[PATCH] mips: add MIPS-specific support for flatmem/discontigmem
[linux-2.6.git] / arch / mips / mm / init.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 2000 Ralf Baechle
7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
9  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
10  */
11 #include <linux/config.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/signal.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/types.h>
20 #include <linux/pagemap.h>
21 #include <linux/ptrace.h>
22 #include <linux/mman.h>
23 #include <linux/mm.h>
24 #include <linux/bootmem.h>
25 #include <linux/highmem.h>
26 #include <linux/swap.h>
27
28 #include <asm/bootinfo.h>
29 #include <asm/cachectl.h>
30 #include <asm/cpu.h>
31 #include <asm/dma.h>
32 #include <asm/mmu_context.h>
33 #include <asm/sections.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
36 #include <asm/tlb.h>
37
38 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
39
40 unsigned long highstart_pfn, highend_pfn;
41
42 /*
43  * We have up to 8 empty zeroed pages so we can map one of the right colour
44  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
45  * where we have to avoid VCED / VECI exceptions for good performance at
46  * any price.  Since page is never written to after the initialization we
47  * don't have to care about aliases on other CPUs.
48  */
49 unsigned long empty_zero_page, zero_page_mask;
50
51 /*
52  * Not static inline because used by IP27 special magic initialization code
53  */
54 unsigned long setup_zero_pages(void)
55 {
56         unsigned long order, size;
57         struct page *page;
58
59         if (cpu_has_vce)
60                 order = 3;
61         else
62                 order = 0;
63
64         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
65         if (!empty_zero_page)
66                 panic("Oh boy, that early out of memory?");
67
68         page = virt_to_page(empty_zero_page);
69         while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
70                 set_bit(PG_reserved, &page->flags);
71                 set_page_count(page, 0);
72                 page++;
73         }
74
75         size = PAGE_SIZE << order;
76         zero_page_mask = (size - 1) & PAGE_MASK;
77
78         return 1UL << order;
79 }
80
81 #ifdef CONFIG_HIGHMEM
82 pte_t *kmap_pte;
83 pgprot_t kmap_prot;
84
85 #define kmap_get_fixmap_pte(vaddr)                                      \
86         pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
87
88 static void __init kmap_init(void)
89 {
90         unsigned long kmap_vstart;
91
92         /* cache the first kmap pte */
93         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
94         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
95
96         kmap_prot = PAGE_KERNEL;
97 }
98
99 #ifdef CONFIG_MIPS64
100 static void __init fixrange_init(unsigned long start, unsigned long end,
101         pgd_t *pgd_base)
102 {
103         pgd_t *pgd;
104         pmd_t *pmd;
105         pte_t *pte;
106         int i, j;
107         unsigned long vaddr;
108
109         vaddr = start;
110         i = __pgd_offset(vaddr);
111         j = __pmd_offset(vaddr);
112         pgd = pgd_base + i;
113
114         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
115                 pmd = (pmd_t *)pgd;
116                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
117                         if (pmd_none(*pmd)) {
118                                 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
119                                 set_pmd(pmd, __pmd(pte));
120                                 if (pte != pte_offset_kernel(pmd, 0))
121                                         BUG();
122                         }
123                         vaddr += PMD_SIZE;
124                 }
125                 j = 0;
126         }
127 }
128 #endif /* CONFIG_MIPS64 */
129 #endif /* CONFIG_HIGHMEM */
130
131 #ifndef CONFIG_NEED_MULTIPLE_NODES
132 extern void pagetable_init(void);
133
134 void __init paging_init(void)
135 {
136         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
137         unsigned long max_dma, high, low;
138
139         pagetable_init();
140
141 #ifdef CONFIG_HIGHMEM
142         kmap_init();
143 #endif
144
145         max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
146         low = max_low_pfn;
147         high = highend_pfn;
148
149 #ifdef CONFIG_ISA
150         if (low < max_dma)
151                 zones_size[ZONE_DMA] = low;
152         else {
153                 zones_size[ZONE_DMA] = max_dma;
154                 zones_size[ZONE_NORMAL] = low - max_dma;
155         }
156 #else
157         zones_size[ZONE_DMA] = low;
158 #endif
159 #ifdef CONFIG_HIGHMEM
160         if (cpu_has_dc_aliases) {
161                 printk(KERN_WARNING "This processor doesn't support highmem.");
162                 if (high - low)
163                         printk(" %ldk highmem ignored", high - low);
