File: /usr/src/linux/arch/mips64/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 by Ralf Baechle
7      * Copyright (C) 1999, 2000 by Silicon Graphics
8      */
9     #include <linux/config.h>
10     #include <linux/init.h>
11     #include <linux/signal.h>
12     #include <linux/sched.h>
13     #include <linux/kernel.h>
14     #include <linux/errno.h>
15     #include <linux/string.h>
16     #include <linux/types.h>
17     #include <linux/pagemap.h>
18     #include <linux/ptrace.h>
19     #include <linux/mman.h>
20     #include <linux/mm.h>
21     #include <linux/bootmem.h>
22     #include <linux/highmem.h>
23     #include <linux/swap.h>
24     #include <linux/swapctl.h>
25     #ifdef CONFIG_BLK_DEV_INITRD
26     #include <linux/blk.h>
27     #endif
28     
29     #include <asm/bootinfo.h>
30     #include <asm/cachectl.h>
31     #include <asm/dma.h>
32     #include <asm/system.h>
33     #include <asm/pgtable.h>
34     #include <asm/pgalloc.h>
35     #ifdef CONFIG_SGI_IP22
36     #include <asm/sgialib.h>
37     #endif
38     #include <asm/mmu_context.h>
39     #include <asm/tlb.h>
40     
41     mmu_gather_t mmu_gathers[NR_CPUS];
42     
43     unsigned long totalram_pages;
44     
45     void pgd_init(unsigned long page)
46     {
47     	unsigned long *p, *end;
48     
49      	p = (unsigned long *) page;
50     	end = p + PTRS_PER_PGD;
51     
52     	while (p < end) {
53     		p[0] = (unsigned long) invalid_pmd_table;
54     		p[1] = (unsigned long) invalid_pmd_table;
55     		p[2] = (unsigned long) invalid_pmd_table;
56     		p[3] = (unsigned long) invalid_pmd_table;
57     		p[4] = (unsigned long) invalid_pmd_table;
58     		p[5] = (unsigned long) invalid_pmd_table;
59     		p[6] = (unsigned long) invalid_pmd_table;
60     		p[7] = (unsigned long) invalid_pmd_table;
61     		p += 8;
62     	}
63     }
64     
65     pgd_t *get_pgd_slow(void)
66     {
67     	pgd_t *ret, *init;
68     
69     	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, 1);
70     	if (ret) {
71     		init = pgd_offset(&init_mm, 0);
72     		pgd_init((unsigned long)ret);
73     		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
74     			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
75     	}
76     	return ret;
77     }
78     
79     void pmd_init(unsigned long addr, unsigned long pagetable)
80     {
81     	unsigned long *p, *end;
82     
83      	p = (unsigned long *) addr;
84     	end = p + PTRS_PER_PMD;
85     
86     	while (p < end) {
87     		p[0] = (unsigned long)pagetable;
88     		p[1] = (unsigned long)pagetable;
89     		p[2] = (unsigned long)pagetable;
90     		p[3] = (unsigned long)pagetable;
91     		p[4] = (unsigned long)pagetable;
92     		p[5] = (unsigned long)pagetable;
93     		p[6] = (unsigned long)pagetable;
94     		p[7] = (unsigned long)pagetable;
95     		p += 8;
96     	}
97     }
98     
99     int do_check_pgt_cache(int low, int high)
100     {
101     	int freed = 0;
102     
103     	if (pgtable_cache_size > high) {
104     		do {
105     			if (pgd_quicklist)
106     				free_pgd_slow(get_pgd_fast()), freed++;
107     			if (pmd_quicklist)
108     				free_pmd_slow(get_pmd_fast()), freed++;
109     			if (pte_quicklist)
110     				free_pte_slow(get_pte_fast()), freed++;
111     		} while (pgtable_cache_size > low);
112     	}
113     	return freed;
114     }
115     
116     
117     asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
118     {
119     	/* XXX Just get it working for now... */
120     	flush_cache_l1();
121     	return 0;
122     }
123     
124     /*
125      * We have up to 8 empty zeroed pages so we can map one of the right colour
126      * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
127      * where we have to avoid VCED / VECI exceptions for good performance at
128      * any price.  Since page is never written to after the initialization we
129      * don't have to care about aliases on other CPUs.
