drm/i915: Wrap external callers to IPS state with appropriate locks

Finishes commit 02d719562ef40483648b2cc46899d4a2ff5953bb
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Aug 9 16:44:54 2012 +0200

    drm/i915: properly guard ilk ips state

The core functions were annotated with their locking requirements, but
we overlooked that they were exported, without any control over the
locking, to debugfs. So in order to enable debugfs to read the registers
without triggering sanity checks, we change the exported entry points to
properly take the required locks before calling the core routines.

Reported-by: yangguang <guang.a.yang@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55304
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -2734,7 +2734,7 @@ static const struct cparams {
 	{ 0, 800, 231, 23784 },
 };
 
-unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
+static unsigned long __i915_chipset_val(struct drm_i915_private *dev_priv)
 {
 	u64 total_count, diff, ret;
 	u32 count1, count2, count3, m = 0, c = 0;
@@ -2788,6 +2788,22 @@ unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
 	return ret;
 }
 
+unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
+{
+	unsigned long val;
+
+	if (dev_priv->info->gen != 5)
+		return 0;
+
+	spin_lock_irq(&mchdev_lock);
+
+	val = __i915_chipset_val(dev_priv);
+
+	spin_unlock_irq(&mchdev_lock);
+
+	return val;
+}
+
 unsigned long i915_mch_val(struct drm_i915_private *dev_priv)
 {
 	unsigned long m, x, b;
@@ -2991,7 +3007,7 @@ void i915_update_gfx_val(struct drm_i915_private *dev_priv)
 	spin_unlock_irq(&mchdev_lock);
 }
 
-unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
+static unsigned long __i915_gfx_val(struct drm_i915_private *dev_priv)
 {
 	unsigned long t, corr, state1, corr2, state2;
 	u32 pxvid, ext_v;
@@ -3028,6 +3044,22 @@ unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
 	return dev_priv->ips.gfx_power + state2;
 }
 
+unsigned long i915_gfx_val(struct drm_i915_private *dev_priv)
+{
+	unsigned long val;
+
+	if (dev_priv->info->gen != 5)
+		return 0;
+
+	spin_lock_irq(&mchdev_lock);
+
+	val = __i915_gfx_val(dev_priv);
+
+	spin_unlock_irq(&mchdev_lock);
+
+	return val;
+}
+
 /**
  * i915_read_mch_val - return value for IPS use
  *
@@ -3044,8 +3076,8 @@ unsigned long i915_read_mch_val(void)
 		goto out_unlock;
 	dev_priv = i915_mch_dev;
 
-	chipset_val = i915_chipset_val(dev_priv);
-	graphics_val = i915_gfx_val(dev_priv);
+	chipset_val = __i915_chipset_val(dev_priv);
+	graphics_val = __i915_gfx_val(dev_priv);
 
 	ret = chipset_val + graphics_val;