1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/parisc/mm/ioremap.c
4 *
5 * (C) Copyright 1995 1996 Linus Torvalds
6 * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de>
7 * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
8 */
9
10 #include <linux/vmalloc.h>
11 #include <linux/errno.h>
12 #include <linux/module.h>
13 #include <linux/io.h>
14 #include <asm/pgalloc.h>
15
16 /*
17 * Generic mapping function (not visible outside):
18 */
19
20 /*
21 * Remap an arbitrary physical address space into the kernel virtual
22 * address space.
23 *
24 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
25 * have to convert them into an offset in a page-aligned mapping, but the
26 * caller shouldn't need to know that small detail.
27 */
__ioremap(unsigned long phys_addr,unsigned long size,unsigned long flags)28 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
29 {
30 void __iomem *addr;
31 struct vm_struct *area;
32 unsigned long offset, last_addr;
33 pgprot_t pgprot;
34
35 #ifdef CONFIG_EISA
36 unsigned long end = phys_addr + size - 1;
37 /* Support EISA addresses */
38 if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
39 (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
40 phys_addr |= F_EXTEND(0xfc000000);
41 flags |= _PAGE_NO_CACHE;
42 }
43 #endif
44
45 /* Don't allow wraparound or zero size */
46 last_addr = phys_addr + size - 1;
47 if (!size || last_addr < phys_addr)
48 return NULL;
49
50 /*
51 * Don't allow anybody to remap normal RAM that we're using..
52 */
53 if (phys_addr < virt_to_phys(high_memory)) {
54 char *t_addr, *t_end;
55 struct page *page;
56
57 t_addr = __va(phys_addr);
58 t_end = t_addr + (size - 1);
59
60 for (page = virt_to_page(t_addr);
61 page <= virt_to_page(t_end); page++) {
62 if(!PageReserved(page))
63 return NULL;
64 }
65 }
66
67 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
68 _PAGE_ACCESSED | flags);
69
70 /*
71 * Mappings have to be page-aligned
72 */
73 offset = phys_addr & ~PAGE_MASK;
74 phys_addr &= PAGE_MASK;
75 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
76
77 /*
78 * Ok, go for it..
79 */
80 area = get_vm_area(size, VM_IOREMAP);
81 if (!area)
82 return NULL;
83
84 addr = (void __iomem *) area->addr;
85 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
86 phys_addr, pgprot)) {
87 vunmap(addr);
88 return NULL;
89 }
90
91 return (void __iomem *) (offset + (char __iomem *)addr);
92 }
93 EXPORT_SYMBOL(__ioremap);
94
iounmap(const volatile void __iomem * io_addr)95 void iounmap(const volatile void __iomem *io_addr)
96 {
97 unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
98
99 if (is_vmalloc_addr((void *)addr))
100 vunmap((void *)addr);
101 }
102 EXPORT_SYMBOL(iounmap);
103
