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v3.1
  1/*
  2 *  linux/arch/arm/mm/init.c
  3 *
  4 *  Copyright (C) 1995-2005 Russell King
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10#include <linux/kernel.h>
 11#include <linux/errno.h>
 12#include <linux/swap.h>
 13#include <linux/init.h>
 14#include <linux/bootmem.h>
 15#include <linux/mman.h>
 
 16#include <linux/nodemask.h>
 17#include <linux/initrd.h>
 18#include <linux/of_fdt.h>
 19#include <linux/highmem.h>
 20#include <linux/gfp.h>
 21#include <linux/memblock.h>
 22#include <linux/sort.h>
 
 
 23
 
 24#include <asm/mach-types.h>
 
 25#include <asm/prom.h>
 26#include <asm/sections.h>
 27#include <asm/setup.h>
 28#include <asm/sizes.h>
 29#include <asm/tlb.h>
 30#include <asm/fixmap.h>
 31
 32#include <asm/mach/arch.h>
 33#include <asm/mach/map.h>
 34
 35#include "mm.h"
 36
 37static unsigned long phys_initrd_start __initdata = 0;
 
 
 
 
 
 
 
 
 38static unsigned long phys_initrd_size __initdata = 0;
 39
 40static int __init early_initrd(char *p)
 41{
 42	unsigned long start, size;
 
 43	char *endp;
 44
 45	start = memparse(p, &endp);
 46	if (*endp == ',') {
 47		size = memparse(endp + 1, NULL);
 48
 49		phys_initrd_start = start;
 50		phys_initrd_size = size;
 51	}
 52	return 0;
 53}
 54early_param("initrd", early_initrd);
 55
 56static int __init parse_tag_initrd(const struct tag *tag)
 57{
 58	printk(KERN_WARNING "ATAG_INITRD is deprecated; "
 59		"please update your bootloader.\n");
 60	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
 61	phys_initrd_size = tag->u.initrd.size;
 62	return 0;
 63}
 64
 65__tagtable(ATAG_INITRD, parse_tag_initrd);
 66
 67static int __init parse_tag_initrd2(const struct tag *tag)
 68{
 69	phys_initrd_start = tag->u.initrd.start;
 70	phys_initrd_size = tag->u.initrd.size;
 71	return 0;
 72}
 73
 74__tagtable(ATAG_INITRD2, parse_tag_initrd2);
 75
 76#ifdef CONFIG_OF_FLATTREE
 77void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end)
 78{
 79	phys_initrd_start = start;
 80	phys_initrd_size = end - start;
 81}
 82#endif /* CONFIG_OF_FLATTREE */
 83
 84/*
 85 * This keeps memory configuration data used by a couple memory
 86 * initialization functions, as well as show_mem() for the skipping
 87 * of holes in the memory map.  It is populated by arm_add_memory().
 88 */
 89struct meminfo meminfo;
 90
 91void show_mem(unsigned int filter)
 92{
 93	int free = 0, total = 0, reserved = 0;
 94	int shared = 0, cached = 0, slab = 0, i;
 95	struct meminfo * mi = &meminfo;
 96
 97	printk("Mem-info:\n");
 98	show_free_areas(filter);
 99
100	for_each_bank (i, mi) {
101		struct membank *bank = &mi->bank[i];
102		unsigned int pfn1, pfn2;
103		struct page *page, *end;
104
105		pfn1 = bank_pfn_start(bank);
106		pfn2 = bank_pfn_end(bank);
107
108		page = pfn_to_page(pfn1);
109		end  = pfn_to_page(pfn2 - 1) + 1;
110
111		do {
112			total++;
113			if (PageReserved(page))
114				reserved++;
115			else if (PageSwapCache(page))
116				cached++;
117			else if (PageSlab(page))
118				slab++;
119			else if (!page_count(page))
120				free++;
121			else
122				shared += page_count(page) - 1;
123			page++;
124		} while (page < end);
125	}
126
127	printk("%d pages of RAM\n", total);
128	printk("%d free pages\n", free);
129	printk("%d reserved pages\n", reserved);
130	printk("%d slab pages\n", slab);
131	printk("%d pages shared\n", shared);
132	printk("%d pages swap cached\n", cached);
133}
134
135static void __init find_limits(unsigned long *min, unsigned long *max_low,
136	unsigned long *max_high)
137{
138	struct meminfo *mi = &meminfo;
139	int i;
140
141	*min = -1UL;
142	*max_low = *max_high = 0;
143
144	for_each_bank (i, mi) {
145		struct membank *bank = &mi->bank[i];
146		unsigned long start, end;
147
148		start = bank_pfn_start(bank);
149		end = bank_pfn_end(bank);
150
151		if (*min > start)
152			*min = start;
153		if (*max_high < end)
154			*max_high = end;
155		if (bank->highmem)
156			continue;
157		if (*max_low < end)
158			*max_low = end;
159	}
160}
161
162static void __init arm_bootmem_init(unsigned long start_pfn,
163	unsigned long end_pfn)
164{
165	struct memblock_region *reg;
166	unsigned int boot_pages;
167	phys_addr_t bitmap;
168	pg_data_t *pgdat;
169
170	/*
171	 * Allocate the bootmem bitmap page.  This must be in a region
172	 * of memory which has already been mapped.
173	 */
174	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
175	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
176				__pfn_to_phys(end_pfn));
177
178	/*
179	 * Initialise the bootmem allocator, handing the
180	 * memory banks over to bootmem.
181	 */
182	node_set_online(0);
183	pgdat = NODE_DATA(0);
184	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
185
186	/* Free the lowmem regions from memblock into bootmem. */
187	for_each_memblock(memory, reg) {
188		unsigned long start = memblock_region_memory_base_pfn(reg);
189		unsigned long end = memblock_region_memory_end_pfn(reg);
190
191		if (end >= end_pfn)
192			end = end_pfn;
193		if (start >= end)
194			break;
195
196		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
197	}
198
199	/* Reserve the lowmem memblock reserved regions in bootmem. */
200	for_each_memblock(reserved, reg) {
201		unsigned long start = memblock_region_reserved_base_pfn(reg);
202		unsigned long end = memblock_region_reserved_end_pfn(reg);
203
204		if (end >= end_pfn)
205			end = end_pfn;
206		if (start >= end)
207			break;
208
209		reserve_bootmem(__pfn_to_phys(start),
210			        (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
211	}
212}
213
214#ifdef CONFIG_ZONE_DMA
215
216unsigned long arm_dma_zone_size __read_mostly;
217EXPORT_SYMBOL(arm_dma_zone_size);
218
219/*
220 * The DMA mask corresponding to the maximum bus address allocatable
221 * using GFP_DMA.  The default here places no restriction on DMA
222 * allocations.  This must be the smallest DMA mask in the system,
223 * so a successful GFP_DMA allocation will always satisfy this.
224 */
225u32 arm_dma_limit;
 
