[PATCH 3/4] drm/i915: Convert shared dpll reference count to a crtc mask

[Ander Conselvan de Oliveira <conselvan2@gmail.com>]

From: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>

This will be used in a follow up patch to properly release shared DPLLs
without relying on the shared_dpll field in pipe_config.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c  |  4 +--
 drivers/gpu/drm/i915/i915_drv.h      |  4 +--
 drivers/gpu/drm/i915/intel_display.c | 63 +++++++++++++++++++++++-------------
 3 files changed, 44 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index da4036d..71885d8 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2627,8 +2627,8 @@ static int i915_shared_dplls_info(struct seq_file *m, void *unused)
 		struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];
 
 		seq_printf(m, "DPLL%i: %s, id: %i\n", i, pll->name, pll->id);
-		seq_printf(m, " refcount: %i, active: %i, on: %s\n", pll->refcount,
-			   pll->active, yesno(pll->on));
+		seq_printf(m, " crtc_mask: 0x%08x, active: %d, on: %s\n",
+			   pll->crtc_mask, pll->active, yesno(pll->on));
 		seq_printf(m, " tracked hardware state:\n");
 		seq_printf(m, " dpll:    0x%08x\n", pll->hw_state.dpll);
 		seq_printf(m, " dpll_md: 0x%08x\n", pll->hw_state.dpll_md);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ac6232b..cb6df07 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -227,8 +227,8 @@ struct intel_dpll_hw_state {
 };
 
 struct intel_shared_dpll {
-	int refcount; /* count of number of CRTCs sharing this PLL */
-	int active; /* count of number of active CRTCs (i.e. DPMS on) */
+	unsigned crtc_mask; /* mask of CRTCs sharing this PLL */
+	int  active; /* count of number of active CRTCs (i.e. DPMS on) */
 	bool on; /* is the PLL actually active? Disabled during modeset */
 	const char *name;
 	/* should match the index in the dev_priv->shared_dplls array */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9d8fe8d..46df2db 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1778,7 +1778,7 @@ static void intel_prepare_shared_dpll(struct intel_crtc *crtc)
 	if (WARN_ON(pll == NULL))
 		return;
 
-	WARN_ON(!pll->refcount);
+	WARN_ON(!pll->crtc_mask);
 	if (pll->active == 0) {
 		DRM_DEBUG_DRIVER("setting up %s\n", pll->name);
 		WARN_ON(pll->on);
@@ -1805,7 +1805,7 @@ static void intel_enable_shared_dpll(struct intel_crtc *crtc)
 	if (WARN_ON(pll == NULL))
 		return;
 
-	if (WARN_ON(pll->refcount == 0))
+	if (WARN_ON(pll->crtc_mask == 0))
 		return;
 
 	DRM_DEBUG_KMS("enable %s (active %d, on? %d) for crtc %d\n",
@@ -1837,7 +1837,7 @@ static void intel_disable_shared_dpll(struct intel_crtc *crtc)
 	if (WARN_ON(pll == NULL))
 	       return;
 
-	if (WARN_ON(pll->refcount == 0))
+	if (WARN_ON(pll->crtc_mask == 0))
 		return;
 
 	DRM_DEBUG_KMS("disable %s (active %d, on? %d) for crtc %d\n",
@@ -3835,12 +3835,13 @@ void intel_put_shared_dpll(struct intel_crtc *crtc)
 	if (pll == NULL)
 		return;
 
-	if (pll->refcount == 0) {
-		WARN(1, "bad %s refcount\n", pll->name);
+	if (!(pll->crtc_mask & (1 << crtc->pipe))) {
+		WARN(1, "bad %s crtc mask\n", pll->name);
 		return;
 	}
 
-	if (--pll->refcount == 0) {
+	pll->crtc_mask &= ~(1 << crtc->pipe);
+	if (pll->crtc_mask == 0) {
 		WARN_ON(pll->on);
 		WARN_ON(pll->active);
 	}
@@ -3868,7 +3869,7 @@ struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
 		DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
 			      crtc->base.base.id, pll->name);
 
-		WARN_ON(pll->refcount);
+		WARN_ON(pll->crtc_mask);
 
 		goto found;
 	}
@@ -3877,14 +3878,15 @@ struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
 		pll = &dev_priv->shared_dplls[i];
 
