From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E3C4C5517A for ; Wed, 11 Nov 2020 01:29:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EA7B216C4 for ; Wed, 11 Nov 2020 01:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732350AbgKKB3L (ORCPT ); Tue, 10 Nov 2020 20:29:11 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:2059 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732372AbgKKB3L (ORCPT ); Tue, 10 Nov 2020 20:29:11 -0500 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4CW6ZW6CSbzVmnF; Wed, 11 Nov 2020 09:28:51 +0800 (CST) Received: from dggemi761-chm.china.huawei.com (10.1.198.147) by dggeme758-chm.china.huawei.com (10.3.19.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Wed, 11 Nov 2020 09:29:08 +0800 Received: from dggemi761-chm.china.huawei.com ([10.9.49.202]) by dggemi761-chm.china.huawei.com ([10.9.49.202]) with mapi id 15.01.1913.007; Wed, 11 Nov 2020 09:29:08 +0800 From: "Song Bao Hua (Barry Song)" To: John Garry , "iommu@lists.linux-foundation.org" , "hch@lst.de" , "robin.murphy@arm.com" , "m.szyprowski@samsung.com" CC: "linux-kselftest@vger.kernel.org" , "Will Deacon" , Joerg Roedel , Linuxarm , "xuwei (O)" , Shuah Khan Subject: RE: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Topic: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Index: AQHWsO+tiT3rvc8AvUKektYgWKvLn6nBDT6Q//+EgQCAAZyYMA== Date: Wed, 11 Nov 2020 01:29:08 +0000 Message-ID: <88e91063b7f041bda7d147438f1c4621@hisilicon.com> References: <20201102080646.2180-1-song.bao.hua@hisilicon.com> <20201102080646.2180-2-song.bao.hua@hisilicon.com> <0658ee16-d539-61c5-1d39-77d50f559803@huawei.com> In-Reply-To: <0658ee16-d539-61c5-1d39-77d50f559803@huawei.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.126.200.81] Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org DQoNCj4gLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0NCj4gRnJvbTogSm9obiBHYXJyeQ0KPiBT ZW50OiBUdWVzZGF5LCBOb3ZlbWJlciAxMCwgMjAyMCA5OjM5IFBNDQo+IFRvOiBTb25nIEJhbyBI dWEgKEJhcnJ5IFNvbmcpIDxzb25nLmJhby5odWFAaGlzaWxpY29uLmNvbT47DQo+IGlvbW11QGxp c3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnOyBoY2hAbHN0LmRlOyByb2Jpbi5tdXJwaHlAYXJtLmNv bTsNCj4gbS5zenlwcm93c2tpQHNhbXN1bmcuY29tDQo+IENjOiBsaW51eC1rc2VsZnRlc3RAdmdl ci5rZXJuZWwub3JnOyBXaWxsIERlYWNvbiA8d2lsbEBrZXJuZWwub3JnPjsgSm9lcmcNCj4gUm9l ZGVsIDxqb3JvQDhieXRlcy5vcmc+OyBMaW51eGFybSA8bGludXhhcm1AaHVhd2VpLmNvbT47IHh1 d2VpIChPKQ0KPiA8eHV3ZWk1QGh1YXdlaS5jb20+OyBTaHVhaCBLaGFuIDxzaHVhaEBrZXJuZWwu b3JnPg0KPiBTdWJqZWN0OiBSZTogW1BBVENIIHYzIDEvMl0gZG1hLW1hcHBpbmc6IGFkZCBiZW5j aG1hcmsgc3VwcG9ydCBmb3INCj4gc3RyZWFtaW5nIERNQSBBUElzDQo+IA0KPiBPbiAxMC8xMS8y