[PATCH 2/2] drm/i915/kvmgt: Add mdev atrr nr_cache_entries

[changbin.du at intel.com]

From: Changbin Du <changbin.du at intel.com>

This patch add a new mdev atrr nr_cache_entries. This will show the number
of entry in dma cache.

$ cat /sys/bus/pci/devices/0000:00:02.0/<uuid>//intel_vgpu/nr_cache_entries
10101

Signed-off-by: Changbin Du <changbin.du at intel.com>
---
 drivers/gpu/drm/i915/gvt/gvt.h   |  1 +
 drivers/gpu/drm/i915/gvt/kvmgt.c | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 45209da..910f2a3 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -210,6 +210,7 @@ struct intel_vgpu {
 		 */
 		struct rb_root gfn_cache;
 		struct rb_root dma_addr_cache;
+		unsigned long nr_cache_entries;
 		struct mutex cache_lock;
 
 		struct notifier_block iommu_notifier;
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index e3629de..b527fa7 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -225,6 +225,8 @@ static void __gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn,
 	}
 	rb_link_node(&new->dma_addr_node, parent, link);
 	rb_insert_color(&new->dma_addr_node, &vgpu->vdev.dma_addr_cache);
+
+	vgpu->vdev.nr_cache_entries++;
 }
 
 static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
@@ -233,6 +235,7 @@ static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
 	rb_erase(&entry->gfn_node, &vgpu->vdev.gfn_cache);
 	rb_erase(&entry->dma_addr_node, &vgpu->vdev.dma_addr_cache);
 	kfree(entry);
+	vgpu->vdev.nr_cache_entries--;
 }
 
 static void gvt_cache_destroy(struct intel_vgpu *vgpu)
@@ -258,6 +261,7 @@ static void gvt_cache_init(struct intel_vgpu *vgpu)
 {
 	vgpu->vdev.gfn_cache = RB_ROOT;
 	vgpu->vdev.dma_addr_cache = RB_ROOT;
+	vgpu->vdev.nr_cache_entries = 0;
 	mutex_init(&vgpu->vdev.cache_lock);
 }
 
@@ -1276,12 +1280,28 @@ hw_id_show(struct device *dev, struct device_attribute *attr,
 	return sprintf(buf, "\n");
 }
 
+static ssize_t
+nr_cache_entries_show(struct device *dev, struct device_attribute *attr,
+	   char *buf)
+{
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct intel_vgpu *vgpu;
+
+	if (mdev) {
+		vgpu = (struct intel_vgpu *)mdev_get_drvdata(mdev);
+		return sprintf(buf, "%lu\n", vgpu->vdev.nr_cache_entries);
+	}
+	return sprintf(buf, "\n");
+}
+
 static DEVICE_ATTR_RO(vgpu_id);
 static DEVICE_ATTR_RO(hw_id);
+static DEVICE_ATTR_RO(nr_cache_entries);
 
 static struct attribute *intel_vgpu_attrs[] = {
 	&dev_attr_vgpu_id.attr,
 	&dev_attr_hw_id.attr,
+	&dev_attr_nr_cache_entries.attr,
 	NULL
 };
 
-- 
2.7.4