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