Hi, Às 12:20 PM de 12/29/2016, Kishon Vijay Abraham I escreveu: > Hi, > > On Thursday 29 December 2016 05:38 PM, Joao Pinto wrote: >> Às 11:58 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: >>> Hi, >>> >>> On Thursday 29 December 2016 05:23 PM, Joao Pinto wrote: >>>> Às 11:48 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: >>>>> Hi, >>>>> >>>>> On Thursday 29 December 2016 04:08 PM, Joao Pinto wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> Às 5:46 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: >>>>>>> Hi, >>>>>>> >>>>>>> On Wednesday 28 December 2016 10:50 PM, Joao Pinto wrote: >>>>>>>> Às 5:17 PM de 12/28/2016, Joao Pinto escreveu: >>>>>>>>> Às 4:41 PM de 12/28/2016, Bjorn Helgaas escreveu: >>>>>>>>>> On Wed, Dec 28, 2016 at 01:57:13PM +0000, Joao Pinto wrote: >>>>>>>>>>> Às 9:22 AM de 12/28/2016, Christoph Hellwig escreveu: >>>>>>>>>>>> On Wed, Dec 28, 2016 at 01:39:37PM +0530, Kishon Vijay Abraham I wrote: >>>>>>>>>>>>> As discussed during our LPC discussions, I'm posting the rename patch >>>>>>>>>>>>> here. I'll post the rest of EP series before the next merge window. >>>>>>>>>>>>> >>>>>>>>>>>>> There might be hiccups because of this renaming but feel this is >>>>>>>>>>>>> necessary for long-term maintenance. >>>>>>>>>>>> >>>>>>>>>>>> if we do this rename it would be great to get it to Linus NOW after >>>>>>>>>>>> -rc1 as that minimizes the impact on the 4.11 merge window. >>>>>>>>>>> >>>>>>>>>>> Rename it to controller is a bit vague I thing since we have the PCI Endpoint IP >>>>>>>>>>> also. Wouldn't be better to name it rc_controller? >>>>>>>>>> >>>>>>>>>> I think Kishon's whole goal is to add PCI Endpoint IP, so he wants a >>>>>>>>>> neutral name that can cover both RC and Endpoint. >>>>>>> >>>>>>> right. >>>>>>>>>> >>>>>>>>>> I'm not a huge fan of "controller" because it feels a little bit long >>>>>>>>>> and while I suppose it technically does include the concept of the PCI >>>>>>>>>> interface of an endpoint, it still suggests more of the host side to >>>>>>>>>> me. >>>>>>>>>> >>>>>>>>>> Doesn't USB have a similar situation? I see there's a >>>>>>>>>> drivers/usb/host/ (probably where we copied from in the first place). >>>>>>>>>> Is a USB gadget the USB analog of what you're doing? How do they >>>>>>>>>> share code between the master/slave sides? >>>>>>>>>> >>>>>>>>> >>>>>>>>> The usb/host contains the implemnentations by the spec of the several >>>>>>>>> *hci (USB Host) and then you can have for example the USB 3.0 Designware >>>>>>>>> Host specific ops in dwc3 and for USB 2.0 in dwc2/. >>>>>>> >>>>>>> right, each IP have a separate directory in USB. I thought of doing something >>>>>>> similar for PCI but decided against it since that would involve identifying all >>>>>>> the PCI IPs used and eventually result in more directories. >>>>>>>>> For device purposes it uses the core/ and then some of the device functions >>>>>>>>> are extended from the gadget/ package in which you can use mass_storage and >>>>>>>>> other types of functions. >>>>>>> >>>>>>> That would be similar for PCI endpoint. All endpoint specific core >>>>>>> functionality will be added in drivers/pci/endpoint (see RFC [1]). >>>>>>>>> >>>>>>>>> In our case in PCI we have the core functions inside /drivers/pci and the host >>>>>>>>> mangled inside host. I suggest: >>>>>>>>> >>>>>>>>> drivers/pci >>>>>>>>> drivers/pci/core/ >>>>>>>>> drivers/pci/core/hotplug >>>>>>>>> drivers/pci/core/pcie >>>>>>>>> drivers/pci/core/<all other files inside pci/ today> >>>>>>>>> drivers/pci/host >>>>>>>>> drivers/pci/dwc -> here would be pcie-designware and the specific vendor drivers >>>>>>>> >>>>>>>> Correction: >>>>>>>> drivers/pci/host/dwc -> here would be pcie-designware and the specific vendor >>>>>>>> drivers >>>>>>>> >>>>>>>>> drivers/pci/<vendorN> -> here would be the drivers for vendorN controller >>>>>>>> >>>>>>>> Correction: >>>>>>>> drivers/pci/host/<vendorN> -> here would be the drivers for vendorN controller >>>>>>>> >>>>>>>>> drivers/pci/endpoint -> common code >>>>>>>>> drivers/pci/endpoint/dwc -> implementation of Synopsys specific endpoint