drm/i915: Markup paired operations on display power domains

The majority of runtime-pm operations are bounded and scoped within a
function; these are easy to verify that the wakeref are handled
correctly. We can employ the compiler to help us, and reduce the number
of wakerefs tracked when debugging, by passing around cookies provided
by the various rpm_get functions to their rpm_put counterpart. This
makes the pairing explicit, and given the required wakeref cookie the
compiler can verify that we pass an initialised value to the rpm_put
(quite handy for double checking error paths).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-16-chris@chris-wilson.co.uk

1 files changed, 45 insertions, 21 deletions

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index d513ca875c67..04870e960537 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -345,9 +345,12 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
 				      struct intel_dpll_hw_state *hw_state)
 {
 	const enum intel_dpll_id id = pll->info->id;
+	intel_wakeref_t wakeref;
 	uint32_t val;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	val = I915_READ(PCH_DPLL(id));
@@ -355,7 +358,7 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
 	hw_state->fp0 = I915_READ(PCH_FP0(id));
 	hw_state->fp1 = I915_READ(PCH_FP1(id));
 
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return val & DPLL_VCO_ENABLE;
 }
@@ -509,15 +512,18 @@ static bool hsw_ddi_wrpll_get_hw_state(struct drm_i915_private *dev_priv,
 				       struct intel_dpll_hw_state *hw_state)
 {
 	const enum intel_dpll_id id = pll->info->id;
+	intel_wakeref_t wakeref;
 	uint32_t val;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	val = I915_READ(WRPLL_CTL(id));
 	hw_state->wrpll = val;
 
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return val & WRPLL_PLL_ENABLE;
 }
@@ -526,15 +532,18 @@ static bool hsw_ddi_spll_get_hw_state(struct drm_i915_private *dev_priv,
 				      struct intel_shared_dpll *pll,
 				      struct intel_dpll_hw_state *hw_state)
 {
+	intel_wakeref_t wakeref;
 	uint32_t val;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	val = I915_READ(SPLL_CTL);
 	hw_state->spll = val;
 
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return val & SPLL_PLL_ENABLE;
 }
@@ -989,9 +998,12 @@ static bool skl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	uint32_t val;
 	const struct skl_dpll_regs *regs = skl_dpll_regs;
 	const enum intel_dpll_id id = pll->info->id;
+	intel_wakeref_t wakeref;
 	bool ret;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	ret = false;
@@ -1011,7 +1023,7 @@ static bool skl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	ret = true;
 
 out:
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return ret;
 }
@@ -1020,12 +1032,15 @@ static bool skl_ddi_dpll0_get_hw_state(struct drm_i915_private *dev_priv,
 				       struct intel_shared_dpll *pll,
 				       struct intel_dpll_hw_state *hw_state)
 {
-	uint32_t val;
 	const struct skl_dpll_regs *regs = skl_dpll_regs;
 	const enum intel_dpll_id id = pll->info->id;
+	intel_wakeref_t wakeref;
+	uint32_t val;
 	bool ret;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	ret = false;
@@ -1041,7 +1056,7 @@ static bool skl_ddi_dpll0_get_hw_state(struct drm_i915_private *dev_priv,
 	ret = true;
 
 out:
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return ret;
 }
@@ -1579,14 +1594,17 @@ static bool bxt_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 					struct intel_dpll_hw_state *hw_state)
 {
 	enum port port = (enum port)pll->info->id; /* 1:1 port->PLL mapping */
-	uint32_t val;
-	bool ret;
+	intel_wakeref_t wakeref;
 	enum dpio_phy phy;
 	enum dpio_channel ch;
+	uint32_t val;
+	bool ret;
 
 	bxt_port_to_phy_channel(dev_priv, port, &phy, &ch);
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	ret = false;
@@ -1643,7 +1661,7 @@ static bool bxt_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	ret = true;
 
 out:
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return ret;
 }
@@ -2091,10 +2109,13 @@ static bool cnl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 				     struct intel_dpll_hw_state *hw_state)
 {
 	const enum intel_dpll_id id = pll->info->id;
+	intel_wakeref_t wakeref;
 	uint32_t val;
 	bool ret;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	ret = false;
@@ -2113,7 +2134,7 @@ static bool cnl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	ret = true;
 
 out:
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 
 	return ret;
 }
@@ -2950,11 +2971,14 @@ static bool icl_pll_get_hw_state(struct drm_i915_private *dev_priv,
 				 struct intel_dpll_hw_state *hw_state)
 {
 	const enum intel_dpll_id id = pll->info->id;
-	uint32_t val;
-	enum port port;
+	intel_wakeref_t wakeref;
 	bool ret = false;
+	enum port port;
+	uint32_t val;
 
-	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	wakeref = intel_display_power_get_if_enabled(dev_priv,
+						     POWER_DOMAIN_PLLS);
+	if (!wakeref)
 		return false;
 
 	val = I915_READ(icl_pll_id_to_enable_reg(id));
@@ -3007,7 +3031,7 @@ static bool icl_pll_get_hw_state(struct drm_i915_private *dev_priv,
 
 	ret = true;
 out:
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS, wakeref);
 	return ret;
 }