MDIwIDA4OjEwLCBTb25nIEJhbyBIdWEgKEJhcnJ5IFNvbmcpIHdyb3RlOg0KPiA+IEhlbGxvIFJv YmluLCBDaHJpc3RvcGgsDQo+ID4gQW55IGZ1cnRoZXIgY29tbWVudD8gSm9obiBzdWdnZXN0ZWQg dGhhdCAiZGVwZW5kcyBvbiBERUJVR19GUyIgc2hvdWxkDQo+IGJlIGFkZGVkIGluIEtjb25maWcu DQo+ID4gSSBhbSBjb2xsZWN0aW5nIG1vcmUgY29tbWVudHMgdG8gc2VuZCB2NCB0b2dldGhlciB3 aXRoIGZpeGluZyB0aGlzIG1pbm9yDQo+IGlzc3VlIDotKQ0KPiA+DQo+ID4gVGhhbmtzDQo+ID4g QmFycnkNCj4gPg0KPiA+PiAtLS0tLU9yaWdpbmFsIE1lc3NhZ2UtLS0tLQ0KPiA+PiBGcm9tOiBT b25nIEJhbyBIdWEgKEJhcnJ5IFNvbmcpDQo+ID4+IFNlbnQ6IE1vbmRheSwgTm92ZW1iZXIgMiwg MjAyMCA5OjA3IFBNDQo+ID4+IFRvOiBpb21tdUBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZzsg aGNoQGxzdC5kZTsNCj4gcm9iaW4ubXVycGh5QGFybS5jb207DQo+ID4+IG0uc3p5cHJvd3NraUBz YW1zdW5nLmNvbQ0KPiA+PiBDYzogTGludXhhcm0gPGxpbnV4YXJtQGh1YXdlaS5jb20+OyBsaW51 eC1rc2VsZnRlc3RAdmdlci5rZXJuZWwub3JnOw0KPiB4dXdlaQ0KPiA+PiAoTykgPHh1d2VpNUBo dWF3ZWkuY29tPjsgU29uZyBCYW8gSHVhIChCYXJyeSBTb25nKQ0KPiA+PiA8c29uZy5iYW8uaHVh QGhpc2lsaWNvbi5jb20+OyBKb2VyZyBSb2VkZWwgPGpvcm9AOGJ5dGVzLm9yZz47IFdpbGwNCj4g RGVhY29uDQo+ID4+IDx3aWxsQGtlcm5lbC5vcmc+OyBTaHVhaCBLaGFuIDxzaHVhaEBrZXJuZWwu b3JnPg0KPiA+PiBTdWJqZWN0OiBbUEFUQ0ggdjMgMS8yXSBkbWEtbWFwcGluZzogYWRkIGJlbmNo bWFyayBzdXBwb3J0IGZvcg0KPiBzdHJlYW1pbmcNCj4gPj4gRE1BIEFQSXMNCj4gPj4NCj4gPj4g Tm93YWRheXMsIHRoZXJlIGFyZSBpbmNyZWFzaW5nIHJlcXVpcmVtZW50cyB0byBiZW5jaG1hcmsg dGhlDQo+IHBlcmZvcm1hbmNlDQo+ID4+IG9mIGRtYV9tYXAgYW5kIGRtYV91bm1hcCBwYXJ0aWN1 YWxseSB3aGlsZSB0aGUgZGV2aWNlIGlzIGF0dGFjaGVkIHRvIGFuDQo+ID4+IElPTU1VLg0KPiA+ Pg0KPiA+PiBUaGlzIHBhdGNoIGVuYWJsZXMgdGhlIHN1cHBvcnQuIFVzZXJzIGNhbiBydW4gc3Bl Y2lmaWVkIG51bWJlciBvZiB0aHJlYWRzDQo+IHRvDQo+ID4+IGRvIGRtYV9tYXBfcGFnZSBhbmQg ZG1hX3VubWFwX3BhZ2Ugb24gYSBzcGVjaWZpYyBOVU1BIG5vZGUgd2l0aA0KPiB0aGUNCj4gPj4g c3BlY2lmaWVkIGR1cmF0aW9uLiBUaGVuIGRtYV9tYXBfYmVuY2htYXJrIHdpbGwgY2FsY3VsYXRl IHRoZSBhdmVyYWdlDQo+ID4+IGxhdGVuY3kgZm9yIG1hcCBhbmQgdW5tYXAuDQo+ID4+DQo+ID4+ IEEgZGlmZmljdWxpdHkgZm9yIHRoaXMgYmVuY2htYXJrIGlzIHRoYXQgZG1hX21hcC91bm1hcCBB UElzIG11c3QgcnVuIG9uIGENCj4gPj4gcGFydGljdWxhciBkZXZpY2UuIEVhY2ggZGV2aWNlIG1p Z2h0IGhhdmUgZGlmZmVyZW50IGJhY2tlbmQgb2YgSU9NTVUgb3INCj4gPj4gbm9uLUlPTU1VLg0K PiA+Pg0KPiA+PiBTbyB3ZSB1c2UgdGhlIGRyaXZlcl9vdmVycmlkZSB0byBiaW5kIGRtYV9tYXBf YmVuY2htYXJrIHRvIGEgcGFydGljdWFsDQo+ID4+IGRldmljZSBieToNCj4gPj4gRm9yIHBsYXRm b3JtIGRldmljZXM6DQo+ID4+IGVjaG8gZG1hX21hcF9iZW5jaG1hcmsgPg0KPiAvc3lzL2J1cy9w bGF0Zm9ybS9kZXZpY2VzL3h4eC9kcml2ZXJfb3ZlcnJpZGUNCj4gPj4gZWNobyB4eHggPiAvc3lz L2J1cy9wbGF0Zm9ybS9kcml2ZXJzL3h4eC91bmJpbmQNCj4gPj4gZWNobyB4eHggPiAvc3lzL2J1 cy9wbGF0Zm9ybS9kcml2ZXJzL2RtYV9tYXBfYmVuY2htYXJrL2JpbmQNCj4gPj4NCj4gDQo+IEhp IEJhcnJ5LA0KPiANCj4gPj4gRm9yIFBDSSBkZXZpY2VzOg0KPiA+PiBlY2hvIGRtYV9tYXBfYmVu