Re: [PATCH v6 01/53] sparc/PCI: Add mem64 resource parsing for root bus

From: Khalid Aziz
Date: Fri Oct 02 2015 - 19:06:19 EST


On 10/02/2015 04:05 PM, Yinghai Lu wrote:
On Fri, Oct 2, 2015 at 1:00 PM, Khalid Aziz <khalid.aziz@xxxxxxxxxx> wrote:
On Wed, 2015-09-30 at 22:52 -0700, Yinghai Lu wrote:
Found "no compatible bridge window" warning in boot log from T5-8.

pci 0000:00:01.0: can't claim BAR 15 [mem 0x100000000-0x4afffffff pref]: no compatible bridge window

That resource is above 4G, but does not get offset correctly as
root bus only report io and mem32.

pci_sun4v f02dbcfc: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x804000000000-0x80400fffffff] (bus address [0x0000-0xfffffff])
pci_bus 0000:00: root bus resource [mem 0x800000000000-0x80007effffff] (bus address [0x00000000-0x7effffff])
pci_bus 0000:00: root bus resource [bus 00-77]

Add mem64 handling in pci_common for sparc, so we can have 64bit resource
registered for root bus at first.

After patch, will have:
pci_sun4v f02dbcfc: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x804000000000-0x80400fffffff] (bus address [0x0000-0xfffffff])
pci_bus 0000:00: root bus resource [mem 0x800000000000-0x80007effffff] (bus address [0x00000000-0x7effffff])
pci_bus 0000:00: root bus resource [mem 0x800100000000-0x8007ffffffff] (bus address [0x100000000-0x7ffffffff])
pci_bus 0000:00: root bus resource [bus 00-77]

-v2: mem64_space should use mem_space.start as offset.
-v3: add IORESOURCE_MEM_64 flag
...
PCI: Scanning PBM /pci@301
pci_sun4v f0339c2c: PCI host bridge to bus 0009:00
pci_bus 0009:00: root bus resource [io 0x2027e40000000-0x2027e4fffffff] (bus address [0x0000-0xfffffff])
pci_bus 0009:00: root bus resource [mem 0x2024000100000-0x202407effffff] (bus address [0x00000000-0x7eefffff])
pci_bus 0009:00: root bus resource [mem 0x2024100000000-0x2024dffffffff] (bus address [0xfff00000-0xdffefffff])

Looks like offset for mmio64 is not right.

Please check attached patch on the this platform and T5-8.

Good catch! That code change looks like the right thing to do and it fixed my issues with ixgbe not attaching. I still see lots of "no compatible bridge window" messages but overlapping address ranges are no longer reserved and as a result drivers are able to ioremap BARs successfully.

I have tested it on a T7 and one other platform where I was seeing problems without mem64 and both platforms work with this patch. I have not been able to get my hands on a T5-8 yet but I will try again on Monday.

Thanks,
Khalid

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