arch/m68k/mm/sun3mmu.c: Eliminate NULL test and memset after alloc_bootmem
[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
34 #undef DEBUG
35
36 #ifndef mm_cachebits
37 /*
38  * Bits to add to page descriptors for "normal" caching mode.
39  * For 68020/030 this is 0.
40  * For 68040, this is _PAGE_CACHE040 (cachable, copyback)
41  */
42 unsigned long mm_cachebits;
43 EXPORT_SYMBOL(mm_cachebits);
44 #endif
45
46 /* size of memory already mapped in head.S */
47 #define INIT_MAPPED_SIZE        (4UL<<20)
48
49 extern unsigned long availmem;
50
51 static pte_t * __init kernel_page_table(void)
52 {
53         pte_t *ptablep;
54
55         ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
56
57         clear_page(ptablep);
58         __flush_page_to_ram(ptablep);
59         flush_tlb_kernel_page(ptablep);
60         nocache_page(ptablep);
61
62         return ptablep;
63 }
64
65 static pmd_t *last_pgtable __initdata = NULL;
66 pmd_t *zero_pgtable __initdata = NULL;
67
68 static pmd_t * __init kernel_ptr_table(void)
69 {
70         if (!last_pgtable) {
71                 unsigned long pmd, last;
72                 int i;
73
74                 /* Find the last ptr table that was used in head.S and
75                  * reuse the remaining space in that page for further
76                  * ptr tables.
77                  */
78                 last = (unsigned long)kernel_pg_dir;
79                 for (i = 0; i < PTRS_PER_PGD; i++) {
80                         if (!pgd_present(kernel_pg_dir[i]))
81                                 continue;
82                         pmd = __pgd_page(kernel_pg_dir[i]);
83                         if (pmd > last)
84                                 last = pmd;
85                 }
86
87                 last_pgtable = (pmd_t *)last;
88 #ifdef DEBUG
89                 printk("kernel_ptr_init: %p\n", last_pgtable);
90 #endif
91         }
92
93         last_pgtable += PTRS_PER_PMD;
94         if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
95                 last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
96
97                 clear_page(last_pgtable);
98                 __flush_page_to_ram(last_pgtable);
99                 flush_tlb_kernel_page(last_pgtable);
100                 nocache_page(last_pgtable);
101         }
102
103         return last_pgtable;
104 }
105
106 static void __init map_node(int node)
107 {
108 #define PTRTREESIZE (256*1024)
109 #define ROOTTREESIZE (32*1024*1024)
110         unsigned long physaddr, virtaddr, size;
111         pgd_t *pgd_dir;
112         pmd_t *pmd_dir;
113         pte_t *pte_dir;
114
115         size = m68k_memory[node].size;
116         physaddr = m68k_memory[node].addr;
117         virtaddr = (unsigned long)phys_to_virt(physaddr);
118         physaddr |= m68k_supervisor_cachemode |
119                     _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
120         if (CPU_IS_040_OR_060)
121                 physaddr |= _PAGE_GLOBAL040;
122
123         while (size > 0) {
124 #ifdef DEBUG
125                 if (!(virtaddr & (PTRTREESIZE-1)))
126                         printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
127                                 virtaddr);
128 #endif
129                 pgd_dir = pgd_offset_k(virtaddr);
130                 if (virtaddr && CPU_IS_020_OR_030) {
131                         if (!(virtaddr & (ROOTTREESIZE-1)) &&
132                             size >= ROOTTREESIZE) {
133 #ifdef DEBUG
134                                 printk ("[very early term]");
135 #endif
136                                 pgd_val(*pgd_dir) = physaddr;
137                                 size -= ROOTTREESIZE;
138                                 virtaddr += ROOTTREESIZE;
139                                 physaddr += ROOTTREESIZE;
140                                 continue;
141                         }
142                 }
143                 if (!pgd_present(*pgd_dir)) {
144                         pmd_dir = kernel_ptr_table();
145 #ifdef DEBUG
146                         printk ("[new pointer %p]", pmd_dir);
147 #endif
148                         pgd_set(pgd_dir, pmd_dir);
149                 } else
150                         pmd_dir = pmd_offset(pgd_dir, virtaddr);
151
152                 if (CPU_IS_020_OR_030) {
153                         if (virtaddr) {
154 #ifdef DEBUG
155                                 printk ("[early term]");
156 #endif
157                                 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
158                                 physaddr += PTRTREESIZE;
159                         } else {
160                                 int i;
161 #ifdef DEBUG
162                                 printk ("[zero map]");
163 #endif
164                                 zero_pgtable = kernel_ptr_table();
165                                 pte_dir = (pte_t *)zero_pgtable;
166                                 pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
167                                         _PAGE_TABLE | _PAGE_ACCESSED;
168                                 pte_val(*pte_dir++) = 0;
169                                 physaddr += PAGE_SIZE;
170                                 for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
171                                         pte_val(*pte_dir++) = physaddr;
172                         }
173                         size -= PTRTREESIZE;
174                         virtaddr += PTRTREESIZE;
175                 } else {
176                         if (!pmd_present(*pmd_dir)) {
177 #ifdef DEBUG
178                                 printk ("[new table]");
179 #endif
180                                 pte_dir = kernel_page_table();
181                                 pmd_set(pmd_dir, pte_dir);
182                         }
183                         pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
184
185                         if (virtaddr) {
186                                 if (!pte_present(*pte_dir))
187                                         pte_val(*pte_dir) = physaddr;
188                         } else
189                                 pte_val(*pte_dir) = 0;
190                         size -= PAGE_SIZE;
191                         virtaddr += PAGE_SIZE;
192                         physaddr += PAGE_SIZE;
193                 }
194
195         }
196 #ifdef DEBUG
197         printk("\n");
198 #endif
199 }
200
201 /*
202  * paging_init() continues the virtual memory environment setup which
203  * was begun by the code in arch/head.S.
