[ofw][mlx4] SRQ attached QP issue

[Leonid Keller]

Applied with some changes in 1625, thank you. 

> -----Original Message-----
> From: Alex Estrin [mailto:alex.estrin at qlogic.com] 
> Sent: Saturday, September 27, 2008 1:20 AM
> To: Leonid Keller
> Cc: ofw at lists.openfabrics.org
> Subject: [ofw][mlx4] SRQ attached QP issue
> 
> Hello,
> 
> This patch seem fixed the create-QP-attached-to-SRQ issue.
> I didn't verify though, if code allowes send queue zero size. 
> Included check anyway.
> Please review.
> 
> Thanks,
> Alex.
> 
> Index: mlx4/kernel/bus/ib/qp.c
> ===================================================================
> --- mlx4/kernel/bus/ib/qp.c	(revision 1622)
> +++ mlx4/kernel/bus/ib/qp.c	(working copy)
> @@ -411,14 +411,20 @@
>  		err = mlx4_buf_write_mtt(dev->dev, &qp->mtt, &qp->buf);
>  		if (err)
>  			goto err_mtt;
> -
> -		qp->sq.wrid  = kmalloc(qp->sq.wqe_cnt * sizeof (u64),
> GFP_KERNEL);
> -		qp->rq.wrid  = kmalloc(qp->rq.wqe_cnt * sizeof (u64),
> GFP_KERNEL);
> -
> -		if (!qp->sq.wrid || !qp->rq.wrid) {
> -			err = -ENOMEM;
> -			goto err_wrid;
> +		if (qp->sq.wqe_cnt) {
> +			qp->sq.wrid  = kmalloc(qp->sq.wqe_cnt * sizeof
> (u64), GFP_KERNEL);
> +			if (!qp->sq.wrid) {
> +				err = -ENOMEM;
> +				goto err_wrid;
> +			}
>  		}
> +		if (qp->rq.wqe_cnt) {
> +			qp->rq.wrid  = kmalloc(qp->rq.wqe_cnt * sizeof
> (u64), GFP_KERNEL);
> +			if (!qp->rq.wrid) {
> +				err = -ENOMEM;
> +				goto err_wrid;
> +			}
> +		}
>  	}
>  
>  	if (!sqpn)
> @@ -452,8 +458,10 @@
>  			mlx4_ib_db_unmap_user(to_mucontext(pd->p_uctx),
>  					      &qp->db);
>  	} else {
> -		kfree(qp->sq.wrid);
> -		kfree(qp->rq.wrid);
> +		if (qp->sq.wrid)
> +			kfree(qp->sq.wrid);
> +		if (qp->rq.wrid)
> +			kfree(qp->rq.wrid);
>  	}
>  
>  err_mtt:
> 
> 
> 
> > Hello,
> > 
> > It seem there is a controversy exist in mlx4 driver that 
> won't allow 
> > to create QP if it was attached to SRQ.
> > 
> > At first it doesn't allow to set any recv queue size (which is fine)
> > 
> > mlx4\kernel\bus\ib\qp.c@ line 219:
> > 		if (cap->max_recv_wr)
> > 			return -EINVAL;
> > 
> > 		qp->rq.wqe_cnt = qp->rq.max_gs = 0;
> > 
> > But then there is assertion for zero size memory request in 
> 'kmalloc':
> > mlx4\kernel\bus\ib\qp.c @ line 416:
> > 
> > 		qp->rq.wrid  = kmalloc(qp->rq.wqe_cnt * sizeof 
> (u64), GFP_KERNEL);
> > 		
> > mlx4\kernel\inc\l2w_memory.h @ line 81:
> > 
> > 		static inline void * kmalloc( SIZE_T bsize, 
> gfp_t gfp_mask)
> > 		{
> > 			void *ptr;
> > 			ASSERT( KeGetCurrentIrql() <= DISPATCH_LEVEL);
> > 			ASSERT(bsize);
> > 		.....
> > 
> > I believe it was added for a reason.
> > Please let me know if I missed anything.
> > 
> > Thanks,
> > Alex.
> > 
> > 
> > 
>