xref: /linux/arch/mips/mm/init.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 #include <linux/proc_fs.h>
28 #include <linux/pfn.h>
29 
30 #include <asm/bootinfo.h>
31 #include <asm/cachectl.h>
32 #include <asm/cpu.h>
33 #include <asm/dma.h>
34 #include <asm/mmu_context.h>
35 #include <asm/sections.h>
36 #include <asm/pgtable.h>
37 #include <asm/pgalloc.h>
38 #include <asm/tlb.h>
39 
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41 
42 unsigned long highstart_pfn, highend_pfn;
43 
44 /*
45  * We have up to 8 empty zeroed pages so we can map one of the right colour
46  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
47  * where we have to avoid VCED / VECI exceptions for good performance at
48  * any price.  Since page is never written to after the initialization we
49  * don't have to care about aliases on other CPUs.
50  */
51 unsigned long empty_zero_page, zero_page_mask;
52 
53 /*
54  * Not static inline because used by IP27 special magic initialization code
55  */
56 unsigned long setup_zero_pages(void)
57 {
58 	unsigned int order;
59 	unsigned long size;
60 	struct page *page;
61 
62 	if (cpu_has_vce)
63 		order = 3;
64 	else
65 		order = 0;
66 
67 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
68 	if (!empty_zero_page)
69 		panic("Oh boy, that early out of memory?");
70 
71 	page = virt_to_page(empty_zero_page);
72 	split_page(page, order);
73 	while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
74 		SetPageReserved(page);
75 		page++;
76 	}
77 
78 	size = PAGE_SIZE << order;
79 	zero_page_mask = (size - 1) & PAGE_MASK;
80 
81 	return 1UL << order;
82 }
83 
84 #ifdef CONFIG_HIGHMEM
85 pte_t *kmap_pte;
86 pgprot_t kmap_prot;
87 
88 #define kmap_get_fixmap_pte(vaddr)					\
89 	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
90 
91 static void __init kmap_init(void)
92 {
93 	unsigned long kmap_vstart;
94 
95 	/* cache the first kmap pte */
96 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
97 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
98 
99 	kmap_prot = PAGE_KERNEL;
100 }
101 
102 #ifdef CONFIG_32BIT
103 void __init fixrange_init(unsigned long start, unsigned long end,
104 	pgd_t *pgd_base)
105 {
106 	pgd_t *pgd;
107 	pud_t *pud;
108 	pmd_t *pmd;
109 	pte_t *pte;
110 	int i, j, k;
111 	unsigned long vaddr;
112 
113 	vaddr = start;
114 	i = __pgd_offset(vaddr);
115 	j = __pud_offset(vaddr);
116 	k = __pmd_offset(vaddr);
117 	pgd = pgd_base + i;
118 
119 	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
120 		pud = (pud_t *)pgd;
121 		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
122 			pmd = (pmd_t *)pud;
123 			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
124 				if (pmd_none(*pmd)) {
125 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
126 					set_pmd(pmd, __pmd(pte));
127 					if (pte != pte_offset_kernel(pmd, 0))
128 						BUG();
129 				}
130 				vaddr += PMD_SIZE;
131 			}
132 			k = 0;
133 		}
134 		j = 0;
135 	}
136 }
137 #endif /* CONFIG_32BIT */
138 #endif /* CONFIG_HIGHMEM */
139 
140 #ifndef CONFIG_NEED_MULTIPLE_NODES
141 extern void pagetable_init(void);
142 
143 void __init paging_init(void)
144 {
145 	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
146 	unsigned long max_dma, high, low;
147 
148 	pagetable_init();
149 
150 #ifdef CONFIG_HIGHMEM
151 	kmap_init();
152 #endif
153 
154 	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
155 	low = max_low_pfn;
156 	high = highend_pfn;
157 
158 #ifdef CONFIG_ISA
159 	if (low < max_dma)
160 		zones_size[ZONE_DMA] = low;
161 	else {
162 		zones_size[ZONE_DMA] = max_dma;
163 		zones_size[ZONE_NORMAL] = low - max_dma;
164 	}
165 #else
166 	zones_size[ZONE_DMA] = low;
167 #endif
168 #ifdef CONFIG_HIGHMEM
169 	if (cpu_has_dc_aliases) {
170 		printk(KERN_WARNING "This processor doesn't support highmem.");
171 		if (high - low)
172 			printk(" %ldk highmem ignored", high - low);
173 		printk("\n");
174 	} else
175 		zones_size[ZONE_HIGHMEM] = high - low;
176 #endif
177 
178 	free_area_init(zones_size);
179 }
180 
181 static inline int page_is_ram(unsigned long pagenr)
182 {
183 	int i;
184 
185 	for (i = 0; i < boot_mem_map.nr_map; i++) {
