Re: [PATCH v3 32/37] drm/i915: Add cpu and lmem fault handlers

Quoting Matthew Auld (2019-08-09 23:26:38)

-void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj) +static vm_fault_t i915_gem_fault_cpu(struct vm_fault *vmf) +{

•   struct vm_area_struct *area = vmf->vma;
  

•   struct i915_mmap_offset *priv = area->vm_private_data;
  

•   struct drm_i915_gem_object *obj = priv->obj;
  

•   struct drm_device *dev = obj->base.dev;
  

•   struct drm_i915_private *dev_priv = to_i915(dev);
  

•   vm_fault_t vmf_ret;
  

•   unsigned long size = area->vm_end - area->vm_start;
  

•   bool write = area->vm_flags & VM_WRITE;
  

•   int i, ret;
  

•   /* Sanity check that we allow writing into this object */
  

•   if (i915_gem_object_is_readonly(obj) && write)
  

•           return VM_FAULT_SIGBUS;
  

•   ret = i915_gem_object_pin_pages(obj);
  

if (err) return i915_error_to_vmf_fault(err);

•           goto err;
  

•   for (i = 0; i < size >> PAGE_SHIFT; i++) {
  

•           struct page *page = i915_gem_object_get_page(obj, i);
  

•           vmf_ret = vmf_insert_pfn(area,
  

•                                    (unsigned long)area->vm_start + i * PAGE_SIZE,
  

•                                    page_to_pfn(page));
  

•           if (vmf_ret & VM_FAULT_ERROR) {
  

•                   ret = vm_fault_to_errno(vmf_ret, 0);
  

•                   break;
  

•           }
  

•   }
  

•   i915_gem_object_unpin_pages(obj);
  

return vmf_ret;