[PATCH v4] bus: fix inconsistent representation of PCI numbers

[Shani Peretz]

> -----Original Message-----
> From: Stephen Hemminger <stephen at networkplumber.org>
> Sent: Wednesday, 29 January 2025 18:25
> To: Shani Peretz <shperetz at nvidia.com>
> Cc: dev at dpdk.org; NBU-Contact-Thomas Monjalon (EXTERNAL)
> <thomas at monjalon.net>; Tyler Retzlaff <roretzla at linux.microsoft.com>; Parav
> Pandit <parav at nvidia.com>; Xueming Li <xuemingl at nvidia.com>; Nipun Gupta
> <nipun.gupta at amd.com>; Nikhil Agarwal <nikhil.agarwal at amd.com>; Hemant
> Agrawal <hemant.agrawal at nxp.com>; Sachin Saxena
> <sachin.saxena at nxp.com>; Rosen Xu <rosen.xu at intel.com>; Chenbo Xia
> <chenbox at nvidia.com>; Tomasz Duszynski <tduszynski at marvell.com>;
> Chengwen Feng <fengchengwen at huawei.com>; NBU-Contact-longli
> (EXTERNAL) <longli at microsoft.com>; Wei Hu <weh at microsoft.com>; Bruce
> Richardson <bruce.richardson at intel.com>; Kevin Laatz
> <kevin.laatz at intel.com>; Jan Blunck <jblunck at infradead.org>
> Subject: Re: [PATCH v4] bus: fix inconsistent representation of PCI numbers
> 
> External email: Use caution opening links or attachments
> 
> 
> On Wed, 29 Jan 2025 10:54:16 +0200
> Shani Peretz <shperetz at nvidia.com> wrote:
> 
> > +create_pci_dev(const char *name)
> > +{
> > +     int port_id;
> > +     uint8_t slave_mac1[] = {0x00, 0xFF, 0x00, 0xFF, 0x00, 0x00 };
> > +     struct rte_ether_addr *mac_addr = (struct rte_ether_addr
> > +*)slave_mac1;
> 
> Use different initializer and you can avoid the need for cast here.
> 
> 
> >
> > +/**
> > + * General device name comparison. Will compare by using the specific
> > +bus
> > + * compare function or by comparing the names directly.
> > + *
> > + * @param dev
> > + *   Device handle.
> > + * @param name
> > + *   Name to compare against.
> > + * @return
> > + *   0 if the device matches the name. Nonzero otherwise.
> > + */
> > +__rte_internal
> > +int rte_cmp_dev_name(const struct rte_device *dev, const void *name);
> 
> It would make more sense to me if name was a character not void pointer.
> 
> The design might be clearer if bus address was more of an typedef with a
> pointer and size together. Treat it more like an object.


Okay so just to understand,
this is the struct I am adding:

	struct rte_bus_address {
	       const void *addr;
	       size_t size;
	};

This is how I pass it to find_device:
	
	struct rte_bus_address dev_addr = {
	          .addr = da->name,
	          .size = RTE_DEV_NAME_MAX_LEN
	};
	dev = da->bus->find_device(NULL, rte_cmp_dev_name, &dev_addr);

And this is how I use it in rte_cmp_dev_name:

	rte_cmp_dev_name(const struct rte_device *dev1, const void *addr)
	 {
	       const struct rte_bus_address *dev2_addr = addr;
	…
	}

Is that what you meant? 
Also, I'm not sure if the size is really needed, because we check the size of the parsed name, which may be different than the size of the original name