xref: /openbmc/linux/arch/x86/mm/init_64.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
1 /*
2  *  linux/arch/x86_64/mm/init.c
3  *
4  *  Copyright (C) 1995  Linus Torvalds
5  *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
7  */
8 
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/proc_fs.h>
25 #include <linux/pci.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/module.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/nmi.h>
32 
33 #include <asm/processor.h>
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/pgtable.h>
37 #include <asm/pgalloc.h>
38 #include <asm/dma.h>
39 #include <asm/fixmap.h>
40 #include <asm/e820.h>
41 #include <asm/apic.h>
42 #include <asm/tlb.h>
43 #include <asm/mmu_context.h>
44 #include <asm/proto.h>
45 #include <asm/smp.h>
46 #include <asm/sections.h>
47 #include <asm/kdebug.h>
48 #include <asm/numa.h>
49 #include <asm/cacheflush.h>
50 
51 /*
52  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
53  * The direct mapping extends to max_pfn_mapped, so that we can directly access
54  * apertures, ACPI and other tables without having to play with fixmaps.
55  */
56 unsigned long max_low_pfn_mapped;
57 unsigned long max_pfn_mapped;
58 
59 static unsigned long dma_reserve __initdata;
60 
61 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
62 
63 int direct_gbpages __meminitdata
64 #ifdef CONFIG_DIRECT_GBPAGES
65 				= 1
66 #endif
67 ;
68 
69 static int __init parse_direct_gbpages_off(char *arg)
70 {
71 	direct_gbpages = 0;
72 	return 0;
73 }
74 early_param("nogbpages", parse_direct_gbpages_off);
75 
76 static int __init parse_direct_gbpages_on(char *arg)
77 {
78 	direct_gbpages = 1;
79 	return 0;
80 }
81 early_param("gbpages", parse_direct_gbpages_on);
82 
83 /*
84  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
85  * physical space so we can cache the place of the first one and move
86  * around without checking the pgd every time.
87  */
88 
89 int after_bootmem;
90 
91 static __init void *spp_getpage(void)
92 {
93 	void *ptr;
94 
95 	if (after_bootmem)
96 		ptr = (void *) get_zeroed_page(GFP_ATOMIC);
97 	else
98 		ptr = alloc_bootmem_pages(PAGE_SIZE);
99 
100 	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
101 		panic("set_pte_phys: cannot allocate page data %s\n",
102 			after_bootmem ? "after bootmem" : "");
103 	}
104 
105 	pr_debug("spp_getpage %p\n", ptr);
106 
107 	return ptr;
108 }
109 
110 void
111 set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
112 {
113 	pud_t *pud;
114 	pmd_t *pmd;
115 	pte_t *pte;
116 
117 	pud = pud_page + pud_index(vaddr);
118 	if (pud_none(*pud)) {
119 		pmd = (pmd_t *) spp_getpage();
120 		pud_populate(&init_mm, pud, pmd);
121 		if (pmd != pmd_offset(pud, 0)) {
122 			printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
123 				pmd, pmd_offset(pud, 0));
124 			return;
125 		}
126 	}
127 	pmd = pmd_offset(pud, vaddr);
128 	if (pmd_none(*pmd)) {
129 		pte = (pte_t *) spp_getpage();
130 		pmd_populate_kernel(&init_mm, pmd, pte);
131 		if (pte != pte_offset_kernel(pmd, 0)) {
132 			printk(KERN_ERR "PAGETABLE BUG #02!\n");
133 			return;
134 		}
135 	}
136 
137 	pte = pte_offset_kernel(pmd, vaddr);
138 	if (!pte_none(*pte) && pte_val(new_pte) &&
139 	    pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
140 		pte_ERROR(*pte);
141 	set_pte(pte, new_pte);
142 
143 	/*
144 	 * It's enough to flush this one mapping.
