[Intel-gfx] [PATCH 3/7] drm/i915: support Haswell-style force waking

[Eugeni Dodonov]

On Haswell, there is a different register for reading force wake ACKs.

v2: simplify forcewake dance and therefore the commit message as suggested by
Daniel Vetter.

Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 10 ++++++++--
 drivers/gpu/drm/i915/i915_reg.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3ef2103..cc8126e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -474,16 +474,22 @@ static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
 static void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
 {
 	unsigned long timeout;
+	u32 forcewake_ack;
+
+	if (IS_HASWELL(dev_priv->dev))
+		forcewake_ack = FORCEWAKE_ACK_HSW;
+	else
+		forcewake_ack = FORCEWAKE_MT_ACK;
 
 	timeout = jiffies + msecs_to_jiffies(1);
-	while (I915_READ_NOTRACE(FORCEWAKE_MT_ACK) & 1 &&
+	while (I915_READ_NOTRACE(forcewake_ack) & 1 &&
 	       time_before(jiffies, timeout))
 		;
 
 	I915_WRITE_NOTRACE(FORCEWAKE_MT, _MASKED_BIT_ENABLE(1));
 
 	timeout = jiffies + msecs_to_jiffies(1);
-	while ((I915_READ_NOTRACE(FORCEWAKE_MT_ACK) & 1) == 0 &&
+	while ((I915_READ_NOTRACE(forcewake_ack) & 1) == 0 &&
 	       time_before(jiffies, timeout))
 		;
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 20f7f0d..f17de3d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4095,6 +4095,7 @@
 #define  FORCEWAKE				0xA18C
 #define  FORCEWAKE_VLV				0x1300b0
 #define  FORCEWAKE_ACK_VLV			0x1300b4
+#define  FORCEWAKE_ACK_HSW			0x130044
 #define  FORCEWAKE_ACK				0x130090
 #define  FORCEWAKE_MT				0xa188 /* multi-threaded */
 #define  FORCEWAKE_MT_ACK			0x130040
-- 
1.7.11.1