2016-07-08 09:56, Neil Horman: > On Fri, Jul 08, 2016 at 10:49:25AM +0200, David Marchand wrote: > > Hello Thomas, Neil, > > > > (will be back in a couple of days, thanks Thomas for pointing this thread) > > > > > > On Thu, Jul 7, 2016 at 6:25 PM, Thomas Monjalon > > <thomas.monjalon at 6wind.com> wrote: > > > 2016-07-07 12:11, Neil Horman: > > >> On Thu, Jul 07, 2016 at 05:36:28PM +0200, Thomas Monjalon wrote: > > >> > Remove include of rte_pci.h in the generic header rte_dev.h > > >> > and move the macro DRIVER_REGISTER_PCI_TABLE in rte_pci.h. > > > [...] > > >> > > >> This seems strange to me, in that its odd for the driver information > > >> export > > >> macros to be spread out in multiple locations. Specifically it enjoins > > >> the use > > >> of the DRV_EXP_TAG macro, which helps centralize tag naming. Perhaps > > >> the happy > > >> medium is to place all the export macros (includnig PMD_REGISTER_DRIVER) > > >> into > > >> its own pmd_register.h header? > > > > > > I don't know. > > > David, your opinion? > > > > - The suggestion I did offline to Thomas was to move pci stuff in pci > > headers. > > We are trying to move from the "all pci" code in eal to accomodate for > > other "buses" / architectures. > I get that, but I'm not sure that applies here. The macro in question is > specific to pci busses, and if there is additional bus information to export, > it > will have its own macro (e.g. DRIVER_REGISTER_USB_TABLE or some such). While > I could see that being an argument for putting each macro in with its own bus > type, I think thats the wrong organization here, in that people writing > drivers > will want to know what export macros are available and will expect to look in > a > single place for it. > > > Having a pci macro in a generic header like rte_dev.h is wrong to me. > > Moving this to a new header like pmd_register.h sounds like a new > > generic header with pci specific stuff in it. > Well, yes, but I see that as no different than rte_ethdev.c or rte_pdump.c. > both of those files will need to know about all the different types of busses > you support and have to include those corresponding header files (i.e. they > will > have to include rte_pci.h, rte_usb.h, rte_i2c.h, etc). This is really no > different in my mind. > > > So, I am not sure I follow you Neil. > > > > Can you elaborate ? > > > I suppose the best way to describe it is that while I understand and support > the > desire to separate and abstract bus information away from device function, I > think theres a pragmatic descision here to prioritize functional domain over > header inclusion. That is to say, I think when people are writing a driver, > it > will be helpful to have all the export macros in a single location so they > know > what information they can export, and that includes registration of various > bus > type identifiers. So a file like pmd_registration.h that includes rte_pci.h, > rte_usb.h, rte_i2c.h, etc is more useful to a developer, than spreading these > macros out to those various header files, for the sake of avoiding a > potentially > unneeded include. > > > > > - Why do you want to centralise the tag naming ? > > To avoid collisions ? > Yes, and to centralize that information. Since the pmdinfogen tool needs to > know what those tag names are as well, its useful to keep them in the same > area > to maintain co-ordination. Its also useful because it means we can use one > macro to define tag naming convention, instead of having to re-implement or > dead-reckon it in multiple files. > > > Well, adding those tags should not happen that often and I think we > > can maintain this with careful reviews. > I don't agree with that. This discussion is based on the fact that you expect > that we will be adding additional bus types in the future correct? Well, > given > that we have a pci bus specific export macro, I would expect that to > proliferate > to every other bus type as well, and so we can expect to at least have a new > tag added for every bus that is added, in addition to any other bus agnostic > information people wish to export (just off hand, looking at the linux modinfo > section, we might expect module author, module version, alias names, licensing > infomration, and others to be potential export candidates). So, depending on > how much this is adopted, I think we can potentially expect a great deal of > additional tagging to be needed.
Anyway, this macro do not need rte_pci.h. So the minimal patch can be to just remove this include.
