On Thu, 20 Feb 2020 13:27:15 +0100 Thomas Hellstrom wrote:
> +
> +static vm_fault_t ttm_bo_vm_huge_fault(struct vm_fault *vmf,
> + enum page_entry_size pe_size)
> +{
> + struct vm_area_struct *vma = vmf->vma;
> + pgprot_t prot;
> + struct ttm_buffer_object *bo = vma->vm_private_data;
> + vm_fault_t ret;
> + pgoff_t fault_page_size = 0;
> + bool write = vmf->flags & FAULT_FLAG_WRITE;
> +
> + switch (pe_size) {
> + case PE_SIZE_PMD:
> + fault_page_size = HPAGE_PMD_SIZE >> PAGE_SHIFT;
> + break;
> +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
> + case PE_SIZE_PUD:
> + fault_page_size = HPAGE_PUD_SIZE >> PAGE_SHIFT;
> + break;
> +#endif
> + default:
> + WARN_ON_ONCE(1);
> + return VM_FAULT_FALLBACK;
> + }
> +
> + /* Fallback on write dirty-tracking or COW */
> + if (write && ttm_pgprot_is_wrprotecting(vma->vm_page_prot))
> + return VM_FAULT_FALLBACK;
> +
> + ret = ttm_bo_vm_reserve(bo, vmf);
> + if (ret)
> + return ret;
> +
> + prot = vm_get_page_prot(vma->vm_flags);
> + ret = ttm_bo_vm_fault_reserved(vmf, prot, 1, fault_page_size);
> + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
> + return ret;
Seems it does not make much sense to check VM_FAULT_RETRY and return as
at least resv lock is left behind without care.
> +
> + dma_resv_unlock(bo->base.resv);
> +
> + return ret;
> +}
