Re: PCIe issue with NIC card that has 64bit BARs

[Murali Karicheri <m-karicheri2@ti.com>]

On 05/09/2016 05:23 PM, Alex Williamson wrote:
> On Mon, 9 May 2016 17:02:23 -0400
> Murali Karicheri <m-karicheri2@ti.com> wrote:
> 
>> Hi Bjorn,
>>
>> Thanks for your quick response!
>> See below for some follow up question.
>>
>> On 05/09/2016 04:34 PM, Bjorn Helgaas wrote:
>>> Hi Murali,
>>>
>>> On Mon, May 09, 2016 at 03:32:42PM -0400, Murali Karicheri wrote:  
>>>> Bjorn,
>>>>
>>>> I am running into an issue with using a rtk8168 GiB NIC card with Keystone PCIe.
>>>> It works for 32bit BARs such as the Marvel SATA controller on K2E. On another
>>>> recent SoC (K2G) that re-uses the same driver and hardware, I have issues
>>>> bringing up PCIe.
>>>>
>>>> The rtk8168 NIC gets detected, but all read values are zeros. Based on the boot
>>>> log, it appears to be getting assigned 64bit BARs. See the log on K2E with Marvell
>>>> controller and that on K2G with rtk8168. Is there way we can get it assigned
>>>> 32Bit BAR and get it functional? Keystone is a 32bit ARM A15 SoC.
>>>>
>>>> Here are the logs.
>>>>
>>>> K2E log with Marvel controller (Good working case).
>>>> ===================================================
>>>> [    0.236353] pci 0000:00:00.0: BAR 8: assigned [mem 0x60000000-0x600fffff]
>>>> [    0.236364] pci 0000:00:00.0: BAR 9: assigned [mem 0x60100000-0x601fffff pref]
>>>> [    0.236373] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
>>>> [    0.236385] pci 0000:01:00.0: BAR 6: assigned [mem 0x60100000-0x6010ffff pref]
>>>> [    0.236394] pci 0000:01:00.0: BAR 5: assigned [mem 0x60000000-0x600001ff]
>>>> [    0.236406] pci 0000:01:00.0: BAR 4: assigned [io  0x1000-0x100f]
>>>> [    0.236418] pci 0000:01:00.0: BAR 0: assigned [io  0x1010-0x1017]
>>>> [    0.236429] pci 0000:01:00.0: BAR 2: assigned [io  0x1018-0x101f]
>>>> [    0.236441] pci 0000:01:00.0: BAR 1: assigned [io  0x1020-0x1023]
>>>> [    0.236452] pci 0000:01:00.0: BAR 3: assigned [io  0x1024-0x1027]
>>>> [    0.236464] pci 0000:00:00.0: PCI bridge to [bus 01]
>>>> [    0.236472] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
>>>> [    0.236481] pci 0000:00:00.0:   bridge window [mem 0x60000000-0x600fffff]
>>>> [    0.236490] pci 0000:00:00.0:   bridge window [mem 0x60100000-0x601fffff pref]
>>>>
>>>> K2G log with Tealtek NIC card
>>>> =============================
>>>> [    2.311572] keystone-pcie 21801000.pcie: PCI host bridge to bus 0000:00
>>>> [    2.318188] pci_bus 0000:00: root bus resource [bus 00-ff]
>>>> [    2.323844] pci_bus 0000:00: root bus resource [io  0x0000-0x3fff]
>>>> [    2.330023] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff]  
>>>
>>> There's no "(bus address ...)" annotation here, which means these
>>> windows map CPU addresses to identical bus addresses.  The
>>> "[mem 0x50000000-0x5fffffff]" window is a 32-bit window.
>>>   
>>>> [    2.337567] PCI: bus0: Fast back to back transfers disabled
>>>> [    2.361159] PCI: bus1: Fast back to back transfers disabled
>>>> [    2.366889] pci 0000:00:00.0: BAR 8: assigned [mem 0x50000000-0x500fffff]
>>>> [    2.373841] pci 0000:00:00.0: BAR 9: assigned [mem 0x50100000-0x501fffff pref]
>>>> [    2.381061] pci 0000:00:00.0: BAR 7: assigned [io  0x1000-0x1fff]
>>>> [    2.387225] pci 0000:01:00.0: BAR 6: assigned [mem 0x50100000-0x5011ffff pref]
