drm/i915: Replace pcu_lock with sb_lock

We now have two locks for sideband access. The general one covering
sideband access across all generation, sb_lock, and a specific one
covering sideband access via the punit on vlv/chv. After lifting the
sb_lock around the punit into the callers, the pcu_lock is now redudant
and can be separated from its other use to regulate RPS (essentially
giving RPS a lock all of its own).

v2: Extract a couple of minor bug fixes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426081725.31217-4-chris@chris-wilson.co.uk

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b2215fb7f562..ca1b35d8faca 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -648,6 +648,8 @@ struct intel_rps_ei {
 };
 
 struct intel_rps {
+	struct mutex lock; /* protects enabling and the worker */
+
 	/*
 	 * work, interrupts_enabled and pm_iir are protected by
 	 * dev_priv->irq_lock
@@ -1710,14 +1712,6 @@ struct drm_i915_private {
 	 */
 	u32 edram_size_mb;
 
-	/*
-	 * Protects RPS/RC6 register access and PCU communication.
-	 * Must be taken after struct_mutex if nested. Note that
-	 * this lock may be held for long periods of time when
-	 * talking to hw - so only take it when talking to hw!
-	 */
-	struct mutex pcu_lock;
-
 	/* gen6+ GT PM state */
 	struct intel_gen6_power_mgmt gt_pm;