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1da177e4 LT |
1 | /* |
2 | * linux/arch/m68k/motorola.c | |
3 | * | |
4 | * Routines specific to the Motorola MMU, originally from: | |
5 | * linux/arch/m68k/init.c | |
6 | * which are Copyright (C) 1995 Hamish Macdonald | |
7 | * | |
8 | * Moved 8/20/1999 Sam Creasey | |
9 | */ | |
10 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/signal.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/swap.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/types.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/bootmem.h> | |
22 | ||
23 | #include <asm/setup.h> | |
24 | #include <asm/uaccess.h> | |
25 | #include <asm/page.h> | |
26 | #include <asm/pgalloc.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/machdep.h> | |
29 | #include <asm/io.h> | |
30 | #include <asm/dma.h> | |
31 | #ifdef CONFIG_ATARI | |
32 | #include <asm/atari_stram.h> | |
33 | #endif | |
34 | ||
35 | #undef DEBUG | |
36 | ||
37 | #ifndef mm_cachebits | |
38 | /* | |
39 | * Bits to add to page descriptors for "normal" caching mode. | |
40 | * For 68020/030 this is 0. | |
41 | * For 68040, this is _PAGE_CACHE040 (cachable, copyback) | |
42 | */ | |
43 | unsigned long mm_cachebits; | |
44 | EXPORT_SYMBOL(mm_cachebits); | |
45 | #endif | |
46 | ||
47 | static pte_t * __init kernel_page_table(void) | |
48 | { | |
49 | pte_t *ptablep; | |
50 | ||
51 | ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); | |
52 | ||
53 | clear_page(ptablep); | |
54 | __flush_page_to_ram(ptablep); | |
55 | flush_tlb_kernel_page(ptablep); | |
56 | nocache_page(ptablep); | |
57 | ||
58 | return ptablep; | |
59 | } | |
60 | ||
61 | static pmd_t *last_pgtable __initdata = NULL; | |
62 | pmd_t *zero_pgtable __initdata = NULL; | |
63 | ||
64 | static pmd_t * __init kernel_ptr_table(void) | |
65 | { | |
66 | if (!last_pgtable) { | |
67 | unsigned long pmd, last; | |
68 | int i; | |
69 | ||
70 | /* Find the last ptr table that was used in head.S and | |
71 | * reuse the remaining space in that page for further | |
72 | * ptr tables. | |
73 | */ | |
74 | last = (unsigned long)kernel_pg_dir; | |
75 | for (i = 0; i < PTRS_PER_PGD; i++) { | |
76 | if (!pgd_present(kernel_pg_dir[i])) | |
77 | continue; | |
78 | pmd = __pgd_page(kernel_pg_dir[i]); | |
79 | if (pmd > last) | |
80 | last = pmd; | |
81 | } | |
82 | ||
83 | last_pgtable = (pmd_t *)last; | |
84 | #ifdef DEBUG | |
85 | printk("kernel_ptr_init: %p\n", last_pgtable); | |
86 | #endif | |
87 | } | |
88 | ||
89 | last_pgtable += PTRS_PER_PMD; | |
90 | if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) { | |
91 | last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); | |
92 | ||
93 | clear_page(last_pgtable); | |
94 | __flush_page_to_ram(last_pgtable); | |
95 | flush_tlb_kernel_page(last_pgtable); | |
96 | nocache_page(last_pgtable); | |
97 | } | |
98 | ||
99 | return last_pgtable; | |
100 | } | |
101 | ||
102 | static unsigned long __init | |
103 | map_chunk (unsigned long addr, long size) | |
104 | { | |
105 | #define PTRTREESIZE (256*1024) | |
106 | #define ROOTTREESIZE (32*1024*1024) | |
107 | static unsigned long virtaddr = PAGE_OFFSET; | |
108 | unsigned long physaddr; | |
109 | pgd_t *pgd_dir; | |
110 | pmd_t *pmd_dir; | |
111 | pte_t *pte_dir; | |
112 | ||
113 | physaddr = (addr | m68k_supervisor_cachemode | | |
114 | _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY); | |
115 | if (CPU_IS_040_OR_060) | |
116 | physaddr |= _PAGE_GLOBAL040; | |
117 | ||
118 | while (size > 0) { | |
119 | #ifdef DEBUG | |
120 | if (!(virtaddr & (PTRTREESIZE-1))) | |
121 | printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, | |
122 | virtaddr); | |
123 | #endif | |
124 | pgd_dir = pgd_offset_k(virtaddr); | |
125 | if (virtaddr && CPU_IS_020_OR_030) { | |
126 | if (!(virtaddr & (ROOTTREESIZE-1)) && | |
127 | size >= ROOTTREESIZE) { | |
128 | #ifdef DEBUG | |
129 | printk ("[very early term]"); | |
130 | #endif | |
131 | pgd_val(*pgd_dir) = physaddr; | |
132 | size -= ROOTTREESIZE; | |
133 | virtaddr += ROOTTREESIZE; | |
134 | physaddr += ROOTTREESIZE; | |
135 | continue; | |
136 | } | |
137 | } | |
138 | if (!pgd_present(*pgd_dir)) { | |
139 | pmd_dir = kernel_ptr_table(); | |
140 | #ifdef DEBUG | |
141 | printk ("[new pointer %p]", pmd_dir); | |
142 | #endif | |
143 | pgd_set(pgd_dir, pmd_dir); | |
144 | } else | |
