On 21.04.2016 11:36, Arnd Bergmann wrote:
On Thursday 21 April 2016 11:28:15 Tomasz Nowicki wrote:
On 19.04.2016 15:06, Arnd Bergmann wrote:
On Monday 18 April 2016 21:31:54 Tomasz Nowicki wrote:
Basically the whole content of pci-thunder-ecam.c and pci-thunder-pem.c.
pci-thunder-ecam.c contains config space accessors. Similar for
pci-thunder-pem.c but it also has extra init call (it is now called
thunder_pem_init) which finds and maps related registers.
They seem to do much more than just override the accessors, they actually
change the contents of the config space as well. Is that really necessary
on ACPI based systems as well?
Yes, the pci-thunder-ecam.c accessors are meant to emulate config space
capabilities. They are necessary to synthesize EA capabilities (fixed
PCI BARs), it wont work without this, for ACPI boot as well.
Why is that? I thought the BARs never get reassigned when using ACPI,
so I'm surprised it's actually needed. Maybe I misunderstood what
you mean by fixed PCI BARs.
Yes, I meant something else. ThunderX has non-programmable PCI BAR
addresses. So it uses PCI EA (Extended allocation) capabilities to get
know PCI BARs addresses. But the early implementation (pass1.x) misses
EA capabilities hence we need to emulate it in config space accessors.
Tomasz
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