1 /*
2 * linux/arch/m68k/mm/sun3mmu.c
3 *
4 * Implementations of mm routines specific to the sun3 MMU.
5 *
6 * Moved here 8/20/1999 Sam Creasey
7 *
8 */
9
10 #include <linux/signal.h>
11 #include <linux/sched.h>
12 #include <linux/mm.h>
13 #include <linux/swap.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 #include <linux/init.h>
18 #include <linux/bootmem.h>
19
20 #include <asm/setup.h>
21 #include <asm/uaccess.h>
22 #include <asm/page.h>
23 #include <asm/pgtable.h>
24 #include <asm/machdep.h>
25 #include <asm/io.h>
26
27 extern void mmu_emu_init (unsigned long bootmem_end);
28
29 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
30
31 extern unsigned long num_pages;
32
free_initmem(void)33 void free_initmem(void)
34 {
35 }
36
37 /* For the sun3 we try to follow the i386 paging_init() more closely */
38 /* start_mem and end_mem have PAGE_OFFSET added already */
39 /* now sets up tables using sun3 PTEs rather than i386 as before. --m */
paging_init(void)40 void __init paging_init(void)
41 {
42 pgd_t * pg_dir;
43 pte_t * pg_table;
44 int i;
45 unsigned long address;
46 unsigned long next_pgtable;
47 unsigned long bootmem_end;
48 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
49 unsigned long size;
50
51 #ifdef TEST_VERIFY_AREA
52 wp_works_ok = 0;
53 #endif
54 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
55
56 address = PAGE_OFFSET;
57 pg_dir = swapper_pg_dir;
58 memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
59 memset (kernel_pg_dir, 0, sizeof (kernel_pg_dir));
60
61 size = num_pages * sizeof(pte_t);
62 size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
63
64 next_pgtable = (unsigned long)alloc_bootmem_pages(size);
65 bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
66
67 /* Map whole memory from PAGE_OFFSET (0x0E000000) */
68 pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
69
70 while (address < (unsigned long)high_memory) {
71 pg_table = (pte_t *) __pa (next_pgtable);
72 next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
73 pgd_val(*pg_dir) = (unsigned long) pg_table;
74 pg_dir++;
75
76 /* now change pg_table to kernel virtual addresses */
77 pg_table = (pte_t *) __va ((unsigned long) pg_table);
78 for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
79 pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
80 if (address >= (unsigned long)high_memory)
81 pte_val (pte) = 0;
82 set_pte (pg_table, pte);
83 address += PAGE_SIZE;
84 }
85 }
86
87 mmu_emu_init(bootmem_end);
88
89 current->mm = NULL;
90
91 /* memory sizing is a hack stolen from motorola.c.. hope it works for us */
92 zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
93
94 /* I really wish I knew why the following change made things better... -- Sam */
95 /* free_area_init(zones_size); */
96 free_area_init_node(0, zones_size,
97 (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);
98
99
100 }
101
102
103