1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Re-map IO memory to kernel address space so that we can access it.
 4 * This is needed for high PCI addresses that aren't mapped in the
 5 * 640k-1MB IO memory area on PC's
 6 *
 7 * (C) Copyright 1995 1996 Linus Torvalds
 8 */
 9#include <linux/vmalloc.h>
10#include <linux/mm.h>
11#include <linux/io.h>
12#include <linux/export.h>
13
14void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
15			   unsigned long prot)
16{
17	unsigned long offset, vaddr;
18	phys_addr_t last_addr;
19	struct vm_struct *area;
20
21	/* Disallow wrap-around or zero size */
22	last_addr = phys_addr + size - 1;
23	if (!size || last_addr < phys_addr)
24		return NULL;
25
26	/* Page-align mappings */
27	offset = phys_addr & (~PAGE_MASK);
28	phys_addr -= offset;
29	size = PAGE_ALIGN(size + offset);
30
31	if (!ioremap_allowed(phys_addr, size, prot))
32		return NULL;
33
34	area = get_vm_area_caller(size, VM_IOREMAP,
35			__builtin_return_address(0));
36	if (!area)
37		return NULL;
38	vaddr = (unsigned long)area->addr;
39	area->phys_addr = phys_addr;
40
41	if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
42			       __pgprot(prot))) {
43		free_vm_area(area);
44		return NULL;
45	}
46
47	return (void __iomem *)(vaddr + offset);
48}
49EXPORT_SYMBOL(ioremap_prot);
50
51void iounmap(volatile void __iomem *addr)
52{
53	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
54
55	if (!iounmap_allowed(vaddr))
56		return;
57
58	if (is_vmalloc_addr(vaddr))
59		vunmap(vaddr);
60}
61EXPORT_SYMBOL(iounmap);