145 	 * (PGE mappings get flushed as well)
146 	 */
147 	__flush_tlb_one(vaddr);
148 }
149 
150 void
151 set_pte_vaddr(unsigned long vaddr, pte_t pteval)
152 {
153 	pgd_t *pgd;
154 	pud_t *pud_page;
155 
156 	pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
157 
158 	pgd = pgd_offset_k(vaddr);
159 	if (pgd_none(*pgd)) {
160 		printk(KERN_ERR
161 			"PGD FIXMAP MISSING, it should be setup in head.S!\n");
162 		return;
163 	}
164 	pud_page = (pud_t*)pgd_page_vaddr(*pgd);
165 	set_pte_vaddr_pud(pud_page, vaddr, pteval);
166 }
167 
168 /*
169  * Create large page table mappings for a range of physical addresses.
170  */
171 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
172 						pgprot_t prot)
173 {
174 	pgd_t *pgd;
175 	pud_t *pud;
176 	pmd_t *pmd;
177 
178 	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
179 	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
180 		pgd = pgd_offset_k((unsigned long)__va(phys));
181 		if (pgd_none(*pgd)) {
182 			pud = (pud_t *) spp_getpage();
183 			set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
184 						_PAGE_USER));
185 		}
186 		pud = pud_offset(pgd, (unsigned long)__va(phys));
187 		if (pud_none(*pud)) {
188 			pmd = (pmd_t *) spp_getpage();
189 			set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
190 						_PAGE_USER));
191 		}
192 		pmd = pmd_offset(pud, phys);
193 		BUG_ON(!pmd_none(*pmd));
194 		set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
195 	}
196 }
197 
198 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
199 {
200 	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
201 }
202 
203 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
204 {
205 	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
206 }
207 
208 /*
209  * The head.S code sets up the kernel high mapping:
210  *
211  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
212  *
213  * phys_addr holds the negative offset to the kernel, which is added
214  * to the compile time generated pmds. This results in invalid pmds up
215  * to the point where we hit the physaddr 0 mapping.
216  *
217  * We limit the mappings to the region from _text to _end.  _end is
218  * rounded up to the 2MB boundary. This catches the invalid pmds as
219  * well, as they are located before _text:
220  */
221 void __init cleanup_highmap(void)
222 {
223 	unsigned long vaddr = __START_KERNEL_map;
224 	unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
225 	pmd_t *pmd = level2_kernel_pgt;
226 	pmd_t *last_pmd = pmd + PTRS_PER_PMD;
227 
228 	for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
229 		if (pmd_none(*pmd))
230 			continue;
231 		if (vaddr < (unsigned long) _text || vaddr > end)
232 			set_pmd(pmd, __pmd(0));
233 	}
234 }
235 
236 static unsigned long __initdata table_start;
237 static unsigned long __meminitdata table_end;
238 static unsigned long __meminitdata table_top;
239 
240 static __meminit void *alloc_low_page(unsigned long *phys)
241 {
242 	unsigned long pfn = table_end++;
243 	void *adr;
244 
245 	if (after_bootmem) {
246 		adr = (void *)get_zeroed_page(GFP_ATOMIC);
247 		*phys = __pa(adr);
248 
249 		return adr;
250 	}
251 
252 	if (pfn >= table_top)
253 		panic("alloc_low_page: ran out of memory");
254 
255 	adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
256 	memset(adr, 0, PAGE_SIZE);
257 	*phys  = pfn * PAGE_SIZE;
258 	return adr;
259 }
260 
261 static __meminit void unmap_low_page(void *adr)
262 {
263 	if (after_bootmem)
264 		return;
265 
266 	early_iounmap(adr, PAGE_SIZE);
267 }
268 
269 static unsigned long __meminit
270 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
271 {
272 	unsigned pages = 0;
273 	unsigned long last_map_addr = end;
274 	int i;
275 
276 	pte_t *pte = pte_page + pte_index(addr);
277 
278 	for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
279 
280 		if (addr >= end) {
281 			if (!after_bootmem) {
282 				for(; i < PTRS_PER_PTE; i++, pte++)
283 					set_pte(pte, __pte(0));
284 			}
285 			break;
286 		}
287 
288 		if (pte_val(*pte))
289 			continue;
290 
291 		if (0)
292 			printk("   pte=%p addr=%lx pte=%016lx\n",
293 			       pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
294 		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL));
295 		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
296 		pages++;
297 	}
298 	update_page_count(PG_LEVEL_4K, pages);
299 
300 	return last_map_addr;
301 }
302 
303 static unsigned long __meminit
304 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end)
305 {
