drm/i915: split out uncore_mmio_debug

Multiple uncore structures will share the debug infrastructure, so
move it to a common place and add extra locking around it.
Also, since we now have a separate object, it is cleaner to have
dedicated functions working on the object to stop and restart the
mmio debug. Apart from the cosmetic changes, this patch introduces
2 functional updates:

- All calls to check_for_unclaimed_mmio will now return false when
  the debug is suspended, not just the ones that are active only when
  i915_modparams.mmio_debug is set. If we don't trust the result of the
  check while a user is doing mmio access then we shouldn't attempt the
  check anywhere.

- i915_modparams.mmio_debug is not save/restored anymore around user
  access. The value is now never touched by the kernel while debug is
  disabled so no need for save/restore.

v2: squash mmio_debug patches, restrict mmio_debug lock usage (Chris)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809063116.7527-1-chris@chris-wilson.co.uk

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 71db63c583a9..4397c6f4bb12 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1369,6 +1369,7 @@ struct drm_i915_private {
 	resource_size_t stolen_usable_size;	/* Total size minus reserved ranges */
 
 	struct intel_uncore uncore;
+	struct intel_uncore_mmio_debug mmio_debug;
 
 	struct i915_virtual_gpu vgpu;