1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
|
/*
* linux/arch/m68k/motorola.c
*
* Routines specific to the Motorola MMU, originally from:
* linux/arch/m68k/init.c
* which are Copyright (C) 1995 Hamish Macdonald
*
* Moved 8/20/1999 Sam Creasey
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/dma.h>
#ifdef CONFIG_ATARI
#include <asm/atari_stram.h>
#endif
#undef DEBUG
#ifndef mm_cachebits
/*
* Bits to add to page descriptors for "normal" caching mode.
* For 68020/030 this is 0.
* For 68040, this is _PAGE_CACHE040 (cachable, copyback)
*/
unsigned long mm_cachebits;
EXPORT_SYMBOL(mm_cachebits);
#endif
static pte_t * __init kernel_page_table(void)
{
pte_t *ptablep;
ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(ptablep);
__flush_page_to_ram(ptablep);
flush_tlb_kernel_page(ptablep);
nocache_page(ptablep);
return ptablep;
}
static pmd_t *last_pgtable __initdata = NULL;
pmd_t *zero_pgtable __initdata = NULL;
static pmd_t * __init kernel_ptr_table(void)
{
if (!last_pgtable) {
unsigned long pmd, last;
int i;
/* Find the last ptr table that was used in head.S and
* reuse the remaining space in that page for further
* ptr tables.
*/
last = (unsigned long)kernel_pg_dir;
for (i = 0; i < PTRS_PER_PGD; i++) {
if (!pgd_present(kernel_pg_dir[i]))
continue;
pmd = __pgd_page(kernel_pg_dir[i]);
if (pmd > last)
last = pmd;
}
last_pgtable = (pmd_t *)last;
#ifdef DEBUG
printk("kernel_ptr_init: %p\n", last_pgtable);
#endif
}
last_pgtable += PTRS_PER_PMD;
if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(last_pgtable);
__flush_page_to_ram(last_pgtable);
flush_tlb_kernel_page(last_pgtable);
nocache_page(last_pgtable);
}
return last_pgtable;
}
static unsigned long __init
map_chunk (unsigned long addr, long size)
{
#define PTRTREESIZE (256*1024)
#define ROOTTREESIZE (32*1024*1024)
static unsigned long virtaddr = PAGE_OFFSET;
unsigned long physaddr;
pgd_t *pgd_dir;
pmd_t *pmd_dir;
pte_t *pte_dir;
physaddr = (addr | m68k_supervisor_cachemode |
_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
if (CPU_IS_040_OR_060)
physaddr |= _PAGE_GLOBAL040;
while (size > 0) {
#ifdef DEBUG
if (!(virtaddr & (PTRTREESIZE-1)))
printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
virtaddr);
#endif
pgd_dir = pgd_offset_k(virtaddr);
if (virtaddr && CPU_IS_020_OR_030) {
if (!(virtaddr & (ROOTTREESIZE-1)) &&
size >= ROOTTREESIZE) {
#ifdef DEBUG
printk ("[very early term]");
#endif
pgd_val(*pgd_dir) = physaddr;
size -= ROOTTREESIZE;
virtaddr += ROOTTREESIZE;
physaddr += ROOTTREESIZE;
continue;
}
}
if (!pgd_present(*pgd_dir)) {
pmd_dir = kernel_ptr_table();
#ifdef DEBUG
printk ("[new pointer %p]", pmd_dir);
#endif
pgd_set(pgd_dir, pmd_dir);
} else
pmd_dir = pmd_offset(pgd_dir, virtaddr);
if (CPU_IS_020_OR_030) {
if (virtaddr) {
#ifdef DEBUG
printk ("[early term]");
#endif
pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
physaddr += PTRTREESIZE;
} else {
int i;
#ifdef DEBUG
printk ("[zero map]");
#endif
zero_pgtable = kernel_ptr_table();
pte_dir = (pte_t *)zero_pgtable;
pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
_PAGE_TABLE | _PAGE_ACCESSED;
pte_val(*pte_dir++) = 0;
physaddr += PAGE_SIZE;
for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
pte_val(*pte_dir++) = physaddr;
}
size -= PTRTREESIZE;
virtaddr += PTRTREESIZE;
} else {
if (!pmd_present(*pmd_dir)) {
#ifdef DEBUG
printk ("[new table]");
#endif
pte_dir = kernel_page_table();
pmd_set(pmd_dir, pte_dir);
}
pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
if (virtaddr) {
if (!pte_present(*pte_dir))
pte_val(*pte_dir) = physaddr;
} else
pte_val(*pte_dir) = 0;
size -= PAGE_SIZE;
virtaddr += PAGE_SIZE;
physaddr += PAGE_SIZE;
}
}
#ifdef DEBUG
printk("\n");
#endif
return virtaddr;
}
/*
* paging_init() continues the virtual memory environment setup which
* was begun by the code in arch/head.S.
*/
void __init paging_init(void)
{
int chunk;
unsigned long mem_avail = 0;
unsigned long zones_size[MAX_NR_ZONES] = { 0, };
#ifdef DEBUG
{
extern unsigned long availmem;
printk ("start of paging_init (%p, %lx, %lx, %lx)\n",
kernel_pg_dir, availmem, start_mem, end_mem);
}
#endif
/* Fix the cache mode in the page descriptors for the 680[46]0. */
if (CPU_IS_040_OR_060) {
int i;
#ifndef mm_cachebits
mm_cachebits = _PAGE_CACHE040;
#endif
for (i = 0; i < 16; i++)
pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
}
/*
* Map the physical memory available into the kernel virtual
* address space. It may allocate some memory for page
* tables and thus modify availmem.
*/
for (chunk = 0; chunk < m68k_num_memory; chunk++) {
mem_avail = map_chunk (m68k_memory[chunk].addr,
m68k_memory[chunk].size);
}
flush_tlb_all();
#ifdef DEBUG
printk ("memory available is %ldKB\n", mem_avail >> 10);
printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
start_mem, end_mem);
#endif
/*
* initialize the bad page table and bad page to point
* to a couple of allocated pages
*/
empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
memset(empty_zero_page, 0, PAGE_SIZE);
/*
* Set up SFC/DFC registers
*/
set_fs(KERNEL_DS);
#ifdef DEBUG
printk ("before free_area_init\n");
#endif
zones_size[ZONE_DMA] = (mach_max_dma_address < (unsigned long)high_memory ?
(mach_max_dma_address+1) : (unsigned long)high_memory);
zones_size[ZONE_NORMAL] = (unsigned long)high_memory - zones_size[0];
zones_size[ZONE_DMA] = (zones_size[ZONE_DMA] - PAGE_OFFSET) >> PAGE_SHIFT;
zones_size[ZONE_NORMAL] >>= PAGE_SHIFT;
free_area_init(zones_size);
}
extern char __init_begin, __init_end;
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)&__init_begin;
for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) {
virt_to_page(addr)->flags &= ~(1 << PG_reserved);
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
}
|