164                 printk("\n");
165         } else
166                 zones_size[ZONE_HIGHMEM] = high - low;
167 #endif
168
169         free_area_init(zones_size);
170 }
171
172 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
173 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
174
175 static inline int page_is_ram(unsigned long pagenr)
176 {
177         int i;
178
179         for (i = 0; i < boot_mem_map.nr_map; i++) {
180                 unsigned long addr, end;
181
182                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
183                         /* not usable memory */
184                         continue;
185
186                 addr = PFN_UP(boot_mem_map.map[i].addr);
187                 end = PFN_DOWN(boot_mem_map.map[i].addr +
188                                boot_mem_map.map[i].size);
189
190                 if (pagenr >= addr && pagenr < end)
191                         return 1;
192         }
193
194         return 0;
195 }
196
197 void __init mem_init(void)
198 {
199         unsigned long codesize, reservedpages, datasize, initsize;
200         unsigned long tmp, ram;
201
202 #ifdef CONFIG_HIGHMEM
203 #ifdef CONFIG_DISCONTIGMEM
204 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
205 #endif
206         max_mapnr = num_physpages = highend_pfn;
207 #else
208         max_mapnr = num_physpages = max_low_pfn;
209 #endif
210         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
211
212         totalram_pages += free_all_bootmem();
213         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
214
215         reservedpages = ram = 0;
216         for (tmp = 0; tmp < max_low_pfn; tmp++)
217                 if (page_is_ram(tmp)) {
218                         ram++;
219                         if (PageReserved(mem_map+tmp))
220                                 reservedpages++;
221                 }
222
223 #ifdef CONFIG_HIGHMEM
224         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
225                 struct page *page = mem_map + tmp;
226
227                 if (!page_is_ram(tmp)) {
228                         SetPageReserved(page);
229                         continue;
230                 }
231                 ClearPageReserved(page);
232 #ifdef CONFIG_LIMITED_DMA
233                 set_page_address(page, lowmem_page_address(page));
234 #endif
235                 set_page_count(page, 1);
236                 __free_page(page);
237                 totalhigh_pages++;
238         }
239         totalram_pages += totalhigh_pages;
240 #endif
241
242         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
243         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
244         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
245
246         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
247                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
248                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
249                ram << (PAGE_SHIFT-10),
250                codesize >> 10,
251                reservedpages << (PAGE_SHIFT-10),
252                datasize >> 10,
253                initsize >> 10,
254                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
255 }
256 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
257
258 #ifdef CONFIG_BLK_DEV_INITRD
259 void free_initrd_mem(unsigned long start, unsigned long end)
260 {
261 #ifdef CONFIG_MIPS64
262         /* Switch from KSEG0 to XKPHYS addresses */
263         start = (unsigned long)phys_to_virt(CPHYSADDR(start));
264         end = (unsigned long)phys_to_virt(CPHYSADDR(end));
265 #endif
266         if (start < end)
267                 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
268                        (end - start) >> 10);
269
270         for (; start < end; start += PAGE_SIZE) {
271                 ClearPageReserved(virt_to_page(start));
272                 set_page_count(virt_to_page(start), 1);
273                 free_page(start);
274                 totalram_pages++;
275         }
276 }
277 #endif
278
279 extern unsigned long prom_free_prom_memory(void);
280
281 void free_initmem(void)
282 {
283         unsigned long addr, page, freed;
284
285         freed = prom_free_prom_memory();
286
287         addr = (unsigned long) &__init_begin;
288         while (addr < (unsigned long) &__init_end) {
289 #ifdef CONFIG_MIPS64
290                 page = PAGE_OFFSET | CPHYSADDR(addr);
291 #else
292                 page = addr;
293 #endif
294                 ClearPageReserved(virt_to_page(page));
295                 set_page_count(virt_to_page(page), 1);
296                 free_page(page);
297                 totalram_pages++;
298                 freed += PAGE_SIZE;
299                 addr += PAGE_SIZE;
300         }
301         printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
302                freed >> 10);
303 }