226
227static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
228	unsigned long dma_size)
229{
230	if (size[0] <= dma_size)
231		return;
232
233	size[ZONE_NORMAL] = size[0] - dma_size;
234	size[ZONE_DMA] = dma_size;
235	hole[ZONE_NORMAL] = hole[0];
236	hole[ZONE_DMA] = 0;
237}
238#endif
239
240static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
 
 
 
 
 
 
 
 
 
 
 
 
241	unsigned long max_high)
242{
243	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
244	struct memblock_region *reg;
245
246	/*
247	 * initialise the zones.
248	 */
249	memset(zone_size, 0, sizeof(zone_size));
250
251	/*
252	 * The memory size has already been determined.  If we need
253	 * to do anything fancy with the allocation of this memory
254	 * to the zones, now is the time to do it.
255	 */
256	zone_size[0] = max_low - min;
257#ifdef CONFIG_HIGHMEM
258	zone_size[ZONE_HIGHMEM] = max_high - max_low;
259#endif
260
261	/*
262	 * Calculate the size of the holes.
263	 *  holes = node_size - sum(bank_sizes)
264	 */
265	memcpy(zhole_size, zone_size, sizeof(zhole_size));
266	for_each_memblock(memory, reg) {
267		unsigned long start = memblock_region_memory_base_pfn(reg);
268		unsigned long end = memblock_region_memory_end_pfn(reg);
269
270		if (start < max_low) {
271			unsigned long low_end = min(end, max_low);
272			zhole_size[0] -= low_end - start;
273		}
274#ifdef CONFIG_HIGHMEM
275		if (end > max_low) {
276			unsigned long high_start = max(start, max_low);
277			zhole_size[ZONE_HIGHMEM] -= end - high_start;
278		}
279#endif
280	}
281
282#ifdef CONFIG_ZONE_DMA
283	/*
284	 * Adjust the sizes according to any special requirements for
285	 * this machine type.
286	 */
287	if (arm_dma_zone_size) {
288		arm_adjust_dma_zone(zone_size, zhole_size,
289			arm_dma_zone_size >> PAGE_SHIFT);
290		arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
291	} else
292		arm_dma_limit = 0xffffffff;
293#endif
294
295	free_area_init_node(0, zone_size, min, zhole_size);
296}
297
298#ifdef CONFIG_HAVE_ARCH_PFN_VALID
299int pfn_valid(unsigned long pfn)
300{
301	return memblock_is_memory(__pfn_to_phys(pfn));
302}
303EXPORT_SYMBOL(pfn_valid);
304#endif
305
306#ifndef CONFIG_SPARSEMEM
307static void arm_memory_present(void)
308{
309}
310#else
311static void arm_memory_present(void)
312{
313	struct memblock_region *reg;
314
315	for_each_memblock(memory, reg)
316		memory_present(0, memblock_region_memory_base_pfn(reg),
317			       memblock_region_memory_end_pfn(reg));
318}
319#endif
320
321static int __init meminfo_cmp(const void *_a, const void *_b)
322{
323	const struct membank *a = _a, *b = _b;
324	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
325	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
326}
327
328void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
329{
330	int i;
331
332	sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
333
334	memblock_init();
335	for (i = 0; i < mi->nr_banks; i++)
336		memblock_add(mi->bank[i].start, mi->bank[i].size);
337
 
 
 
 
 
338	/* Register the kernel text, kernel data and initrd with memblock. */
339#ifdef CONFIG_XIP_KERNEL
340	memblock_reserve(__pa(_sdata), _end - _sdata);
341#else
342	memblock_reserve(__pa(_stext), _end - _stext);
343#endif
344#ifdef CONFIG_BLK_DEV_INITRD
 
 
 
 
 
 
345	if (phys_initrd_size &&
346	    !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
347		pr_err("INITRD: 0x%08lx+0x%08lx is not a memory region - disabling initrd\n",
348		       phys_initrd_start, phys_initrd_size);
349		phys_initrd_start = phys_initrd_size = 0;
350	}
351	if (phys_initrd_size &&
352	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
353		pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region - disabling initrd\n",
354		       phys_initrd_start, phys_initrd_size);
355		phys_initrd_start = phys_initrd_size = 0;
356	}
357	if (phys_initrd_size) {
358		memblock_reserve(phys_initrd_start, phys_initrd_size);
359
360		/* Now convert initrd to virtual addresses */
361		initrd_start = __phys_to_virt(phys_initrd_start);
362		initrd_end = initrd_start + phys_initrd_size;
363	}
364#endif
365
366	arm_mm_memblock_reserve();
367	arm_dt_memblock_reserve();
368
369	/* reserve any platform specific memblock areas */
370	if (mdesc->reserve)
371		mdesc->reserve();
372
373	memblock_analyze();
 
