drm/i915: Introduce wait_until_reg

The most common usage pattern for wait_for() macro is to wait for some
register value. Instead of bloating all callsites, encapsulate this
complex wait_for macro into a helper function.

v2: s/for/until, macro readability (Chris)

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>

2 files changed, 34 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1885eee11135..7cd185000d69 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2866,6 +2866,31 @@ static inline bool intel_vgpu_active(struct drm_device *dev)
 	return to_i915(dev)->vgpu.active;
 }
 
+int intel_wait_until_register(struct drm_i915_private *dev_priv,
+			      i915_reg_t reg,
+			      u32 mask,
+			      u32 value,
+			      unsigned long timeout_ms);
+
+#define wait_until_reg(reg, mask, value, timeout_ms) ({ \
+	if (__builtin_constant_p(timeout_ms)) \
+		BUILD_BUG_ON((timeout_ms) > 60000); \
+	intel_wait_until_register(dev_priv, \
+				  (reg), (mask), (value), (timeout_ms)); \
+	})
+
+#define wait_until_reg_set(reg, v, timeout_ms) ({ \
+	if (__builtin_constant_p(v)) \
+		BUILD_BUG_ON_NOT_POWER_OF_2((u32)(v)); \
+	wait_until_reg(reg, v, v, timeout_ms); \
+	})
+
+#define wait_until_reg_clr(reg, v, timeout_ms) ({ \
+	if (__builtin_constant_p((u32)(v))) \
+		BUILD_BUG_ON_NOT_POWER_OF_2((u32)(v)); \
+	wait_until_reg(reg, v, 0, timeout_ms); \
+	})
+
 void
 i915_enable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
 		     u32 status_mask);
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 349c266007bd..94b08107b84f 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1705,3 +1705,12 @@ intel_uncore_arm_unclaimed_mmio_detection(struct drm_i915_private *dev_priv)
 
 	return false;
 }
+
+int intel_wait_until_register(struct drm_i915_private *dev_priv,
+			      i915_reg_t reg,
+			      u32 mask,
+			      u32 value,
+			      unsigned long timeout_ms)
+{
+	return wait_for((I915_READ(reg) & mask) == value, timeout_ms);
+}