drm/i915: Pull VM lists under the VM mutex.

A starting point to counter the pervasive struct_mutex. For the goal of
avoiding (or at least blocking under them!) global locks during user
request submission, a simple but important step is being able to manage
each clients GTT separately. For which, we want to replace using the
struct_mutex as the guard for all things GTT/VM and switch instead to a
specific mutex inside i915_address_space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128102356.15037-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f45186d..538fa54 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -245,18 +245,19 @@ int
 i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
                            struct drm_file *file)
 {
-       struct drm_i915_private *dev_priv = to_i915(dev);
-       struct i915_ggtt *ggtt = &dev_priv->ggtt;
+       struct i915_ggtt *ggtt = &to_i915(dev)->ggtt;
        struct drm_i915_gem_get_aperture *args = data;
        struct i915_vma *vma;
        u64 pinned;
 
+       mutex_lock(&ggtt->vm.mutex);
+
        pinned = ggtt->vm.reserved;
-       mutex_lock(&dev->struct_mutex);
        list_for_each_entry(vma, &ggtt->vm.bound_list, vm_link)
                if (i915_vma_is_pinned(vma))
                        pinned += vma->node.size;
-       mutex_unlock(&dev->struct_mutex);
+
+       mutex_unlock(&ggtt->vm.mutex);
 
        args->aper_size = ggtt->vm.total;
        args->aper_available_size = args->aper_size - pinned;
@@ -1529,20 +1530,21 @@ err:
 
 static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj)
 {
-       struct drm_i915_private *i915;
+       struct drm_i915_private *i915 = to_i915(obj->base.dev);
        struct list_head *list;
        struct i915_vma *vma;
 
        GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
 
+       mutex_lock(&i915->ggtt.vm.mutex);
        for_each_ggtt_vma(vma, obj) {
                if (!drm_mm_node_allocated(&vma->node))
                        continue;
 
                list_move_tail(&vma->vm_link, &vma->vm->bound_list);
        }
+       mutex_unlock(&i915->ggtt.vm.mutex);
 
-       i915 = to_i915(obj->base.dev);
        spin_lock(&i915->mm.obj_lock);
        list = obj->bind_count ? &i915->mm.bound_list : &i915->mm.unbound_list;
        list_move_tail(&obj->mm.link, list);

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index d768396..68d74c5 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -430,6 +430,7 @@ int i915_gem_evict_vm(struct i915_address_space *vm)
        }
 
        INIT_LIST_HEAD(&eviction_list);
+       mutex_lock(&vm->mutex);
        list_for_each_entry(vma, &vm->bound_list, vm_link) {
                if (i915_vma_is_pinned(vma))
                        continue;
@@ -437,6 +438,7 @@ int i915_gem_evict_vm(struct i915_address_space *vm)
                __i915_vma_pin(vma);
                list_add(&vma->evict_link, &eviction_list);
        }
+       mutex_unlock(&vm->mutex);
 
        ret = 0;
        list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 2ad9070..49b0099 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1931,7 +1931,10 @@ static struct i915_vma *pd_vma_create(struct gen6_hw_ppgtt *ppgtt, int size)
        vma->ggtt_view.type = I915_GGTT_VIEW_ROTATED; /* prevent fencing */
 
        INIT_LIST_HEAD(&vma->obj_link);
+
+       mutex_lock(&vma->vm->mutex);
        list_add(&vma->vm_link, &vma->vm->unbound_list);
+       mutex_unlock(&vma->vm->mutex);
 
        return vma;
 }
@@ -3504,9 +3507,10 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)
 
        i915_check_and_clear_faults(dev_priv);
 
+       mutex_lock(&ggtt->vm.mutex);
+
        /* First fill our portion of the GTT with scratch pages */
        ggtt->vm.clear_range(&ggtt->vm, 0, ggtt->vm.total);
-
        ggtt->vm.closed = true; /* skip rewriting PTE on VMA unbind */
 
        /* clflush objects bound into the GGTT and rebind them. */
@@ -3516,19 +3520,26 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)
                if (!(vma->flags & I915_VMA_GLOBAL_BIND))
                        continue;
 
+               mutex_unlock(&ggtt->vm.mutex);
+
                if (!i915_vma_unbind(vma))
-                       continue;
+                       goto lock;
 
                WARN_ON(i915_vma_bind(vma,
                                      obj ? obj->cache_level : 0,
                                      PIN_UPDATE));
                if (obj)
                        WARN_ON(i915_gem_object_set_to_gtt_domain(obj, false));
+
+lock:
+               mutex_lock(&ggtt->vm.mutex);
        }
 
        ggtt->vm.closed = false;
        i915_ggtt_invalidate(dev_priv);
 
+       mutex_unlock(&ggtt->vm.mutex);
+
        if (INTEL_GEN(dev_priv) >= 8) {
                struct intel_ppat *ppat = &dev_priv->ppat;
 

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index a76d6c9..6da795c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -461,6 +461,7 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
                                               I915_SHRINK_VMAPS);
 
        /* We also want to clear any cached iomaps as they wrap vmap */
+       mutex_lock(&i915->ggtt.vm.mutex);
        list_for_each_entry_safe(vma, next,
                                 &i915->ggtt.vm.bound_list, vm_link) {
                unsigned long count = vma->node.size >> PAGE_SHIFT;
@@ -468,9 +469,12 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
                if (!vma->iomap || i915_vma_is_active(vma))
                        continue;
 
+               mutex_unlock(&i915->ggtt.vm.mutex);
                if (i915_vma_unbind(vma) == 0)
                        freed_pages += count;
+               mutex_lock(&i915->ggtt.vm.mutex);
        }
+       mutex_unlock(&i915->ggtt.vm.mutex);
 
 out:
        shrinker_unlock(i915, unlock);

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index a9e3657..74a9661 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -702,7 +702,9 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private *dev_priv
        vma->flags |= I915_VMA_GLOBAL_BIND;
        __i915_vma_set_map_and_fenceable(vma);
 
+       mutex_lock(&ggtt->vm.mutex);
        list_move_tail(&vma->vm_link, &ggtt->vm.bound_list);
+       mutex_unlock(&ggtt->vm.mutex);
 
        spin_lock(&dev_priv->mm.obj_lock);
        list_move_tail(&obj->mm.link, &dev_priv->mm.bound_list);

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 7de28ba..dcbd0d3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -213,7 +213,10 @@ vma_create(struct drm_i915_gem_object *obj,
        }
        rb_link_node(&vma->obj_node, rb, p);
        rb_insert_color(&vma->obj_node, &obj->vma_tree);
+
+       mutex_lock(&vm->mutex);
        list_add(&vma->vm_link, &vm->unbound_list);
+       mutex_unlock(&vm->mutex);
 
        return vma;
 
@@ -656,7 +659,9 @@ i915_vma_insert(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
        GEM_BUG_ON(!drm_mm_node_allocated(&vma->node));
        GEM_BUG_ON(!i915_gem_valid_gtt_space(vma, cache_level));
 
+       mutex_lock(&vma->vm->mutex);
        list_move_tail(&vma->vm_link, &vma->vm->bound_list);
+       mutex_unlock(&vma->vm->mutex);
 
        if (vma->obj) {
                struct drm_i915_gem_object *obj = vma->obj;
@@ -689,8 +694,10 @@ i915_vma_remove(struct i915_vma *vma)
 
        vma->ops->clear_pages(vma);
 
+       mutex_lock(&vma->vm->mutex);
        drm_mm_remove_node(&vma->node);
        list_move_tail(&vma->vm_link, &vma->vm->unbound_list);
+       mutex_unlock(&vma->vm->mutex);
 
        /*
         * Since the unbound list is global, only move to that list if
@@ -802,7 +809,11 @@ static void __i915_vma_destroy(struct i915_vma *vma)
        GEM_BUG_ON(i915_gem_active_isset(&vma->last_fence));
 
        list_del(&vma->obj_link);
+
+       mutex_lock(&vma->vm->mutex);
        list_del(&vma->vm_link);
+       mutex_unlock(&vma->vm->mutex);
+
        if (vma->obj)
                rb_erase(&vma->obj_node, &vma->obj->vma_tree);
 

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
index af9b85c..32dce71 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
@@ -94,11 +94,14 @@ static int populate_ggtt(struct drm_i915_private *i915,
 
 static void unpin_ggtt(struct drm_i915_private *i915)
 {
+       struct i915_ggtt *ggtt = &i915->ggtt;
        struct i915_vma *vma;
 
+       mutex_lock(&ggtt->vm.mutex);
        list_for_each_entry(vma, &i915->ggtt.vm.bound_list, vm_link)
                if (vma->obj->mm.quirked)
                        i915_vma_unpin(vma);
+       mutex_unlock(&ggtt->vm.mutex);
 }
 
 static void cleanup_objects(struct drm_i915_private *i915,

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 8feb4af..3850ef4 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1237,7 +1237,10 @@ static void track_vma_bind(struct i915_vma *vma)
        __i915_gem_object_pin_pages(obj);
 
        vma->pages = obj->mm.pages;
+
+       mutex_lock(&vma->vm->mutex);
        list_move_tail(&vma->vm_link, &vma->vm->bound_list);
+       mutex_unlock(&vma->vm->mutex);
 }
 
 static int exercise_mock(struct drm_i915_private *i915,