186 		unsigned long addr, end;
187 
188 		if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
189 			/* not usable memory */
190 			continue;
191 
192 		addr = PFN_UP(boot_mem_map.map[i].addr);
193 		end = PFN_DOWN(boot_mem_map.map[i].addr +
194 			       boot_mem_map.map[i].size);
195 
196 		if (pagenr >= addr && pagenr < end)
197 			return 1;
198 	}
199 
200 	return 0;
201 }
202 
203 static struct kcore_list kcore_mem, kcore_vmalloc;
204 #ifdef CONFIG_64BIT
205 static struct kcore_list kcore_kseg0;
206 #endif
207 
208 void __init mem_init(void)
209 {
210 	unsigned long codesize, reservedpages, datasize, initsize;
211 	unsigned long tmp, ram;
212 
213 #ifdef CONFIG_HIGHMEM
214 #ifdef CONFIG_DISCONTIGMEM
215 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
216 #endif
217 	max_mapnr = num_physpages = highend_pfn;
218 #else
219 	max_mapnr = num_physpages = max_low_pfn;
220 #endif
221 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
222 
223 	totalram_pages += free_all_bootmem();
224 	totalram_pages -= setup_zero_pages();	/* Setup zeroed pages.  */
225 
226 	reservedpages = ram = 0;
227 	for (tmp = 0; tmp < max_low_pfn; tmp++)
228 		if (page_is_ram(tmp)) {
229 			ram++;
230 			if (PageReserved(pfn_to_page(tmp)))
231 				reservedpages++;
232 		}
233 
234 #ifdef CONFIG_HIGHMEM
235 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
236 		struct page *page = mem_map + tmp;
237 
238 		if (!page_is_ram(tmp)) {
239 			SetPageReserved(page);
240 			continue;
241 		}
242 		ClearPageReserved(page);
243 #ifdef CONFIG_LIMITED_DMA
244 		set_page_address(page, lowmem_page_address(page));
245 #endif
246 		init_page_count(page);
247 		__free_page(page);
248 		totalhigh_pages++;
249 	}
250 	totalram_pages += totalhigh_pages;
251 #endif
252 
253 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
254 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
255 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
256 
257 #ifdef CONFIG_64BIT
258 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
259 		/* The -4 is a hack so that user tools don't have to handle
260 		   the overflow.  */
261 		kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
262 #endif
263 	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
264 	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
265 		   VMALLOC_END-VMALLOC_START);
266 
267 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
268 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
269 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
270 	       ram << (PAGE_SHIFT-10),
271 	       codesize >> 10,
272 	       reservedpages << (PAGE_SHIFT-10),
273 	       datasize >> 10,
274 	       initsize >> 10,
275 	       (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
276 }
277 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
278 
279 void free_init_pages(char *what, unsigned long begin, unsigned long end)
280 {
281 	unsigned long addr;
282 
283 	for (addr = begin; addr < end; addr += PAGE_SIZE) {
284 		ClearPageReserved(virt_to_page(addr));
285 		init_page_count(virt_to_page(addr));
286 		memset((void *)addr, 0xcc, PAGE_SIZE);
287 		free_page(addr);
288 		totalram_pages++;
289 	}
290 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
291 }
292 
293 #ifdef CONFIG_BLK_DEV_INITRD
294 void free_initrd_mem(unsigned long start, unsigned long end)
295 {
296 #ifdef CONFIG_64BIT
297 	/* Switch from KSEG0 to XKPHYS addresses */
298 	start = (unsigned long)phys_to_virt(CPHYSADDR(start));
299 	end = (unsigned long)phys_to_virt(CPHYSADDR(end));
300 #endif
301 	free_init_pages("initrd memory", start, end);
302 }
303 #endif
304 
305 extern unsigned long prom_free_prom_memory(void);
306 
307 void free_initmem(void)
308 {
309 	unsigned long start, end, freed;
310 
311 	freed = prom_free_prom_memory();
312 	if (freed)
313 		printk(KERN_INFO "Freeing firmware memory: %ldk freed\n",freed);
314 
315 	start = (unsigned long)(&__init_begin);
316 	end = (unsigned long)(&__init_end);
317 #ifdef CONFIG_64BIT
318 	start = PAGE_OFFSET | CPHYSADDR(start);
319 	end = PAGE_OFFSET | CPHYSADDR(end);
320 #endif
321 	free_init_pages("unused kernel memory", start, end);
322 }
323