306 	pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
307 
308 	return phys_pte_init(pte, address, end);
309 }
310 
311 static unsigned long __meminit
312 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
313 			 unsigned long page_size_mask)
314 {
315 	unsigned long pages = 0;
316 	unsigned long last_map_addr = end;
317 
318 	int i = pmd_index(address);
319 
320 	for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
321 		unsigned long pte_phys;
322 		pmd_t *pmd = pmd_page + pmd_index(address);
323 		pte_t *pte;
324 
325 		if (address >= end) {
326 			if (!after_bootmem) {
327 				for (; i < PTRS_PER_PMD; i++, pmd++)
328 					set_pmd(pmd, __pmd(0));
329 			}
330 			break;
331 		}
332 
333 		if (pmd_val(*pmd)) {
334 			if (!pmd_large(*pmd))
335 				last_map_addr = phys_pte_update(pmd, address,
336 								 end);
337 			continue;
338 		}
339 
340 		if (page_size_mask & (1<<PG_LEVEL_2M)) {
341 			pages++;
342 			set_pte((pte_t *)pmd,
343 				pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
344 			last_map_addr = (address & PMD_MASK) + PMD_SIZE;
345 			continue;
346 		}
347 
348 		pte = alloc_low_page(&pte_phys);
349 		last_map_addr = phys_pte_init(pte, address, end);
350 		unmap_low_page(pte);
351 
352 		pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
353 	}
354 	update_page_count(PG_LEVEL_2M, pages);
355 	return last_map_addr;
356 }
357 
358 static unsigned long __meminit
359 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
360 			 unsigned long page_size_mask)
361 {
362 	pmd_t *pmd = pmd_offset(pud, 0);
363 	unsigned long last_map_addr;
364 
365 	spin_lock(&init_mm.page_table_lock);
366 	last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);
367 	spin_unlock(&init_mm.page_table_lock);
368 	__flush_tlb_all();
369 	return last_map_addr;
370 }
371 
372 static unsigned long __meminit
373 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
374 			 unsigned long page_size_mask)
375 {
376 	unsigned long pages = 0;
377 	unsigned long last_map_addr = end;
378 	int i = pud_index(addr);
379 
380 	for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
381 		unsigned long pmd_phys;
382 		pud_t *pud = pud_page + pud_index(addr);
383 		pmd_t *pmd;
384 
385 		if (addr >= end)
386 			break;
387 
388 		if (!after_bootmem &&
389 				!e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
390 			set_pud(pud, __pud(0));
391 			continue;
392 		}
393 
394 		if (pud_val(*pud)) {
395 			if (!pud_large(*pud))
396 				last_map_addr = phys_pmd_update(pud, addr, end,
397 							 page_size_mask);
398 			continue;
399 		}
400 
401 		if (page_size_mask & (1<<PG_LEVEL_1G)) {
402 			pages++;
403 			set_pte((pte_t *)pud,
404 				pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
405 			last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
406 			continue;
407 		}
408 
409 		pmd = alloc_low_page(&pmd_phys);
410 
411 		spin_lock(&init_mm.page_table_lock);
412 		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask);
413 		unmap_low_page(pmd);
414 		pud_populate(&init_mm, pud, __va(pmd_phys));
415 		spin_unlock(&init_mm.page_table_lock);
416 
417 	}
418 	__flush_tlb_all();
419 	update_page_count(PG_LEVEL_1G, pages);
420 
421 	return last_map_addr;
422 }
423 
424 static unsigned long __meminit
425 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
426 		 unsigned long page_size_mask)
427 {
428 	pud_t *pud;
429 
430 	pud = (pud_t *)pgd_page_vaddr(*pgd);
431 
432 	return phys_pud_init(pud, addr, end, page_size_mask);
433 }
434 
435 static void __init find_early_table_space(unsigned long end)
436 {
437 	unsigned long puds, pmds, ptes, tables, start;
438 
439 	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
440 	tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
441 	if (direct_gbpages) {
442 		unsigned long extra;
443 		extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
444 		pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
445 	} else
446 		pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
447 	tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
448 
449 	if (cpu_has_pse) {
450 		unsigned long extra;
451 		extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
452 		ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
453 	} else
454 		ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
455 	tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
456 
457 	/*
458 	 * RED-PEN putting page tables only on node 0 could
459 	 * cause a hotspot and fill up ZONE_DMA. The page tables
460 	 * need roughly 0.5KB per GB.
