Re: [dpdk-dev] [PATCH] ethdev: missing typecast from void in eth_dev_pci_specific_init

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 12 Apr 2019 18:29:46 +0100
Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> On 4/12/2019 6:25 PM, Ferruh Yigit wrote:
> > On 4/12/2019 6:15 PM, Ananyev, Konstantin wrote:  
> >>
> >>  
> >>> -----Original Message-----
> >>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ferruh Yigit
> >>> Sent: Friday, April 12, 2019 6:09 PM
> >>> To: Stephen Hemminger <stephen@networkplumber.org>; Richardson, Bruce <bruce.richardson@intel.com>
> >>> Cc: David Christensen <drc@linux.vnet.ibm.com>; thomas@monjalon.net; arybchenko@solarflare.com; dev@dpdk.org;
> >>> radhika.chirra@ibm.com; stable@dpdk.org
> >>> Subject: Re: [dpdk-dev] [PATCH] ethdev: missing typecast from void in eth_dev_pci_specific_init
> >>>
> >>> On 4/11/2019 12:08 AM, Stephen Hemminger wrote:  
> >>>> On Wed, 10 Apr 2019 22:00:18 +0100
> >>>> Bruce Richardson <bruce.richardson@intel.com> wrote:
> >>>>  
> >>>>> On Wed, Apr 10, 2019 at 03:16:16PM -0500, David Christensen wrote:  
> >>>>>> The function eth_dev_pci_specific_init is missing a typecast to
> >>>>>> (struct rte_pci_device *) for the input argument bus_device.
> >>>>>>
> >>>>>> Cc: stable@dpdk.org
> >>>>>>
> >>>>>> Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
> >>>>>> Tested-by: Radhika Chirra <radhika.chirra@ibm.com>
> >>>>>> ---
> >>>>>>  lib/librte_ethdev/rte_ethdev_pci.h | 2 +-
> >>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>>>
> >>>>>> diff --git a/lib/librte_ethdev/rte_ethdev_pci.h b/lib/librte_ethdev/rte_ethdev_pci.h
> >>>>>> index 23257e9..a325311 100644
> >>>>>> --- a/lib/librte_ethdev/rte_ethdev_pci.h
> >>>>>> +++ b/lib/librte_ethdev/rte_ethdev_pci.h
> >>>>>> @@ -72,7 +72,7 @@
> >>>>>>
> >>>>>>  static inline int
> >>>>>>  eth_dev_pci_specific_init(struct rte_eth_dev *eth_dev, void *bus_device) {
> >>>>>> -	struct rte_pci_device *pci_dev = bus_device;
> >>>>>> +	struct rte_pci_device *pci_dev = (struct rte_pci_device *)bus_device;
> >>>>>>  
> >>>>>
> >>>>> Is this needed for building some C++ apps that are including the header
> >>>>> file (directly, or indirectly), because for pure C, "void *" types should
> >>>>> be assignable to any other pointer type without casting?
> >>>>>
> >>>>> /Bruce  
> >>>>
> >>>> Another example of Why the Hell is this inline?
> >>>>  
> >>>
> >>> It has been done inline intentionally at the time as far as remember, this
> >>> header is for drivers not for applications, it has helper functions.
> >>>
> >>> The common code from drivers related to the bus put into header files, so the
> >>> code itself belongs to drivers not ethdev and reduces duplicates in them.  
> >>
> >> Ok that's the common code used by the drivers...
> >> But why it still can't be in .c file?  
> > 
> > When it is in .c file, it will be either in ethdev library, single location in
> > .c file and binary file, but location is not exactly right, because code belongs
> > to drivers.
> > Or code should be in .c files of each drivers, this will be code duplication.
> > 
> > Having in .h file makes code in single place, but when compiled code will be in
> > each driver object file/ library.
> > 
> > Of course it works when put into a .c file in ehtdev, but bus (pci and vdev)
> > related code are not belongs to ethdev library and I believe shouldn't be part
> > of ethdev binary. And those bus helper headers are only for drivers to include,
> > so having inline shouldn't be a problem at all because there is not stability
> > concern in that interface.
> >   
> 
> btw, if you put those into .c file in ethdev, you will be creating a dependency
> from ethdev to bus code, to all available buses which will make impossible to
> disable any bus type if you use ethdev.

The problem I see is rte_ethdev_pci.h, it should be headers only and then put
code rte_ethdev_pci.c