 		/* Only want to check enabled timings first */
-		if (pll->refcount == 0)
+		if (pll->crtc_mask == 0)
 			continue;
 
 		if (memcmp(&crtc->config.dpll_hw_state, &pll->hw_state,
 			   sizeof(pll->hw_state)) == 0) {
-			DRM_DEBUG_KMS("CRTC:%d sharing existing %s (refcount %d, ative %d)\n",
-				      crtc->base.base.id,
-				      pll->name, pll->refcount, pll->active);
+			DRM_DEBUG_KMS("CRTC:%d sharing existing %s "
+				      "(crtc_mask 0x%08x, active %d)\n",
+				      crtc->base.base.id, pll->name,
+				      pll->crtc_mask, pll->active);
 
 			goto found;
 		}
@@ -3893,7 +3895,7 @@ struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
 	/* Ok no matching timings, maybe there's a free one? */
 	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
 		pll = &dev_priv->shared_dplls[i];
-		if (pll->refcount == 0) {
+		if (pll->crtc_mask == 0) {
 			DRM_DEBUG_KMS("CRTC:%d allocated %s\n",
 				      crtc->base.base.id, pll->name);
 			goto found;
@@ -3903,14 +3905,14 @@ struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
 	return NULL;
 
 found:
-	if (pll->refcount == 0)
+	if (pll->crtc_mask == 0)
 		pll->hw_state = crtc->config.dpll_hw_state;
 
 	crtc->config.shared_dpll = i;
 	DRM_DEBUG_DRIVER("using %s for pipe %c\n", pll->name,
 			 pipe_name(crtc->pipe));
 
-	pll->refcount++;
+	pll->crtc_mask |= 1 << crtc->pipe;
 
 	return pll;
 }
@@ -10812,6 +10814,19 @@ check_crtc_state(struct drm_device *dev)
 	}
 }
 
+static int mask_to_refcount(unsigned mask)
+{
+	int refcount = 0;
+
+	while (mask) {
+		if (mask & 1)
+			refcount++;
+		mask >>= 1;
+	}
+
+	return refcount;
+}
+
 static void
 check_shared_dpll_state(struct drm_device *dev)
 {
@@ -10831,9 +10846,9 @@ check_shared_dpll_state(struct drm_device *dev)
 
 		active = pll->get_hw_state(dev_priv, pll, &dpll_hw_state);
 
-		WARN(pll->active > pll->refcount,
+		WARN(pll->active > mask_to_refcount(pll->crtc_mask),
 		     "more active pll users than references: %i vs %i\n",
-		     pll->active, pll->refcount);
+		     pll->active, mask_to_refcount(pll->crtc_mask));
 		WARN(pll->active && !pll->on,
 		     "pll in active use but not on in sw tracking\n");
 		WARN(pll->on && !pll->active,
@@ -10851,9 +10866,9 @@ check_shared_dpll_state(struct drm_device *dev)
 		WARN(pll->active != active_crtcs,
 		     "pll active crtcs mismatch (expected %i, found %i)\n",
 		     pll->active, active_crtcs);
-		WARN(pll->refcount != enabled_crtcs,
+		WARN(mask_to_refcount(pll->crtc_mask) != enabled_crtcs,
 		     "pll enabled crtcs mismatch (expected %i, found %i)\n",
-		     pll->refcount, enabled_crtcs);
+		     mask_to_refcount(pll->crtc_mask), enabled_crtcs);
 
 		WARN(pll->on && memcmp(&pll->hw_state, &dpll_hw_state,
 				       sizeof(dpll_hw_state)),
@@ -13270,16 +13285,18 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 
 		pll->on = pll->get_hw_state(dev_priv, pll, &pll->hw_state);
 		pll->active = 0;
+		pll->crtc_mask = 0;
 		for_each_intel_crtc(dev, crtc) {
-			if (crtc->active && intel_crtc_to_shared_dpll(crtc) == pll)
+			if (crtc->active && intel_crtc_to_shared_dpll(crtc) == pll) {
 				pll->active++;
+				pll->crtc_mask |= 1 << crtc->pipe;
+			}
 		}
-		pll->refcount = pll->active;
 
-		DRM_DEBUG_KMS("%s hw state readout: refcount %i, on %i\n",
-			      pll->name, pll->refcount, pll->on);
+		DRM_DEBUG_KMS("%s hw state readout: crtc_mask 0x%08x, on %i\n",
+			      pll->name, pll->crtc_mask, pll->on);
 
-		if (pll->refcount)
+		if (pll->crtc_mask)
 			intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
 	}
 
-- 
1.8.3.2