 
 
 
 
 
374	memblock_dump_all();
375}
376
377void __init bootmem_init(void)
378{
379	unsigned long min, max_low, max_high;
380
 
381	max_low = max_high = 0;
382
383	find_limits(&min, &max_low, &max_high);
384
385	arm_bootmem_init(min, max_low);
 
386
387	/*
388	 * Sparsemem tries to allocate bootmem in memory_present(),
389	 * so must be done after the fixed reservations
390	 */
391	arm_memory_present();
392
393	/*
394	 * sparse_init() needs the bootmem allocator up and running.
395	 */
396	sparse_init();
397
398	/*
399	 * Now free the memory - free_area_init_node needs
400	 * the sparse mem_map arrays initialized by sparse_init()
401	 * for memmap_init_zone(), otherwise all PFNs are invalid.
402	 */
403	arm_bootmem_free(min, max_low, max_high);
404
405	high_memory = __va(((phys_addr_t)max_low << PAGE_SHIFT) - 1) + 1;
406
407	/*
408	 * This doesn't seem to be used by the Linux memory manager any
409	 * more, but is used by ll_rw_block.  If we can get rid of it, we
410	 * also get rid of some of the stuff above as well.
411	 *
412	 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
413	 * the system, not the maximum PFN.
414	 */
415	max_low_pfn = max_low - PHYS_PFN_OFFSET;
416	max_pfn = max_high - PHYS_PFN_OFFSET;
417}
418
419static inline int free_area(unsigned long pfn, unsigned long end, char *s)
420{
421	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
422
423	for (; pfn < end; pfn++) {
424		struct page *page = pfn_to_page(pfn);
425		ClearPageReserved(page);
426		init_page_count(page);
427		__free_page(page);
428		pages++;
429	}
430
431	if (size && s)
432		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
433
434	return pages;
435}
436
437/*
438 * Poison init memory with an undefined instruction (ARM) or a branch to an
439 * undefined instruction (Thumb).
440 */
441static inline void poison_init_mem(void *s, size_t count)
442{
443	u32 *p = (u32 *)s;
444	for (; count != 0; count -= 4)
445		*p++ = 0xe7fddef0;
446}
447
448static inline void
449free_memmap(unsigned long start_pfn, unsigned long end_pfn)
450{
451	struct page *start_pg, *end_pg;
452	unsigned long pg, pgend;
453
454	/*
455	 * Convert start_pfn/end_pfn to a struct page pointer.
456	 */
457	start_pg = pfn_to_page(start_pfn - 1) + 1;
458	end_pg = pfn_to_page(end_pfn - 1) + 1;
459
460	/*
461	 * Convert to physical addresses, and
462	 * round start upwards and end downwards.
463	 */
464	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
465	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
466
467	/*
468	 * If there are free pages between these,
469	 * free the section of the memmap array.
470	 */
471	if (pg < pgend)
472		free_bootmem(pg, pgend - pg);
473}
474
475/*
476 * The mem_map array can get very big.  Free the unused area of the memory map.
477 */
478static void __init free_unused_memmap(struct meminfo *mi)
479{
480	unsigned long bank_start, prev_bank_end = 0;
481	unsigned int i;
482
483	/*
484	 * This relies on each bank being in address order.
485	 * The banks are sorted previously in bootmem_init().
486	 */
487	for_each_bank(i, mi) {
488		struct membank *bank = &mi->bank[i];
489
490		bank_start = bank_pfn_start(bank);
491
492#ifdef CONFIG_SPARSEMEM
493		/*
494		 * Take care not to free memmap entries that don't exist
495		 * due to SPARSEMEM sections which aren't present.
496		 */
497		bank_start = min(bank_start,
498				 ALIGN(prev_bank_end, PAGES_PER_SECTION));
499#else
500		/*
501		 * Align down here since the VM subsystem insists that the
502		 * memmap entries are valid from the bank start aligned to
503		 * MAX_ORDER_NR_PAGES.
504		 */
505		bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES);
506#endif
507		/*
508		 * If we had a previous bank, and there is a space
509		 * between the current bank and the previous, free it.
510		 */
511		if (prev_bank_end && prev_bank_end < bank_start)
512			free_memmap(prev_bank_end, bank_start);
513
514		/*
515		 * Align up here since the VM subsystem insists that the
516		 * memmap entries are valid from the bank end aligned to
517		 * MAX_ORDER_NR_PAGES.
518		 */
519		prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
 
520	}
521
522#ifdef CONFIG_SPARSEMEM
523	if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
524		free_memmap(prev_bank_end,
525			    ALIGN(prev_bank_end, PAGES_PER_SECTION));
526#endif
527}
528
 
 
 
 
 
 
 
 
529static void __init free_highpages(void)
530{
531#ifdef CONFIG_HIGHMEM
532	unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
533	struct memblock_region *mem, *res;
534
535	/* set highmem page free */
536	for_each_memblock(memory, mem) {
537		unsigned long start = memblock_region_memory_base_pfn(mem);
538		unsigned long end = memblock_region_memory_end_pfn(mem);
539
540		/* Ignore complete lowmem entries */
541		if (end <= max_low)
542			continue;
543
 
