Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas...
[linux-2.6.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 #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
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
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
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  */
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
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