461 	 */
462 	start = 0x8000;
463 	table_start = find_e820_area(start, end, tables, PAGE_SIZE);
464 	if (table_start == -1UL)
465 		panic("Cannot find space for the kernel page tables");
466 
467 	table_start >>= PAGE_SHIFT;
468 	table_end = table_start;
469 	table_top = table_start + (tables >> PAGE_SHIFT);
470 
471 	printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
472 		end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
473 }
474 
475 static void __init init_gbpages(void)
476 {
477 	if (direct_gbpages && cpu_has_gbpages)
478 		printk(KERN_INFO "Using GB pages for direct mapping\n");
479 	else
480 		direct_gbpages = 0;
481 }
482 
483 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
484 						unsigned long end,
485 						unsigned long page_size_mask)
486 {
487 
488 	unsigned long next, last_map_addr = end;
489 
490 	start = (unsigned long)__va(start);
491 	end = (unsigned long)__va(end);
492 
493 	for (; start < end; start = next) {
494 		pgd_t *pgd = pgd_offset_k(start);
495 		unsigned long pud_phys;
496 		pud_t *pud;
497 
498 		next = (start + PGDIR_SIZE) & PGDIR_MASK;
499 		if (next > end)
500 			next = end;
501 
502 		if (pgd_val(*pgd)) {
503 			last_map_addr = phys_pud_update(pgd, __pa(start),
504 						 __pa(end), page_size_mask);
505 			continue;
506 		}
507 
508 		if (after_bootmem)
509 			pud = pud_offset(pgd, start & PGDIR_MASK);
510 		else
511 			pud = alloc_low_page(&pud_phys);
512 
513 		last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
514 						 page_size_mask);
515 		unmap_low_page(pud);
516 		pgd_populate(&init_mm, pgd_offset_k(start),
517 			     __va(pud_phys));
518 	}
519 
520 	return last_map_addr;
521 }
522 
523 struct map_range {
524 	unsigned long start;
525 	unsigned long end;
526 	unsigned page_size_mask;
527 };
528 
529 #define NR_RANGE_MR 5
530 
531 static int save_mr(struct map_range *mr, int nr_range,
532 		   unsigned long start_pfn, unsigned long end_pfn,
533 		   unsigned long page_size_mask)
534 {
535 
536 	if (start_pfn < end_pfn) {
537 		if (nr_range >= NR_RANGE_MR)
538 			panic("run out of range for init_memory_mapping\n");
539 		mr[nr_range].start = start_pfn<<PAGE_SHIFT;
540 		mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
541 		mr[nr_range].page_size_mask = page_size_mask;
542 		nr_range++;
543 	}
544 
545 	return nr_range;
546 }
547 
548 /*
549  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
550  * This runs before bootmem is initialized and gets pages directly from
551  * the physical memory. To access them they are temporarily mapped.
552  */
553 unsigned long __init_refok init_memory_mapping(unsigned long start,
554 					       unsigned long end)
555 {
556 	unsigned long last_map_addr = 0;
557 	unsigned long page_size_mask = 0;
558 	unsigned long start_pfn, end_pfn;
559 
560 	struct map_range mr[NR_RANGE_MR];
561 	int nr_range, i;
562 
563 	printk(KERN_INFO "init_memory_mapping\n");
564 
565 	/*
566 	 * Find space for the kernel direct mapping tables.
