drm/nouveau/fault/tu102: switch to explicit intr handlers

- reads vectors from HW, rather than being hardcoded
- removes hacks to support routing via old interfaces

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fault: switch non-replayable faults to nvkm_event_ntfy

v2: fix flush_work() being called uninitialised during init

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fault: switch to instanced constructor

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fault: Add support for GP10B

There is no BAR2 on GP10B and there is no need to map through BAR2
because all memory is shared between the GPU and the CPU. Add a custom
implementation of the fault sub-device that uses nvkm_memory_addr()
instead of nvkm_memory_bar2() to return the address of a pinned fault
buffer.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/fault/gp100: expose MaxwellFaultBufferA

This nvclass exposes the replayable fault buffer, which will be used
by SVM to manage GPU page faults.

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

drm/nouveau/fault/tu104: initial support

New registers.

Currently uncertain how exactly to mask fault buffer interrupts. This will
likely be corrected at around the same time as the new MC interrupt stuff
has been properly figured out and implemented.

For the moment, it shouldn't matter too much.

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

drm/nouveau/fault: add explicit control over fault buffer interrupts

The GPU will continually fire interrupts while a fault buffer GET != PUT,
and to stop the spurious interrupts while the handler does its thing, we
were disabling the fault buffer temporarily.

This is not actually a great idea to begin with, and made worse by Volta
resetting GET/PUT when it's reactivated. So, let's not do that.

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

drm/nouveau/fault: store get/put pri address in nvkm_fault_buffer

Will allow more shared fault buffer handling code between Pascal/Volta.

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

drm/nouveau/fault: remove manual mapping of fault buffers into BAR2

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

drm/nouveau/fault/gv100: fix fault buffer initialisation

Not sure how this happened, it worked last time I tested it!

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

drm/nouveau/fault: add infrastructure to support fault buffers

GPU-specific support will be added separately.

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