 
 
544		/* Truncate partial highmem entries */
545		if (start < max_low)
546			start = max_low;
547
548		/* Find and exclude any reserved regions */
549		for_each_memblock(reserved, res) {
550			unsigned long res_start, res_end;
551
552			res_start = memblock_region_reserved_base_pfn(res);
553			res_end = memblock_region_reserved_end_pfn(res);
554
555			if (res_end < start)
556				continue;
557			if (res_start < start)
558				res_start = start;
559			if (res_start > end)
560				res_start = end;
561			if (res_end > end)
562				res_end = end;
563			if (res_start != start)
564				totalhigh_pages += free_area(start, res_start,
565							     NULL);
566			start = res_end;
567			if (start == end)
568				break;
569		}
570
571		/* And now free anything which remains */
572		if (start < end)
573			totalhigh_pages += free_area(start, end, NULL);
574	}
575	totalram_pages += totalhigh_pages;
576#endif
577}
578
579/*
580 * mem_init() marks the free areas in the mem_map and tells us how much
581 * memory is free.  This is done after various parts of the system have
582 * claimed their memory after the kernel image.
583 */
584void __init mem_init(void)
585{
586	unsigned long reserved_pages, free_pages;
587	struct memblock_region *reg;
588	int i;
589#ifdef CONFIG_HAVE_TCM
590	/* These pointers are filled in on TCM detection */
591	extern u32 dtcm_end;
592	extern u32 itcm_end;
593#endif
594
595	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
596
597	/* this will put all unused low memory onto the freelists */
598	free_unused_memmap(&meminfo);
599
600	totalram_pages += free_all_bootmem();
601
602#ifdef CONFIG_SA1111
603	/* now that our DMA memory is actually so designated, we can free it */
604	totalram_pages += free_area(PHYS_PFN_OFFSET,
605				    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
606#endif
607
608	free_highpages();
609
610	reserved_pages = free_pages = 0;
611
612	for_each_bank(i, &meminfo) {
613		struct membank *bank = &meminfo.bank[i];
614		unsigned int pfn1, pfn2;
615		struct page *page, *end;
616
617		pfn1 = bank_pfn_start(bank);
618		pfn2 = bank_pfn_end(bank);
619
620		page = pfn_to_page(pfn1);
621		end  = pfn_to_page(pfn2 - 1) + 1;
622
623		do {
624			if (PageReserved(page))
625				reserved_pages++;
626			else if (!page_count(page))
627				free_pages++;
628			page++;
629		} while (page < end);
630	}
631
632	/*
633	 * Since our memory may not be contiguous, calculate the
634	 * real number of pages we have in this system
635	 */
636	printk(KERN_INFO "Memory:");
637	num_physpages = 0;
638	for_each_memblock(memory, reg) {
639		unsigned long pages = memblock_region_memory_end_pfn(reg) -
640			memblock_region_memory_base_pfn(reg);
641		num_physpages += pages;
642		printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
643	}
644	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
645
646	printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
647		nr_free_pages() << (PAGE_SHIFT-10),
648		free_pages << (PAGE_SHIFT-10),
649		reserved_pages << (PAGE_SHIFT-10),
650		totalhigh_pages << (PAGE_SHIFT-10));
651
652#define MLK(b, t) b, t, ((t) - (b)) >> 10
653#define MLM(b, t) b, t, ((t) - (b)) >> 20
654#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
655
656	printk(KERN_NOTICE "Virtual kernel memory layout:\n"
657			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
658#ifdef CONFIG_HAVE_TCM
659			"    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
660			"    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
661#endif
662			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
663#ifdef CONFIG_MMU
664			"    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
665#endif
666			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
667			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
668#ifdef CONFIG_HIGHMEM
669			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
670#endif
 
671			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
672			"      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
673			"      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
674			"      .data : 0x%p" " - 0x%p" "   (%4d kB)\n"
675			"       .bss : 0x%p" " - 0x%p" "   (%4d kB)\n",
 
676
677			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
678				(PAGE_SIZE)),
679#ifdef CONFIG_HAVE_TCM
680			MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
681			MLK(ITCM_OFFSET, (unsigned long) itcm_end),
682#endif
683			MLK(FIXADDR_START, FIXADDR_TOP),
684#ifdef CONFIG_MMU
685			MLM(CONSISTENT_BASE, CONSISTENT_END),
686#endif
687			MLM(VMALLOC_START, VMALLOC_END),
688			MLM(PAGE_OFFSET, (unsigned long)high_memory),
689#ifdef CONFIG_HIGHMEM
690			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
691				(PAGE_SIZE)),
692#endif
 
693			MLM(MODULES_VADDR, MODULES_END),
 
694
695			MLK_ROUNDUP(_text, _etext),
696			MLK_ROUNDUP(__init_begin, __init_end),
697			MLK_ROUNDUP(_sdata, _edata),
698			MLK_ROUNDUP(__bss_start, __bss_stop));
699
700#undef MLK
701#undef MLM
702#undef MLK_ROUNDUP
703
704	/*
705	 * Check boundaries twice: Some fundamental inconsistencies can
706	 * be detected at build time already.
707	 */
708#ifdef CONFIG_MMU
709	BUILD_BUG_ON(VMALLOC_END			> CONSISTENT_BASE);
710	BUG_ON(VMALLOC_END				> CONSISTENT_BASE);
711
712	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
713	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
714#endif
715
716#ifdef CONFIG_HIGHMEM
717	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
718	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
719#endif
720
721	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
722		extern int sysctl_overcommit_memory;
723		/*
724		 * On a machine this small we won't get
725		 * anywhere without overcommit, so turn
726		 * it on by default.
727		 */
728		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
729	}
730}
731
732void free_initmem(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
733{
734#ifdef CONFIG_HAVE_TCM
735	extern char __tcm_start, __tcm_end;
736
737	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
738	totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
739				    __phys_to_pfn(__pa(&__tcm_end)),
740				    "TCM link");
741#endif
 