567 	 *
568 	 * Later we should allocate these tables in the local node of the
569 	 * memory mapped. Unfortunately this is done currently before the
570 	 * nodes are discovered.
571 	 */
572 	if (!after_bootmem)
573 		init_gbpages();
574 
575 	if (direct_gbpages)
576 		page_size_mask |= 1 << PG_LEVEL_1G;
577 	if (cpu_has_pse)
578 		page_size_mask |= 1 << PG_LEVEL_2M;
579 
580 	memset(mr, 0, sizeof(mr));
581 	nr_range = 0;
582 
583 	/* head if not big page alignment ?*/
584 	start_pfn = start >> PAGE_SHIFT;
585 	end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
586 			<< (PMD_SHIFT - PAGE_SHIFT);
587 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
588 
589 	/* big page (2M) range*/
590 	start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
591 			 << (PMD_SHIFT - PAGE_SHIFT);
592 	end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
593 			 << (PUD_SHIFT - PAGE_SHIFT);
594 	if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
595 		end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
596 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
597 			page_size_mask & (1<<PG_LEVEL_2M));
598 
599 	/* big page (1G) range */
600 	start_pfn = end_pfn;
601 	end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
602 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
603 				page_size_mask &
604 				 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
605 
606 	/* tail is not big page (1G) alignment */
607 	start_pfn = end_pfn;
608 	end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
609 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
610 			page_size_mask & (1<<PG_LEVEL_2M));
611 
612 	/* tail is not big page (2M) alignment */
613 	start_pfn = end_pfn;
614 	end_pfn = end>>PAGE_SHIFT;
615 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
616 
617 	/* try to merge same page size and continuous */
618 	for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
619 		unsigned long old_start;
620 		if (mr[i].end != mr[i+1].start ||
621 		    mr[i].page_size_mask != mr[i+1].page_size_mask)
622 			continue;
623 		/* move it */
624 		old_start = mr[i].start;
625 		memmove(&mr[i], &mr[i+1],
626 			 (nr_range - 1 - i) * sizeof (struct map_range));
627 		mr[i].start = old_start;
628 		nr_range--;
629 	}
630 
631 	for (i = 0; i < nr_range; i++)
632 		printk(KERN_DEBUG " %010lx - %010lx page %s\n",
633 				mr[i].start, mr[i].end,
634 			(mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
635 			 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
636 
637 	if (!after_bootmem)
638 		find_early_table_space(end);
639 
640 	for (i = 0; i < nr_range; i++)
641 		last_map_addr = kernel_physical_mapping_init(
642 					mr[i].start, mr[i].end,
643 					mr[i].page_size_mask);
644 
645 	if (!after_bootmem)
646 		mmu_cr4_features = read_cr4();
647 	__flush_tlb_all();
648 
649 	if (!after_bootmem && table_end > table_start)
650 		reserve_early(table_start << PAGE_SHIFT,
651 				 table_end << PAGE_SHIFT, "PGTABLE");
652 
653 	printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
654 			 last_map_addr, end);
655 
656 	if (!after_bootmem)
657 		early_memtest(start, end);
658 
659 	return last_map_addr >> PAGE_SHIFT;
660 }
661 
662 #ifndef CONFIG_NUMA
663 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
664 {
665 	unsigned long bootmap_size, bootmap;
666 
667 	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
668 	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
669 				 PAGE_SIZE);
670 	if (bootmap == -1L)
671 		panic("Cannot find bootmem map of size %ld\n", bootmap_size);
672 	/* don't touch min_low_pfn */
673 	bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
674 					 0, end_pfn);
675 	e820_register_active_regions(0, start_pfn, end_pfn);
676 	free_bootmem_with_active_regions(0, end_pfn);
677 	early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
678 	reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
679 }
680 
681 void __init paging_init(void)
682 {
683 	unsigned long max_zone_pfns[MAX_NR_ZONES];
684 
685 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
686 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
687 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
688 	max_zone_pfns[ZONE_NORMAL] = max_pfn;
689 
690 	memory_present(0, 0, max_pfn);
691 	sparse_init();
692 	free_area_init_nodes(max_zone_pfns);
693 }
694 #endif
695 
696 /*
697  * Memory hotplug specific functions
698  */
699 #ifdef CONFIG_MEMORY_HOTPLUG
700 /*
701  * Memory is added always to NORMAL zone. This means you will never get
702  * additional DMA/DMA32 memory.
