Many of the nv50 cards have their shader and/or memory pll
disabled at some stage.
This patch addresses those cases, so that the function
returns the correct frequency.

When the shader pll is disabled, the blob reports 2*core clock
Whereas for memory, the data stored in the vbios. This action
is incorrect as some vbioses store a clock value that is less
than the refference clock of the pll.

Thus we are reporting the reff_clk as it is the frequency the
pll actually operates

v2 - Convert NV_INFO() messages to NV_DEBUG()
Provide more information in the actuall message
Signed-off-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

This will end up quite different, it makes sense for it to be completely
separate.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

On certain boards, there's BIOS scripts and memory timings that need to
be modified with the memclk.  Just pass in the entire perflvl struct and
let the chipset-specific code decide what to do.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Guarded by a module parameter for the moment, read the code for the
magic value which enables it.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

This will make nouveau_pm attempt to report the card's current performance
level both during bootup, and through sysfs.

This is a very initial implementation, and can be improved a *lot*
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>