Re: [Intel-gfx] [RFC PATCH 092/162] drm/i915/uapi: introduce drm_i915_gem_create_ext

Quoting Matthew Auld (2020-11-27 12:06:08)

+int +i915_gem_create_ioctl(struct drm_device *dev, void *data,

•                 struct drm_file *file)
  

+{

•   struct drm_i915_private *i915 = to_i915(dev);
  

•   struct create_ext ext_data = { .i915 = i915 };
  

•   struct drm_i915_gem_create_ext *args = data;
  

•   int ret;
  

•   i915_gem_flush_free_objects(i915);
  

•   ret = i915_user_extensions(u64_to_user_ptr(args->extensions),
  

•                              create_extensions,
  

•                              ARRAY_SIZE(create_extensions),
  

•                              &ext_data);
  

•   if (ret)
  

•           goto err_free;
  

•   if (!ext_data.placements) {
  

•           struct intel_memory_region **placements;
  

•           enum intel_memory_type mem_type = INTEL_MEMORY_SYSTEM;
  

•           placements = kmalloc(sizeof(struct intel_memory_region *),
  

•                                GFP_KERNEL);
  

•           if (!placements)
  

•                   return -ENOMEM;
  

•           placements[0] = intel_memory_region_by_type(i915, mem_type);
  

•           ext_data.placements = placements;
  

•           ext_data.n_placements = 1;
  

•   }
  

•   ret = i915_gem_create(file,
  

•                         ext_data.placements,
  

•                         ext_data.n_placements,
  

•                         &args->size, &args->handle);
  

•   if (!ret)
  

•           return 0;
  

Applying the extensions has to happen after creating the vanilla object.

It literally is the equivalent of applying the setparam ioctl to a fresh object.

Look at the PXP series for how badly wrong this goes if you try it this way around. -Chris