Re: lspci: Display path to device

[Logan Gunthorpe]

On 17/07/18 02:39 PM, Matthew Wilcox wrote:
> On Tue, Jul 17, 2018 at 11:02:00AM -0600, Logan Gunthorpe wrote:
>> The second patch expands the new helper to optionally take a path of
>> PCI devfns. This is to address Alex's renumbering concern when using
>> simple bus-devfns. The implementation is essentially how he described it and
>> similar to the Intel VT-d spec (Section 8.3.1).
> 
> I don't like telling the user to grovel around lspci -t by hand.  It's
> not many lines of code to add a new -P option to lspci to show the path
> to each device instead of bus:dev.fn

Thanks, this looks great! I also found parsing the lspci -t output
cumbersome.

I've also got patches pending for switchtec-user[1] that help users find
the path of downstream ports for Microsemi switches. (An example is
shown below). As the ACS feature is primarily for PCI switch users, this
should help a good segment of people. The lspci patches should cover a
lot more people though.

Logan

sudo switchtec status /dev/switchtec0 -v
Partition 0:    (LOCAL)
    Logical Port ID 0 (USP):
	Phys Port ID:    	32 (Stack 4, Port 0)
	Bus-Dev-Func:    	0000:02:00.0
	Bus-Dev-Func Path:	0000:00:02:0/00.0
	Status:          	UP
	LTSSM:           	L0
	Max-Width:       	x16
	Neg Width:       	x16
	Rate:            	Gen3 - 8 GT/s  15.76 GB/s
	Out Bytes:       	70.3 GB
	In Bytes:        	70.8 GB
    Logical Port ID 1 (DSP):
	Phys Port ID:    	8 (Stack 1, Port 0)
	Bus-Dev-Func:    	0000:03:00.0
	Bus-Dev-Func Path:	0000:00:02:0/00.0/00.0
	Status:          	UP
	LTSSM:           	L0
	Max-Width:       	x8
	Neg Width:       	x8
	Rate:            	Gen3 - 8 GT/s  7.88 GB/s
	Out Bytes:       	12.2 MB
	In Bytes:        	441 MB
	ACS:             	SrcValid- TransBlk- ReqRedir- CmpltRedir-
UpstreamFwd- EgressCtrl- DirectTrans-
	Device:          	10b5:8724 (0000:04:00.0)
	                 	0000:05
    Logical Port ID 2 (DSP):
	Phys Port ID:    	12 (Stack 1, Port 4)
	Bus-Dev-Func:    	0000:03:01.0
	Bus-Dev-Func Path:	0000:00:02:0/00.0/01.0
	Status:          	UP
	LTSSM:           	L0
	Max-Width:       	x8
	Neg Width:       	x8
	Rate:            	Gen3 - 8 GT/s  7.88 GB/s
	Out Bytes:       	1.65 MB
	In Bytes:        	107 MB
	ACS:             	SrcValid- TransBlk- ReqRedir- CmpltRedir-
UpstreamFwd- EgressCtrl- DirectTrans-
	Device:          	11f8:f117 (0000:0b:00.0)
	                 	nvme4




[1] https://github.com/Microsemi/switchtec-user/pull/25