130      */
131     unsigned long empty_zero_page, zero_page_mask;
132     
133     unsigned long setup_zero_pages(void)
134     {
135     	unsigned long order, size;
136     	struct page *page;
137     
138     	switch (mips_cputype) {
139     	case CPU_R4000SC:
140     	case CPU_R4000MC:
141     	case CPU_R4400SC:
142     	case CPU_R4400MC:
143     		order = 3;
144     		break;
145     	default:
146     		order = 0;
147     	}
148     
149     	empty_zero_page = __get_free_pages(GFP_KERNEL, order);
150     	if (!empty_zero_page)
151     		panic("Oh boy, that early out of memory?");
152     
153     	page = virt_to_page(empty_zero_page);
154     	while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
155     		set_bit(PG_reserved, &page->flags);
156     		set_page_count(page, 0);
157     		page++;
158     	}
159     
160     	size = PAGE_SIZE << order;
161     	zero_page_mask = (size - 1) & PAGE_MASK;
162     	memset((void *)empty_zero_page, 0, size);
163     
164     	return 1UL << order;
165     }
166     
167     void __init add_memory_region(unsigned long start, unsigned long size,
168                                   long type)
169     {
170             int x = boot_mem_map.nr_map;
171     
172             if (x == BOOT_MEM_MAP_MAX) {
173                     printk("Ooops! Too many entries in the memory map!\n");
174                     return;
175             }
176     
177             boot_mem_map.map[x].addr = start;
178             boot_mem_map.map[x].size = size;
179             boot_mem_map.map[x].type = type;
180             boot_mem_map.nr_map++;
181     }
182     
183     static void __init print_memory_map(void)
184     {
185             int i;
186     
187             for (i = 0; i < boot_mem_map.nr_map; i++) {
188                     printk(" memory: %08lx @ %08lx ",
189                             boot_mem_map.map[i].size, boot_mem_map.map[i].addr);
190                     switch (boot_mem_map.map[i].type) {
191                     case BOOT_MEM_RAM:
192                             printk("(usable)\n");
193                             break;
194                     case BOOT_MEM_ROM_DATA:
195                             printk("(ROM data)\n");
196                             break;
197                     case BOOT_MEM_RESERVED:
198                             printk("(reserved)\n");
199                             break;
200                     default:
201                             printk("type %lu\n", boot_mem_map.map[i].type);
202                             break;
203                     }
204             }
205     }
206     
207     void bootmem_init(void) {
208     #ifdef CONFIG_BLK_DEV_INITRD
209     	unsigned long tmp;
210     	unsigned long *initrd_header;
211     #endif
212     	unsigned long bootmap_size;
213     	unsigned long start_pfn, max_pfn;
214     	int i;
215     	extern int _end;
216     
217     #define PFN_UP(x)	(((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
218     #define PFN_DOWN(x)	((x) >> PAGE_SHIFT)
219     #define PFN_PHYS(x)	((x) << PAGE_SHIFT)
220     
221     	/*
222     	 * Partially used pages are not usable - thus
223     	 * we are rounding upwards.
224     	 */
225     	start_pfn = PFN_UP(__pa(&_end));
226     
227     	/* Find the highest page frame number we have available.  */
228     	max_pfn = 0;
229     	for (i = 0; i < boot_mem_map.nr_map; i++) {
230     		unsigned long start, end;
231     
232     		if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
233     			continue;
234     
235     		start = PFN_UP(boot_mem_map.map[i].addr);
236     		end = PFN_DOWN(boot_mem_map.map[i].addr
237     		      + boot_mem_map.map[i].size);
238     
239     		if (start >= end)
240     			continue;
241     		if (end > max_pfn)
242     			max_pfn = end;
243     	}
244     
245     	/* Initialize the boot-time allocator.  */
246     	bootmap_size = init_bootmem(start_pfn, max_pfn);
247     
248     	/*
249     	 * Register fully available low RAM pages with the bootmem allocator.
