[Intel-gfx] [RFC 12/39] drm/i915: Added scheduler hook when closing DRM file handles

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

The scheduler decouples the submission of batch buffers to the driver with
submission of batch buffers to the hardware. Thus it is possible for an
application to submit work, then close the DRM handle and free up all the
resources that piece of work wishes to use before the work has even been
submitted to the hardware. To prevent this, the scheduler needs to be informed
of the DRM close event so that it can force through any outstanding work
attributed to that file handle.

Change-Id: I24ac056c062b075ff1cc5e2ed2d3fa8e17e85951
For: VIZ-1587
Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c       |  3 ++
 drivers/gpu/drm/i915/i915_scheduler.c | 66 +++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_scheduler.h |  2 ++
 3 files changed, 71 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 5e63076..0a25017 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -47,6 +47,7 @@
 #include <linux/vga_switcheroo.h>
 #include <linux/slab.h>
 #include <acpi/video.h>
+#include "i915_scheduler.h"
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/oom.h>
@@ -1186,6 +1187,8 @@ void i915_driver_lastclose(struct drm_device *dev)
 
 void i915_driver_preclose(struct drm_device *dev, struct drm_file *file)
 {
+	i915_scheduler_closefile(dev, file);
+
 	mutex_lock(&dev->struct_mutex);
 	i915_gem_context_close(dev, file);
 	i915_gem_release(dev, file);
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index f7fd9a4..50bcccb 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -812,3 +812,69 @@ bool i915_scheduler_is_request_tracked(struct drm_i915_gem_request *req,
 
 	return true;
 }
+
+int i915_scheduler_closefile(struct drm_device *dev, struct drm_file *file)
+{
+	struct i915_scheduler_queue_entry  *node;
+	struct drm_i915_private            *dev_priv = dev->dev_private;
+	struct i915_scheduler              *scheduler = dev_priv->scheduler;
+	struct drm_i915_gem_request        *req;
+	struct intel_engine_cs  *ring;
+	int                     i, ret;
+	unsigned long           flags;
+	bool                    found;
+
+	if (!scheduler)
+		return 0;
+
+	for_each_ring(ring, dev_priv, i) {
+		do {
+			spin_lock_irqsave(&scheduler->lock, flags);
+
+			found = false;
+			list_for_each_entry(node, &scheduler->node_queue[ring->id], link) {
+				if (I915_SQS_IS_COMPLETE(node))
+					continue;
+
+				if (node->params.file != file)
+					continue;
+
+				found = true;
+				req = node->params.request;
+				i915_gem_request_reference(req);
+				break;
+			}
+
+			spin_unlock_irqrestore(&scheduler->lock, flags);
+
+			if (found) {
+				do {
+					mutex_lock(&dev->struct_mutex);
+					ret = i915_wait_request(req);
+					mutex_unlock(&dev->struct_mutex);
+					if (ret == -EAGAIN)
+						msleep(20);
+				} while (ret == -EAGAIN);
+
+				mutex_lock(&dev->struct_mutex);
+				i915_gem_request_unreference(req);
+				mutex_unlock(&dev->struct_mutex);
+			}
+		} while (found);
+	}
+
+	spin_lock_irqsave(&scheduler->lock, flags);
+	for_each_ring(ring, dev_priv, i) {
+		list_for_each_entry(node, &scheduler->node_queue[ring->id], link) {
+			if (node->params.file != file)
+				continue;
+
+			WARN_ON(!I915_SQS_IS_COMPLETE(node));
+
+			node->params.file = NULL;
+		}
+	}
+	spin_unlock_irqrestore(&scheduler->lock, flags);
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 88cbfba..fbb6f7b 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -86,6 +86,8 @@ enum {
 
 bool        i915_scheduler_is_enabled(struct drm_device *dev);
 int         i915_scheduler_init(struct drm_device *dev);
+int         i915_scheduler_closefile(struct drm_device *dev,
+				     struct drm_file *file);
 int         i915_scheduler_queue_execbuffer(struct i915_scheduler_queue_entry *qe);
 int         i915_scheduler_handle_irq(struct intel_engine_cs *ring);
 bool        i915_scheduler_is_request_tracked(struct drm_i915_gem_request *req,
-- 
1.9.1