drm/i915: Lift acquiring the vlv punit magic to a common sb-get

As we now employ a very heavy pm_qos around the punit access, we want to
minimise the number of synchronous requests by performing one for the
whole punit sequence rather than around individual accesses. The
sideband lock is used for this, so push the pm_qos into the sideband
lock acquisition and release, moving it from the lowlevel punit rw
routine to the callers. In the first step, we move the punit magic into
the common sideband lock so that we can acquire a bunch of ports
simultaneously, and if need be extend the workaround protection later.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426081725.31217-2-chris@chris-wilson.co.uk

1 files changed, 29 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index fc8913461622..b2fc605e2e29 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -73,6 +73,22 @@ static void __vlv_punit_put(struct drm_i915_private *i915)
 	iosf_mbi_punit_release();
 }
 
+void vlv_iosf_sb_get(struct drm_i915_private *i915, unsigned long ports)
+{
+	if (ports & BIT(VLV_IOSF_SB_PUNIT))
+		__vlv_punit_get(i915);
+
+	mutex_lock(&i915->sb_lock);
+}
+
+void vlv_iosf_sb_put(struct drm_i915_private *i915, unsigned long ports)
+{
+	mutex_unlock(&i915->sb_lock);
+
+	if (ports & BIT(VLV_IOSF_SB_PUNIT))
+		__vlv_punit_put(i915);
+}
+
 static int vlv_sideband_rw(struct drm_i915_private *i915,
 			   u32 devfn, u32 port, u32 opcode,
 			   u32 addr, u32 *val)
@@ -82,6 +98,8 @@ static int vlv_sideband_rw(struct drm_i915_private *i915,
 	int err;
 
 	lockdep_assert_held(&i915->sb_lock);
+	if (port == IOSF_PORT_PUNIT)
+		iosf_mbi_assert_punit_acquired();
 
 	/* Flush the previous comms, just in case it failed last time. */
 	if (intel_wait_for_register(uncore,
@@ -125,16 +143,14 @@ u32 vlv_punit_read(struct drm_i915_private *i915, u32 addr)
 {
 	u32 val = 0;
 
-	WARN_ON(!mutex_is_locked(&i915->pcu_lock));
+	lockdep_assert_held(&i915->pcu_lock);
 
-	mutex_lock(&i915->sb_lock);
-	__vlv_punit_get(i915);
+	vlv_punit_get(i915);
 
 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
 			SB_CRRDDA_NP, addr, &val);
 
-	__vlv_punit_put(i915);
-	mutex_unlock(&i915->sb_lock);
+	vlv_punit_put(i915);
 
 	return val;
 }
@@ -143,16 +159,14 @@ int vlv_punit_write(struct drm_i915_private *i915, u32 addr, u32 val)
 {
 	int err;
 
-	WARN_ON(!mutex_is_locked(&i915->pcu_lock));
+	lockdep_assert_held(&i915->pcu_lock);
 
-	mutex_lock(&i915->sb_lock);
-	__vlv_punit_get(i915);
+	vlv_punit_get(i915);
 
 	err = vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
 			      SB_CRWRDA_NP, addr, &val);
 
-	__vlv_punit_put(i915);
-	mutex_unlock(&i915->sb_lock);
+	vlv_punit_put(i915);
 
 	return err;
 }
@@ -177,12 +191,10 @@ u32 vlv_nc_read(struct drm_i915_private *i915, u8 addr)
 {
 	u32 val = 0;
 
-	WARN_ON(!mutex_is_locked(&i915->pcu_lock));
-
-	mutex_lock(&i915->sb_lock);
+	vlv_nc_get(i915);
 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_NC,
 			SB_CRRDDA_NP, addr, &val);
-	mutex_unlock(&i915->sb_lock);
+	vlv_nc_put(i915);
 
 	return val;
 }
@@ -281,7 +293,8 @@ u32 intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg,
 		   enum intel_sbi_destination destination)
 {
 	u32 value = 0;
-	WARN_ON(!mutex_is_locked(&dev_priv->sb_lock));
+
+	lockdep_assert_held(&dev_priv->sb_lock);
 
 	if (intel_wait_for_register(&dev_priv->uncore,
 				    SBI_CTL_STAT, SBI_BUSY, 0,
@@ -321,7 +334,7 @@ void intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value,
 {
 	u32 tmp;
 
-	WARN_ON(!mutex_is_locked(&dev_priv->sb_lock));
+	lockdep_assert_held(&dev_priv->sb_lock);
 
 	if (intel_wait_for_register(&dev_priv->uncore,
 				    SBI_CTL_STAT, SBI_BUSY, 0,