Y2htYXJrID4NCj4gPj4gL3N5cy9idXMvcGNpL2RldmljZXMvMDAwMDowMDowMS4wL2RyaXZlcl9v dmVycmlkZQ0KPiA+PiBlY2hvIDAwMDA6MDA6MDEuMCA+IC9zeXMvYnVzL3BjaS9kcml2ZXJzL3h4 eC91bmJpbmQgZWNobyAwMDAwOjAwOjAxLjAgPg0KPiA+PiAvc3lzL2J1cy9wY2kvZHJpdmVycy9k bWFfbWFwX2JlbmNobWFyay9iaW5kDQo+IA0KPiBEbyB3ZSBuZWVkIHRvIGNoZWNrIGlmIHRoZSBk ZXZpY2UgdG8gd2hpY2ggd2UgYXR0YWNoIGFjdHVhbGx5IGhhcyBETUENCj4gbWFwcGluZyBjYXBh YmlsaXR5Pw0KDQpIZWxsbyBKb2huLA0KDQpJJ2QgbGlrZSB0byB0aGluayBjaGVja2luZyB0aGlz IGhlcmUgd291bGQgYmUgb3ZlcmRlc2lnbi4gV2UganVzdCBnaXZlIHVzZXJzIHRoZQ0KZnJlZWRv bSB0byBiaW5kIGFueSBkZXZpY2UgdGhleSBjYXJlIGFib3V0IHRvIHRoZSBiZW5jaG1hcmsgZHJp dmVyLiBVc3VhbGx5DQp0aGF0IG1lYW5zIGEgcmVhbCBoYXJkd2FyZSBlaXRoZXIgYmVoaW5kIGFu IElPTU1VIG9yIHRocm91Z2ggYSBkaXJlY3QNCm1hcHBpbmcuDQoNCmlmIGZvciBhbnkgcmVhc29u IHVzZXJzIHB1dCBhIHdyb25nICJkZXZpY2UiLCB0aGF0IGlzIHRoZSBjaG9pY2Ugb2YgdXNlcnMu IEFueWhvdywNCnRoZSBiZWxvdyBjb2RlIHdpbGwgc3RpbGwgaGFuZGxlIGl0IHByb3Blcmx5IGFu ZCB1c2VycyB3aWxsIGdldCBhIHJlcG9ydCBpbiB3aGljaA0KZXZlcnl0aGluZyBpcyB6ZXJvLg0K DQorc3RhdGljIGludCBtYXBfYmVuY2htYXJrX3RocmVhZCh2b2lkICpkYXRhKQ0KK3sNCi4uLg0K KwkJZG1hX2FkZHIgPSBkbWFfbWFwX3NpbmdsZShtYXAtPmRldiwgYnVmLCBQQUdFX1NJWkUsIERN QV9CSURJUkVDVElPTkFMKTsNCisJCWlmICh1bmxpa2VseShkbWFfbWFwcGluZ19lcnJvcihtYXAt PmRldiwgZG1hX2FkZHIpKSkgew0KKwkJCXByX2VycigiZG1hX21hcF9zaW5nbGUgZmFpbGVkIG9u ICVzXG4iLCBkZXZfbmFtZShtYXAtPmRldikpOw0KKwkJCXJldCA9IC1FTk9NRU07DQorCQkJZ290 byBvdXQ7DQorCQl9DQouLi4NCit9DQoNCj4gDQo+ID4+DQo+ID4+IENjOiBKb2VyZyBSb2VkZWwg PGpvcm9AOGJ5dGVzLm9yZz4NCj4gPj4gQ2M6IFdpbGwgRGVhY29uIDx3aWxsQGtlcm5lbC5vcmc+ DQo+ID4+IENjOiBTaHVhaCBLaGFuIDxzaHVhaEBrZXJuZWwub3JnPg0KPiA+PiBDYzogQ2hyaXN0 b3BoIEhlbGx3aWcgPGhjaEBsc3QuZGU+DQo+ID4+IENjOiBNYXJlayBTenlwcm93c2tpIDxtLnN6 eXByb3dza2lAc2Ftc3VuZy5jb20+DQo+ID4+IENjOiBSb2JpbiBNdXJwaHkgPHJvYmluLm11cnBo eUBhcm0uY29tPg0KPiA+PiBTaWduZWQtb2ZmLWJ5OiBCYXJyeSBTb25nIDxzb25nLmJhby5odWFA aGlzaWxpY29uLmNvbT4NCj4gPj4gLS0tDQo+IA0KPiBUaGFua3MsDQo+IEpvaG4NCg0KVGhhbmtz DQpCYXJyeQ0KDQo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 628D4C388F7 for ; Wed, 11 Nov 2020 01:30:55 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 854F521D91 for ; Wed, 11 Nov 2020 01:30:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 854F521D91 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hisilicon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id EC2D086BE5; Wed, 11 Nov 2020 01:30:53 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id et5lcXP9gXgc; Wed, 11 Nov 2020 01:30:51 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 064D386BE1; Wed, 11 Nov 2020 01:30:51 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id E12D0C088B; Wed, 11 Nov 2020 01:30:50 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id