File: /usr/src/linux/arch/sparc64/mm/generic.c
1 /* $Id: generic.c,v 1.17 2001/04/09 04:08:06 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
17 static inline void forget_pte(pte_t page)
18 {
19 if (pte_none(page))
20 return;
21 if (pte_present(page)) {
22 struct page *ptpage = pte_page(page);
23 if ((!VALID_PAGE(ptpage)) || PageReserved(ptpage))
24 return;
25 page_cache_release(ptpage);
26 return;
27 }
28 swap_free(pte_to_swp_entry(page));
29 }
30
31 /* Remap IO memory, the same way as remap_page_range(), but use
32 * the obio memory space.
33 *
34 * They use a pgprot that sets PAGE_IO and does not check the
35 * mem_map table as this is independent of normal memory.
36 *
37 * As a special hack if the lowest bit of offset is set the
38 * side-effect bit will be turned off. This is used as a
39 * performance improvement on FFB/AFB. -DaveM
40 */
41 static inline void io_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
42 unsigned long offset, pgprot_t prot, int space)
43 {
44 unsigned long end;
45
46 address &= ~PMD_MASK;
47 end = address + size;
48 if (end > PMD_SIZE)
49 end = PMD_SIZE;
50 do {
51 pte_t oldpage;
52 pte_t entry;
53 unsigned long curend = address + PAGE_SIZE;
54
55 entry = mk_pte_io((offset & ~(0x1UL)), prot, space);
56 if (!(address & 0xffff)) {
57 if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
58 entry = mk_pte_io((offset & ~(0x1UL)),
59 __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
60 space);
61 curend = address + 0x400000;
62 offset += 0x400000;
63 } else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
64 entry = mk_pte_io((offset & ~(0x1UL)),
65 __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
66 space);
67 curend = address + 0x80000;
68 offset += 0x80000;
69 } else if (!(offset & 0xfffe) && end >= address + 0x10000) {
70 entry = mk_pte_io((offset & ~(0x1UL)),
71 __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
72 space);
73 curend = address + 0x10000;
74 offset += 0x10000;
75 } else
76 offset += PAGE_SIZE;
77 } else
78 offset += PAGE_SIZE;
79
80 if (offset & 0x1UL)
81 pte_val(entry) &= ~(_PAGE_E);
82 do {
83 oldpage = *pte;
84 pte_clear(pte);
85 set_pte(pte, entry);
86 forget_pte(oldpage);
87 address += PAGE_SIZE;
88 pte++;
89 } while (address < curend);
90 } while (address < end);
91 }
92
93 static inline int io_remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
94 unsigned long offset, pgprot_t prot, int space)
95 {
96 unsigned long end;
97
98 address &= ~PGDIR_MASK;
99 end = address + size;
100 if (end > PGDIR_SIZE)
101 end = PGDIR_SIZE;
102 offset -= address;
103 do {
104 pte_t * pte = pte_alloc(current->mm, pmd, address);
105 if (!pte)
106 return -ENOMEM;
107 io_remap_pte_range(pte, address, end - address, address + offset, prot, space);
108 address = (address + PMD_SIZE) & PMD_MASK;
109 pmd++;
110 } while (address < end);
111 return 0;
112 }
113
114 int io_remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
115 {
116 int error = 0;
117 pgd_t * dir;
118 unsigned long beg = from;
119 unsigned long end = from + size;
120 struct mm_struct *mm = current->mm;
121
122 prot = __pgprot(pg_iobits);
123 offset -= from;
124 dir = pgd_offset(mm, from);
125 flush_cache_range(mm, beg, end);
126
127 spin_lock(&mm->page_table_lock);
128 while (from < end) {
129 pmd_t *pmd = pmd_alloc(current->mm, dir, from);
130 error = -ENOMEM;
131 if (!pmd)
132 break;
133 error = io_remap_pmd_range(pmd, from, end - from, offset + from, prot, space);
134 if (error)
135 break;
136 from = (from + PGDIR_SIZE) & PGDIR_MASK;
137 dir++;
138 }
139 spin_unlock(&mm->page_table_lock);
140
141 flush_tlb_range(current->mm, beg, end);
142 return error;
143 }
144