[PATCH 22/28] drm/i915: Make i915_gem_evict_vm work correctly for already locked objects

[Maarten Lankhorst]

i915_gem_execbuf will call i915_gem_evict_vm() after failing to pin
all objects in the first round. We are about to remove those short-term
pins, but even without those the objects are still locked. Add a special
case to allow i915_gem_evict_vm to evict locked objects as well.

This might also allow multiple objects sharing the same resv to be evicted.

Signed-off-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem_evict.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c 
b/drivers/gpu/drm/i915/i915_gem_evict.c
index 24f5e3345e43..f502a617b35c 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -410,21 +410,42 @@ int i915_gem_evict_vm(struct i915_address_space *vm, 
struct i915_gem_ww_ctx *ww)
        do {
                struct i915_vma *vma, *vn;
                LIST_HEAD(eviction_list);
+               LIST_HEAD(locked_eviction_list);
 
                list_for_each_entry(vma, &vm->bound_list, vm_link) {
                        if (i915_vma_is_pinned(vma))
                                continue;
 
+                       /*
+                        * If we already own the lock, trylock fails. In case 
the resv
+                        * is shared among multiple objects, we still need the 
object ref.
+                        */
+                       if (ww && (dma_resv_locking_ctx(vma->obj->base.resv) == 
&ww->ctx)) {
+                               __i915_vma_pin(vma);
+                               list_add(&vma->evict_link, 
&locked_eviction_list);
+                               continue;
+                       }
+
                        if (!i915_gem_object_trylock(vma->obj, ww))
                                continue;
 
                        __i915_vma_pin(vma);
                        list_add(&vma->evict_link, &eviction_list);
                }
-               if (list_empty(&eviction_list))
+               if (list_empty(&eviction_list) && 
list_empty(&locked_eviction_list))
                        break;
 
                ret = 0;
+               /* Unbind locked objects first, before unlocking the 
eviction_list */
+               list_for_each_entry_safe(vma, vn, &locked_eviction_list, 
evict_link) {
+                       __i915_vma_unpin(vma);
+
+                       if (ret == 0)
+                               ret = __i915_vma_unbind(vma);
+                       if (ret != -EINTR) /* "Get me out of here!" */
+                               ret = 0;
+               }
+
                list_for_each_entry_safe(vma, vn, &eviction_list, evict_link) {
                        __i915_vma_unpin(vma);
                        if (ret == 0)
-- 
2.33.0