145 | pmd_dir = pmd_offset(pgd_dir, virtaddr); | |
146 | ||
147 | if (CPU_IS_020_OR_030) { | |
148 | if (virtaddr) { | |
149 | #ifdef DEBUG | |
150 | printk ("[early term]"); | |
151 | #endif | |
152 | pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; | |
153 | physaddr += PTRTREESIZE; | |
154 | } else { | |
155 | int i; | |
156 | #ifdef DEBUG | |
157 | printk ("[zero map]"); | |
158 | #endif | |
159 | zero_pgtable = kernel_ptr_table(); | |
160 | pte_dir = (pte_t *)zero_pgtable; | |
161 | pmd_dir->pmd[0] = virt_to_phys(pte_dir) | | |
162 | _PAGE_TABLE | _PAGE_ACCESSED; | |
163 | pte_val(*pte_dir++) = 0; | |
164 | physaddr += PAGE_SIZE; | |
165 | for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) | |
166 | pte_val(*pte_dir++) = physaddr; | |
167 | } | |
168 | size -= PTRTREESIZE; | |
169 | virtaddr += PTRTREESIZE; | |
170 | } else { | |
171 | if (!pmd_present(*pmd_dir)) { | |
172 | #ifdef DEBUG | |
173 | printk ("[new table]"); | |
174 | #endif | |
175 | pte_dir = kernel_page_table(); | |
176 | pmd_set(pmd_dir, pte_dir); | |
177 | } | |
178 | pte_dir = pte_offset_kernel(pmd_dir, virtaddr); | |
179 | ||
180 | if (virtaddr) { | |
181 | if (!pte_present(*pte_dir)) | |
182 | pte_val(*pte_dir) = physaddr; | |
183 | } else | |
184 | pte_val(*pte_dir) = 0; | |
185 | size -= PAGE_SIZE; | |
186 | virtaddr += PAGE_SIZE; | |
187 | physaddr += PAGE_SIZE; | |
188 | } | |
189 | ||
190 | } | |
191 | #ifdef DEBUG | |
192 | printk("\n"); | |
193 | #endif | |
194 | ||
195 | return virtaddr; | |
196 | } | |
197 | ||
198 | /* | |
199 | * paging_init() continues the virtual memory environment setup which | |
200 | * was begun by the code in arch/head.S. | |
201 | */ | |
202 | void __init paging_init(void) | |
203 | { | |
204 | int chunk; | |
205 | unsigned long mem_avail = 0; | |
206 | unsigned long zones_size[3] = { 0, }; | |
207 | ||
208 | #ifdef DEBUG | |
209 | { | |
210 | extern unsigned long availmem; | |
211 | printk ("start of paging_init (%p, %lx, %lx, %lx)\n", | |
212 | kernel_pg_dir, availmem, start_mem, end_mem); | |
213 | } | |
214 | #endif | |
215 | ||
216 | /* Fix the cache mode in the page descriptors for the 680[46]0. */ | |
217 | if (CPU_IS_040_OR_060) { | |
218 | int i; | |
219 | #ifndef mm_cachebits | |
220 | mm_cachebits = _PAGE_CACHE040; | |
221 | #endif | |
222 | for (i = 0; i < 16; i++) | |
223 | pgprot_val(protection_map[i]) |= _PAGE_CACHE040; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Map the physical memory available into the kernel virtual | |
228 | * address space. It may allocate some memory for page | |
229 | * tables and thus modify availmem. | |
230 | */ | |
231 | ||
232 | for (chunk = 0; chunk < m68k_num_memory; chunk++) { | |
233 | mem_avail = map_chunk (m68k_memory[chunk].addr, | |
234 | m68k_memory[chunk].size); | |
235 | ||
236 | } | |
237 | ||
238 | flush_tlb_all(); | |
239 | #ifdef DEBUG | |
240 | printk ("memory available is %ldKB\n", mem_avail >> 10); | |
241 | printk ("start_mem is %#lx\nvirtual_end is %#lx\n", | |
242 | start_mem, end_mem); | |
243 | #endif | |
244 | ||
245 | /* | |
246 | * initialize the bad page table and bad page to point | |
247 | * to a couple of allocated pages | |
248 | */ | |
249 | empty_zero_page = alloc_bootmem_pages(PAGE_SIZE); | |
250 | memset(empty_zero_page, 0, PAGE_SIZE); | |
251 | ||
252 | /* | |
253 | * Set up SFC/DFC registers | |
254 | */ | |
255 | set_fs(KERNEL_DS); | |
256 | ||
257 | #ifdef DEBUG | |
258 | printk ("before free_area_init\n"); | |
259 | #endif | |
260 | zones_size[0] = (mach_max_dma_address < (unsigned long)high_memory ? | |
261 | (mach_max_dma_address+1) : (unsigned long)high_memory); | |
262 | zones_size[1] = (unsigned long)high_memory - zones_size[0]; | |
263 | ||
264 | zones_size[0] = (zones_size[0] - PAGE_OFFSET) >> PAGE_SHIFT; | |
265 | zones_size[1] >>= PAGE_SHIFT; | |
266 | ||
267 | free_area_init(zones_size); | |
268 | } | |
269 | ||
270 | extern char __init_begin, __init_end; | |
271 | ||
272 | void free_initmem(void) | |
273 | { | |
274 | unsigned long addr; | |
275 | ||
276 | addr = (unsigned long)&__init_begin; | |
277 | for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) { | |
278 | virt_to_page(addr)->flags &= ~(1 << PG_reserved); | |
7835e98b | 279 | init_page_count(virt_to_page(addr)); |
1da177e4 LT |
280 | free_page(addr); |
281 | totalram_pages++; | |
282 | } | |
283 | } | |
284 | ||
285 |