B9278C016F for ; Wed, 11 Nov 2020 01:30:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id A7FB186BAB for ; Wed, 11 Nov 2020 01:30:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1JAH0QSUbMg5 for ; Wed, 11 Nov 2020 01:30:44 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by whitealder.osuosl.org (Postfix) with ESMTPS id 0A92D85540 for ; Wed, 11 Nov 2020 01:29:12 +0000 (UTC) Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4CW6ZW6CSbzVmnF; Wed, 11 Nov 2020 09:28:51 +0800 (CST) Received: from dggemi761-chm.china.huawei.com (10.1.198.147) by dggeme758-chm.china.huawei.com (10.3.19.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Wed, 11 Nov 2020 09:29:08 +0800 Received: from dggemi761-chm.china.huawei.com ([10.9.49.202]) by dggemi761-chm.china.huawei.com ([10.9.49.202]) with mapi id 15.01.1913.007; Wed, 11 Nov 2020 09:29:08 +0800 From: "Song Bao Hua (Barry Song)" To: John Garry , "iommu@lists.linux-foundation.org" , "hch@lst.de" , "robin.murphy@arm.com" , "m.szyprowski@samsung.com" Subject: RE: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Topic: [PATCH v3 1/2] dma-mapping: add benchmark support for streaming DMA APIs Thread-Index: AQHWsO+tiT3rvc8AvUKektYgWKvLn6nBDT6Q//+EgQCAAZyYMA== Date: Wed, 11 Nov 2020 01:29:08 +0000 Message-ID: <88e91063b7f041bda7d147438f1c4621@hisilicon.com> References: <20201102080646.2180-1-song.bao.hua@hisilicon.com> <20201102080646.2180-2-song.bao.hua@hisilicon.com> <0658ee16-d539-61c5-1d39-77d50f559803@huawei.com> In-Reply-To: <0658ee16-d539-61c5-1d39-77d50f559803@huawei.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.126.200.81] MIME-Version: 1.0 X-CFilter-Loop: Reflected Cc: "linux-kselftest@vger.kernel.org" , Will Deacon , Linuxarm , "xuwei \(O\)" , Shuah Khan X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > -----Original Message----- > From: John Garry > Sent: Tuesday, November 10, 2020 9:39 PM > To: Song Bao Hua (Barry Song) ; > iommu@lists.linux-foundation.org; hch@lst.de; robin.murphy@arm.com; > m.szyprowski@samsung.com > Cc: linux-kselftest@vger.kernel.org; Will Deacon ; Joerg > Roedel ; Linuxarm ; xuwei (O) > ; Shuah Khan > Subject: Re: [PATCH v3 1/2] dma-mapping: add benchmark support for > streaming DMA APIs > > On 10/11/2020 08:10, Song Bao Hua (Barry Song) wrote: > > Hello Robin, Christoph, > > Any further comment? John suggested that "depends on DEBUG_FS" should > be added in Kconfig. > > I am collecting more comments to send v4 together with fixing this minor > issue :-) > > > > Thanks > > Barry > > > >> -----Original Message----- > >> From: Song Bao Hua (Barry Song) > >> Sent: Monday, November 2, 2020 9:07 