From patchwork Wed Jun 8 07:53:46 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 9163557 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0A2F860572 for ; Wed, 8 Jun 2016 07:59:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF2C928384 for ; Wed, 8 Jun 2016 07:59:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E356D2838E; Wed, 8 Jun 2016 07:59:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9CE3028384 for ; Wed, 8 Jun 2016 07:59:32 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bAYNO-0004Wi-PV; Wed, 08 Jun 2016 07:58:10 +0000 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bAYNM-0004T7-Bv for linux-arm-kernel@lists.infradead.org; Wed, 08 Jun 2016 07:58:09 +0000 Received: from pps.filterd (m0045851.ppops.net [127.0.0.1]) by mx0b-0016f401.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u587uwaa000411; Wed, 8 Jun 2016 00:57:43 -0700 Received: from sc-exch02.marvell.com ([199.233.58.182]) by mx0b-0016f401.pphosted.com with ESMTP id 23e39u25sk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 08 Jun 2016 00:57:43 -0700 Received: from SC-EXCH04.marvell.com (10.93.176.84) by SC-EXCH02.marvell.com (10.93.176.82) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Wed, 8 Jun 2016 00:57:41 -0700 Received: from maili.marvell.com (10.93.176.43) by SC-EXCH04.marvell.com (10.93.176.84) with Microsoft SMTP Server id 15.0.1104.5 via Frontend Transport; Wed, 8 Jun 2016 00:57:41 -0700 Received: from xhacker.marvell.com (unknown [10.37.130.136]) by maili.marvell.com (Postfix) with ESMTP id 06FE53F7041; Wed, 8 Jun 2016 00:57:40 -0700 (PDT) From: Jisheng Zhang To: , Subject: [PATCH] arm64: mm: only initialize swiotlb when necessary Date: Wed, 8 Jun 2016 15:53:46 +0800 Message-ID: <1465372426-4077-1-git-send-email-jszhang@marvell.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-06-08_02:, , signatures=0 X-Proofpoint-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606080094 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160608_005808_563729_02D5047E X-CRM114-Status: GOOD ( 12.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jisheng Zhang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP we only initialize swiotlb when swiotlb_force is true or not all system memory is DMA-able, this trivial optimization saves us 64MB when swiotlb is not necessary. Signed-off-by: Jisheng Zhang --- arch/arm64/mm/dma-mapping.c | 15 ++++++++++++++- arch/arm64/mm/init.c | 3 ++- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index c566ec8..46a4157 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -19,6 +19,7 @@ #include #include +#include #include #include #include @@ -29,6 +30,8 @@ #include +static int swiotlb __read_mostly; + static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot, bool coherent) { @@ -341,6 +344,13 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt, return ret; } +static int __swiotlb_dma_supported(struct device *hwdev, u64 mask) +{ + if (swiotlb) + return swiotlb_dma_supported(hwdev, mask); + return 1; +} + static struct dma_map_ops swiotlb_dma_ops = { .alloc = __dma_alloc, .free = __dma_free, @@ -354,7 +364,7 @@ static struct dma_map_ops swiotlb_dma_ops = { .sync_single_for_device = __swiotlb_sync_single_for_device, .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu, .sync_sg_for_device = __swiotlb_sync_sg_for_device, - .dma_supported = swiotlb_dma_supported, + .dma_supported = __swiotlb_dma_supported, .mapping_error = swiotlb_dma_mapping_error, }; @@ -513,6 +523,9 @@ EXPORT_SYMBOL(dummy_dma_ops); static int __init arm64_dma_init(void) { + if (swiotlb_force || max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT)) + swiotlb = 1; + return atomic_pool_init(); } arch_initcall(arm64_dma_init); diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index d45f862..7d25b4d 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -403,7 +403,8 @@ static void __init free_unused_memmap(void) */ void __init mem_init(void) { - swiotlb_init(1); + if (swiotlb_force || max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT)) + swiotlb_init(1); set_max_mapnr(pfn_to_page(max_pfn) - mem_map);