703  */
704 int arch_add_memory(int nid, u64 start, u64 size)
705 {
706 	struct pglist_data *pgdat = NODE_DATA(nid);
707 	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
708 	unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
709 	unsigned long nr_pages = size >> PAGE_SHIFT;
710 	int ret;
711 
712 	last_mapped_pfn = init_memory_mapping(start, start + size-1);
713 	if (last_mapped_pfn > max_pfn_mapped)
714 		max_pfn_mapped = last_mapped_pfn;
715 
716 	ret = __add_pages(zone, start_pfn, nr_pages);
717 	WARN_ON(1);
718 
719 	return ret;
720 }
721 EXPORT_SYMBOL_GPL(arch_add_memory);
722 
723 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
724 int memory_add_physaddr_to_nid(u64 start)
725 {
726 	return 0;
727 }
728 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
729 #endif
730 
731 #endif /* CONFIG_MEMORY_HOTPLUG */
732 
733 /*
734  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
735  * is valid. The argument is a physical page number.
736  *
737  *
738  * On x86, access has to be given to the first megabyte of ram because that area
739  * contains bios code and data regions used by X and dosemu and similar apps.
740  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
741  * mmio resources as well as potential bios/acpi data regions.
742  */
743 int devmem_is_allowed(unsigned long pagenr)
744 {
745 	if (pagenr <= 256)
746 		return 1;
747 	if (!page_is_ram(pagenr))
748 		return 1;
749 	return 0;
750 }
751 
752 
753 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
754 			 kcore_modules, kcore_vsyscall;
755 
756 void __init mem_init(void)
757 {
758 	long codesize, reservedpages, datasize, initsize;
759 
760 	pci_iommu_alloc();
761 
762 	/* clear_bss() already clear the empty_zero_page */
763 
764 	reservedpages = 0;
765 
766 	/* this will put all low memory onto the freelists */
767 #ifdef CONFIG_NUMA
768 	totalram_pages = numa_free_all_bootmem();
769 #else
770 	totalram_pages = free_all_bootmem();
771 #endif
772 	reservedpages = max_pfn - totalram_pages -
773 					absent_pages_in_range(0, max_pfn);
774 	after_bootmem = 1;
775 
776 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
777 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
778 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
779 
780 	/* Register memory areas for /proc/kcore */
781 	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
782 	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
783 		   VMALLOC_END-VMALLOC_START);
784 	kclist_add(&kcore_kernel, &_stext, _end - _stext);
785 	kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
786 	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
787 				 VSYSCALL_END - VSYSCALL_START);
788 
789 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
790 				"%ldk reserved, %ldk data, %ldk init)\n",
791 		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
792 		max_pfn << (PAGE_SHIFT-10),
793 		codesize >> 10,
794 		reservedpages << (PAGE_SHIFT-10),
795 		datasize >> 10,
796 		initsize >> 10);
797 
798 	cpa_init();
799 }
800 
801 void free_init_pages(char *what, unsigned long begin, unsigned long end)
802 {
803 	unsigned long addr = begin;
804 
805 	if (addr >= end)
806 		return;
807 
808 	/*
809 	 * If debugging page accesses then do not free this memory but
810 	 * mark them not present - any buggy init-section access will
811 	 * create a kernel page fault:
812 	 */
813 #ifdef CONFIG_DEBUG_PAGEALLOC
814 	printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
815 		begin, PAGE_ALIGN(end));
816 	set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
817 #else
818 	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
819 
820 	for (; addr < end; addr += PAGE_SIZE) {
821 		ClearPageReserved(virt_to_page(addr));
822 		init_page_count(virt_to_page(addr));
823 		memset((void *)(addr & ~(PAGE_SIZE-1)),
824 			POISON_FREE_INITMEM, PAGE_SIZE);
825 		free_page(addr);
826 		totalram_pages++;
827 	}
828 #endif
829 }
830 
831 void free_initmem(void)
832 {
833 	free_init_pages("unused kernel memory",
834 			(unsigned long)(&__init_begin),
835 			(unsigned long)(&__init_end));
836 }
837 
838 #ifdef CONFIG_DEBUG_RODATA
839 const int rodata_test_data = 0xC3;
840 EXPORT_SYMBOL_GPL(rodata_test_data);
841 
842 void mark_rodata_ro(void)
843 {
844 	unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
845 	unsigned long rodata_start =
846 		((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
847 
848 #ifdef CONFIG_DYNAMIC_FTRACE
849 	/* Dynamic tracing modifies the kernel text section */
850 	start = rodata_start;
851 #endif
852 
853 	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
854 	       (end - start) >> 10);
855 	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
856 
857 	/*
858 	 * The rodata section (but not the kernel text!) should also be
859 	 * not-executable.
