From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B0256525B for ; Fri, 1 Mar 2024 17:24:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.58.85.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709313885; cv=none; b=LymygdJtmWgr9JLnY7VrVVeZ2C9QhGj3d9971RZvCc1ireFbUFJW2T7j76DBF5abTZhxBob8B+yLmct3vrhWooMBds8NPknqNweAa0U242QQGNCQ+K7cke79IRbJ/uC4Hr0TTq0rIX9mObLykjGnZDlfcCwImW1xR31XF/m4XdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709313885; c=relaxed/simple; bh=h58DFjaPojLEK3fLX4+ixq3XIVk5I8uJifwq7HQg9ig=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: MIME-Version:Content-Type; b=IPkCSVSMePBErOX3jer5HpzKH4ket3RQQ8oATQj20hYNdudNDbmQJ0regcP0fSGHSYEhyJECcxX/lorwCYgDc1FmVb4U/DAgyw1jpENNosfiYS+75/tF2U5quUdV9Bn0WAu9nNvC8oZWyDgh4IBExfs2wqsBpVpvyxnADX6Gs9E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM; spf=pass smtp.mailfrom=aculab.com; arc=none smtp.client-ip=185.58.85.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aculab.com Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-208-tXp_pUJVPlyy9kGWfCrWjw-1; Fri, 01 Mar 2024 17:24:41 +0000 X-MC-Unique: tXp_pUJVPlyy9kGWfCrWjw-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Fri, 1 Mar 2024 17:24:39 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Fri, 1 Mar 2024 17:24:39 +0000 From: David Laight To: 'Charlie Jenkins' , Christophe Leroy CC: Guenter Roeck , Palmer Dabbelt , Andrew Morton , Helge Deller , "James E.J. Bottomley" , Parisc List , Arnd Bergmann , "Geert Uytterhoeven" , Russell King , "linux-kernel@vger.kernel.org" , Palmer Dabbelt , Linux ARM , "netdev@vger.kernel.org" Subject: RE: [PATCH v11] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests Thread-Topic: [PATCH v11] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests Thread-Index: AQHaa/sz2G6zh0QEYUOonhCQoX0NCrEjHqIg Date: Fri, 1 Mar 2024 17:24:39 +0000 Message-ID: <3e0e2b25ea2d4ab99e78aff04af94b69@AcuMS.aculab.com> References: <20240229-fix_sparse_errors_checksum_tests-v11-1-f608d9ec7574@rivosinc.com> <41a5d1e8-6f30-4907-ba63-8a7526e71e04@csgroup.eu> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable From: Charlie Jenkins > Sent: 01 March 2024 17:09 >=20 > On Fri, Mar 01, 2024 at 07:17:38AM +0000, Christophe Leroy wrote: > > +CC netdev ARM Russell > > > > Le 29/02/2024 =C3=A0 23:46, Charlie Jenkins a =C3=A9crit=C2=A0: > > > The test cases for ip_fast_csum and csum_ipv6_magic were not properly > > > aligning the IP header, which were causing failures on architectures > > > that do not support misaligned accesses like some ARM platforms. To > > > solve this, align the data along (14 + NET_IP_ALIGN) bytes which is t= he > > > standard alignment of an IP header and must be supported by the > > > architecture. > > > > In your description, please provide more details on platforms that have > > a problem, what the problem is exactly (Failed calculation, slowliness, > > kernel Oops, panic, ....) on each platform. > > > > And please copy maintainers and lists of platforms your are specificall= y > > addressing with this change. And as this is network related, netdev lis= t > > should have been copied as well. > > > > I still think that your patch is not the good approach, it looks like > > you are ignoring all the discussion. Below is a quote of what Geert sai= d > > and I fully agree with that: > > > > =09IMHO the tests should validate the expected functionality. If a tes= t > > =09fails, either functionality is missing or behaves wrong, or the test > > =09is wrong. > > > > =09What is the point of writing tests for a core functionality like net= work > > =09checksumming that do not match the expected functionality? > > > > > > So we all agree that there is something to fix, because today's test > > does odd-address accesses which is unexpected for those functions, but > > 2-byte alignments should be supported hence tested by the test. Limitin= g > > the test to a 16-bytes alignment deeply reduces the usefullness of the = test. > > >=20 > Maybe I am lost in the conversations. This isn't limited to 16-bytes > alignment? It aligns along 14 + NET_IP_ALIGN. That is 16 on some > platforms and 14 on platforms where unaligned accesses are desired. > These functions are expected to be called with this offset. Testing with > any other alignment is not the expected behavior. These tests are > testing the expected functionality. Aligned received frames can have a 4 byte VLAN header (or two) removed. So the alignment of the IP header is either 4n or 4n+2. If the cpu fault misaligned accesses you really want the alignment to be 4n. You pretty much never want to trap and fixup a misaligned access. Especially in the network stack. I suspect it is better to do a realignment copy of the entire frame. At some point the data will be copied again, although you may want a CBU (crystal ball unit) to decide whether to align on an 8n or 8n+4 boundary to optimise a later copy. CPU that support misaligned transfers just make coders sloppy :-) =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales) 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8A17AC5475B for ; Fri, 1 Mar 2024 17:24:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/YhiQotOuFGovB77wkoYURiYngTnPr/InR9xV8lHFlg=; b=OL98X4g5uUVvVY CxF6PqR6DJjHnjK0EjEY9vIUavueY5m6gZwGyEHN9nvVLAasokgWicpb6DYXfDmbxQh0u8LSmkiXn bAw81cc+CZOuXYwLcTreClJ2R/flErI0UE2rGrBuaTUu2lhdOD0ZdSfu6MZWdSuChXcMZq69i6MLF lPkez9arzxdNs1eZHpcyePkc8BYupxhu47EW/drvUCnVRGAxPke7j9sawL3AJhv81b41RNjRVvM8x 3Cj87cI27HJJAhbnjB/YH41z8w705qBNrYLmmKKVyUtBUlCoLHeFtZKvcJEnGK1cJz2oQyQBoUYS9 x9uaTKQtzkT1NIu6Es/g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rg6cp-00000001KT9-1YOZ; Fri, 01 Mar 2024 17:24:47 +0000 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.85.151]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rg6cm-00000001KS3-4853 for linux-arm-kernel@lists.infradead.org; Fri, 01 Mar 2024 17:24:46 +0000 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-208-tXp_pUJVPlyy9kGWfCrWjw-1; Fri, 01 Mar 2024 17:24:41 +0000 X-MC-Unique: tXp_pUJVPlyy9kGWfCrWjw-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Fri, 1 Mar 2024 17:24:39 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Fri, 1 Mar 2024 17:24:39 +0000 From: David Laight To: 'Charlie Jenkins' , Christophe Leroy CC: Guenter Roeck , Palmer Dabbelt , Andrew Morton , Helge Deller , "James E.J. Bottomley" , Parisc List , Arnd Bergmann , "Geert Uytterhoeven" , Russell King , "linux-kernel@vger.kernel.org" , Palmer Dabbelt , Linux ARM , "netdev@vger.kernel.org" Subject: RE: [PATCH v11] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests Thread-Topic: [PATCH v11] lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests Thread-Index: AQHaa/sz2G6zh0QEYUOonhCQoX0NCrEjHqIg Date: Fri, 1 Mar 2024 17:24:39 +0000 Message-ID: <3e0e2b25ea2d4ab99e78aff04af94b69@AcuMS.aculab.com> References: <20240229-fix_sparse_errors_checksum_tests-v11-1-f608d9ec7574@rivosinc.com> <41a5d1e8-6f30-4907-ba63-8a7526e71e04@csgroup.eu> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240301_092445_317719_4F43FF43 X-CRM114-Status: GOOD ( 31.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org RnJvbTogQ2hhcmxpZSBKZW5raW5zCj4gU2VudDogMDEgTWFyY2ggMjAyNCAxNzowOQo+IAo+IE9u IEZyaSwgTWFyIDAxLCAyMDI0IGF0IDA3OjE3OjM4QU0gKzAwMDAsIENocmlzdG9waGUgTGVyb3kg d3JvdGU6Cj4gPiArQ0MgbmV0ZGV2IEFSTSBSdXNzZWxsCj4gPgo+ID4gTGUgMjkvMDIvMjAyNCDD oCAyMzo0NiwgQ2hhcmxpZSBKZW5raW5zIGEgw6ljcml0wqA6Cj4gPiA+IFRoZSB0ZXN0IGNhc2Vz IGZvciBpcF9mYXN0X2NzdW0gYW5kIGNzdW1faXB2Nl9tYWdpYyB3ZXJlIG5vdCBwcm9wZXJseQo+ ID4gPiBhbGlnbmluZyB0aGUgSVAgaGVhZGVyLCB3aGljaCB3ZXJlIGNhdXNpbmcgZmFpbHVyZXMg b24gYXJjaGl0ZWN0dXJlcwo+ID4gPiB0aGF0IGRvIG5vdCBzdXBwb3J0IG1pc2FsaWduZWQgYWNj ZXNzZXMgbGlrZSBzb21lIEFSTSBwbGF0Zm9ybXMuIFRvCj4gPiA+IHNvbHZlIHRoaXMsIGFsaWdu IHRoZSBkYXRhIGFsb25nICgxNCArIE5FVF9JUF9BTElHTikgYnl0ZXMgd2hpY2ggaXMgdGhlCj4g PiA+IHN0YW5kYXJkIGFsaWdubWVudCBvZiBhbiBJUCBoZWFkZXIgYW5kIG11c3QgYmUgc3VwcG9y dGVkIGJ5IHRoZQo+ID4gPiBhcmNoaXRlY3R1cmUuCj4gPgo+ID4gSW4geW91ciBkZXNjcmlwdGlv biwgcGxlYXNlIHByb3ZpZGUgbW9yZSBkZXRhaWxzIG9uIHBsYXRmb3JtcyB0aGF0IGhhdmUKPiA+ IGEgcHJvYmxlbSwgd2hhdCB0aGUgcHJvYmxlbSBpcyBleGFjdGx5IChGYWlsZWQgY2FsY3VsYXRp b24sIHNsb3dsaW5lc3MsCj4gPiBrZXJuZWwgT29wcywgcGFuaWMsIC4uLi4pIG9uIGVhY2ggcGxh dGZvcm0uCj4gPgo+ID4gQW5kIHBsZWFzZSBjb3B5IG1haW50YWluZXJzIGFuZCBsaXN0cyBvZiBw bGF0Zm9ybXMgeW91ciBhcmUgc3BlY2lmaWNhbGx5Cj4gPiBhZGRyZXNzaW5nIHdpdGggdGhpcyBj aGFuZ2UuIEFuZCBhcyB0aGlzIGlzIG5ldHdvcmsgcmVsYXRlZCwgbmV0ZGV2IGxpc3QKPiA+IHNo b3VsZCBoYXZlIGJlZW4gY29waWVkIGFzIHdlbGwuCj4gPgo+ID4gSSBzdGlsbCB0aGluayB0aGF0 IHlvdXIgcGF0Y2ggaXMgbm90IHRoZSBnb29kIGFwcHJvYWNoLCBpdCBsb29rcyBsaWtlCj4gPiB5 b3UgYXJlIGlnbm9yaW5nIGFsbCB0aGUgZGlzY3Vzc2lvbi4gQmVsb3cgaXMgYSBxdW90ZSBvZiB3 aGF0IEdlZXJ0IHNhaWQKPiA+IGFuZCBJIGZ1bGx5IGFncmVlIHdpdGggdGhhdDoKPiA+Cj4gPiAJ SU1ITyB0aGUgdGVzdHMgc2hvdWxkIHZhbGlkYXRlIHRoZSBleHBlY3RlZCBmdW5jdGlvbmFsaXR5 LiAgSWYgYSB0ZXN0Cj4gPiAJZmFpbHMsIGVpdGhlciBmdW5jdGlvbmFsaXR5IGlzIG1pc3Npbmcg b3IgYmVoYXZlcyB3cm9uZywgb3IgdGhlIHRlc3QKPiA+IAlpcyB3cm9uZy4KPiA+Cj4gPiAJV2hh dCBpcyB0aGUgcG9pbnQgb2Ygd3JpdGluZyB0ZXN0cyBmb3IgYSBjb3JlIGZ1bmN0aW9uYWxpdHkg bGlrZSBuZXR3b3JrCj4gPiAJY2hlY2tzdW1taW5nIHRoYXQgZG8gbm90IG1hdGNoIHRoZSBleHBl Y3RlZCBmdW5jdGlvbmFsaXR5Pwo+ID4KPiA+Cj4gPiBTbyB3ZSBhbGwgYWdyZWUgdGhhdCB0aGVy ZSBpcyBzb21ldGhpbmcgdG8gZml4LCBiZWNhdXNlIHRvZGF5J3MgdGVzdAo+ID4gZG9lcyBvZGQt YWRkcmVzcyBhY2Nlc3NlcyB3aGljaCBpcyB1bmV4cGVjdGVkIGZvciB0aG9zZSBmdW5jdGlvbnMs IGJ1dAo+ID4gMi1ieXRlIGFsaWdubWVudHMgc2hvdWxkIGJlIHN1cHBvcnRlZCBoZW5jZSB0ZXN0 ZWQgYnkgdGhlIHRlc3QuIExpbWl0aW5nCj4gPiB0aGUgdGVzdCB0byBhIDE2LWJ5dGVzIGFsaWdu bWVudCBkZWVwbHkgcmVkdWNlcyB0aGUgdXNlZnVsbG5lc3Mgb2YgdGhlIHRlc3QuCj4gPgo+IAo+ IE1heWJlIEkgYW0gbG9zdCBpbiB0aGUgY29udmVyc2F0aW9ucy4gVGhpcyBpc24ndCBsaW1pdGVk IHRvIDE2LWJ5dGVzCj4gYWxpZ25tZW50PyBJdCBhbGlnbnMgYWxvbmcgMTQgKyBORVRfSVBfQUxJ R04uIFRoYXQgaXMgMTYgb24gc29tZQo+IHBsYXRmb3JtcyBhbmQgMTQgb24gcGxhdGZvcm1zIHdo ZXJlIHVuYWxpZ25lZCBhY2Nlc3NlcyBhcmUgZGVzaXJlZC4KPiBUaGVzZSBmdW5jdGlvbnMgYXJl IGV4cGVjdGVkIHRvIGJlIGNhbGxlZCB3aXRoIHRoaXMgb2Zmc2V0LiBUZXN0aW5nIHdpdGgKPiBh bnkgb3RoZXIgYWxpZ25tZW50IGlzIG5vdCB0aGUgZXhwZWN0ZWQgYmVoYXZpb3IuIFRoZXNlIHRl c3RzIGFyZQo+IHRlc3RpbmcgdGhlIGV4cGVjdGVkIGZ1bmN0aW9uYWxpdHkuCgpBbGlnbmVkIHJl Y2VpdmVkIGZyYW1lcyBjYW4gaGF2ZSBhIDQgYnl0ZSBWTEFOIGhlYWRlciAob3IgdHdvKSByZW1v dmVkLgpTbyB0aGUgYWxpZ25tZW50IG9mIHRoZSBJUCBoZWFkZXIgaXMgZWl0aGVyIDRuIG9yIDRu KzIuCklmIHRoZSBjcHUgZmF1bHQgbWlzYWxpZ25lZCBhY2Nlc3NlcyB5b3UgcmVhbGx5IHdhbnQg dGhlIGFsaWdubWVudAp0byBiZSA0bi4KCllvdSBwcmV0dHkgbXVjaCBuZXZlciB3YW50IHRvIHRy YXAgYW5kIGZpeHVwIGEgbWlzYWxpZ25lZCBhY2Nlc3MuCkVzcGVjaWFsbHkgaW4gdGhlIG5ldHdv cmsgc3RhY2suCkkgc3VzcGVjdCBpdCBpcyBiZXR0ZXIgdG8gZG8gYSByZWFsaWdubWVudCBjb3B5 IG9mIHRoZSBlbnRpcmUgZnJhbWUuCkF0IHNvbWUgcG9pbnQgdGhlIGRhdGEgd2lsbCBiZSBjb3Bp ZWQgYWdhaW4sIGFsdGhvdWdoIHlvdSBtYXkgd2FudAphIENCVSAoY3J5c3RhbCBiYWxsIHVuaXQp IHRvIGRlY2lkZSB3aGV0aGVyIHRvIGFsaWduIG9uIGFuIDhuCm9yIDhuKzQgYm91bmRhcnkgdG8g b3B0aW1pc2UgYSBsYXRlciBjb3B5LgoKQ1BVIHRoYXQgc3VwcG9ydCBtaXNhbGlnbmVkIHRyYW5z ZmVycyBqdXN0IG1ha2UgY29kZXJzIHNsb3BweSA6LSkKCglEYXZpZAoKLQpSZWdpc3RlcmVkIEFk ZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwgTWlsdG9uIEtleW5lcywg TUsxIDFQVCwgVUsKUmVnaXN0cmF0aW9uIE5vOiAxMzk3Mzg2IChXYWxlcykKCgpfX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1h aWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xp c3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==