250     	 */
251     	for (i = 0; i < boot_mem_map.nr_map; i++) {
252     		unsigned long curr_pfn, last_pfn, size;
253     
254     		/*
255     		 * Reserve usable memory.
256     		 */
257     		if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
258     			continue;
259     
260     		/*
261     		 * We are rounding up the start address of usable memory:
262     		 */
263     		curr_pfn = PFN_UP(boot_mem_map.map[i].addr);
264     		if (curr_pfn >= max_pfn)
265     			continue;
266     		if (curr_pfn < start_pfn)
267     			curr_pfn = start_pfn;
268     
269     		/*
270     		 * ... and at the end of the usable range downwards:
271     		 */
272     		last_pfn = PFN_DOWN(boot_mem_map.map[i].addr
273     				    + boot_mem_map.map[i].size);
274     
275     		if (last_pfn > max_pfn)
276     			last_pfn = max_pfn;
277     
278     		/*
279     		 * ... finally, did all the rounding and playing
280     		 * around just make the area go away?
281     		 */
282     		if (last_pfn <= curr_pfn)
283     			continue;
284     
285     		size = last_pfn - curr_pfn;
286     		free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
287     	}
288     
289     	/* Reserve the bootmap memory.  */
290     	reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size);
291     
292     #ifdef CONFIG_BLK_DEV_INITRD
293     #error "Initrd is broken, please fit it."
294     	tmp = (((unsigned long)&_end + PAGE_SIZE-1) & PAGE_MASK) - 8;
295     	if (tmp < (unsigned long)&_end)
296     		tmp += PAGE_SIZE;
297     	initrd_header = (unsigned long *)tmp;
298     	if (initrd_header[0] == 0x494E5244) {
299     		initrd_start = (unsigned long)&initrd_header[2];
300     		initrd_end = initrd_start + initrd_header[1];
301     		initrd_below_start_ok = 1;
302     		if (initrd_end > memory_end) {
303     			printk("initrd extends beyond end of memory "
304     			       "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
305     			       initrd_end,memory_end);
306     			initrd_start = 0;
307     		} else
308     			*memory_start_p = initrd_end;
309     	}
310     #endif
311     
312     #undef PFN_UP
313     #undef PFN_DOWN
314     #undef PFN_PHYS
315     
316     }
317     
318     void show_mem(void)
319     {
320     	int i, free = 0, total = 0, reserved = 0;
321     	int shared = 0, cached = 0;
322     
323     	printk("Mem-info:\n");
324     	show_free_areas();
325     	printk("Free swap:       %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
326     	i = max_mapnr;
327     	while (i-- > 0) {
328     		total++;
329     		if (PageReserved(mem_map+i))
330     			reserved++;
331     		else if (PageSwapCache(mem_map+i))
332     			cached++;
333     		else if (!page_count(mem_map + i))
334     			free++;
335     		else
336     			shared += page_count(mem_map + i) - 1;
337     	}
338     	printk("%d pages of RAM\n", total);
339     	printk("%d reserved pages\n", reserved);
340     	printk("%d pages shared\n", shared);
341     	printk("%d pages swap cached\n",cached);
342     	printk("%ld pages in page table cache\n", pgtable_cache_size);
343     	printk("%d free pages\n", free);
344     	show_buffers();
345     }
346     
347     #ifndef CONFIG_DISCONTIGMEM
348     /* References to section boundaries */
349     
350     extern char _stext, _etext, _fdata, _edata;
351     extern char __init_begin, __init_end;
352     
353     void __init paging_init(void)
354     {
355     	pmd_t *pmd = kpmdtbl;
356     	pte_t *pte = kptbl;
357     
358     	unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
359     	unsigned long max_dma, low;
360     	int i;
361     
362     	/* Initialize the entire pgd.  */
363     	pgd_init((unsigned long)swapper_pg_dir);
364     	pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