 
 
 
 
 
742
743	poison_init_mem(__init_begin, __init_end - __init_begin);
744	if (!machine_is_integrator() && !machine_is_cintegrator())
745		totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
746					    __phys_to_pfn(__pa(__init_end)),
747					    "init");
748}
749
750#ifdef CONFIG_BLK_DEV_INITRD
751
752static int keep_initrd;
753
754void free_initrd_mem(unsigned long start, unsigned long end)
755{
756	if (!keep_initrd) {
 
 
 
 
 
757		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
758		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
759					    __phys_to_pfn(__pa(end)),
760					    "initrd");
761	}
762}
763
764static int __init keepinitrd_setup(char *__unused)
765{
766	keep_initrd = 1;
767	return 1;
768}
769
770__setup("keepinitrd", keepinitrd_setup);
771#endif
v4.6
  1/*
  2 *  linux/arch/arm/mm/init.c
  3 *
  4 *  Copyright (C) 1995-2005 Russell King
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10#include <linux/kernel.h>
 11#include <linux/errno.h>
 12#include <linux/swap.h>
 13#include <linux/init.h>
 14#include <linux/bootmem.h>
 15#include <linux/mman.h>
 16#include <linux/export.h>
 17#include <linux/nodemask.h>
 18#include <linux/initrd.h>
 19#include <linux/of_fdt.h>
 20#include <linux/highmem.h>
 21#include <linux/gfp.h>
 22#include <linux/memblock.h>
 23#include <linux/dma-contiguous.h>
 24#include <linux/sizes.h>
 25#include <linux/stop_machine.h>
 26
 27#include <asm/cp15.h>
 28#include <asm/mach-types.h>
 29#include <asm/memblock.h>
 30#include <asm/prom.h>
 31#include <asm/sections.h>
 32#include <asm/setup.h>
 33#include <asm/system_info.h>
 34#include <asm/tlb.h>
 35#include <asm/fixmap.h>
 36
 37#include <asm/mach/arch.h>
 38#include <asm/mach/map.h>
 39
 40#include "mm.h"
 41
 42#ifdef CONFIG_CPU_CP15_MMU
 43unsigned long __init __clear_cr(unsigned long mask)
 44{
 45	cr_alignment = cr_alignment & ~mask;
 46	return cr_alignment;
 47}
 48#endif
 49
 50static phys_addr_t phys_initrd_start __initdata = 0;
 51static unsigned long phys_initrd_size __initdata = 0;
 52
 53static int __init early_initrd(char *p)
 54{
 55	phys_addr_t start;
 56	unsigned long size;
 57	char *endp;
 58
 59	start = memparse(p, &endp);
 60	if (*endp == ',') {
 61		size = memparse(endp + 1, NULL);
 62
 63		phys_initrd_start = start;
 64		phys_initrd_size = size;
 65	}
 66	return 0;
 67}
 68early_param("initrd", early_initrd);
 69
 70static int __init parse_tag_initrd(const struct tag *tag)
 71{
 72	pr_warn("ATAG_INITRD is deprecated; "
 73		"please update your bootloader.\n");
 74	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
 75	phys_initrd_size = tag->u.initrd.size;
 76	return 0;
 77}
 78
 79__tagtable(ATAG_INITRD, parse_tag_initrd);
 80
 81static int __init parse_tag_initrd2(const struct tag *tag)
 82{
 83	phys_initrd_start = tag->u.initrd.start;
 84	phys_initrd_size = tag->u.initrd.size;
 85	return 0;
 86}
 87
 88__tagtable(ATAG_INITRD2, parse_tag_initrd2);
 89
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 90static void __init find_limits(unsigned long *min, unsigned long *max_low,
 91			       unsigned long *max_high)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 92{
 93	*max_low = PFN_DOWN(memblock_get_current_limit());
 94	*min = PFN_UP(memblock_start_of_DRAM());
 95	*max_high = PFN_DOWN(memblock_end_of_DRAM());
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 96}
 97
 98#ifdef CONFIG_ZONE_DMA
 99
100phys_addr_t arm_dma_zone_size __read_mostly;
101EXPORT_SYMBOL(arm_dma_zone_size);
102
103/*
104 * The DMA mask corresponding to the maximum bus address allocatable
105 * using GFP_DMA.  The default here places no restriction on DMA
106 * allocations.  This must be the smallest DMA mask in the system,
107 * so a successful GFP_DMA allocation will always satisfy this.
108 */
109phys_addr_t arm_dma_limit;
110unsigned long arm_dma_pfn_limit;
111
112static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
113	unsigned long dma_size)
114{
115	if (size[0] <= dma_size)
116		return;
117
118	size[ZONE_NORMAL] = size[0] - dma_size;
119	size[ZONE_DMA] = dma_size;
120	hole[ZONE_NORMAL] = hole[0];
121	hole[ZONE_DMA] = 0;
122}
123#endif
124
125void __init setup_dma_zone(const struct machine_desc *mdesc)
126{
127#ifdef CONFIG_ZONE_DMA
128	if (mdesc->dma_zone_size) {
129		arm_dma_zone_size = mdesc->dma_zone_size;
130		arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
131	} else
132		arm_dma_limit = 0xffffffff;
133	arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
134#endif
135}
136
137static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
138	unsigned long max_high)
139{
140	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
141	struct memblock_region *reg;
142
143	/*
144	 * initialise the zones.
145	 */
146	memset(zone_size, 0, sizeof(zone_size));
147
148	/*
149	 * The memory size has already been determined.  If we need
150	 * to do anything fancy with the allocation of this memory
151	 * to the zones, now is the time to do it.
152	 */
153	zone_size[0] = max_low - min;
154#ifdef CONFIG_HIGHMEM
155	zone_size[ZONE_HIGHMEM] = max_high - max_low;
156#endif
157
158	/*
159	 * Calculate the size of the holes.
160	 *  holes = node_size - sum(bank_sizes)
161	 */
162	memcpy(zhole_size, zone_size, sizeof(zhole_size));
163	for_each_memblock(memory, reg) {
164		unsigned long start = memblock_region_memory_base_pfn(reg);
165		unsigned long end = memblock_region_memory_end_pfn(reg);
166
167		if (start < max_low) {
168			unsigned long low_end = min(end, max_low);
169			zhole_size[0] -= low_end - start;
170		}
171#ifdef CONFIG_HIGHMEM
172		if (end > max_low) {
173			unsigned long high_start = max(start, max_low);
174			zhole_size[ZONE_HIGHMEM] -= end - high_start;
175		}
176#endif
177	}
178
179#ifdef CONFIG_ZONE_DMA
180	/*
181	 * Adjust the sizes according to any special requirements for
182	 * this machine type.
183	 */
184	if (arm_dma_zone_size)
185		arm_adjust_dma_zone(zone_size, zhole_size,
186			arm_dma_zone_size >> PAGE_SHIFT);
 
