drm/i915: Don't touch South Display when PCH_NOP

Interrupts, clock gating, LVDS, and GMBUS are all within the, "this will
be bad for CPU" range when we have PCH_NOP.

There is a bit of a hack in init clock gating. We want to do most of the
clock gating, but the part we skip will hang the system. It could
probably be abstracted a bit better, but I don't feel it's too
unsightly.

v2: Use inverse HAS_PCH_NOP check (Jani)

v3: Actually do what I claimed in v2 (spotted by Daniel)
Merge Ivybridge IRQ handler PCH check to decrease whitespace (Daniel)
Move LVDS bail into this patch (Ben)

v4: logical rebase conflict resolution with SDEIIR (Ben)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

Brush up patch a bit and resolve conflicts:
- Adjust PCH_NOP checks due to Egbert's hpd handling rework.
- Addd a PCH_NOP check in the irq uninstall code.
- Resolve conflicts with Paulo's SDE irq handling race fix.

v5: Drop the added hunks in the ilk irq handler again, they're bogus.
OOps.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -758,7 +758,7 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
-	u32 de_iir, gt_iir, de_ier, pm_iir, sde_ier;
+	u32 de_iir, gt_iir, de_ier, pm_iir, sde_ier = 0;
 	irqreturn_t ret = IRQ_NONE;
 	int i;
 
@@ -773,9 +773,11 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 	 * able to process them after we restore SDEIER (as soon as we restore
 	 * it, we'll get an interrupt if SDEIIR still has something to process
 	 * due to its back queue). */
-	sde_ier = I915_READ(SDEIER);
-	I915_WRITE(SDEIER, 0);
-	POSTING_READ(SDEIER);
+	if (!HAS_PCH_NOP(dev)) {
+		sde_ier = I915_READ(SDEIER);
+		I915_WRITE(SDEIER, 0);
+		POSTING_READ(SDEIER);
+	}
 
 	gt_iir = I915_READ(GTIIR);
 	if (gt_iir) {
@@ -802,7 +804,7 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 		}
 
 		/* check event from PCH */
-		if (de_iir & DE_PCH_EVENT_IVB) {
+		if (!HAS_PCH_NOP(dev) && (de_iir & DE_PCH_EVENT_IVB)) {
 			u32 pch_iir = I915_READ(SDEIIR);
 
 			cpt_irq_handler(dev, pch_iir);
@@ -825,8 +827,10 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 
 	I915_WRITE(DEIER, de_ier);
 	POSTING_READ(DEIER);
-	I915_WRITE(SDEIER, sde_ier);
-	POSTING_READ(SDEIER);
+	if (!HAS_PCH_NOP(dev)) {
+		I915_WRITE(SDEIER, sde_ier);
+		POSTING_READ(SDEIER);
+	}
 
 	return ret;
 }
@@ -2027,6 +2031,9 @@ static void ironlake_irq_preinstall(struct drm_device *dev)
 	I915_WRITE(GTIER, 0x0);
 	POSTING_READ(GTIER);
 
+	if (HAS_PCH_NOP(dev))
+		return;
+
 	/* south display irq */
 	I915_WRITE(SDEIMR, 0xffffffff);
 	/*
@@ -2112,6 +2119,10 @@ static void ibx_irq_postinstall(struct drm_device *dev)
 		mask = SDE_GMBUS | SDE_AUX_MASK;
 	else
 		mask = SDE_GMBUS_CPT | SDE_AUX_MASK_CPT;
+
+	if (HAS_PCH_NOP(dev))
+		return;
+
 	I915_WRITE(SDEIIR, I915_READ(SDEIIR));
 	I915_WRITE(SDEIMR, ~mask);
 }
@@ -2306,6 +2317,9 @@ static void ironlake_irq_uninstall(struct drm_device *dev)
 	I915_WRITE(GTIER, 0x0);
 	I915_WRITE(GTIIR, I915_READ(GTIIR));
 
+	if (HAS_PCH_NOP(dev))
+		return;
+
 	I915_WRITE(SDEIMR, 0xffffffff);
 	I915_WRITE(SDEIER, 0x0);
 	I915_WRITE(SDEIIR, I915_READ(SDEIIR));

drivers/gpu/drm/i915/intel_bios.c

@@ -692,6 +692,9 @@ intel_parse_bios(struct drm_device *dev)
 	struct bdb_header *bdb = NULL;
 	u8 __iomem *bios = NULL;
 
+	if (HAS_PCH_NOP(dev))
+		return -ENODEV;
+
 	init_vbt_defaults(dev_priv);
 
 	/* XXX Should this validation be moved to intel_opregion.c? */

drivers/gpu/drm/i915/intel_i2c.c

@@ -522,7 +522,9 @@ int intel_setup_gmbus(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int ret, i;
 
-	if (HAS_PCH_SPLIT(dev))
+	if (HAS_PCH_NOP(dev))
+		return 0;
+	else if (HAS_PCH_SPLIT(dev))
 		dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
 	else if (IS_VALLEYVIEW(dev))
 		dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE;

drivers/gpu/drm/i915/intel_pm.c

@@ -3890,7 +3890,8 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
 	snpcr |= GEN6_MBC_SNPCR_MED;
 	I915_WRITE(GEN6_MBCUNIT_SNPCR, snpcr);
 
-	cpt_init_clock_gating(dev);
+	if (!HAS_PCH_NOP(dev))
+		cpt_init_clock_gating(dev);
 
 	gen6_check_mch_setup(dev);
 }