From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030625AbbJ3NyR (ORCPT ); Fri, 30 Oct 2015 09:54:17 -0400 Received: from mout.kundenserver.de ([212.227.17.10]:55683 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965620AbbJ3NyO (ORCPT ); Fri, 30 Oct 2015 09:54:14 -0400 From: Arnd Bergmann To: John Garry Cc: JBottomley@odin.com, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linuxarm@huawei.com, john.garry2@mail.dcu.ie, hare@suse.de, xuwei5@hisilicon.com, zhangfei.gao@linaro.org Subject: Re: [PATCH v2 27/32] scsi: hisi_sas: add smp protocol support Date: Fri, 30 Oct 2015 14:53:51 +0100 Message-ID: <3976707.At0tktvfqn@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1445868903-183817-28-git-send-email-john.garry@huawei.com> References: <1445868903-183817-1-git-send-email-john.garry@huawei.com> <1445868903-183817-28-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:Wmimi4LbfO5ZgmRknlbgvg2NblAfhZ1aUPyyHqibQnQzjZVVok5 VpFetWwAfKLL7i/7oPJkC7o/C5CXqLF8H1W4aGVMOtZx88AQ4VOl0pE1T98CdECVPm7Vqg5 7I0vtE1gPHxoFWOj6M3DbSs3pV/kaN2aJksXsj6OjAO+KpF/I0EHfFiGMtn/vqVAtOga5+b NVoTUHXXO5iMEWbYm9CyA== X-UI-Out-Filterresults: notjunk:1;V01:K0:KATDspRPDU8=:oUoSM8NK6QhlqbCKfjs9/f ZDhoboTtBSbZ41Dn+mKIemivwD7D8b/R7kzlws6TeCFE/aNoJS51mvW9NDw8a1SkGd54Otn3Y ONXQajnaU5bJvMUOaeaZL6N3TrvjuXfSl68NmRUcxqSD0qwMJ+tz6YzJ97zhkF5yV69P2I5ZH 7uxW9adaJ46461xfvZHfKxLcULe6mwFTNHEcqmNxg2KKUBZVUlAljdiFY+mtXaHCpaJRj9k8a kTVGVjr1XoiNwjbIQAsV5X6xh1RLTyYI9JHJQrjilxtyjqz0/79DGvVFebLlJlvhJchr513vZ 9/uGcgpTBI/LRngoKwMGDqU31vgEpn37VcHkT1vQ6VO2VWSpu/BAhxxXclO2pUNNNVgM+1+f2 iBDd/r1mCk2jKQMAkcbIYaRQuPiOdy6lZikUCSDny8h7t+fTUO2qUimJ/ffRQ7UTQiZQTyjQM BX5LVxLV7L+qNlIbBviRnaxhI+dEVCvKRcWeUnZy/32g7v4JYNgsoMke76xTRAJVHKD6n3Zyj vEJwH/ml5y3nGNU658S7o8urxuUgzcFo/K0xxwLfG7GTzejSRY0VyJ6dKWlrJ6+Ypma5W1X81 6nqIcaxfGEPYOjq5r9xcTJtDicDopaCXaecUoyzqsi2K0f+PzKp0SJmaBRn0gmJhCDj1nFyRp 0qZQOYsqinRj1JgIAs9mRUTgLK7ttquCI47OCxYAXiNDdps2NyyWbGN1p+gzLiEXqOjCnBL4J LLPPH3RLfzz99zL/ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 26 October 2015 22:14:58 John Garry wrote: > + /* > + * DMA-map SMP request, response buffers > + */ > + /* req */ > + sg_req = &task->smp_task.smp_req; > + elem = dma_map_sg(dev, sg_req, 1, DMA_TO_DEVICE); > + if (!elem) > + return -ENOMEM; > + req_len = sg_dma_len(sg_req); > + req_dma_addr = sg_dma_address(sg_req); If you only use the first element, could you just use dma_map_single()? > + hdr->cmd_table_addr_lo = cpu_to_le32(lower_32_bits(req_dma_addr)); > + hdr->cmd_table_addr_hi = cpu_to_le32(upper_32_bits(req_dma_addr)); > + > + hdr->sts_buffer_addr_lo = > + cpu_to_le32(lower_32_bits(slot->status_buffer_dma)); > + hdr->sts_buffer_addr_hi = > + cpu_to_le32(upper_32_bits(slot->status_buffer_dma)); > + > I see these a lot in your code. Could you replace this wit hdr->cmd_table_addr = cpu_to_le64(req_dma_addr); and so on? That would be much more readable. Or are the two __le32 variables swapped? If so, you could add a small helper function like static inline __le64 cpu_to_le64_wordswapped(u64 val) { return cpu_to_le64(val >> 32 | val << 32); } Arnd