860 	 */
861 	set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
862 
863 	rodata_test();
864 
865 #ifdef CONFIG_CPA_DEBUG
866 	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
867 	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
868 
869 	printk(KERN_INFO "Testing CPA: again\n");
870 	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
871 #endif
872 }
873 
874 #endif
875 
876 #ifdef CONFIG_BLK_DEV_INITRD
877 void free_initrd_mem(unsigned long start, unsigned long end)
878 {
879 	free_init_pages("initrd memory", start, end);
880 }
881 #endif
882 
883 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
884 				   int flags)
885 {
886 #ifdef CONFIG_NUMA
887 	int nid, next_nid;
888 	int ret;
889 #endif
890 	unsigned long pfn = phys >> PAGE_SHIFT;
891 
892 	if (pfn >= max_pfn) {
893 		/*
894 		 * This can happen with kdump kernels when accessing
895 		 * firmware tables:
896 		 */
897 		if (pfn < max_pfn_mapped)
898 			return -EFAULT;
899 
900 		printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
901 				phys, len);
902 		return -EFAULT;
903 	}
904 
905 	/* Should check here against the e820 map to avoid double free */
906 #ifdef CONFIG_NUMA
907 	nid = phys_to_nid(phys);
908 	next_nid = phys_to_nid(phys + len - 1);
909 	if (nid == next_nid)
910 		ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
911 	else
912 		ret = reserve_bootmem(phys, len, flags);
913 
914 	if (ret != 0)
915 		return ret;
916 
917 #else
918 	reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
919 #endif
920 
921 	if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
922 		dma_reserve += len / PAGE_SIZE;
923 		set_dma_reserve(dma_reserve);
924 	}
925 
926 	return 0;
927 }
928 
929 int kern_addr_valid(unsigned long addr)
930 {
931 	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
932 	pgd_t *pgd;
933 	pud_t *pud;
934 	pmd_t *pmd;
935 	pte_t *pte;
936 
937 	if (above != 0 && above != -1UL)
938 		return 0;
939 
940 	pgd = pgd_offset_k(addr);
941 	if (pgd_none(*pgd))
942 		return 0;
943 
944 	pud = pud_offset(pgd, addr);
945 	if (pud_none(*pud))
946 		return 0;
947 
948 	pmd = pmd_offset(pud, addr);
949 	if (pmd_none(*pmd))
950 		return 0;
951 
952 	if (pmd_large(*pmd))
953 		return pfn_valid(pmd_pfn(*pmd));
954 
955 	pte = pte_offset_kernel(pmd, addr);
956 	if (pte_none(*pte))
957 		return 0;
958 
959 	return pfn_valid(pte_pfn(*pte));
960 }
961 
962 /*
963  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
964  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
965  * not need special handling anymore:
966  */
967 static struct vm_area_struct gate_vma = {
968 	.vm_start	= VSYSCALL_START,
969 	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
970 	.vm_page_prot	= PAGE_READONLY_EXEC,
971 	.vm_flags	= VM_READ | VM_EXEC
972 };
973 
974 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
975 {
976 #ifdef CONFIG_IA32_EMULATION
977 	if (test_tsk_thread_flag(tsk, TIF_IA32))
978 		return NULL;
979 #endif
980 	return &gate_vma;
981 }
982 
983 int in_gate_area(struct task_struct *task, unsigned long addr)
984 {
985 	struct vm_area_struct *vma = get_gate_vma(task);
