drm/i915: Support for GuC interrupts

There are certain types of interrupts which Host can receive from GuC.
GuC ukernel sends an interrupt to Host for certain events, like for
example retrieve/consume the logs generated by ukernel.
This patch adds support to receive interrupts from GuC but currently
enables & partially handles only the interrupt sent by GuC ukernel.
Future patches will add support for handling other interrupt types.

v2:
- Use common low level routines for PM IER/IIR programming (Chris)
- Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
- Replace disabling of wake ref asserts with rpm get/put (Chris)

v3:
- Update comments for more clarity. (Tvrtko)
- Remove the masking of GuC interrupt, which was kept masked till the
  start of bottom half, its not really needed as there is only a
  single instance of work item & wq is ordered. (Tvrtko)

v4:
- Rebase.
- Rename guc_events to pm_guc_events so as to be indicative of the
  register/control block it is associated with. (Chris)
- Add handling for back to back log buffer flush interrupts.

v5:
- Move the read & clearing of register, containing Guc2Host message
  bits, outside the irq spinlock. (Tvrtko)

v6:
- Move the log buffer flush interrupt related stuff to the following
  patch so as to do only generic bits in this patch. (Tvrtko)
- Rebase.

v7:
- Remove the interrupts_enabled check from gen9_guc_irq_handler, want to
  process that last interrupt also before disabling the interrupt, sync
  against the work queued by irq handler will be done by caller disabling
  the interrupt.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

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 58d332bda227..72215b7b5b89 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1839,6 +1839,7 @@ struct drm_i915_private {
 	u32 pm_imr;
 	u32 pm_ier;
 	u32 pm_rps_events;
+	u32 pm_guc_events;
 	u32 pipestat_irq_mask[I915_MAX_PIPES];
 
 	struct i915_hotplug hotplug;