204  */
205 void __init paging_init(void)
206 {
207         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
208         unsigned long min_addr, max_addr;
209         unsigned long addr, size, end;
210         int i;
211
212 #ifdef DEBUG
213         printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
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         min_addr = m68k_memory[0].addr;
227         max_addr = min_addr + m68k_memory[0].size;
228         for (i = 1; i < m68k_num_memory;) {
229                 if (m68k_memory[i].addr < min_addr) {
230                         printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
231                                 m68k_memory[i].addr, m68k_memory[i].size);
232                         printk("Fix your bootloader or use a memfile to make use of this area!\n");
233                         m68k_num_memory--;
234                         memmove(m68k_memory + i, m68k_memory + i + 1,
235                                 (m68k_num_memory - i) * sizeof(struct mem_info));
236                         continue;
237                 }
238                 addr = m68k_memory[i].addr + m68k_memory[i].size;
239                 if (addr > max_addr)
240                         max_addr = addr;
241                 i++;
242         }
243         m68k_memoffset = min_addr - PAGE_OFFSET;
244         m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
245
246         module_fixup(NULL, __start_fixup, __stop_fixup);
247         flush_icache();
248
249         high_memory = phys_to_virt(max_addr);
250
251         min_low_pfn = availmem >> PAGE_SHIFT;
252         max_low_pfn = max_addr >> PAGE_SHIFT;
253
254         for (i = 0; i < m68k_num_memory; i++) {
255                 addr = m68k_memory[i].addr;
256                 end = addr + m68k_memory[i].size;
257                 m68k_setup_node(i);
258                 availmem = PAGE_ALIGN(availmem);
259                 availmem += init_bootmem_node(NODE_DATA(i),
260                                               availmem >> PAGE_SHIFT,
261                                               addr >> PAGE_SHIFT,
262                                               end >> PAGE_SHIFT);
263         }
264
265         /*
266          * Map the physical memory available into the kernel virtual
267          * address space. First initialize the bootmem allocator with
268          * the memory we already mapped, so map_node() has something
269          * to allocate.
270          */
271         addr = m68k_memory[0].addr;
272         size = m68k_memory[0].size;
273         free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr));
274         map_node(0);
275         if (size > INIT_MAPPED_SIZE)
276                 free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE);
277
278         for (i = 1; i < m68k_num_memory; i++)
279                 map_node(i);
280
281         flush_tlb_all();
282
283         /*
284          * initialize the bad page table and bad page to point
285          * to a couple of allocated pages
286          */
287         empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
288
289         /*
290          * Set up SFC/DFC registers
291          */
292         set_fs(KERNEL_DS);
293
294 #ifdef DEBUG
295         printk ("before free_area_init\n");
296 #endif
297         for (i = 0; i < m68k_num_memory; i++) {
298                 zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT;
299                 free_area_init_node(i, pg_data_map + i, zones_size,
300                                     m68k_memory[i].addr >> PAGE_SHIFT, NULL);
301         }
302 }
303
304 extern char __init_begin, __init_end;
305
306 void free_initmem(void)
307 {
308         unsigned long addr;
309
310         addr = (unsigned long)&__init_begin;
311         for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) {
312                 virt_to_page(addr)->flags &= ~(1 << PG_reserved);
313                 init_page_count(virt_to_page(addr));
314                 free_page(addr);
315                 totalram_pages++;
316         }
317 }
318
319