fastrpc_buf_alloc
err = fastrpc_buf_alloc(ctx->fl, dev, pkt_size, &ctx->buf);
err = fastrpc_buf_alloc(fl, fl->sctx->dev, memlen,
err = fastrpc_buf_alloc(fl, fl->sctx->dev, bp.size, &buf);
err = fastrpc_buf_alloc(fl, dev, req.size, &buf);