On 10/27/2015 02:54 PM, Yinghai Lu wrote:
> Hi,
>
> After 5b28541552ef (PCI: Restrict 64-bit prefetchable bridge windows
> to 64-bit resources), we have several reports on resource allocation
> failure, and we try to fix the problem with resource clip, and find
> more problems.
>
> One is realloc fail with two graphics cards above 4G.
> One is from sparc that have problem with clip as we don't parse
> mem64 for it.
>
> Other report is about pci remove/rescan does not work on some setup
> when BIOS tend to allocate small bus size.
>
> This patchset enhance resource allocation to address those problems.
>
> patch 1-11: parse MEM64 for sparc and other system with OF
> patch 12-16: MMIO64 allocation enhancement
> 	treat non-pref mmio64 if parent bridges are all pcie.
> 	restore old pref allocation logic if hostbridge does not support mmio64.
> patch 17-19: FIXED resource handling during realloc
> 	don't realloc resource if device firmware does not support bar change.
> patch 20-23: bridge MMIO allocation with hotplug and last try.
> 	treat optional as required on first try when hotplug.
> 	MMIO size set to 0 for last try during realloc
> patch 24-57: enhancement for mmio resource allocation:
> 	optimize bus mmio alignment calculation.
> 	optimize bus mmio optional alignment calculation.
> 	add support for alt size to prefer small bus size to small bus alignment.
> 	treat ROM bar as optional resource.
> 	during allocation, will pick up best fit resource, and allocate near end.
> patch 58: add pci=assign_pref_bars to clear and assign pref bars.
> patch 59-60: don't clear resource when allocation fails
> patch 61: don't try io port allocation if root bus does not have io port.
>

Hi Yinghai,

I applied patches 1-8 and 11-16 to 4.3.0-rc7 to test on sparc platforms. 
I am seeing a "can't claim BAR" message on a T4:

pci 0000:04:00.0: can't claim BAR 6 [mem 0x84000000000-0x8400000ffff]: 
address conflict with 0000:04:00.0 [mem 0x84000000000-0x840007fffff]

I have attached boot up log, /proc/iomem, and output from "lspci -tv" 
and "lsspci -vvxxx".

These patches worked fine on a T7 and there were no PCI issues in the log.

Thanks,
Khalid