ops >>>>>>>>> drivers/pci/<vendorN> -> implementation of other vendors specific endpoint ops >>>>>>> >>>>>>> There are some parts of the dwc driver that is common to both root complex and >>>>>>> endpoint. Where should that be? I'm sure no one wants to duplicate the common >>>>>>> piece in both root complex and endpoint. >>>>>> >>>>>> You are right, the config space is almost the same and some ops also common. >>>>>> I would suggest: >>>>>> >>>>>> drivers/pci >>>>>> drivers/pci/core/ >>>>>> drivers/pci/core/hotplug >>>>>> drivers/pci/core/pcie >>>>>> drivers/pci/core/<all other files inside pci/ today> >>>>>> drivers/pci/dwc >>>>>> drivers/pci/dwc/common.c -> common ops and registers between RC and endpoint >>>>>> drivers/pci/dwc/host/ >>>>>> drivers/pci/dwc/endpoint/ >>>>>> >>>>>> What do you think? >>>>> >>>>> I don't think we should have sub-directories within dwc (USB too doesn't have >>>>> sub-directories). Where should the platform specific driver be kept? For >>>>> example pci-dra7xx.c (which use dwc) has both rc and ep specific parts but the >>>>> changes are so minimal that splitting the file won't make much sense. >>>>> >>>>> And such a change would also mean we create a separate directory for every >>>>> other driver present right now in pci/host. >>>> >>>> I understand you idea. We can simplify it this way: >>>> >>>> drivers/pci >>>> drivers/pci/core/ >>>> drivers/pci/core/hotplug >>>> drivers/pci/core/pcie >>>> drivers/pci/core/<all other files inside pci/ today> >>>> drivers/pci/dwc -> Common files (RC and EP), specific vendor drivers for EP >>>> and EP >>>> >>>> BTW dwc states for DesigWare Controller. >>>> >>>> What do you think? >>> >>> I'd like to avoid using different directory structures for different IPs. Lets >>> try to make it uniform. >> >> I understand, but mixing them all up is not a good aproach in my opinion, since >> a SoCs using Synopsys IP will only use the common files for that IP. Today in >> the host/ folder you have a bunch of drivers that is not clear which are using >> Synopsys IP or not. Of course I mention Synopsys, because it is where I work, >> but the opinion would be the same for other IP vendor. > > right, but it has been that way always. My point is why should we disturb it > for the sake of adding endpoint support. >> >> I understand that you want to do a common Endpoint framework to be used by any >> IP vendor based, and maybe this partition makes it a bit harder, but in my >> personal opinion each IP vendor should have its own folder for clarity and >> organization of the code. >> >> You framework should be outside those IP vendor folders and be available for >> their drivers to use it, and so it should be completely vendor agnostic. > > right, that's how it was designed (please see drivers/pci/endpoint/ directories > in RFC [1] which has the endpoint framework). > > [1] -> https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2016_9_14_27&d=DgID-g&c=DPL6_X_6JkXFx7AXWqB0tg&r=s2fO0hii0OGNOv9qQy_HRXy-xAJUD1NNoEcc3io_kx0&m=Usq-eV6vJQ4rVg_Jj-JzgYyH26VfwLaqXDrE_54JCmg&s=wSindfuj1wjD3QeOSzLJNPmgMyqcZNtNX0X-D5yCpqw&e= I have checked your patch and seems very useful for certain that I am going to use to add support a DWC reference Endpoint driver. Synopsys Endpoint has a DMA engine available that can be used or not by the IP client. To configure and use it the IP as a set of registers that like other IP must be configured and managed. Other IP vendors won't have this feature for sure. So I am saying is, although it gets simpler to have a host/ and a endpoint/ folder with everything inside, I still feel that we should isolate IP vendor stuff in isolated ecosystems creating host/dwc and endpoint/dwc where Synopsys clients can put their drivers and use the common functions. Current host/ is just a place where every Root Complex driver is deployed. I know it works of course, but if you are improving structure why not organize it better? I think that organizing right now would be the perfect timming, in my opinion of course! >> >>> >>> Thanks >>> Kishon >>> >> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
