drm/i915: Stop using obj->obj_exec_link outside of execbuf

i915_gem_stolen_list_info() sneakily takes advantage of the
obj->obj_exec_link to save itself from having to allocate. Enough of the
subterfuge, just allocate an array of pointers and sort them instead of
the list.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316132006.7976-7-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index aea51fb3851001fa1a0684abe5bd32a898779f07..47e707d83c4dad4d4855aca1143724007e81c141 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -27,7 +27,7 @@
  */
 
 #include <linux/debugfs.h>
-#include <linux/list_sort.h>
+#include <linux/sort.h>
 #include "intel_drv.h"
 
 static inline struct drm_i915_private *node_to_i915(struct drm_info_node *node)
@@ -204,13 +204,12 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
                seq_printf(m, " (frontbuffer: 0x%03x)", frontbuffer_bits);
 }
 
-static int obj_rank_by_stolen(void *priv,
-                             struct list_head *A, struct list_head *B)
+static int obj_rank_by_stolen(const void *A, const void *B)
 {
-       struct drm_i915_gem_object *a =
-               container_of(A, struct drm_i915_gem_object, obj_exec_link);
-       struct drm_i915_gem_object *b =
-               container_of(B, struct drm_i915_gem_object, obj_exec_link);
+       const struct drm_i915_gem_object *a =
+               *(const struct drm_i915_gem_object **)A;
+       const struct drm_i915_gem_object *b =
+               *(const struct drm_i915_gem_object **)B;
 
        if (a->stolen->start < b->stolen->start)
                return -1;
@@ -223,49 +222,60 @@ static int i915_gem_stolen_list_info(struct seq_file *m, void *data)
 {
        struct drm_i915_private *dev_priv = node_to_i915(m->private);
        struct drm_device *dev = &dev_priv->drm;
+       struct drm_i915_gem_object **objects;
        struct drm_i915_gem_object *obj;
        u64 total_obj_size, total_gtt_size;
-       LIST_HEAD(stolen);
-       int count, ret;
+       unsigned long total, count, n;
+       int ret;
+
+       total = READ_ONCE(dev_priv->mm.object_count);
+       objects = drm_malloc_ab(total, sizeof(*objects));
+       if (!objects)
+               return -ENOMEM;
 
        ret = mutex_lock_interruptible(&dev->struct_mutex);
        if (ret)
-               return ret;
+               goto out;
 
        total_obj_size = total_gtt_size = count = 0;
        list_for_each_entry(obj, &dev_priv->mm.bound_list, global_link) {
+               if (count == total)
+                       break;
+
                if (obj->stolen == NULL)
                        continue;
 
-               list_add(&obj->obj_exec_link, &stolen);
-
+               objects[count++] = obj;
                total_obj_size += obj->base.size;
                total_gtt_size += i915_gem_obj_total_ggtt_size(obj);
-               count++;
+
        }
        list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_link) {
+               if (count == total)
+                       break;
+
                if (obj->stolen == NULL)
                        continue;
 
-               list_add(&obj->obj_exec_link, &stolen);
-
+               objects[count++] = obj;
                total_obj_size += obj->base.size;
-               count++;
        }
-       list_sort(NULL, &stolen, obj_rank_by_stolen);
+
+       sort(objects, count, sizeof(*objects), obj_rank_by_stolen, NULL);
+
        seq_puts(m, "Stolen:\n");
-       while (!list_empty(&stolen)) {
-               obj = list_first_entry(&stolen, typeof(*obj), obj_exec_link);
+       for (n = 0; n < count; n++) {
                seq_puts(m, "   ");
-               describe_obj(m, obj);
+               describe_obj(m, objects[n]);
                seq_putc(m, '\n');
-               list_del_init(&obj->obj_exec_link);
        }
-       mutex_unlock(&dev->struct_mutex);
-
-       seq_printf(m, "Total %d objects, %llu bytes, %llu GTT size\n",
+       seq_printf(m, "Total %lu objects, %llu bytes, %llu GTT size\n",
                   count, total_obj_size, total_gtt_size);
-       return 0;
+
+       mutex_unlock(&dev->struct_mutex);
+out:
+       drm_free_large(objects);
+       return ret;
 }
 
 struct file_stats {