986 
987 	if (!vma)
988 		return 0;
989 
990 	return (addr >= vma->vm_start) && (addr < vma->vm_end);
991 }
992 
993 /*
994  * Use this when you have no reliable task/vma, typically from interrupt
995  * context. It is less reliable than using the task's vma and may give
996  * false positives:
997  */
998 int in_gate_area_no_task(unsigned long addr)
999 {
1000 	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1001 }
1002 
1003 const char *arch_vma_name(struct vm_area_struct *vma)
1004 {
1005 	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1006 		return "[vdso]";
1007 	if (vma == &gate_vma)
1008 		return "[vsyscall]";
1009 	return NULL;
1010 }
1011 
1012 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1013 /*
1014  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1015  */
1016 static long __meminitdata addr_start, addr_end;
1017 static void __meminitdata *p_start, *p_end;
1018 static int __meminitdata node_start;
1019 
1020 int __meminit
1021 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1022 {
1023 	unsigned long addr = (unsigned long)start_page;
1024 	unsigned long end = (unsigned long)(start_page + size);
1025 	unsigned long next;
1026 	pgd_t *pgd;
1027 	pud_t *pud;
1028 	pmd_t *pmd;
1029 
1030 	for (; addr < end; addr = next) {
1031 		void *p = NULL;
1032 
1033 		pgd = vmemmap_pgd_populate(addr, node);
1034 		if (!pgd)
1035 			return -ENOMEM;
1036 
1037 		pud = vmemmap_pud_populate(pgd, addr, node);
1038 		if (!pud)
1039 			return -ENOMEM;
1040 
1041 		if (!cpu_has_pse) {
1042 			next = (addr + PAGE_SIZE) & PAGE_MASK;
1043 			pmd = vmemmap_pmd_populate(pud, addr, node);
1044 
1045 			if (!pmd)
1046 				return -ENOMEM;
1047 
1048 			p = vmemmap_pte_populate(pmd, addr, node);
1049 
1050 			if (!p)
1051 				return -ENOMEM;
1052 
1053 			addr_end = addr + PAGE_SIZE;
1054 			p_end = p + PAGE_SIZE;
1055 		} else {
1056 			next = pmd_addr_end(addr, end);
1057 
1058 			pmd = pmd_offset(pud, addr);
1059 			if (pmd_none(*pmd)) {
1060 				pte_t entry;
1061 
1062 				p = vmemmap_alloc_block(PMD_SIZE, node);
1063 				if (!p)
1064 					return -ENOMEM;
1065 
1066 				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1067 						PAGE_KERNEL_LARGE);
1068 				set_pmd(pmd, __pmd(pte_val(entry)));
1069 
1070 				/* check to see if we have contiguous blocks */
1071 				if (p_end != p || node_start != node) {
1072 					if (p_start)
1073 						printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1074 						       addr_start, addr_end-1, p_start, p_end-1, node_start);
1075 					addr_start = addr;
1076 					node_start = node;
1077 					p_start = p;
1078 				}
1079 
1080 				addr_end = addr + PMD_SIZE;
1081 				p_end = p + PMD_SIZE;
1082 			} else
1083 				vmemmap_verify((pte_t *)pmd, node, addr, next);
1084 		}
1085 
1086 	}
1087 	return 0;
1088 }
1089 
1090 void __meminit vmemmap_populate_print_last(void)
1091 {
1092 	if (p_start) {
1093 		printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1094 			addr_start, addr_end-1, p_start, p_end-1, node_start);
1095 		p_start = NULL;
1096 		p_end = NULL;
1097 		node_start = 0;
1098 	}
1099 }
1100 #endif
1101