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 #include <linux/ioremap.h>
14 
generic_ioremap_prot(phys_addr_t phys_addr,size_t size,pgprot_t prot)15 void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
16 				   pgprot_t prot)
17 {
18 	unsigned long offset, vaddr;
19 	phys_addr_t last_addr;
20 	struct vm_struct *area;
21 
22 	/* An early platform driver might end up here */
23 	if (WARN_ON_ONCE(!slab_is_available()))
24 		return NULL;
25 
26 	/* Disallow wrap-around or zero size */
27 	last_addr = phys_addr + size - 1;
28 	if (!size || last_addr < phys_addr)
29 		return NULL;
30 
31 	/* Page-align mappings */
32 	offset = phys_addr & (~PAGE_MASK);
33 	phys_addr -= offset;
34 	size = PAGE_ALIGN(size + offset);
35 
36 	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
37 				    IOREMAP_END, __builtin_return_address(0));
38 	if (!area)
39 		return NULL;
40 	vaddr = (unsigned long)area->addr;
41 	area->phys_addr = phys_addr;
42 
43 	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
44 		free_vm_area(area);
45 		return NULL;
46 	}
47 
48 	return (void __iomem *)(vaddr + offset);
49 }
50 
51 #ifndef ioremap_prot
ioremap_prot(phys_addr_t phys_addr,size_t size,unsigned long prot)52 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
53 			   unsigned long prot)
54 {
55 	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
56 }
57 EXPORT_SYMBOL(ioremap_prot);
58 #endif
59 
generic_iounmap(volatile void __iomem * addr)60 void generic_iounmap(volatile void __iomem *addr)
61 {
62 	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
63 
64 	if (is_ioremap_addr(vaddr))
65 		vunmap(vaddr);
66 }
67 
68 #ifndef iounmap
iounmap(volatile void __iomem * addr)69 void iounmap(volatile void __iomem *addr)
70 {
71 	generic_iounmap(addr);
72 }
73 EXPORT_SYMBOL(iounmap);
74 #endif
75