On Fri, Dec 18, 2015 at 06:56:39PM +0000, okaya@codeaurora.org wrote:
[...]
Here is what I have as an IO resource.
QWORDIO( //Consumed-And-produced resource ResourceProducer, // bit 0 of general flags is 0 MinFixed, // Range is fixed MaxFixed, // Range is fixed PosDecode, EntireRange, 0x0000, // Granularity 0x1000, // Min, 0 is not accepted 0x10FFF, // Max 0x8FFFFFEF000, // Translation 0x10000, // Range Length ,, PI00 )I don't have any type specified.
I agree with Lorenzo's assessment. The min and max values represent the PCI IO bus addresses. The translation offset is added to these values to figure out the CPU view of the PCI IO range.
The endpoints BAR addresses are programmed with IO addresses ranging between 0x1000 and 0x10FFF for this example above.
Here is another question. Chris Covington and I asked this question on a private email to you but we didn't hear back.
We were referring to a Linaro IO hack patch as we were not sure whether this was a limitation of the hack or a general expectation for ARM64 PCI in general.
I'll repeat it here.
I have multiple root ports with the same IO port configuration in the current ACPI table.
Root port 0 = IO range 0x1000-0x10FFF Root port 1 = IO range 0x1000-0x10FFF Root port 2 = IO range 0x1000-0x10FFF
It is fine. You end up mapping for each of those a 4k window of the virtual address space allocated to IO and that's what you will have in the kernel PCI resources (not in the HW BARs though). If that was a problem it would be even for the current DT host controllers eg:
arch/arm64/boot/dts/apm/apm-storm.dtsi
it should not be (again I will let Arnd comment on this since he may be aware of issues encountered on other arches/platforms).
Lorenzo
Each root port can have the same IO address range configuration, are we expecting IO port numbers to be unique across the whole system for ARM64?
Something like
Root port 0 = IO range 0x1000-0x10FFF Root port 1 = IO range 0x11000-0x20FFF Root port 2 = IO range 0x21000-0x30FFF
since the IO addresses are being remapped into PCI IO range printed during boot.
PCI I/O : 0xffff7ffffae00000 - 0xffff7ffffbe00000 ( 16 MB)
and each root port would remap to 64k of the 16MB range.
Any comments are very appreciated!
Tomasz
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