>>>> [    2.394505] pci 0000:01:00.0: BAR 4: assigned [mem 0x50120000-0x5012ffff 64bit pref]
>>>> [    2.402288] pci 0000:01:00.0: BAR 2: assigned [mem 0x50000000-0x50000fff 64bit]  
>>>
>>> I assume these BARs (2 and 4) are the ones in question.  They are
>>> 64-bit BARs, but the addresses currently assigned to them fit in 32
>>> bits, so the space is already all below 4GB.
>>>
>>> The BAR type (32-bit or 64-bit) is built into the device; Linux
>>> doesn't have any influence on that.  The type is encoded in the
>>> low-order four bits of the BAR, which are read-only.
>>>   
>>>> [    2.409610] pci 0000:01:00.0: BAR 0: assigned [io  0x1000-0x10ff]
>>>> [    2.415729] pci 0000:00:00.0: PCI bridge to [bus 01]
>>>> [    2.420693] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
>>>> [    2.426806] pci 0000:00:00.0:   bridge window [mem 0x50000000-0x500fffff]
>>>> [    2.433610] pci 0000:00:00.0:   bridge window [mem 0x50100000-0x501fffff pref]
>>>> [    2.441365] pcieport 0000:00:00.0: Signaling PME through PCIe PME interrupt
>>>> [    2.448323] pci 0000:01:00.0: Signaling PME through PCIe PME interrupt
>>>> [    2.455567] r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
>>>> [    2.461332] r8169 0000:01:00.0: enabling device (0140 -> 0143)
>>>> [    2.468789] r8169 0000:01:00.0 eth0: RTL8169 at 0xf0d6a000, 00:00:00:00:00:00, XID 00000000 IRQ 286  
>>>
>>> Looks like this is printed by rtl_init_one().  I see that we read
>>> zeroes from MAC0 and TxConfig, but I don't see any PCI problem here.  
>> So if device specific configuration registers for this device are mapped
>> to the window to have 64bit access, they are to be accessed with proper
>> address to get the lower 32 bits of the data, right? So is there a chance
>> it is making access to upper 4 bytes and hence reading all zeros?
>>  
>>> Could it be that some EEPROM on the card hasn't been programmed yet?
>>> Does the card work if you put it in a different machine?
>>>   
>> Probably. I will ask this to the owner of r8169 driver. He seems to think
>> the access is not right.  I need to find a PC that has PCIe slot to do this
>> test. Meanwhile do you know of any 1GiB NIC card that has 32bit BARs and
>> driver in Linux? 
> 
> I happen to have an Intel 82571EB (PRO/1000 PT Dual Port Server
> Adapter) that only has 32bit BARs:
> 
> 02:00.0 Ethernet controller [0200]: Intel Corporation 82571EB Gigabit Ethernet Controller [8086:105e] (rev 06)
> 	Region 0: Memory at fe7e0000 (32-bit, non-prefetchable) [size=128K]
> 	Region 1: Memory at fe7c0000 (32-bit, non-prefetchable) [size=128K]
> 	Region 2: I/O ports at e800 [size=32]
> 02:00.1 Ethernet controller [0200]: Intel Corporation 82571EB Gigabit Ethernet Controller [8086:105e] (rev 06)
> 	Region 0: Memory at fe7a0000 (32-bit, non-prefetchable) [size=128K]
> 	Region 1: Memory at fe780000 (32-bit, non-prefetchable) [size=128K]
> 	Region 2: I/O ports at e400 [size=32]
Alex,

Thanks for the response. I see following mini pci card which match with your
description.

http://www.amazon.com/Intel-1000-Dual-Server-Adapter/dp/B000BMZHX2/ref=sr_1_1?ie=UTF8&qid=1462829688&sr=8-1&keywords=intel+expi9402pt

Is this same thing? I assume e1000e/82571.c is the driver for this.
Could you please confirm so that I can procure the same?

Murali
> 
> Thanks,
> Alex
> 


-- 
Murali Karicheri
Linux Kernel, Keystone