projects/linux·blob v3.7 · refs

94 lines · 2.1 KiB

1/*
2 * Re-map IO memory to kernel address space so that we can access it.
3 * This is needed for high PCI addresses that aren't mapped in the
4 * 640k-1MB IO memory area on PC's
5 *
6 * (C) Copyright 1995 1996 Linus Torvalds
7 */
8#include <linux/vmalloc.h>
9#include <linux/mm.h>
10#include <linux/sched.h>
11#include <linux/io.h>
12#include <linux/export.h>
13#include <asm/cacheflush.h>
14#include <asm/pgtable.h>
15
16static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
17 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
18{
19 pte_t *pte;
20 u64 pfn;
21
22 pfn = phys_addr >> PAGE_SHIFT;
23 pte = pte_alloc_kernel(pmd, addr);
24 if (!pte)
25 return -ENOMEM;
26 do {
27 BUG_ON(!pte_none(*pte));
28 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
29 pfn++;
30 } while (pte++, addr += PAGE_SIZE, addr != end);
31 return 0;
32}
33
34static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
35 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
36{
37 pmd_t *pmd;
38 unsigned long next;
39
40 phys_addr -= addr;
41 pmd = pmd_alloc(&init_mm, pud, addr);
42 if (!pmd)
43 return -ENOMEM;
44 do {
45 next = pmd_addr_end(addr, end);
46 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
47 return -ENOMEM;
48 } while (pmd++, addr = next, addr != end);
49 return 0;
50}
51
52static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
53 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
54{
55 pud_t *pud;
56 unsigned long next;
57
58 phys_addr -= addr;
59 pud = pud_alloc(&init_mm, pgd, addr);
60 if (!pud)
61 return -ENOMEM;
62 do {
63 next = pud_addr_end(addr, end);
64 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
65 return -ENOMEM;
66 } while (pud++, addr = next, addr != end);
67 return 0;
68}
69
70int ioremap_page_range(unsigned long addr,
71 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
72{
73 pgd_t *pgd;
74 unsigned long start;
75 unsigned long next;
76 int err;
77
78 BUG_ON(addr >= end);
79
80 start = addr;
81 phys_addr -= addr;
82 pgd = pgd_offset_k(addr);
83 do {
84 next = pgd_addr_end(addr, end);
85 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
86 if (err)
87 break;
88 } while (pgd++, addr = next, addr != end);
89
90 flush_cache_vmap(start, end);
91
92 return err;
93}
94EXPORT_SYMBOL_GPL(ioremap_page_range);