blob: 0f6e9ecbefe279eac6a9eca550860ef5aecc81b6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * arch/s390/mm/ioremap.c
3 *
4 * S390 version
5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Hartmut Penner (hp@de.ibm.com)
7 *
8 * Derived from "arch/i386/mm/extable.c"
9 * (C) Copyright 1995 1996 Linus Torvalds
10 *
11 * Re-map IO memory to kernel address space so that we can access it.
12 * This is needed for high PCI addresses that aren't mapped in the
13 * 640k-1MB IO memory area on PC's
14 */
15
16#include <linux/vmalloc.h>
17#include <linux/mm.h>
18#include <asm/io.h>
19#include <asm/pgalloc.h>
20#include <asm/cacheflush.h>
21#include <asm/tlbflush.h>
22
23static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
24 unsigned long phys_addr, unsigned long flags)
25{
26 unsigned long end;
27 unsigned long pfn;
28
29 address &= ~PMD_MASK;
30 end = address + size;
31 if (end > PMD_SIZE)
32 end = PMD_SIZE;
33 if (address >= end)
34 BUG();
35 pfn = phys_addr >> PAGE_SHIFT;
36 do {
37 if (!pte_none(*pte)) {
38 printk("remap_area_pte: page already exists\n");
39 BUG();
40 }
41 set_pte(pte, pfn_pte(pfn, __pgprot(flags)));
42 address += PAGE_SIZE;
43 pfn++;
44 pte++;
45 } while (address && (address < end));
46}
47
48static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
49 unsigned long phys_addr, unsigned long flags)
50{
51 unsigned long end;
52
53 address &= ~PGDIR_MASK;
54 end = address + size;
55 if (end > PGDIR_SIZE)
56 end = PGDIR_SIZE;
57 phys_addr -= address;
58 if (address >= end)
59 BUG();
60 do {
Hugh Dickins872fec12005-10-29 18:16:21 -070061 pte_t * pte = pte_alloc_kernel(pmd, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 if (!pte)
63 return -ENOMEM;
64 remap_area_pte(pte, address, end - address, address + phys_addr, flags);
65 address = (address + PMD_SIZE) & PMD_MASK;
66 pmd++;
67 } while (address && (address < end));
68 return 0;
69}
70
71static int remap_area_pages(unsigned long address, unsigned long phys_addr,
72 unsigned long size, unsigned long flags)
73{
74 int error;
75 pgd_t * dir;
76 unsigned long end = address + size;
77
78 phys_addr -= address;
79 dir = pgd_offset(&init_mm, address);
80 flush_cache_all();
81 if (address >= end)
82 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 do {
84 pmd_t *pmd;
85 pmd = pmd_alloc(&init_mm, dir, address);
86 error = -ENOMEM;
87 if (!pmd)
88 break;
89 if (remap_area_pmd(pmd, address, end - address,
90 phys_addr + address, flags))
91 break;
92 error = 0;
93 address = (address + PGDIR_SIZE) & PGDIR_MASK;
94 dir++;
95 } while (address && (address < end));
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 flush_tlb_all();
97 return 0;
98}
99
100/*
101 * Generic mapping function (not visible outside):
102 */
103
104/*
105 * Remap an arbitrary physical address space into the kernel virtual
106 * address space. Needed when the kernel wants to access high addresses
107 * directly.
108 */
109void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
110{
111 void * addr;
112 struct vm_struct * area;
113
114 if (phys_addr < virt_to_phys(high_memory))
115 return phys_to_virt(phys_addr);
116 if (phys_addr & ~PAGE_MASK)
117 return NULL;
118 size = PAGE_ALIGN(size);
119 if (!size || size > phys_addr + size)
120 return NULL;
121 area = get_vm_area(size, VM_IOREMAP);
122 if (!area)
123 return NULL;
124 addr = area->addr;
125 if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
126 vfree(addr);
127 return NULL;
128 }
129 return addr;
130}
131
132void iounmap(void *addr)
133{
134 if (addr > high_memory)
135 vfree(addr);
136}