xref: /linux/arch/mips/mm/init.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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 
29 #include <asm/bootinfo.h>
30 #include <asm/cachectl.h>
31 #include <asm/cpu.h>
32 #include <asm/dma.h>
33 #include <asm/mmu_context.h>
34 #include <asm/sections.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/tlb.h>
38 
39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
40 
41 unsigned long highstart_pfn, highend_pfn;
42 
43 /*
44  * We have up to 8 empty zeroed pages so we can map one of the right colour
45  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
46  * where we have to avoid VCED / VECI exceptions for good performance at
47  * any price.  Since page is never written to after the initialization we
48  * don't have to care about aliases on other CPUs.
49  */
50 unsigned long empty_zero_page, zero_page_mask;
51 
52 /*
53  * Not static inline because used by IP27 special magic initialization code
54  */
55 unsigned long setup_zero_pages(void)
56 {
57 	unsigned long order, size;
58 	struct page *page;
59 
60 	if (cpu_has_vce)
61 		order = 3;
62 	else
63 		order = 0;
64 
65 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
66 	if (!empty_zero_page)
67 		panic("Oh boy, that early out of memory?");
68 
69 	page = virt_to_page(empty_zero_page);
70 	while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
71 		SetPageReserved(page);
72 		set_page_count(page, 1);
73 		page++;
74 	}
75 
76 	size = PAGE_SIZE << order;
77 	zero_page_mask = (size - 1) & PAGE_MASK;
78 
79 	return 1UL << order;
80 }
81 
82 #ifdef CONFIG_HIGHMEM
83 pte_t *kmap_pte;
84 pgprot_t kmap_prot;
85 
86 #define kmap_get_fixmap_pte(vaddr)					\
87 	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
88 
89 static void __init kmap_init(void)
90 {
91 	unsigned long kmap_vstart;
92 
93 	/* cache the first kmap pte */
94 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
95 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
96 
97 	kmap_prot = PAGE_KERNEL;
98 }
99 
100 #ifdef CONFIG_32BIT
101 void __init fixrange_init(unsigned long start, unsigned long end,
102 	pgd_t *pgd_base)
103 {
104 	pgd_t *pgd;
105 	pud_t *pud;
106 	pmd_t *pmd;
107 	pte_t *pte;
108 	int i, j, k;
109 	unsigned long vaddr;
110 
111 	vaddr = start;
112 	i = __pgd_offset(vaddr);
113 	j = __pud_offset(vaddr);
114 	k = __pmd_offset(vaddr);
115 	pgd = pgd_base + i;
116 
117 	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
118 		pud = (pud_t *)pgd;
119 		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
120 			pmd = (pmd_t *)pud;
121 			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
122 				if (pmd_none(*pmd)) {
123 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
124 					set_pmd(pmd, __pmd(pte));
125 					if (pte != pte_offset_kernel(pmd, 0))
126 						BUG();
127 				}
128 				vaddr += PMD_SIZE;
129 			}
130 			k = 0;
131 		}
132 		j = 0;
133 	}
134 }
135 #endif /* CONFIG_32BIT */
136 #endif /* CONFIG_HIGHMEM */
137 
138 #ifndef CONFIG_NEED_MULTIPLE_NODES
139 extern void pagetable_init(void);
140 
141 void __init paging_init(void)
142 {
143 	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
144 	unsigned long max_dma, high, low;
145 
146 	pagetable_init();
147 
148 #ifdef CONFIG_HIGHMEM
149 	kmap_init();
150 #endif
151 
152 	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
153 	low = max_low_pfn;
154 	high = highend_pfn;
155 
156 #ifdef CONFIG_ISA
157 	if (low < max_dma)
158 		zones_size[ZONE_DMA] = low;
159 	else {
160 		zones_size[ZONE_DMA] = max_dma;
161 		zones_size[ZONE_NORMAL] = low - max_dma;
162 	}
163 #else
164 	zones_size[ZONE_DMA] = low;
165 #endif
166 #ifdef CONFIG_HIGHMEM
167 	if (cpu_has_dc_aliases) {
168 		printk(KERN_WARNING "This processor doesn't support highmem.");
169 		if (high - low)
170 			printk(" %ldk highmem ignored", high - low);
171 		printk("\n");
172 	} else
173 		zones_size[ZONE_HIGHMEM] = high - low;
174 #endif
175 
176 	free_area_init(zones_size);
177 }
178 
179 #define PFN_UP(x)	(((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
180 #define PFN_DOWN(x)	((x) >> PAGE_SHIFT)
181 
182 static inline int page_is_ram(unsigned long pagenr)
183 {
184 	int i;
185 
