static vm_fault_t __dev_dax_pte_fault()

in device.c [103:134]

• 25 lines of code
• 5 McCabe index (conditional complexity)

static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
				struct vm_fault *vmf)
{
	struct device *dev = &dev_dax->dev;
	phys_addr_t phys;
	pfn_t pfn;
	unsigned int fault_size = PAGE_SIZE;

	if (check_vma(dev_dax, vmf->vma, __func__))
		return VM_FAULT_SIGBUS;

	if (dev_dax->align > PAGE_SIZE) {
		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
			dev_dax->align, fault_size);
		return VM_FAULT_SIGBUS;
	}

	if (fault_size != dev_dax->align)
		return VM_FAULT_SIGBUS;

	phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
	if (phys == -1) {
		dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", vmf->pgoff);
		return VM_FAULT_SIGBUS;
	}

	pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);

	dax_set_mapping(vmf, pfn, fault_size);

	return vmf_insert_mixed(vmf->vma, vmf->address, pfn);
}