1 /* $Id: generic.c,v 1.14 2001/12/21 04:56:15 davem Exp $
2 * generic.c: Generic Sparc mm routines that are not dependent upon
3 * MMU type but are Sparc specific.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/mm.h>
10 #include <linux/swap.h>
11 #include <linux/pagemap.h>
12
13 #include <asm/pgalloc.h>
14 #include <asm/pgtable.h>
15 #include <asm/page.h>
16 #include <asm/cacheflush.h>
17 #include <asm/tlbflush.h>
18
19 static inline void forget_pte(pte_t page)
20 {
21 #if 0 /* old 2.4 code */
22 if (pte_none(page))
23 return;
24 if (pte_present(page)) {
25 unsigned long pfn = pte_pfn(page);
26 struct page *ptpage;
27 if (!pfn_valid(pfn))
28 return;
29 ptpage = pfn_to_page(pfn);
30 if (PageReserved(ptpage))
31 return;
32 page_cache_release(ptpage);
33 return;
34 }
35 swap_free(pte_to_swp_entry(page));
36 #else
37 if (!pte_none(page)) {
38 printk("forget_pte: old mapping existed!\n");
39 BUG();
40 }
41 #endif
42 }
43
44 /* Remap IO memory, the same way as remap_pfn_range(), but use
45 * the obio memory space.
46 *
47 * They use a pgprot that sets PAGE_IO and does not check the
48 * mem_map table as this is independent of normal memory.
49 */
50 static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
51 unsigned long offset, pgprot_t prot, int space)
52 {
53 unsigned long end;
54
55 address &= ~PMD_MASK;
56 end = address + size;
57 if (end > PMD_SIZE)
58 end = PMD_SIZE;
59 do {
60 pte_t oldpage = *pte;
61 pte_clear(pte);
62 set_pte(pte, mk_pte_io(offset, prot, space));
63 forget_pte(oldpage);
64 address += PAGE_SIZE;
65 offset += PAGE_SIZE;
66 pte++;
67 } while (address < end);
68 }
69
70 static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
71 unsigned long offset, pgprot_t prot, int space)
72 {
73 unsigned long end;
74
75 address &= ~PGDIR_MASK;
76 end = address + size;
77 if (end > PGDIR_SIZE)
78 end = PGDIR_SIZE;
79 offset -= address;
80 do {
81 pte_t * pte = pte_alloc_map(current->mm, pmd, address);
82 if (!pte)
83 return -ENOMEM;
84 io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
85 address = (address + PMD_SIZE) & PMD_MASK;
86 pmd++;
87 } while (address < end);
88 return 0;
89 }
90
91 int io_remap_page_range(struct vm_area_struct *vma, unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
92 {
93 int error = 0;
94 pgd_t * dir;
95 unsigned long beg = from;
96 unsigned long end = from + size;
97 struct mm_struct *mm = vma->vm_mm;
98
99 prot = __pgprot(pg_iobits);
100 offset -= from;
101 dir = pgd_offset(mm, from);
102 flush_cache_range(vma, beg, end);
103
104 spin_lock(&mm->page_table_lock);
105 while (from < end) {
106 pmd_t *pmd = pmd_alloc(current->mm, dir, from);
107 error = -ENOMEM;
108 if (!pmd)
109 break;
110 error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
111 if (error)
112 break;
113 from = (from + PGDIR_SIZE) & PGDIR_MASK;
114 dir++;
115 }
116 spin_unlock(&mm->page_table_lock);
117
118 flush_tlb_range(vma, beg, end);
119 return error;
120 }
121
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