186 	for (i = 0; i < boot_mem_map.nr_map; i++) {
187 		unsigned long addr, end;
188 
189 		if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
190 			/* not usable memory */
191 			continue;
192 
193 		addr = PFN_UP(boot_mem_map.map[i].addr);
194 		end = PFN_DOWN(boot_mem_map.map[i].addr +
195 			       boot_mem_map.map[i].size);
196 
197 		if (pagenr >= addr && pagenr < end)
198 			return 1;
199 	}
200 
201 	return 0;
202 }
203 
204 static struct kcore_list kcore_mem, kcore_vmalloc;
205 #ifdef CONFIG_64BIT
206 static struct kcore_list kcore_kseg0;
207 #endif
208 
209 void __init mem_init(void)
210 {
211 	unsigned long codesize, reservedpages, datasize, initsize;
212 	unsigned long tmp, ram;
213 
214 #ifdef CONFIG_HIGHMEM
215 #ifdef CONFIG_DISCONTIGMEM
216 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
217 #endif
218 	max_mapnr = num_physpages = highend_pfn;
219 #else
220 	max_mapnr = num_physpages = max_low_pfn;
221 #endif
222 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
223 
224 	totalram_pages += free_all_bootmem();
225 	totalram_pages -= setup_zero_pages();	/* Setup zeroed pages.  */
226 
227 	reservedpages = ram = 0;
228 	for (tmp = 0; tmp < max_low_pfn; tmp++)
229 		if (page_is_ram(tmp)) {
230 			ram++;
231 			if (PageReserved(mem_map+tmp))
232 				reservedpages++;
233 		}
234 
235 #ifdef CONFIG_HIGHMEM
236 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
237 		struct page *page = mem_map + tmp;
238 
239 		if (!page_is_ram(tmp)) {
240 			SetPageReserved(page);
241 			continue;
242 		}
243 		ClearPageReserved(page);
244 #ifdef CONFIG_LIMITED_DMA
245 		set_page_address(page, lowmem_page_address(page));
246 #endif
247 		set_page_count(page, 1);
248 		__free_page(page);
249 		totalhigh_pages++;
250 	}
251 	totalram_pages += totalhigh_pages;
252 #endif
253 
254 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
255 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
256 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
257 
258 #ifdef CONFIG_64BIT
259 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
260 		/* The -4 is a hack so that user tools don't have to handle
261 		   the overflow.  */
262 		kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
263 #endif
264 	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
265 	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
266 		   VMALLOC_END-VMALLOC_START);
267 
268 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
269 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
270 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
271 	       ram << (PAGE_SHIFT-10),
272 	       codesize >> 10,
273 	       reservedpages << (PAGE_SHIFT-10),
274 	       datasize >> 10,
275 	       initsize >> 10,
276 	       (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
277 }
278 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
279 
280 #ifdef CONFIG_BLK_DEV_INITRD
281 void free_initrd_mem(unsigned long start, unsigned long end)
282 {
283 #ifdef CONFIG_64BIT
284 	/* Switch from KSEG0 to XKPHYS addresses */
285 	start = (unsigned long)phys_to_virt(CPHYSADDR(start));
286 	end = (unsigned long)phys_to_virt(CPHYSADDR(end));
287 #endif
288 	if (start < end)
289 		printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
290 		       (end - start) >> 10);
291 
292 	for (; start < end; start += PAGE_SIZE) {
293 		ClearPageReserved(virt_to_page(start));
294 		set_page_count(virt_to_page(start), 1);
295 		free_page(start);
296 		totalram_pages++;
297 	}
298 }
299 #endif
300 
301 extern unsigned long prom_free_prom_memory(void);
302 
303 void free_initmem(void)
304 {
305 	unsigned long addr, page, freed;
306 
307 	freed = prom_free_prom_memory();
308 
309 	addr = (unsigned long) &__init_begin;
310 	while (addr < (unsigned long) &__init_end) {
311 #ifdef CONFIG_64BIT
312 		page = PAGE_OFFSET | CPHYSADDR(addr);
313 #else
314 		page = addr;
315 #endif
316 		ClearPageReserved(virt_to_page(page));
317 		set_page_count(virt_to_page(page), 1);
318 		free_page(page);
319 		totalram_pages++;
320 		freed += PAGE_SIZE;
321 		addr += PAGE_SIZE;
322 	}
323 	printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
324 	       freed >> 10);
325 }
326