PCI/sysfs: Make I/O resource depend on HAS_IOPORT

If legacy I/O spaces are not supported simply return an error when
trying to access them via pci_resource_io(). This allows inb() and
friends to become undefined when they are known at compile time to be
non-functional in a later patch.

Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Link: https://lore.kernel.org/r/20230703135255.2202721-3-schnelle@linux.ibm.com
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Author: niklas88

drivers/pci/pci-sysfs.c

@@ -1083,6 +1083,7 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
 			       struct bin_attribute *attr, char *buf,
 			       loff_t off, size_t count, bool write)
 {
+#ifdef CONFIG_HAS_IOPORT
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 	int bar = (unsigned long)attr->private;
 	unsigned long port = off;
@@ -1116,6 +1117,9 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
 		return 4;
 	}
 	return -EINVAL;
+#else
+	return -ENXIO;
+#endif
 }
 
 static ssize_t pci_read_resource_io(struct file *filp, struct kobject *kobj,