Re: [dpdk-dev] [PATCH 2/3] eal: PCI domain should be 32 bits

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 23 Jun 2017 00:41:43 +0000
"Chang, Cunyin" <cunyin.chang@intel.com> wrote:

> > -----Original Message-----
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Thursday, June 22, 2017 11:52 PM
> > To: Chang, Cunyin <cunyin.chang@intel.com>
> > Cc: dev@dpdk.org; Stephen Hemminger <sthemmin@microsoft.com>
> > Subject: Re: [dpdk-dev] [PATCH 2/3] eal: PCI domain should be 32 bits
> > 
> > On Thu, 22 Jun 2017 09:28:31 +0000
> > "Chang, Cunyin" <cunyin.chang@intel.com> wrote:
> >   
> > > I think the series patches does not cover all area which need to adapt
> > > to u32 PCI domain, We still need some other work to do:
> > > we need define another macro such as PCI_PRI_FMT. Something like:
> > > #define PCI_XXX_PRI_FMT "%.5" PRIx32 ":%.2" PRIx8 ":%.2" PRIx8 ".%"
> > > PRIx8
> > >
> > > PCI_PRI_STR_SIZE also need to be modified:
> > > #define PCI_PRI_STR_SIZE sizeof("XXXXX:XX:XX.X")
> > >
> > > The macro PCI_PRI_FMT will not works if The domain exceed 16bits. It
> > > will impact the following functions:
> > > 1  RTE_LOG function, there a lots of RTE_LOG such as:
> > > RTE_LOG(WARNING, EAL,
> > > 			"Requested device " PCI_PRI_FMT " cannot be  
> > used\n",  
> > > 			addr->domain, addr->bus, addr->devid, addr-
> > >function);
> > > 2  pci_dump_one_device().
> > > 3 rte_eal_pci_device_name()
> > > 4 pci_update_device()
> > > 5 pci_ioport_map()
> > > 6 pci_get_uio_dev()
> > > 7 pci_uio_map_resource_by_index()
> > > 8 pci_uio_ioport_map()
> > > 9 pci_vfio_map_resource()
> > > 10 pci_vfio_unmap_resource()
> > > All the above functions will related with the macro PCI_PRI_FMT, so I think  
> > they need to be modified too.  
> > >
> > > There are some other code need modify:
> > > In function rte_eal_compare_pci_addr(), we need do the following work:
> > > dev_addr = ((uint64_t)addr->domain << 24) | ((uint64_t)addr->bus << 16) |
> > > 				((uint64_t)addr->devid << 8) |  
> > (uint64_t)addr->function;  
> > > dev_addr2 = ((uint64_t)addr2->domain << 24) | ((uint64_t)addr2->bus <<  
> > 16) |  
> > > 				((uint64_t)addr2->devid << 8) |  
> > (uint64_t)addr2->function;  
> > >
> > > In function eal_parse_pci_BDF(), we need do the following work:
> > > GET_PCIADDR_FIELD(input, dev_addr->domain, UINT32_MAX, ':');  
> > 
> > Good catch, the string size must be increased.
> > 
> > It turns out that you don't need to change the PCI print format. Printing the
> > domain with %.4x works correctly with 32 bit. It just gets wider. This is how
> > pciutils works, so no change is necessary there.  
> 
> I suppose we should use %4x, not %.4x?, the %.4x will cut the 10000:05:00.0 as 0000:05:00.0.
> So the macro:
> #define PCI_PRI_FMT "%.4" PRIx32 ":%.2" PRIx8 ":%.2" PRIx8 ".%" PRIx8
> Should be:
> #define PCI_PRI_FMT "%4" PRIx32 ":%.2" PRIx8 ":%.2" PRIx8 ".%" PRIx8
> 
> Make sense?

No, that format would not be correct. I want to keep the visible output the
same for the normal case of 16 bit domains.  Output of printf test program
shows that %.4x is the correct format to use.

Domain            %4x       %.4x      %4.4x
0                   0       0000       0000
0x1                 1       0001       0001
0x1000           1000       1000       1000
0x10000         10000      10000      10000
0x12345678   12345678   12345678   12345678
0xdeadbeef   deadbeef   deadbeef   deadbeef