drm/i915: Mark up Ironlake ips with rpm wakerefs

Currently Ironlake operates under the assumption that rpm awake (and its
error checking is disabled). As such, we have missed a few places where we
access registers without taking the rpm wakeref and thus trigger
warnings. intel_ips being one culprit.

As this involved adding a potentially sleeping rpm_get, we have to
rearrange the spinlocks slightly and so switch to acquiring a device-ref
under the spinlock rather than hold the spinlock for the whole
operation. To be consistent, we make the change in pattern common to the
intel_ips interface even though this adds a few more atomic operations
than necessary in a few cases.

v2: Sagar noted the mb around setting mch_dev were overkill as we only
need ordering there, and that i915_emon_status was still using
struct_mutex for no reason, but lacked rpm.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-21-chris@chris-wilson.co.uk

1 files changed, 12 insertions, 20 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 926acd5b6e5d..37c9aff234e0 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1741,32 +1741,24 @@ static int i915_sr_status(struct seq_file *m, void *unused)
 
 static int i915_emon_status(struct seq_file *m, void *unused)
 {
-	struct drm_i915_private *dev_priv = node_to_i915(m->private);
-	struct drm_device *dev = &dev_priv->drm;
-	unsigned long temp, chipset, gfx;
+	struct drm_i915_private *i915 = node_to_i915(m->private);
 	intel_wakeref_t wakeref;
-	int ret;
 
-	if (!IS_GEN(dev_priv, 5))
+	if (!IS_GEN(i915, 5))
 		return -ENODEV;
 
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
+	with_intel_runtime_pm(i915, wakeref) {
+		unsigned long temp, chipset, gfx;
 
-	wakeref = intel_runtime_pm_get(dev_priv);
-
-	temp = i915_mch_val(dev_priv);
-	chipset = i915_chipset_val(dev_priv);
-	gfx = i915_gfx_val(dev_priv);
-	mutex_unlock(&dev->struct_mutex);
+		temp = i915_mch_val(i915);
+		chipset = i915_chipset_val(i915);
+		gfx = i915_gfx_val(i915);
 
-	intel_runtime_pm_put(dev_priv, wakeref);
-
-	seq_printf(m, "GMCH temp: %ld\n", temp);
-	seq_printf(m, "Chipset power: %ld\n", chipset);
-	seq_printf(m, "GFX power: %ld\n", gfx);
-	seq_printf(m, "Total power: %ld\n", chipset + gfx);
+		seq_printf(m, "GMCH temp: %ld\n", temp);
+		seq_printf(m, "Chipset power: %ld\n", chipset);
+		seq_printf(m, "GFX power: %ld\n", gfx);
+		seq_printf(m, "Total power: %ld\n", chipset + gfx);
+	}
 
 	return 0;
 }