m68k: Kill several external declarations in source files
[linux-3.10.git] / arch / m68k / mm / motorola.c
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
22 #include <asm/setup.h>
23 #include <asm/uaccess.h>
24 #include <asm/page.h>
25 #include <asm/pgalloc.h>
26 #include <asm/system.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
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
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
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  */
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         }
303 }
304
305 void free_initmem(void)
306 {
307         unsigned long addr;
308
309         addr = (unsigned long)__init_begin;
310         for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
311                 virt_to_page(addr)->flags &= ~(1 << PG_reserved);
312                 init_page_count(virt_to_page(addr));
313                 free_page(addr);
314                 totalram_pages++;
315         }
316 }
317
318