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/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 #include <asm/sections.h>
35
36 #undef DEBUG
37
38 #ifndef mm_cachebits
39 /*
40 * Bits to add to page descriptors for "normal" caching mode.
41 * For 68020/030 this is 0.
42 * For 68040, this is _PAGE_CACHE040 (cachable, copyback)
43 */
44 unsigned long mm_cachebits;
45 EXPORT_SYMBOL(mm_cachebits);
46 #endif
47
48 /* size of memory already mapped in head.S */
49 #define INIT_MAPPED_SIZE (4UL<<20)
50
51 extern unsigned long availmem;
52
kernel_page_table(void)53 static pte_t * __init kernel_page_table(void)
54 {
55 pte_t *ptablep;
56
57 ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
58
59 clear_page(ptablep);
60 __flush_page_to_ram(ptablep);
61 flush_tlb_kernel_page(ptablep);
62 nocache_page(ptablep);
63
64 return ptablep;
65 }
66
67 static pmd_t *last_pgtable __initdata = NULL;
68 pmd_t *zero_pgtable __initdata = NULL;
69
kernel_ptr_table(void)70 static pmd_t * __init kernel_ptr_table(void)
71 {
72 if (!last_pgtable) {
73 unsigned long pmd, last;
74 int i;
75
76 /* Find the last ptr table that was used in head.S and
77 * reuse the remaining space in that page for further
78 * ptr tables.
79 */
80 last = (unsigned long)kernel_pg_dir;
81 for (i = 0; i < PTRS_PER_PGD; i++) {
82 if (!pgd_present(kernel_pg_dir[i]))
83 continue;
84 pmd = __pgd_page(kernel_pg_dir[i]);
85 if (pmd > last)
86 last = pmd;
87 }
88
89 last_pgtable = (pmd_t *)last;
90 #ifdef DEBUG
91 printk("kernel_ptr_init: %p\n", last_pgtable);
92 #endif
93 }
94
95 last_pgtable += PTRS_PER_PMD;
96 if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
97 last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
98
99 clear_page(last_pgtable);
100 __flush_page_to_ram(last_pgtable);
101 flush_tlb_kernel_page(last_pgtable);
102 nocache_page(last_pgtable);
103 }
104
105 return last_pgtable;
106 }
107
map_node(int node)108 static void __init map_node(int node)
109 {
110 #define PTRTREESIZE (256*1024)
111 #define ROOTTREESIZE (32*1024*1024)
112 unsigned long physaddr, virtaddr, size;
113 pgd_t *pgd_dir;
114 pmd_t *pmd_dir;
115 pte_t *pte_dir;
116
117 size = m68k_memory[node].size;
118 physaddr = m68k_memory[node].addr;
119 virtaddr = (unsigned long)phys_to_virt(physaddr);
120 physaddr |= m68k_supervisor_cachemode |
121 _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
122 if (CPU_IS_040_OR_060)
123 physaddr |= _PAGE_GLOBAL040;
124
125 while (size > 0) {
126 #ifdef DEBUG
127 if (!(virtaddr & (PTRTREESIZE-1)))
128 printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
129 virtaddr);
130 #endif
131 pgd_dir = pgd_offset_k(virtaddr);
132 if (virtaddr && CPU_IS_020_OR_030) {
133 if (!(virtaddr & (ROOTTREESIZE-1)) &&
134 size >= ROOTTREESIZE) {
135 #ifdef DEBUG
136 printk ("[very early term]");
137 #endif
138 pgd_val(*pgd_dir) = physaddr;
139 size -= ROOTTREESIZE;
140 virtaddr += ROOTTREESIZE;
141 physaddr += ROOTTREESIZE;
142 continue;
143 }
144 }
145 if (!pgd_present(*pgd_dir)) {
146 pmd_dir = kernel_ptr_table();
147 #ifdef DEBUG
148 printk ("[new pointer %p]", pmd_dir);
149 #endif
150 pgd_set(pgd_dir, pmd_dir);
151 } else
152 pmd_dir = pmd_offset(pgd_dir, virtaddr);
153
154 if (CPU_IS_020_OR_030) {
155 if (virtaddr) {
156 #ifdef DEBUG
157 printk ("[early term]");
158 #endif
159 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
160 physaddr += PTRTREESIZE;
161 } else {
162 int i;
163 #ifdef DEBUG
164 printk ("[zero map]");
165 #endif
166 zero_pgtable = kernel_ptr_table();
167 pte_dir = (pte_t *)zero_pgtable;
168 pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
169 _PAGE_TABLE | _PAGE_ACCESSED;
170 pte_val(*pte_dir++) = 0;
171 physaddr += PAGE_SIZE;
172 for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
173 pte_val(*pte_dir++) = physaddr;
174 }
175 size -= PTRTREESIZE;
176 virtaddr += PTRTREESIZE;
177 } else {
178 if (!pmd_present(*pmd_dir)) {
179 #ifdef DEBUG
180 printk ("[new table]");
181 #endif
182 pte_dir = kernel_page_table();
183 pmd_set(pmd_dir, pte_dir);
184 }
185 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
186
187 if (virtaddr) {
188 if (!pte_present(*pte_dir))
189 pte_val(*pte_dir) = physaddr;
190 } else
191 pte_val(*pte_dir) = 0;
192 size -= PAGE_SIZE;
193 virtaddr += PAGE_SIZE;
194 physaddr += PAGE_SIZE;
195 }
196
197 }
198 #ifdef DEBUG
199 printk("\n");
200 #endif
201 }
202
203 /*
204 * paging_init() continues the virtual memory environment setup which
205 * was begun by the code in arch/head.S.
206 */
paging_init(void)207 void __init paging_init(void)
208 {
209 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
210 unsigned long min_addr, max_addr;
211 unsigned long addr, size, end;
212 int i;
213
214 #ifdef DEBUG
215 printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
216 #endif
217
218 /* Fix the cache mode in the page descriptors for the 680[46]0. */
219 if (CPU_IS_040_OR_060) {
220 int i;
221 #ifndef mm_cachebits
222 mm_cachebits = _PAGE_CACHE040;
223 #endif
224 for (i = 0; i < 16; i++)
225 pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
226 }
227
228 min_addr = m68k_memory[0].addr;
229 max_addr = min_addr + m68k_memory[0].size;
230 for (i = 1; i < m68k_num_memory;) {
231 if (m68k_memory[i].addr < min_addr) {
232 printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
233 m68k_memory[i].addr, m68k_memory[i].size);
234 printk("Fix your bootloader or use a memfile to make use of this area!\n");
235 m68k_num_memory--;
236 memmove(m68k_memory + i, m68k_memory + i + 1,
237 (m68k_num_memory - i) * sizeof(struct mem_info));
238 continue;
239 }
240 addr = m68k_memory[i].addr + m68k_memory[i].size;
241 if (addr > max_addr)
242 max_addr = addr;
243 i++;
244 }
245 m68k_memoffset = min_addr - PAGE_OFFSET;
246 m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
247
248 module_fixup(NULL, __start_fixup, __stop_fixup);
249 flush_icache();
250
251 high_memory = phys_to_virt(max_addr);
252
253 min_low_pfn = availmem >> PAGE_SHIFT;
254 max_low_pfn = max_addr >> PAGE_SHIFT;
255
256 for (i = 0; i < m68k_num_memory; i++) {
257 addr = m68k_memory[i].addr;
258 end = addr + m68k_memory[i].size;
259 m68k_setup_node(i);
260 availmem = PAGE_ALIGN(availmem);
261 availmem += init_bootmem_node(NODE_DATA(i),
262 availmem >> PAGE_SHIFT,
263 addr >> PAGE_SHIFT,
264 end >> PAGE_SHIFT);
265 }
266
267 /*
268 * Map the physical memory available into the kernel virtual
269 * address space. First initialize the bootmem allocator with
270 * the memory we already mapped, so map_node() has something
271 * to allocate.
272 */
273 addr = m68k_memory[0].addr;
274 size = m68k_memory[0].size;
275 free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr));
276 map_node(0);
277 if (size > INIT_MAPPED_SIZE)
278 free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE);
279
280 for (i = 1; i < m68k_num_memory; i++)
281 map_node(i);
282
283 flush_tlb_all();
284
285 /*
286 * initialize the bad page table and bad page to point
287 * to a couple of allocated pages
288 */
289 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
290
291 /*
292 * Set up SFC/DFC registers
293 */
294 set_fs(KERNEL_DS);
295
296 #ifdef DEBUG
297 printk ("before free_area_init\n");
298 #endif
299 for (i = 0; i < m68k_num_memory; i++) {
300 zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT;
301 free_area_init_node(i, zones_size,
302 m68k_memory[i].addr >> PAGE_SHIFT, NULL);
303 if (node_present_pages(i))
304 node_set_state(i, N_NORMAL_MEMORY);
305 }
306 }
307
free_initmem(void)308 void free_initmem(void)
309 {
310 unsigned long addr;
311
312 addr = (unsigned long)__init_begin;
313 for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
314 virt_to_page(addr)->flags &= ~(1 << PG_reserved);
315 init_page_count(virt_to_page(addr));
316 free_page(addr);
317 totalram_pages++;
318 }
319 }
320
321
322