PM > >> To: iommu@lists.linux-foundation.org; hch@lst.de; > robin.murphy@arm.com; > >> m.szyprowski@samsung.com > >> Cc: Linuxarm ; linux-kselftest@vger.kernel.org; > xuwei > >> (O) ; Song Bao Hua (Barry Song) > >> ; Joerg Roedel ; Will > Deacon > >> ; Shuah Khan > >> Subject: [PATCH v3 1/2] dma-mapping: add benchmark support for > streaming > >> DMA APIs > >> > >> Nowadays, there are increasing requirements to benchmark the > performance > >> of dma_map and dma_unmap particually while the device is attached to an > >> IOMMU. > >> > >> This patch enables the support. Users can run specified number of threads > to > >> do dma_map_page and dma_unmap_page on a specific NUMA node with > the > >> specified duration. Then dma_map_benchmark will calculate the average > >> latency for map and unmap. > >> > >> A difficulity for this benchmark is that dma_map/unmap APIs must run on a > >> particular device. Each device might have different backend of IOMMU or > >> non-IOMMU. > >> > >> So we use the driver_override to bind dma_map_benchmark to a particual > >> device by: > >> For platform devices: > >> echo dma_map_benchmark > > /sys/bus/platform/devices/xxx/driver_override > >> echo xxx > /sys/bus/platform/drivers/xxx/unbind > >> echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind > >> > > Hi Barry, > > >> For PCI devices: > >> echo dma_map_benchmark > > >> /sys/bus/pci/devices/0000:00:01.0/driver_override > >> echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind echo 0000:00:01.0 > > >> /sys/bus/pci/drivers/dma_map_benchmark/bind > > Do we need to check if the device to which we attach actually has DMA > mapping capability? Hello John, I'd like to think checking this here would be overdesign. We just give users the freedom to bind any device they care about to the benchmark driver. Usually that means a real hardware either behind an IOMMU or through a direct mapping. if for any reason users put a wrong "device", that is the choice of users. Anyhow, the below code will still handle it properly and users will get a report in which everything is zero. +static int map_benchmark_thread(void *data) +{ ... + dma_addr = dma_map_single(map->dev, buf, PAGE_SIZE, DMA_BIDIRECTIONAL); + if (unlikely(dma_mapping_error(map->dev, dma_addr))) { + pr_err("dma_map_single failed on %s\n", dev_name(map->dev)); + ret = -ENOMEM; + goto out; + } ... +} > > >> > >> Cc: Joerg Roedel > >> Cc: Will Deacon > >> Cc: Shuah Khan > >> Cc: Christoph Hellwig > >> Cc: Marek Szyprowski > >> Cc: Robin Murphy > >> Signed-off-by: Barry Song > >> --- > > Thanks, > John Thanks Barry _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu