From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756955AbeDBTp6 (ORCPT ); Mon, 2 Apr 2018 15:45:58 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43180 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752321AbeDBTp4 (ORCPT ); Mon, 2 Apr 2018 15:45:56 -0400 Date: Mon, 2 Apr 2018 15:45:53 -0400 From: Jerome Glisse To: Logan Gunthorpe Cc: Christian =?iso-8859-1?Q?K=F6nig?= , Christoph Hellwig , Will Davis , Joerg Roedel , linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH 2/8] PCI: Add pci_find_common_upstream_dev() Message-ID: <20180402194553.GC18231@redhat.com> References: <8d050848-8970-b8c4-a657-429fefd31769@amd.com> <20180330015854.GA3572@redhat.com> <0234bc5e-495e-0f68-fb0a-debb17a35761@deltatee.com> <20180330194519.GC3198@redhat.com> <31266710-f6bb-99ee-c73d-6e58afe5c38c@deltatee.com> <20180402172027.GA18231@redhat.com> <6f796779-0ba3-d056-de33-341ee55d6b38@deltatee.com> <20180402191649.GB18231@redhat.com> <4c672c71-6202-0775-7825-37f8077d1d35@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4c672c71-6202-0775-7825-37f8077d1d35@deltatee.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 02, 2018 at 01:32:37PM -0600, Logan Gunthorpe wrote: > > > On 02/04/18 01:16 PM, Jerome Glisse wrote: > > There isn't good API at the moment AFAIK, closest thing would either be > > lookup_resource() or region_intersects(), but a more appropriate one can > > easily be added, code to walk down the tree is readily available. More- > > over this can be optimize like vma lookup are, even more as resource are > > seldomly added so read side (finding a resource) can be heavily favor > > over write side (adding|registering a new resource). > > So someone needs to create a highly optimized tree that registers all > physical address on the system and maps them to devices? That seems a > long way from being realized. I'd hardly characterize that as "easily". > If we can pass both devices to the API I'd suspect it would be preferred > over the complicated tree. This, of course, depends on what users of the > API need. This tree already exist, it is all there upstream see kernel/resource.c What is missing is something that take a single address and return the device struct. There is function that take a range region_intersects() or one that take the start address lookup_resource(). It isn't hard to think that using roughly same code as region_intersects() an helper that return the device for a resource can be added. And yes currently this does not have a pointer back to the device that own the resource but this can be added. It wasn't needed until now. It can latter be optimize if device lookup shows as a bottleneck in perf profile. > > > cache coherency protocol (bit further than PCIE snoop). But also the > > other direction the CPU access to device memory can also be cache coherent, > > which is not the case in PCIE. > > I was not aware that CAPI allows PCI device memory to be cache coherent. > That sounds like it would be very tricky... And yet CAPI, CCIX, Gen-Z, NVLink, ... are all inter-connect that aim at achieving this cache coherency between multiple devices and CPUs. Jérôme From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerome Glisse Subject: Re: [PATCH 2/8] PCI: Add pci_find_common_upstream_dev() Date: Mon, 2 Apr 2018 15:45:53 -0400 Message-ID: <20180402194553.GC18231@redhat.com> References: <8d050848-8970-b8c4-a657-429fefd31769@amd.com> <20180330015854.GA3572@redhat.com> <0234bc5e-495e-0f68-fb0a-debb17a35761@deltatee.com> <20180330194519.GC3198@redhat.com> <31266710-f6bb-99ee-c73d-6e58afe5c38c@deltatee.com> <20180402172027.GA18231@redhat.com> <6f796779-0ba3-d056-de33-341ee55d6b38@deltatee.com> <20180402191649.GB18231@redhat.com> <4c672c71-6202-0775-7825-37f8077d1d35@deltatee.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <4c672c71-6202-0775-7825-37f8077d1d35@deltatee.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Logan Gunthorpe Cc: linaro-mm-sig@lists.linaro.org, Will Davis , amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Christoph Hellwig , dri-devel@lists.freedesktop.org, Bjorn Helgaas , Christian =?iso-8859-1?Q?K=F6nig?= , linux-media@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org T24gTW9uLCBBcHIgMDIsIDIwMTggYXQgMDE6MzI6MzdQTSAtMDYwMCwgTG9nYW4gR3VudGhvcnBl IHdyb3RlOgo+IAo+IAo+IE9uIDAyLzA0LzE4IDAxOjE2IFBNLCBKZXJvbWUgR2xpc3NlIHdyb3Rl Ogo+ID4gVGhlcmUgaXNuJ3QgZ29vZCBBUEkgYXQgdGhlIG1vbWVudCBBRkFJSywgY2xvc2VzdCB0 aGluZyB3b3VsZCBlaXRoZXIgYmUKPiA+IGxvb2t1cF9yZXNvdXJjZSgpIG9yIHJlZ2lvbl9pbnRl cnNlY3RzKCksIGJ1dCBhIG1vcmUgYXBwcm9wcmlhdGUgb25lIGNhbgo+ID4gZWFzaWx5IGJlIGFk ZGVkLCBjb2RlIHRvIHdhbGsgZG93biB0aGUgdHJlZSBpcyByZWFkaWx5IGF2YWlsYWJsZS4gTW9y ZS0KPiA+IG92ZXIgdGhpcyBjYW4gYmUgb3B0aW1pemUgbGlrZSB2bWEgbG9va3VwIGFyZSwgZXZl biBtb3JlIGFzIHJlc291cmNlIGFyZQo+ID4gc2VsZG9tbHkgYWRkZWQgc28gcmVhZCBzaWRlIChm aW5kaW5nIGEgcmVzb3VyY2UpIGNhbiBiZSBoZWF2aWx5IGZhdm9yCj4gPiBvdmVyIHdyaXRlIHNp ZGUgKGFkZGluZ3xyZWdpc3RlcmluZyBhIG5ldyByZXNvdXJjZSkuCj4gCj4gU28gc29tZW9uZSBu ZWVkcyB0byBjcmVhdGUgYSBoaWdobHkgb3B0aW1pemVkIHRyZWUgdGhhdCByZWdpc3RlcnMgYWxs Cj4gcGh5c2ljYWwgYWRkcmVzcyBvbiB0aGUgc3lzdGVtIGFuZCBtYXBzIHRoZW0gdG8gZGV2aWNl cz8gVGhhdCBzZWVtcyBhCj4gbG9uZyB3YXkgZnJvbSBiZWluZyByZWFsaXplZC4gSSdkIGhhcmRs eSBjaGFyYWN0ZXJpemUgdGhhdCBhcyAiZWFzaWx5Ii4KPiBJZiB3ZSBjYW4gcGFzcyBib3RoIGRl dmljZXMgdG8gdGhlIEFQSSBJJ2Qgc3VzcGVjdCBpdCB3b3VsZCBiZSBwcmVmZXJyZWQKPiBvdmVy IHRoZSBjb21wbGljYXRlZCB0cmVlLiBUaGlzLCBvZiBjb3Vyc2UsIGRlcGVuZHMgb24gd2hhdCB1 c2VycyBvZiB0aGUKPiBBUEkgbmVlZC4KClRoaXMgdHJlZSBhbHJlYWR5IGV4aXN0LCBpdCBpcyBh bGwgdGhlcmUgdXBzdHJlYW0gc2VlIGtlcm5lbC9yZXNvdXJjZS5jCldoYXQgaXMgbWlzc2luZyBp cyBzb21ldGhpbmcgdGhhdCB0YWtlIGEgc2luZ2xlIGFkZHJlc3MgYW5kIHJldHVybiB0aGUKZGV2 aWNlIHN0cnVjdC4gVGhlcmUgaXMgZnVuY3Rpb24gdGhhdCB0YWtlIGEgcmFuZ2UgcmVnaW9uX2lu dGVyc2VjdHMoKQpvciBvbmUgdGhhdCB0YWtlIHRoZSBzdGFydCBhZGRyZXNzIGxvb2t1cF9yZXNv dXJjZSgpLiBJdCBpc24ndCBoYXJkIHRvCnRoaW5rIHRoYXQgdXNpbmcgcm91Z2hseSBzYW1lIGNv ZGUgYXMgcmVnaW9uX2ludGVyc2VjdHMoKSBhbiBoZWxwZXIKdGhhdCByZXR1cm4gdGhlIGRldmlj ZSBmb3IgYSByZXNvdXJjZSBjYW4gYmUgYWRkZWQuCgpBbmQgeWVzIGN1cnJlbnRseSB0aGlzIGRv ZXMgbm90IGhhdmUgYSBwb2ludGVyIGJhY2sgdG8gdGhlIGRldmljZSB0aGF0Cm93biB0aGUgcmVz b3VyY2UgYnV0IHRoaXMgY2FuIGJlIGFkZGVkLiBJdCB3YXNuJ3QgbmVlZGVkIHVudGlsIG5vdy4K Ckl0IGNhbiBsYXR0ZXIgYmUgb3B0aW1pemUgaWYgZGV2aWNlIGxvb2t1cCBzaG93cyBhcyBhIGJv dHRsZW5lY2sgaW4gcGVyZgpwcm9maWxlLgoKCj4gCj4gPiBjYWNoZSBjb2hlcmVuY3kgcHJvdG9j b2wgKGJpdCBmdXJ0aGVyIHRoYW4gUENJRSBzbm9vcCkuIEJ1dCBhbHNvIHRoZQo+ID4gb3RoZXIg ZGlyZWN0aW9uIHRoZSBDUFUgYWNjZXNzIHRvIGRldmljZSBtZW1vcnkgY2FuIGFsc28gYmUgY2Fj aGUgY29oZXJlbnQsCj4gPiB3aGljaCBpcyBub3QgdGhlIGNhc2UgaW4gUENJRS4KPiAKPiBJIHdh cyBub3QgYXdhcmUgdGhhdCBDQVBJIGFsbG93cyBQQ0kgZGV2aWNlIG1lbW9yeSB0byBiZSBjYWNo ZSBjb2hlcmVudC4KPiBUaGF0IHNvdW5kcyBsaWtlIGl0IHdvdWxkIGJlIHZlcnkgdHJpY2t5Li4u CgpBbmQgeWV0IENBUEksIENDSVgsIEdlbi1aLCBOVkxpbmssIC4uLiBhcmUgYWxsIGludGVyLWNv bm5lY3QgdGhhdCBhaW0gYXQKYWNoaWV2aW5nIHRoaXMgY2FjaGUgY29oZXJlbmN5IGJldHdlZW4g bXVsdGlwbGUgZGV2aWNlcyBhbmQgQ1BVcy4KCkrDqXLDtG1lCl9fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRl dmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9t YWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo=