
5. limit virtually contiguous sndbufs or RMBs to 256MiB
6. add tcp2smc sysctl interface 
 
Link:https://gitee.com/openeuler/kernel/pulls/811

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>