 
 
187#endif
188
189	free_area_init_node(0, zone_size, min, zhole_size);
190}
191
192#ifdef CONFIG_HAVE_ARCH_PFN_VALID
193int pfn_valid(unsigned long pfn)
194{
195	return memblock_is_map_memory(__pfn_to_phys(pfn));
196}
197EXPORT_SYMBOL(pfn_valid);
198#endif
199
200#ifndef CONFIG_SPARSEMEM
201static void __init arm_memory_present(void)
202{
203}
204#else
205static void __init arm_memory_present(void)
206{
207	struct memblock_region *reg;
208
209	for_each_memblock(memory, reg)
210		memory_present(0, memblock_region_memory_base_pfn(reg),
211			       memblock_region_memory_end_pfn(reg));
212}
213#endif
214
215static bool arm_memblock_steal_permitted = true;
 
 
 
 
 
216
217phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
218{
219	phys_addr_t phys;
220
221	BUG_ON(!arm_memblock_steal_permitted);
222
223	phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
224	memblock_free(phys, size);
225	memblock_remove(phys, size);
226
227	return phys;
228}
229
230void __init arm_memblock_init(const struct machine_desc *mdesc)
231{
232	/* Register the kernel text, kernel data and initrd with memblock. */
233#ifdef CONFIG_XIP_KERNEL
234	memblock_reserve(__pa(_sdata), _end - _sdata);
235#else
236	memblock_reserve(__pa(_stext), _end - _stext);
237#endif
238#ifdef CONFIG_BLK_DEV_INITRD
239	/* FDT scan will populate initrd_start */
240	if (initrd_start && !phys_initrd_size) {
241		phys_initrd_start = __virt_to_phys(initrd_start);
242		phys_initrd_size = initrd_end - initrd_start;
243	}
244	initrd_start = initrd_end = 0;
245	if (phys_initrd_size &&
246	    !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
247		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
248		       (u64)phys_initrd_start, phys_initrd_size);
249		phys_initrd_start = phys_initrd_size = 0;
250	}
251	if (phys_initrd_size &&
252	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
253		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
254		       (u64)phys_initrd_start, phys_initrd_size);
255		phys_initrd_start = phys_initrd_size = 0;
256	}
257	if (phys_initrd_size) {
258		memblock_reserve(phys_initrd_start, phys_initrd_size);
259
260		/* Now convert initrd to virtual addresses */
261		initrd_start = __phys_to_virt(phys_initrd_start);
262		initrd_end = initrd_start + phys_initrd_size;
263	}
264#endif
265
266	arm_mm_memblock_reserve();
 
267
268	/* reserve any platform specific memblock areas */
269	if (mdesc->reserve)
270		mdesc->reserve();
271
272	early_init_fdt_reserve_self();
273	early_init_fdt_scan_reserved_mem();
274
275	/* reserve memory for DMA contiguous allocations */
276	dma_contiguous_reserve(arm_dma_limit);
277
278	arm_memblock_steal_permitted = false;
279	memblock_dump_all();
280}
281
282void __init bootmem_init(void)
283{
284	unsigned long min, max_low, max_high;
285
286	memblock_allow_resize();
287	max_low = max_high = 0;
288
289	find_limits(&min, &max_low, &max_high);
290
291	early_memtest((phys_addr_t)min << PAGE_SHIFT,
292		      (phys_addr_t)max_low << PAGE_SHIFT);
293
294	/*
295	 * Sparsemem tries to allocate bootmem in memory_present(),
296	 * so must be done after the fixed reservations
297	 */
298	arm_memory_present();
299
300	/*
301	 * sparse_init() needs the bootmem allocator up and running.
302	 */
303	sparse_init();
304
305	/*
306	 * Now free the memory - free_area_init_node needs
307	 * the sparse mem_map arrays initialized by sparse_init()
308	 * for memmap_init_zone(), otherwise all PFNs are invalid.
309	 */
310	zone_sizes_init(min, max_low, max_high);
 
 
311
312	/*
313	 * This doesn't seem to be used by the Linux memory manager any
314	 * more, but is used by ll_rw_block.  If we can get rid of it, we
315	 * also get rid of some of the stuff above as well.
 
