[SLOF] [PATCH slof] pci: Put non-prefetchable 64bit BARs into 32bit MMIO window

[Laurent Vivier]

On 25/04/2017 12:36, Laurent Vivier wrote:
> On 24/04/2017 05:01, Alexey Kardashevskiy wrote:
>> At the moment 64bit non-prefetchable BARs of devices behind PCI p2p
>> bridge go to a 64bit prefetchable windows which is not correct and
>> causes linux guests to fail to ioremap() such resources.
>>
>> This moves 64bit non-prefetchable BARs 32bit non-prefetchable window.
>>
>> Note that this does not make distinction between P2P and PHB so
>> from now on XHCI BARs will be allocated from 32bit MMIO space.
>> However since most 64bit-MMIO-capable devices have prefetchable BARs,
>> and XHCI BAR is just 4K (so it is unlikely to cause any space problems),
>> this should not affect usual behavior.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>> ---
>>
>> This fixes QEMU's XHCI when it is put on a P2P PCI bridge.
>>
>> There is a little naming confusion as it may look like the patch
>> is changing assignment for all 64bit BAR but it does not as:
>> - "mmio" is used for non-prefetchable memory,
>> - "mem" is used for prefetchable memory.
>> ---
>>  slof/fs/pci-properties.fs | 6 +-----
>>  1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/slof/fs/pci-properties.fs b/slof/fs/pci-properties.fs
>> index e6fd843..8594e5d 100644
>> --- a/slof/fs/pci-properties.fs
>> +++ b/slof/fs/pci-properties.fs
>> @@ -166,11 +166,7 @@
>>  \ Setup a non-prefetchable 64bit BAR and return its size
>>  : assign-mmio64-bar ( bar-addr -- 8 )
>>          dup pci-bar-size-mem64          \ fetch size
>> -        pci-next-mem64 @ 0 = IF          \ Check if we have 64-bit memory range
>> -	    pci-next-mmio
>> -	ELSE
>> -	    pci-next-mem64              \ for board-qemu we will use same range
>> -	THEN
>> +        pci-next-mmio
>>          assign-bar-value64              \ and set it all
>>  ;
>>  
>>
> Tested-by: Laurent Vivier <lvivier at redhat.com>

This fixes the problem when the BAR is mem, not when it is io.

I have the same problem as with XHCI as with virtio-blk devices behind a
pci bridge, and the error is:

...
PCI: Cannot allocate resource region 0 of device 0000:01:01.0, will remap
...
virtio-pci 0000:01:01.0: can't enable device: BAR 0 [io  size 0x0040]
not assigned
...

And this patch doesn't fix it.

XHCI error was:

PCI: Cannot allocate resource region 0 of device 0000:01:03.0, will remap
...
xhci_hcd 0000:01:03.0: can't enable device: BAR 0 [mem size 0x00004000]
not assigned

Laurent