1 /*
2 * linux/arch/m68k/mm/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/module.h>
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/swap.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/init.h>
20 #include <linux/bootmem.h>
21 #include <linux/gfp.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/machdep.h>
28 #include <asm/io.h>
29 #include <asm/dma.h>
30 #ifdef CONFIG_ATARI
31 #include <asm/atari_stram.h>
32 #endif
33 #include <asm/sections.h>
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 /* size of memory already mapped in head.S */
48 #define INIT_MAPPED_SIZE (4UL<<20)
49
50 extern unsigned long availmem;
51
kernel_page_table(void)52 static pte_t * __init kernel_page_table(void)
53 {
54 pte_t *ptablep;
55
56 ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
57
58 clear_page(ptablep);
59 __flush_page_to_ram(ptablep);
60 flush_tlb_kernel_page(ptablep);
61 nocache_page(ptablep);
62
63 return ptablep;
64 }
65
66 static pmd_t *last_pgtable __initdata = NULL;
67 pmd_t *zero_pgtable __initdata = NULL;
68
kernel_ptr_table(void)69 static pmd_t * __init kernel_ptr_table(void)
70 {
71 if (!last_pgtable) {
72 unsigned long pmd, last;
73 int i;
74
75 /* Find the last ptr table that was used in head.S and
76 * reuse the remaining space in that page for further
77 * ptr tables.
78 */
79 last = (unsigned long)kernel_pg_dir;
80 for (i = 0; i < PTRS_PER_PGD; i++) {
81 if (!pgd_present(kernel_pg_dir[i]))
82 continue;
83 pmd = __pgd_page(kernel_pg_dir[i]);
84 if (pmd > last)
85 last = pmd;
86 }
87
88 last_pgtable = (pmd_t *)last;
89 #ifdef DEBUG
90 printk("kernel_ptr_init: %p\n", last_pgtable);
91 #endif
92 }
93
94 last_pgtable += PTRS_PER_PMD;
95 if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
96 last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
97
98 clear_page(last_pgtable);
99 __flush_page_to_ram(last_pgtable);
100 flush_tlb_kernel_page(last_pgtable);
101 nocache_page(last_pgtable);
102 }
103
104 return last_pgtable;
105 }
106
map_node(int node)107 static void __init map_node(int node)
108 {
109 #define PTRTREESIZE (256*1024)
110 #define ROOTTREESIZE (32*1024*1024)
111 unsigned long physaddr, virtaddr, size;
112 pgd_t *pgd_dir;
113 pmd_t *pmd_dir;
114 pte_t *pte_dir;
115
116 size = m68k_memory[node].size;
117 physaddr = m68k_memory[node].addr;
118 virtaddr = (unsigned long)phys_to_virt(physaddr);
119 physaddr |= m68k_supervisor_cachemode |
120 _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
121 if (CPU_IS_040_OR_060)
122 physaddr |= _PAGE_GLOBAL040;
123
124 while (size > 0) {
125 #ifdef DEBUG
126 if (!(virtaddr & (PTRTREESIZE-1)))
127 printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
128 virtaddr);
129 #endif
130 pgd_dir = pgd_offset_k(virtaddr);
131 if (virtaddr && CPU_IS_020_OR_030) {
132 if (!(virtaddr & (ROOTTREESIZE-1)) &&
133 size >= ROOTTREESIZE) {
134 #ifdef DEBUG
135 printk ("[very early term]");
136 #endif
137 pgd_val(*pgd_dir) = physaddr;
138 size -= ROOTTREESIZE;
139 virtaddr += ROOTTREESIZE;
140 physaddr += ROOTTREESIZE;
141 continue;
142 }
143 }
144 if (!pgd_present(*pgd_dir)) {
145 pmd_dir = kernel_ptr_table();
146 #ifdef DEBUG
147 printk ("[new pointer %p]", pmd_dir);
148 #endif
149 pgd_set(pgd_dir, pmd_dir);
150 } else
151 pmd_dir = pmd_offset(pgd_dir, virtaddr);
152
153 if (CPU_IS_020_OR_030) {
154 if (virtaddr) {
155 #ifdef DEBUG
156 printk ("[early term]");
157 #endif
158 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
159 physaddr += PTRTREESIZE;
160 } else {
161 int i;
162 #ifdef DEBUG
163 printk ("[zero map]");
164 #endif
165 zero_pgtable = kernel_ptr_table();
166 pte_dir = (pte_t *)zero_pgtable;
167 pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
168 _PAGE_TABLE | _PAGE_ACCESSED;
169 pte_val(*pte_dir++) = 0;
170 physaddr += PAGE_SIZE;
171 for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
172 pte_val(*pte_dir++) = physaddr;
173 }
174 size -= PTRTREESIZE;
175 virtaddr += PTRTREESIZE;
176 } else {
177 if (!pmd_present(*pmd_dir)) {
178 #ifdef DEBUG
179 printk ("[new table]");
180 #endif
181 pte_dir = kernel_page_table();
182 pmd_set(pmd_dir, pte_dir);
183 }
184 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
185
186 if (virtaddr) {
187 if (!pte_present(*pte_dir))
188 pte_val(*pte_dir) = physaddr;
189 } else
190 pte_val(*pte_dir) = 0;
191 size -= PAGE_SIZE;
192 virtaddr += PAGE_SIZE;
193 physaddr += PAGE_SIZE;
194 }
195
196 }
197 #ifdef DEBUG
198 printk("\n");
199 #endif
200 }
201
202 /*
203 * paging_init() continues the virtual memory environment setup which
204 * was begun by the code in arch/head.S.
