[PATCH 1/5] drm/i915: Drop user contexts on device remove

[Janusz Krzysztofik]

Contexts associated with open file descriptors are now closed on file
close.  If a device is removed while being open, DMA API warns about
device associated mappings still active.  Moreover, subsequent removal
of contexts on device close may trigger a bug in intel-iommu code on
dma_unmap attempt.

As contexts become useless after the device is removed, drop them on
device removal.

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 38 +++++++++++++++++++++
 drivers/gpu/drm/i915/gem/i915_gem_context.h |  1 +
 drivers/gpu/drm/i915/i915_gem.c             |  2 ++
 3 files changed, 41 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 900ea8b7fc8f..0096a69fbfd3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -927,6 +927,44 @@ void i915_gem_driver_release__contexts(struct drm_i915_private *i915)
 	rcu_barrier(); /* and flush the left over RCU frees */
 }
 
+void i915_gem_driver_remove__contexts(struct drm_i915_private *i915)
+{
+	struct i915_gem_context *ctx, *cn;
+
+	list_for_each_entry_safe(ctx, cn, &i915->gem.contexts.list, link) {
+		struct drm_i915_file_private *file_priv = ctx->file_priv;
+		struct i915_gem_context *entry;
+		unsigned long int id;
+
+		if (i915_gem_context_is_closed(ctx) || IS_ERR(file_priv))
+			continue;
+
+		xa_for_each(&file_priv->context_xa, id, entry) {
+			struct i915_address_space *vm;
+			unsigned long int idx;
+
+			if (entry != ctx)
+				continue;
+
+			xa_erase(&file_priv->context_xa, id);
+
+			if (id)
+				break;
+
+			xa_for_each(&file_priv->vm_xa, idx, vm) {
+				xa_erase(&file_priv->vm_xa, idx);
+				i915_vm_put(vm);
+			}
+
+			break;
+		}
+
+		context_close(ctx);
+	}
+
+	i915_gem_driver_release__contexts(i915);
+}
+
 static int gem_context_register(struct i915_gem_context *ctx,
 				struct drm_i915_file_private *fpriv,
 				u32 *id)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 3702b2fb27ab..62808bea9239 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -110,6 +110,7 @@ i915_gem_context_clear_user_engines(struct i915_gem_context *ctx)
 
 /* i915_gem_context.c */
 void i915_gem_init__contexts(struct drm_i915_private *i915);
+void i915_gem_driver_remove__contexts(struct drm_i915_private *i915);
 void i915_gem_driver_release__contexts(struct drm_i915_private *i915);
 
 int i915_gem_context_open(struct drm_i915_private *i915,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0cbcb9f54e7d..87d3c4f5b6c6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1189,6 +1189,8 @@ void i915_gem_driver_remove(struct drm_i915_private *dev_priv)
 	/* Flush any outstanding unpin_work. */
 	i915_gem_drain_workqueue(dev_priv);
 
+	i915_gem_driver_remove__contexts(dev_priv);
+
 	i915_gem_drain_freed_objects(dev_priv);
 }
 
-- 
2.21.1