Re: [dpdk-dev] [PATCH v3 06/12] eal: pci: vfio: add rd/wr func for pci bar space

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 7 Jan 2016 18:26:30 +0000
"Wiles, Keith" <keith.wiles@intel.com> wrote:

> On 1/7/16, 12:19 PM, "dev on behalf of Stephen Hemminger" <dev-bounces@dpdk.org on behalf of stephen@networkplumber.org> wrote:
> 
> >On Thu,  7 Jan 2016 22:03:03 +0530
> >Santosh Shukla <sshukla@mvista.com> wrote:
> >
> >>  
> >> +int rte_eal_pci_read_bar(const struct rte_pci_device *device __rte_unused,
> >> +			 void *buf __rte_unused,
> >> +			 size_t len __rte_unused,
> >> +			 off_t offset __rte_unused,
> >> +			 int bar_idx __rte_unused)
> >> +{
> >> +#ifdef VFIO_PRESENT
> >> +	const struct rte_intr_handle *intr_handle = &device->intr_handle;
> >> +	return pci_vfio_read_bar(intr_handle, buf, len, offset, bar_idx);
> >> +#else
> >> +	return 0; /* UIO's not applicable */
> >> +#endif
> >> +}
> >
> >It seems wrong to declare all the parameters as unused but then use them.
> >Maybe there is a way to have a macro for USED(x) in the #else case
> 
> I would suggest we create a macro '#define RTE_UNUSED(x)  ((void)x)’, unless we have one and I missed it groping though the code.
> >
> 
> 
> Regards,
> Keith
> 
> 
> 
> 

Or just move the #ifdef outside the function and have two versions

#ifdef VFIO_PRESENT
int rte_eal_pci_read_bar(const struct rte_pci_device *device,
			 void *buf, size_t len,
			  off_t offset, int bar_idx)
{
	const struct rte_intr_handle *intr_handle = &device->intr_handle;

	return pci_vfio_read_bar(intr_handle, buf, len, offset, bar_idx);
}
}
#else
int rte_eal_pci_read_bar(const struct rte_pci_device *device __rte_unused,
			 void *buf __rte_unused,
			 size_t len __rte_unused,
			 off_t offset __rte_unused,
			 int bar_idx __rte_unused)
{
	return 0; /* UIO's not applicable */
}
#endif