1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * arch/parisc/mm/ioremap.c
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * (C) Copyright 1995 1996 Linus Torvalds
6*4882a593Smuzhiyun * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de>
7*4882a593Smuzhiyun * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/vmalloc.h>
11*4882a593Smuzhiyun #include <linux/errno.h>
12*4882a593Smuzhiyun #include <linux/module.h>
13*4882a593Smuzhiyun #include <linux/io.h>
14*4882a593Smuzhiyun #include <linux/mm.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun * Generic mapping function (not visible outside):
18*4882a593Smuzhiyun */
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun /*
21*4882a593Smuzhiyun * Remap an arbitrary physical address space into the kernel virtual
22*4882a593Smuzhiyun * address space.
23*4882a593Smuzhiyun *
24*4882a593Smuzhiyun * NOTE! We need to allow non-page-aligned mappings too: we will obviously
25*4882a593Smuzhiyun * have to convert them into an offset in a page-aligned mapping, but the
26*4882a593Smuzhiyun * caller shouldn't need to know that small detail.
27*4882a593Smuzhiyun */
ioremap(unsigned long phys_addr,unsigned long size)28*4882a593Smuzhiyun void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun void __iomem *addr;
31*4882a593Smuzhiyun struct vm_struct *area;
32*4882a593Smuzhiyun unsigned long offset, last_addr;
33*4882a593Smuzhiyun pgprot_t pgprot;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun #ifdef CONFIG_EISA
36*4882a593Smuzhiyun unsigned long end = phys_addr + size - 1;
37*4882a593Smuzhiyun /* Support EISA addresses */
38*4882a593Smuzhiyun if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
39*4882a593Smuzhiyun (phys_addr >= 0x00500000 && end < 0x03bfffff))
40*4882a593Smuzhiyun phys_addr |= F_EXTEND(0xfc000000);
41*4882a593Smuzhiyun #endif
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /* Don't allow wraparound or zero size */
44*4882a593Smuzhiyun last_addr = phys_addr + size - 1;
45*4882a593Smuzhiyun if (!size || last_addr < phys_addr)
46*4882a593Smuzhiyun return NULL;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun /*
49*4882a593Smuzhiyun * Don't allow anybody to remap normal RAM that we're using..
50*4882a593Smuzhiyun */
51*4882a593Smuzhiyun if (phys_addr < virt_to_phys(high_memory)) {
52*4882a593Smuzhiyun char *t_addr, *t_end;
53*4882a593Smuzhiyun struct page *page;
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun t_addr = __va(phys_addr);
56*4882a593Smuzhiyun t_end = t_addr + (size - 1);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun for (page = virt_to_page(t_addr);
59*4882a593Smuzhiyun page <= virt_to_page(t_end); page++) {
60*4882a593Smuzhiyun if(!PageReserved(page))
61*4882a593Smuzhiyun return NULL;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
66*4882a593Smuzhiyun _PAGE_ACCESSED | _PAGE_NO_CACHE);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /*
69*4882a593Smuzhiyun * Mappings have to be page-aligned
70*4882a593Smuzhiyun */
71*4882a593Smuzhiyun offset = phys_addr & ~PAGE_MASK;
72*4882a593Smuzhiyun phys_addr &= PAGE_MASK;
73*4882a593Smuzhiyun size = PAGE_ALIGN(last_addr + 1) - phys_addr;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun /*
76*4882a593Smuzhiyun * Ok, go for it..
77*4882a593Smuzhiyun */
78*4882a593Smuzhiyun area = get_vm_area(size, VM_IOREMAP);
79*4882a593Smuzhiyun if (!area)
80*4882a593Smuzhiyun return NULL;
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun addr = (void __iomem *) area->addr;
83*4882a593Smuzhiyun if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
84*4882a593Smuzhiyun phys_addr, pgprot)) {
85*4882a593Smuzhiyun vunmap(addr);
86*4882a593Smuzhiyun return NULL;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun return (void __iomem *) (offset + (char __iomem *)addr);
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun EXPORT_SYMBOL(ioremap);
92*4882a593Smuzhiyun
iounmap(const volatile void __iomem * io_addr)93*4882a593Smuzhiyun void iounmap(const volatile void __iomem *io_addr)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun if (is_vmalloc_addr((void *)addr))
98*4882a593Smuzhiyun vunmap((void *)addr);
99*4882a593Smuzhiyun }
100*4882a593Smuzhiyun EXPORT_SYMBOL(iounmap);
101