drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET

This is really just an alias of mmap_gtt. The 'mmap offset' nomenclature
comes from the value returned by this ioctl which is the offset into the
device fd which userpace uses with mmap(2).

mmap_gtt was our initial mmap_offset implementation, this extends
our CPU mmap support to allow additional fault handlers that depends on
the object's backing pages.

Note that we multiplex mmap_gtt and mmap_offset through the same ioctl,
and use the zero extending behaviour of drm to differentiate between
them, when we inspect the flags.

To support multiple mmap types on an object we need to support multiple
mmap_offsets for an object (each offset in the global device address
space corresponding to a unique instance of the object for a file + mmap
type). As we drop the simplified drm core idea of a single mmap_offset,
we need to provide replacement hooks for the dumb mmap interface as
well.

Link: https://gitlab.freedesktop.org/mesa/mesa/merge_requests/1675
Testcase: igt/gem_mmap_offset
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191204120032.3682839-1-chris@chris-wilson.co.uk

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 458945e1823e..16d611db9ca6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -29,6 +29,7 @@
 #include "i915_drv.h"
 #include "i915_gem_clflush.h"
 #include "i915_gem_context.h"
+#include "i915_gem_mman.h"
 #include "i915_gem_object.h"
 #include "i915_globals.h"
 #include "i915_trace.h"
@@ -61,6 +62,9 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
 
 	INIT_LIST_HEAD(&obj->lut_list);
 
+	spin_lock_init(&obj->mmo.lock);
+	INIT_LIST_HEAD(&obj->mmo.offsets);
+
 	init_rcu_head(&obj->rcu);
 
 	obj->ops = ops;
@@ -97,6 +101,7 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
 	struct drm_i915_gem_object *obj = to_intel_bo(gem);
 	struct drm_i915_file_private *fpriv = file->driver_priv;
 	struct i915_lut_handle *lut, *ln;
+	struct i915_mmap_offset *mmo;
 	LIST_HEAD(close);
 
 	i915_gem_object_lock(obj);
@@ -111,6 +116,17 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
 	}
 	i915_gem_object_unlock(obj);
 
+	spin_lock(&obj->mmo.lock);
+	list_for_each_entry(mmo, &obj->mmo.offsets, offset) {
+		if (mmo->file != file)
+			continue;
+
+		spin_unlock(&obj->mmo.lock);
+		drm_vma_node_revoke(&mmo->vma_node, file);
+		spin_lock(&obj->mmo.lock);
+	}
+	spin_unlock(&obj->mmo.lock);
+
 	list_for_each_entry_safe(lut, ln, &close, obj_link) {
 		struct i915_gem_context *ctx = lut->ctx;
 		struct i915_vma *vma;
@@ -158,6 +174,8 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
 
 	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
 	llist_for_each_entry_safe(obj, on, freed, freed) {
+		struct i915_mmap_offset *mmo, *mn;
+
 		trace_i915_gem_object_destroy(obj);
 
 		if (!list_empty(&obj->vma.list)) {
@@ -183,6 +201,15 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
 			spin_unlock(&obj->vma.lock);
 		}
 
+		i915_gem_object_release_mmap(obj);
+
+		list_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset) {
+			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
+					      &mmo->vma_node);
+			kfree(mmo);
+		}
+		INIT_LIST_HEAD(&obj->mmo.offsets);
+
 		GEM_BUG_ON(atomic_read(&obj->bind_count));
 		GEM_BUG_ON(obj->userfault_count);
 		GEM_BUG_ON(!list_empty(&obj->lut_list));