205 */
paging_init(void)206 void __init paging_init(void)
207 {
208 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
209 unsigned long min_addr, max_addr;
210 unsigned long addr, size, end;
211 int i;
212
213 #ifdef DEBUG
214 printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
215 #endif
216
217 /* Fix the cache mode in the page descriptors for the 680[46]0. */
218 if (CPU_IS_040_OR_060) {
219 int i;
220 #ifndef mm_cachebits
221 mm_cachebits = _PAGE_CACHE040;
222 #endif
223 for (i = 0; i < 16; i++)
224 pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
225 }
226
227 min_addr = m68k_memory[0].addr;
228 max_addr = min_addr + m68k_memory[0].size;
229 for (i = 1; i < m68k_num_memory;) {
230 if (m68k_memory[i].addr < min_addr) {
231 printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
232 m68k_memory[i].addr, m68k_memory[i].size);
233 printk("Fix your bootloader or use a memfile to make use of this area!\n");
234 m68k_num_memory--;
235 memmove(m68k_memory + i, m68k_memory + i + 1,
236 (m68k_num_memory - i) * sizeof(struct mem_info));
237 continue;
238 }
239 addr = m68k_memory[i].addr + m68k_memory[i].size;
240 if (addr > max_addr)
241 max_addr = addr;
242 i++;
243 }
244 m68k_memoffset = min_addr - PAGE_OFFSET;
245 m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
246
247 module_fixup(NULL, __start_fixup, __stop_fixup);
248 flush_icache();
249
250 high_memory = phys_to_virt(max_addr);
251
252 min_low_pfn = availmem >> PAGE_SHIFT;
253 max_low_pfn = max_addr >> PAGE_SHIFT;
254
255 for (i = 0; i < m68k_num_memory; i++) {
256 addr = m68k_memory[i].addr;
257 end = addr + m68k_memory[i].size;
258 m68k_setup_node(i);
259 availmem = PAGE_ALIGN(availmem);
260 availmem += init_bootmem_node(NODE_DATA(i),
261 availmem >> PAGE_SHIFT,
262 addr >> PAGE_SHIFT,
263 end >> PAGE_SHIFT);
264 }
265
266 /*
267 * Map the physical memory available into the kernel virtual
268 * address space. First initialize the bootmem allocator with
269 * the memory we already mapped, so map_node() has something
270 * to allocate.
271 */
272 addr = m68k_memory[0].addr;
273 size = m68k_memory[0].size;
274 free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr));
275 map_node(0);
276 if (size > INIT_MAPPED_SIZE)
277 free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE);
278
279 for (i = 1; i < m68k_num_memory; i++)
280 map_node(i);
281
282 flush_tlb_all();
283
284 /*
285 * initialize the bad page table and bad page to point
286 * to a couple of allocated pages
287 */
288 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
289
290 /*
291 * Set up SFC/DFC registers
292 */
293 set_fs(KERNEL_DS);
294
295 #ifdef DEBUG
296 printk ("before free_area_init\n");
297 #endif
298 for (i = 0; i < m68k_num_memory; i++) {
299 zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT;
300 free_area_init_node(i, zones_size,
301 m68k_memory[i].addr >> PAGE_SHIFT, NULL);
302 if (node_present_pages(i))
303 node_set_state(i, N_NORMAL_MEMORY);
304 }
305 }
306
free_initmem(void)307 void free_initmem(void)
308 {
309 unsigned long addr;
310
311 addr = (unsigned long)__init_begin;
312 for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
313 virt_to_page(addr)->flags &= ~(1 << PG_reserved);
314 init_page_count(virt_to_page(addr));
315 free_page(addr);
316 totalram_pages++;
317 }
318 }
319
320
321