Use common fdt_intr_to_rl() function, enhance that to handle interrupt-extended properties, remove duplicated code.

[• ian]

Summary

We have multiple nearly-identical copies of code to walk through a node's interrupts=<...> property creating resource list entries. This change makes fdt_intr_to_rl() the one true copy of that code and removes the copies of it from other places.

This also adds handling of the interrupts-extended property, which allows specifying multiple interrupts for a node where each interrupt can have a separate interrupt-parent. The bindings for this state that the property cells contain an xref phandle to the interrupt parent followed by whatever interrupt info that parent normally expects. This leads to having a variable number of icells per interrupt in the property. For example you could have <&intc1 1 &intc2 26 9 0 &intc3 9 4>.

Test Plan

Compile-tested. Run-tested on wandboard only right now.

[• ian]

Cleans up a few unused variable warnings, and fixes the WII build by including dev/fdt/fdt_common.c for both fdt and aim options/devices.

[nwhitehorn]

This will probably break all non-FDT Open Firmware platforms, which do not include anything in sys/dev/fdt into their kernels. It's possible that the change to conf/files.powerpc fixes it, but it highlights a more general issue: there is nothing whatever FDT-specific about the code. Could you move the function into dev/ofw/ofw_bus_subr.c? That's where these things belong.

A minor comment on the algorithm: I think all of the OF_searchencprop() calls are bogus and should be OF_getencprop(), at least per the spec. Are you aware of any boards that require OF_searchencprop()? The code itself otherwise looks fine.

[• ian]

You helped me add that OF_searchencprop() stuff a few months ago because I was tripping over malformed data on some platform, I forget which one.

[nwhitehorn]

Right! Then we should keep that.

[• ian]

Closed by commit rS272109 (authored by @ian).