[PATCH 2/9] drm/i915: add HAS_FORCEWAKE flag to uncore

[Daniele Ceraolo Spurio]

We have several cases where we don't have forcewake (older gens, GVT and
planned display-only uncore), so, instead of checking every time against
the various condition, save the info in a flag and use that.

Note that this patch also change the behavior for gen5 with vpgu
enabled, but this is not an issue since we don't support vgpu on gen5.

v2: split out from previous path, fix check for missing case (Paulo)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_uncore.c | 31 +++++++++++++++++++----------
 drivers/gpu/drm/i915/intel_uncore.h |  3 +++
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index ca6ff9c62646..479a95f1aed5 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1392,7 +1392,7 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore_to_i915(uncore);
 
-	if (INTEL_GEN(i915) <= 5 || intel_vgpu_active(i915))
+	if (!(uncore->flags & UNCORE_HAS_FORCEWAKE))
 		return;
 
 	if (INTEL_GEN(i915) >= 11) {
@@ -1591,6 +1591,9 @@ int intel_uncore_init(struct intel_uncore *uncore)
 
 	i915_check_vgpu(i915);
 
+	if (INTEL_GEN(i915) > 5 && !intel_vgpu_active(i915))
+		uncore->flags |= UNCORE_HAS_FORCEWAKE;
+
 	intel_uncore_edram_detect(i915);
 	intel_uncore_fw_domains_init(uncore);
 	__intel_uncore_early_sanitize(uncore, 0);
@@ -1599,12 +1602,14 @@ int intel_uncore_init(struct intel_uncore *uncore)
 	uncore->pmic_bus_access_nb.notifier_call =
 		i915_pmic_bus_access_notifier;
 
-	if (IS_GEN_RANGE(i915, 2, 4) || intel_vgpu_active(i915)) {
-		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen2);
-		ASSIGN_READ_MMIO_VFUNCS(uncore, gen2);
-	} else if (IS_GEN(i915, 5)) {
-		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen5);
-		ASSIGN_READ_MMIO_VFUNCS(uncore, gen5);
+	if (!(uncore->flags & UNCORE_HAS_FORCEWAKE)) {
+		if (IS_GEN(i915, 5)) {
+			ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen5);
+			ASSIGN_READ_MMIO_VFUNCS(uncore, gen5);
+		} else {
+			ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen2);
+			ASSIGN_READ_MMIO_VFUNCS(uncore, gen2);
+		}
 	} else if (IS_GEN_RANGE(i915, 6, 7)) {
 		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen6);
 
@@ -1913,7 +1918,10 @@ intel_uncore_forcewake_for_read(struct drm_i915_private *dev_priv,
 	} else if (INTEL_GEN(dev_priv) >= 6) {
 		fw_domains = __gen6_reg_read_fw_domains(uncore, offset);
 	} else {
-		WARN_ON(!IS_GEN_RANGE(dev_priv, 2, 5));
+		/* on devices with FW we expect to hit one of the above cases */
+		if (unlikely(uncore->flags & UNCORE_HAS_FORCEWAKE))
+			MISSING_CASE(INTEL_GEN(dev_priv));
+
 		fw_domains = 0;
 	}
 
@@ -1939,7 +1947,10 @@ intel_uncore_forcewake_for_write(struct drm_i915_private *dev_priv,
 	} else if (IS_GEN_RANGE(dev_priv, 6, 7)) {
 		fw_domains = FORCEWAKE_RENDER;
 	} else {
-		WARN_ON(!IS_GEN_RANGE(dev_priv, 2, 5));
+		/* on devices with FW we expect to hit one of the above cases */
+		if (unlikely(uncore->flags & UNCORE_HAS_FORCEWAKE))
+			MISSING_CASE(INTEL_GEN(dev_priv));
+
 		fw_domains = 0;
 	}
 
@@ -1970,7 +1981,7 @@ intel_uncore_forcewake_for_reg(struct drm_i915_private *dev_priv,
 
 	WARN_ON(!op);
 
-	if (intel_vgpu_active(dev_priv))
+	if (!(dev_priv->uncore.flags & UNCORE_HAS_FORCEWAKE))
 		return 0;
 
 	if (op & FW_REG_READ)
diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h
index 42d88b159c08..56c07595ffe6 100644
--- a/drivers/gpu/drm/i915/intel_uncore.h
+++ b/drivers/gpu/drm/i915/intel_uncore.h
@@ -127,6 +127,9 @@ struct intel_uncore {
 	} user_forcewake;
 
 	int unclaimed_mmio_check;
+
+	u32 flags;
+#define UNCORE_HAS_FORCEWAKE		BIT(0)
 };
 
 /* Iterate over initialised fw domains */
-- 
2.20.1