PowerPC 40x Processor Support To Be Dropped From The Linux Kernel

In addition to Linux 6.10 expected to drop support for very old DEC Alpha processors (EV5 and earlier), it looks like the PowerPC 40x (early PowerPC 400 series) processor and platform support will be retired too.

Back in 2020 was a proposal for dropping PowerPC 40x support from the Linux kernel given that the code was orphaned for a long time with no apparent users. The PowerPC 40x processors were found in thin clients, set-top boxes, and other devices during the 90's. Finally now it looks like that the PowerPC 40x removal is set to happen.

Michael Ellerman sent out the patch series today for removing the 40x processor support. This removes the PowerPC 401/403/405 support while leaving the PowerPC 440 and later processor support. Ellerman explained in the patch series:

"The 40x platforms & CPUs are old and have been unmaintained for years, and as far as we can tell have no users.

Note 44x and 476 are not affected.
...
So unless anyone steps up to maintain it, remove 40x as unused. RIP."

Dropping this early PowerPC code from the Linux kernel clears out 4.4k lines of old and unmaintained code. We'll see if these patches get queued in time for the upcoming Linux v6.10 merge window.