PPC floating point in the kernel?

No.

Longer answer:

Software FP: you need to add FP libraries to the kernel. Usually quite big and "slow"... Compared to integer/fixed point math. Hardware FP: the kernel or you will need to keep track on FP registers all the time, since the kernel tries to be lazy about them - only save/restore when needed and only when in use. - Preemptive kernel? (Monta Vista) then you will need to disable/enable preemptions around the floating point code - see linux/Documentation/preempt-locking.txt "RULE #2: CPU state must be protected." Any FP: Portability?

Summary: Don't use it if you find any way to avoid it. For what would you want to use it anyway? Interrupt driver with floating point?

/RogerL