 
 
316	 */
317	min_low_pfn = min;
318	max_low_pfn = max_low;
319	max_pfn = max_high;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
320}
321
322/*
323 * Poison init memory with an undefined instruction (ARM) or a branch to an
324 * undefined instruction (Thumb).
325 */
326static inline void poison_init_mem(void *s, size_t count)
327{
328	u32 *p = (u32 *)s;
329	for (; count != 0; count -= 4)
330		*p++ = 0xe7fddef0;
331}
332
333static inline void
334free_memmap(unsigned long start_pfn, unsigned long end_pfn)
335{
336	struct page *start_pg, *end_pg;
337	phys_addr_t pg, pgend;
338
339	/*
340	 * Convert start_pfn/end_pfn to a struct page pointer.
341	 */
342	start_pg = pfn_to_page(start_pfn - 1) + 1;
343	end_pg = pfn_to_page(end_pfn - 1) + 1;
344
345	/*
346	 * Convert to physical addresses, and
347	 * round start upwards and end downwards.
348	 */
349	pg = PAGE_ALIGN(__pa(start_pg));
350	pgend = __pa(end_pg) & PAGE_MASK;
351
352	/*
353	 * If there are free pages between these,
354	 * free the section of the memmap array.
355	 */
356	if (pg < pgend)
357		memblock_free_early(pg, pgend - pg);
358}
359
360/*
361 * The mem_map array can get very big.  Free the unused area of the memory map.
362 */
363static void __init free_unused_memmap(void)
364{
365	unsigned long start, prev_end = 0;
366	struct memblock_region *reg;
367
368	/*
369	 * This relies on each bank being in address order.
370	 * The banks are sorted previously in bootmem_init().
371	 */
372	for_each_memblock(memory, reg) {
373		start = memblock_region_memory_base_pfn(reg);
 
 
374
375#ifdef CONFIG_SPARSEMEM
376		/*
377		 * Take care not to free memmap entries that don't exist
378		 * due to SPARSEMEM sections which aren't present.
379		 */
380		start = min(start,
381				 ALIGN(prev_end, PAGES_PER_SECTION));
382#else
383		/*
384		 * Align down here since the VM subsystem insists that the
385		 * memmap entries are valid from the bank start aligned to
386		 * MAX_ORDER_NR_PAGES.
387		 */
388		start = round_down(start, MAX_ORDER_NR_PAGES);
389#endif
390		/*
391		 * If we had a previous bank, and there is a space
392		 * between the current bank and the previous, free it.
393		 */
394		if (prev_end && prev_end < start)
395			free_memmap(prev_end, start);
396
397		/*
398		 * Align up here since the VM subsystem insists that the
399		 * memmap entries are valid from the bank end aligned to
400		 * MAX_ORDER_NR_PAGES.
401		 */
402		prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
403				 MAX_ORDER_NR_PAGES);
404	}
405
406#ifdef CONFIG_SPARSEMEM
407	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
408		free_memmap(prev_end,
409			    ALIGN(prev_end, PAGES_PER_SECTION));
410#endif
411}
412
413#ifdef CONFIG_HIGHMEM
414static inline void free_area_high(unsigned long pfn, unsigned long end)
415{
416	for (; pfn < end; pfn++)
417		free_highmem_page(pfn_to_page(pfn));
418}
419#endif
420
421static void __init free_highpages(void)
422{
423#ifdef CONFIG_HIGHMEM
424	unsigned long max_low = max_low_pfn;
425	struct memblock_region *mem, *res;
426
427	/* set highmem page free */
428	for_each_memblock(memory, mem) {
429		unsigned long start = memblock_region_memory_base_pfn(mem);
430		unsigned long end = memblock_region_memory_end_pfn(mem);
431
432		/* Ignore complete lowmem entries */
433		if (end <= max_low)
434			continue;
435
436		if (memblock_is_nomap(mem))
437			continue;
438
439		/* Truncate partial highmem entries */
440		if (start < max_low)
441			start = max_low;
442
443		/* Find and exclude any reserved regions */
444		for_each_memblock(reserved, res) {
445			unsigned long res_start, res_end;
446
447			res_start = memblock_region_reserved_base_pfn(res);
448			res_end = memblock_region_reserved_end_pfn(res);
449
450			if (res_end < start)
451				continue;
452			if (res_start < start)
453				res_start = start;
454			if (res_start > end)
455				res_start = end;
456			if (res_end > end)
457				res_end = end;
458			if (res_start != start)
459				free_area_high(start, res_start);
 
460			start = res_end;
461			if (start == end)
462				break;
463		}
464
465		/* And now free anything which remains */
466		if (start < end)
467			free_area_high(start, end);
468	}
 
469#endif
470}
471
472/*
473 * mem_init() marks the free areas in the mem_map and tells us how much
474 * memory is free.  This is done after various parts of the system have
475 * claimed their memory after the kernel image.
476 */
477void __init mem_init(void)
478{
 
 
 
479#ifdef CONFIG_HAVE_TCM
480	/* These pointers are filled in on TCM detection */
481	extern u32 dtcm_end;
482	extern u32 itcm_end;
483#endif
484
485	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
486
487	/* this will put all unused low memory onto the freelists */
488	free_unused_memmap();
489	free_all_bootmem();
 
