Anup and I have been working on moving the core CPUPM support from the CPU driver - into the kernel. Our goal is to make the CPU driver specific to polling CPU power management and not have PAD depend on the driver at all. That means moving a fair bit of the i86pc specific CPU power management support (ACPI parsing and caching, speedstep, pwrnow, cstate and tstate handling) into the kernel. This eliminates the need for callback mechanism into the CPU driver. Unfortunately, since acpica is a module, it does require callbacks for that. But those have been centralized into the existing uts/i86pc/os/acpi_stubs.c file.
We've posted a webrev of our effort at: http://cr.opensolaris.org/~mhaywood/cpupm-move/ We'd appreciate any comments. Thanks! Mark
