[Intel-gfx] [PATCH V2 2/3] FBC status on sysfs interface

[Alexandra Yates]

This interface allows viewing the status of the FBC.

Exposing this feature on sysfs interface would allow tools such as
powertop to provide status of the Graphics subsystem and aid
debugging RPM

Signed-off-by: Alexandra Yates <alexandra.yates at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_sysfs.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 36f4aff..a25bdd7 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -121,6 +121,20 @@ show_psr(struct device *kdev, struct device_attribute *attr, char *buf)
 	return ret;
 }
 
+static ssize_t
+show_fbc(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+	struct drm_minor *dminor = dev_to_drm_minor(kdev);
+	struct drm_device *dev = dminor->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	ssize_t ret;
+
+	mutex_lock(&dev_priv->fbc.lock);
+	ret = snprintf(buf, PAGE_SIZE, "%s\n", dev_priv->fbc.enabled ?
+			"enabled":"disabled");
+	mutex_unlock(&dev_priv->fbc.lock);
+	return ret;
+}
 
 static DEVICE_ATTR(rc6_enable, S_IRUGO, show_rc6_mask, NULL);
 static DEVICE_ATTR(rc6_residency_ms, S_IRUGO, show_rc6_ms, NULL);
@@ -128,6 +142,7 @@ static DEVICE_ATTR(rc6p_residency_ms, S_IRUGO, show_rc6p_ms, NULL);
 static DEVICE_ATTR(rc6pp_residency_ms, S_IRUGO, show_rc6pp_ms, NULL);
 static DEVICE_ATTR(media_rc6_residency_ms, S_IRUGO, show_media_rc6_ms, NULL);
 static DEVICE_ATTR(psr_enable, S_IRUGO, show_psr, NULL);
+static DEVICE_ATTR(fbc_enable, S_IRUGO, show_fbc, NULL);
 
 static struct attribute *rc6_attrs[] = {
 	&dev_attr_rc6_enable.attr,
@@ -171,6 +186,16 @@ static struct attribute_group psr_attr_group = {
 	.attrs = psr_attrs
 };
 
+static struct attribute *fbc_attrs[] = {
+	&dev_attr_fbc_enable.attr,
+	NULL
+};
+
+static struct attribute_group fbc_attr_group = {
+	.name = power_group_name,
+	.attrs = fbc_attrs
+};
+
 #endif
 
 static int l3_access_valid(struct drm_device *dev, loff_t offset)
@@ -648,6 +673,12 @@ void i915_setup_sysfs(struct drm_device *dev)
 		if (ret)
 			DRM_ERROR("PSR sysfs setup failed\n");
 	}
+	if (HAS_FBC(dev)) {
+		ret = sysfs_merge_group(&dev->primary->kdev->kobj,
+					&fbc_attr_group);
+		if (ret)
+			DRM_ERROR("FBC sysfs setup failed\n");
+	}
 #endif
 	if (HAS_L3_DPF(dev)) {
 		ret = device_create_bin_file(dev->primary->kdev, &dpf_attrs);
@@ -689,5 +720,6 @@ void i915_teardown_sysfs(struct drm_device *dev)
 	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6_attr_group);
 	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6p_attr_group);
 	sysfs_unmerge_group(&dev->primary->kdev->kobj, &psr_attr_group);
+	sysfs_unmerge_group(&dev->primary->kdev->kobj, &fbc_attr_group);
 #endif
 }
-- 
2.5.0