drm/nouveau/nvkm: Replace -ENOSYS with -ENODEV

nvkm test builds fail with the following error.

drivers/gpu/drm/nouveau/nvkm/engine/device/ctrl.c: In function 'nvkm_control_mthd_pstate_info':
drivers/gpu/drm/nouveau/nvkm/engine/device/ctrl.c:60:35: error: overflow in conversion from 'int' to '__s8' {aka 'signed char'} changes value from '-251' to '5'

The code builds on most architectures, but fails on parisc where ENOSYS
is defined as 251.

Replace the error code with -ENODEV (-19). The actual error code does
not really matter and is not passed to userspace - it just has to be
negative.

Fixes: 7238eca4cf18 ("drm/nouveau: expose pstate selection per-power source in sysfs")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/nouveau/nvif: modify nvif_unvers/nvif_unpack macros to be more obvious

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

drm/nouveau/nvif: split out device control interface definitions

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

drm/nouveau/nvif: move internal class identifiers to class.h

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

drm/nouveau/clk: convert to new-style nvkm_subdev

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

drm/nouveau/device: convert ctrl class to new-style nvkm_object

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

drm/nouveau/object: rename some functions to avoid upcoming conflicts

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

drm/nouveau/core: remove last printks

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

drm/nouveau/device: namespace + nvidia gpu names (no binary change)

The namespace of NVKM is being changed to nvkm_ instead of nouveau_,
which will be used for the DRM part of the driver. This is being
done in order to make it very clear as to what part of the driver a
given symbol belongs to, and as a minor step towards splitting the
DRM driver out to be able to stand on its own (for virt).

Because there's already a large amount of churn here anyway, this is
as good a time as any to also switch to NVIDIA's device and chipset
naming to ease collaboration with them.

A comparison of objdump disassemblies proves no code changes.

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

drm/nouveau/clk: rename from clock (no binary change)

Rename to match the Linux subsystem responsible for the same kind of
things. Will be investigating how feasible it will be to expose the
GPU clock trees with it at some point.

The namespace of NVKM is being changed to nvkm_ instead of nouveau_,
which will be used for the DRM part of the driver. This is being
done in order to make it very clear as to what part of the driver a
given symbol belongs to, and as a minor step towards splitting the
DRM driver out to be able to stand on its own (for virt).

Because there's already a large amount of churn here anyway, this is
as good a time as any to also switch to NVIDIA's device and chipset
naming to ease collaboration with them.

A comparison of objdump disassemblies proves no code changes.

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

drm/nouveau: remove symlinks, move core/ to nvkm/ (no code changes)

The symlinks were annoying some people, and they're not used anywhere
else in the kernel tree. The include directory structure has been
changed so that symlinks aren't needed anymore.

NVKM has been moved from core/ to nvkm/ to make it more obvious as to
what the directory is for, and as some minor prep for when NVKM gets
split out into its own module (virt) at a later date.

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