infiniband: cxgb4: GCC warnings for 32 bit

From: Paul Bolle
Date: Tue Feb 05 2013 - 05:16:12 EST


0) Compiling cm.o for 32 bit triggers these GCC warnings:
drivers/infiniband/hw/cxgb4/cm.c: In function âpassive_ofld_conn_replyâ:
drivers/infiniband/hw/cxgb4/cm.c:2803:12: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
drivers/infiniband/hw/cxgb4/cm.c: In function âsend_fw_pass_open_reqâ:
drivers/infiniband/hw/cxgb4/cm.c:2941:16: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
[last line repeated a number of times]

1) These two lines were added in commit
1cab775c3e75f1250c965feafd061d696df36e53 ("RDMA/cxgb4: Fix LE hash
collision bug for passive open connection"). That commit was first
released in v3.8-rc1. It's not obvious to me how to fix these warnings,
since these lines are a bit puzzling.

2) These lines read:
rpl_skb = (struct sk_buff *)cpu_to_be64(req->cookie);

and:
req->cookie = cpu_to_be64((u64)skb);

3) It is odd that both use cpu_to_be64(). It seems the first one should
have been be64_to_cpu().

But 'cookie' is of type __u64 (see struct
cpl_fw6_msg_ofld_connection_wr_rpl in
drivers/net/ethernet/chelsio/cxgb4/t4_msg.h). So the use of both that
type and the cpu_to_be64() macro looks a bit odd too.

And why is 'cookie' __u64? Is struct cpl_fw6_msg_ofld_connection_wr_rpl
used in userspace code? Can't 'cookie' be of type "struct sk_buff *"? Is
there a requirement for it to be 64 bits wide on both 32 bit and 64 bit?


Paul Bolle

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/