Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
11#include <asm/cacheflush.h>
12#include <asm/pgtable.h>
13
14static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
15 unsigned long end, unsigned long phys_addr, pgprot_t prot)
16{
17 pte_t *pte;
18 unsigned long pfn;
19
20 pfn = phys_addr >> PAGE_SHIFT;
21 pte = pte_alloc_kernel(pmd, addr);
22 if (!pte)
23 return -ENOMEM;
24 do {
25 BUG_ON(!pte_none(*pte));
26 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
27 pfn++;
28 } while (pte++, addr += PAGE_SIZE, addr != end);
29 return 0;
30}
31
32static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
33 unsigned long end, unsigned long phys_addr, pgprot_t prot)
34{
35 pmd_t *pmd;
36 unsigned long next;
37
38 phys_addr -= addr;
39 pmd = pmd_alloc(&init_mm, pud, addr);
40 if (!pmd)
41 return -ENOMEM;
42 do {
43 next = pmd_addr_end(addr, end);
44 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
45 return -ENOMEM;
46 } while (pmd++, addr = next, addr != end);
47 return 0;
48}
49
50static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
51 unsigned long end, unsigned long phys_addr, pgprot_t prot)
52{
53 pud_t *pud;
54 unsigned long next;
55
56 phys_addr -= addr;
57 pud = pud_alloc(&init_mm, pgd, addr);
58 if (!pud)
59 return -ENOMEM;
60 do {
61 next = pud_addr_end(addr, end);
62 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
63 return -ENOMEM;
64 } while (pud++, addr = next, addr != end);
65 return 0;
66}
67
68int ioremap_page_range(unsigned long addr,
69 unsigned long end, unsigned long phys_addr, pgprot_t prot)
70{
71 pgd_t *pgd;
72 unsigned long start;
73 unsigned long next;
74 int err;
75
76 BUG_ON(addr >= end);
77
78 start = addr;
79 phys_addr -= addr;
80 pgd = pgd_offset_k(addr);
81 do {
82 next = pgd_addr_end(addr, end);
83 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
84 if (err)
85 break;
86 } while (pgd++, addr = next, addr != end);
87
88 flush_cache_vmap(start, end);
89
90 return err;
91}