ppc32: panic in map_page() via mpic_alloc()

ppc32: panic in map_page() via mpic_alloc()

[Morton, Jonathan]

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We're trying to bring Linux up on a custom board based on the P2020 SoC.  We've got U-Boot and a devicetree put together, but the kernel is panicing in map_page() due to apparently finding duplicate ioremaps.  This happens quite early - the MPIC seems to be the first real device to be initialised.

I added a printk in map_page() to figure out what is going on, and there don't actually seem to be any genuine duplicates.  The last three calls are setting up the MPIC GREG, CPU and IRQ areas - the IRQ one triggers the panic.  This is presumably well-tested code given the variety of PowerPC platforms supported, so the failure is surprising.

I have already added some code to MPIC to avoid the same panic while setting up the TIMER area, which is within the mapping set up for the GREG area.  This failure is probably related to the same problem.

I've attached gzipped kernel log (extracted from RAM buffer with a BDI debugger), config and devicetree.

Any insight into what is going on, and how to make it work as designed, would be appreciated.

 - Jonathan Morton


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[-- Attachment #2: config.gz --]
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[-- Attachment #3: klog.txt.gz --]
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[-- Attachment #4: p2020.dts.gz --]
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