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
ioremap_prot(phys_addr_t phys_addr,size_t size,unsigned long prot)14 void __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 }
49 EXPORT_SYMBOL(ioremap_prot);
50
iounmap(volatile void __iomem * addr)51 void 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 }
61 EXPORT_SYMBOL(iounmap);
62
