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 <linux/mm.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)28 void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
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 #endif
42 
43 	/* Don't allow wraparound or zero size */
44 	last_addr = phys_addr + size - 1;
45 	if (!size || last_addr < phys_addr)
46 		return NULL;
47 
48 	/*
49 	 * Don't allow anybody to remap normal RAM that we're using..
50 	 */
51 	if (phys_addr < virt_to_phys(high_memory)) {
52 		char *t_addr, *t_end;
53 		struct page *page;
54 
55 		t_addr = __va(phys_addr);
56 		t_end = t_addr + (size - 1);
57 
58 		for (page = virt_to_page(t_addr);
59 		     page <= virt_to_page(t_end); page++) {
60 			if(!PageReserved(page))
61 				return NULL;
62 		}
63 	}
64 
65 	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
66 			  _PAGE_ACCESSED | _PAGE_NO_CACHE);
67 
68 	/*
69 	 * Mappings have to be page-aligned
70 	 */
71 	offset = phys_addr & ~PAGE_MASK;
72 	phys_addr &= PAGE_MASK;
73 	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
74 
75 	/*
76 	 * Ok, go for it..
77 	 */
78 	area = get_vm_area(size, VM_IOREMAP);
79 	if (!area)
80 		return NULL;
81 
82 	addr = (void __iomem *) area->addr;
83 	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
84 			       phys_addr, pgprot)) {
85 		vunmap(addr);
86 		return NULL;
87 	}
88 
89 	return (void __iomem *) (offset + (char __iomem *)addr);
90 }
91 EXPORT_SYMBOL(ioremap);
92 
iounmap(const volatile void __iomem * io_addr)93 void iounmap(const volatile void __iomem *io_addr)
94 {
95 	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
96 
97 	if (is_vmalloc_addr((void *)addr))
98 		vunmap((void *)addr);
99 }
100 EXPORT_SYMBOL(iounmap);
101