365     	memset((void *)invalid_pte_table, 0, sizeof(pte_t) * PTRS_PER_PTE);
366     
367     	max_dma =  virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
368     	low = max_low_pfn;
369     
370     #if defined(CONFIG_PCI) || defined(CONFIG_ISA)
371     	if (low < max_dma)
372     		zones_size[ZONE_DMA] = low;
373     	else {
374     		zones_size[ZONE_DMA] = max_dma;
375     		zones_size[ZONE_NORMAL] = low - max_dma;
376     	}
377     #else
378     	zones_size[ZONE_DMA] = low;
379     #endif
380     
381     	free_area_init(zones_size);
382     	
383     	memset((void *)kptbl, 0, PAGE_SIZE << KPTBL_PAGE_ORDER);
384     	memset((void *)kpmdtbl, 0, PAGE_SIZE);
385     	pgd_set(swapper_pg_dir, kpmdtbl);
386     	for (i = 0; i < (1 << KPTBL_PAGE_ORDER); pmd++,i++,pte+=PTRS_PER_PTE)
387     		pmd_val(*pmd) = (unsigned long)pte;
388     }
389     
390     extern int page_is_ram(unsigned long pagenr);
391     
392     void __init mem_init(void)
393     {
394     	unsigned long codesize, reservedpages, datasize, initsize;
395     	unsigned long tmp, ram;
396     
397     	max_mapnr = num_physpages = max_low_pfn;
398     	high_memory = (void *) __va(max_mapnr << PAGE_SHIFT);
399     
400     	totalram_pages += free_all_bootmem();
401     	totalram_pages -= setup_zero_pages();	/* Setup zeroed pages.  */
402     
403     	reservedpages = ram = 0;
404     	for (tmp = 0; tmp < max_low_pfn; tmp++)
405     		if (page_is_ram(tmp)) {
406     			ram++;
407     			if (PageReserved(mem_map+tmp))
408     				reservedpages++;
409     		}
410     
411     	codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
412     	datasize =  (unsigned long) &_edata - (unsigned long) &_fdata;
413     	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
414     
415     	printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, "
416     	       "%ldk data, %ldk init)\n",
417     	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
418     	       ram << (PAGE_SHIFT-10),
419     	       codesize >> 10,
420     	       reservedpages << (PAGE_SHIFT-10),
421     	       datasize >> 10,
422     	       initsize >> 10);
423     }
424     #endif /* !CONFIG_DISCONTIGMEM */
425     
426     #ifdef CONFIG_BLK_DEV_INITRD
427     void free_initrd_mem(unsigned long start, unsigned long end)
428     {
429     	for (; start < end; start += PAGE_SIZE) {
430     		ClearPageReserved(virt_to_page(start));
431     		set_page_count(virt_to_page(start), 1);
432     		free_page(start);
433     		totalram_pages++;
434     	}
435     	printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
436     }
437     #endif
438     
439     extern char __init_begin, __init_end;
440     extern void prom_free_prom_memory(void);
441     
442     void
443     free_initmem(void)
444     {
445     	unsigned long addr, page;
446     
447     	prom_free_prom_memory();
448         
449     	addr = (unsigned long)(&__init_begin);
450     	while (addr < (unsigned long)&__init_end) {
451     		page = PAGE_OFFSET | CPHYSADDR(addr);
452     		ClearPageReserved(virt_to_page(page));
453     		set_page_count(virt_to_page(page), 1);
454     		free_page(page);
455     		totalram_pages++;
456     		addr += PAGE_SIZE;
457     	}
458     	printk("Freeing unused kernel memory: %ldk freed\n",
459     	       (&__init_end - &__init_begin) >> 10);
460     }
461     
462     void
463     si_meminfo(struct sysinfo *val)
464     {
465     	val->totalram = totalram_pages;
466     	val->sharedram = atomic_read(&shmem_nrpages);
467     	val->freeram = nr_free_pages();
468     	val->bufferram = atomic_read(&buffermem_pages);
469     	val->totalhigh = 0;
470     	val->freehigh = nr_free_highpages();
471     	val->mem_unit = PAGE_SIZE;
472     
473     	return;
474     }
475