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

Chris Wilson
2019-08-10T11:38:52Z

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;