490
491#ifdef CONFIG_SA1111
492	/* now that our DMA memory is actually so designated, we can free it */
493	free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 
494#endif
495
496	free_highpages();
497
498	mem_init_print_info(NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
499
500#define MLK(b, t) b, t, ((t) - (b)) >> 10
501#define MLM(b, t) b, t, ((t) - (b)) >> 20
502#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
503
504	pr_notice("Virtual kernel memory layout:\n"
505			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
506#ifdef CONFIG_HAVE_TCM
507			"    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
508			"    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
509#endif
510			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 
 
 
511			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
512			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
513#ifdef CONFIG_HIGHMEM
514			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
515#endif
516#ifdef CONFIG_MODULES
517			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
518#endif
519			"      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
520			"      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
521			"      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
522			"       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
523
524			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
525				(PAGE_SIZE)),
526#ifdef CONFIG_HAVE_TCM
527			MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
528			MLK(ITCM_OFFSET, (unsigned long) itcm_end),
529#endif
530			MLK(FIXADDR_START, FIXADDR_END),
 
 
 
531			MLM(VMALLOC_START, VMALLOC_END),
532			MLM(PAGE_OFFSET, (unsigned long)high_memory),
533#ifdef CONFIG_HIGHMEM
534			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
535				(PAGE_SIZE)),
536#endif
537#ifdef CONFIG_MODULES
538			MLM(MODULES_VADDR, MODULES_END),
539#endif
540
541			MLK_ROUNDUP(_text, _etext),
542			MLK_ROUNDUP(__init_begin, __init_end),
543			MLK_ROUNDUP(_sdata, _edata),
544			MLK_ROUNDUP(__bss_start, __bss_stop));
545
546#undef MLK
547#undef MLM
548#undef MLK_ROUNDUP
549
550	/*
551	 * Check boundaries twice: Some fundamental inconsistencies can
552	 * be detected at build time already.
553	 */
554#ifdef CONFIG_MMU
 
 
 
555	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
556	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
557#endif
558
559#ifdef CONFIG_HIGHMEM
560	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
561	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
562#endif
563
564	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
565		extern int sysctl_overcommit_memory;
566		/*
567		 * On a machine this small we won't get
568		 * anywhere without overcommit, so turn
569		 * it on by default.
570		 */
571		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
572	}
573}
574
575#ifdef CONFIG_DEBUG_RODATA
576struct section_perm {
577	const char *name;
578	unsigned long start;
579	unsigned long end;
580	pmdval_t mask;
581	pmdval_t prot;
582	pmdval_t clear;
583};
584
585/* First section-aligned location at or after __start_rodata. */
586extern char __start_rodata_section_aligned[];
587
588static struct section_perm nx_perms[] = {
589	/* Make pages tables, etc before _stext RW (set NX). */
590	{
591		.name	= "pre-text NX",
592		.start	= PAGE_OFFSET,
593		.end	= (unsigned long)_stext,
594		.mask	= ~PMD_SECT_XN,
595		.prot	= PMD_SECT_XN,
596	},
597	/* Make init RW (set NX). */
598	{
599		.name	= "init NX",
600		.start	= (unsigned long)__init_begin,
601		.end	= (unsigned long)_sdata,
602		.mask	= ~PMD_SECT_XN,
603		.prot	= PMD_SECT_XN,
604	},
605	/* Make rodata NX (set RO in ro_perms below). */
606	{
607		.name	= "rodata NX",
608		.start  = (unsigned long)__start_rodata_section_aligned,
609		.end    = (unsigned long)__init_begin,
610		.mask   = ~PMD_SECT_XN,
611		.prot   = PMD_SECT_XN,
612	},
613};
614
615static struct section_perm ro_perms[] = {
616	/* Make kernel code and rodata RX (set RO). */
617	{
618		.name	= "text/rodata RO",
619		.start  = (unsigned long)_stext,
620		.end    = (unsigned long)__init_begin,
621#ifdef CONFIG_ARM_LPAE
622		.mask   = ~L_PMD_SECT_RDONLY,
623		.prot   = L_PMD_SECT_RDONLY,
624#else
625		.mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
626		.prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
627		.clear  = PMD_SECT_AP_WRITE,
628#endif
629	},
630};
631
632/*
633 * Updates section permissions only for the current mm (sections are
634 * copied into each mm). During startup, this is the init_mm. Is only
635 * safe to be called with preemption disabled, as under stop_machine().
636 */
637static inline void section_update(unsigned long addr, pmdval_t mask,
638				  pmdval_t prot, struct mm_struct *mm)
639{
640	pmd_t *pmd;
641
642	pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
643
644#ifdef CONFIG_ARM_LPAE
645	pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
646#else
647	if (addr & SECTION_SIZE)
648		pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
649	else
650		pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
651#endif
652	flush_pmd_entry(pmd);
653	local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
654}
655
656/* Make sure extended page tables are in use. */
657static inline bool arch_has_strict_perms(void)
658{
659	if (cpu_architecture() < CPU_ARCH_ARMv6)
660		return false;
661
662	return !!(get_cr() & CR_XP);
663}
664
665void set_section_perms(struct section_perm *perms, int n, bool set,
666			struct mm_struct *mm)
667{
668	size_t i;
669	unsigned long addr;
670
671	if (!arch_has_strict_perms())
672		return;
673
674	for (i = 0; i < n; i++) {
675		if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
676		    !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
677			pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
678				perms[i].name, perms[i].start, perms[i].end,
679				SECTION_SIZE);
680			continue;
681		}
682
683		for (addr = perms[i].start;
684		     addr < perms[i].end;
685		     addr += SECTION_SIZE)
686			section_update(addr, perms[i].mask,
687				set ? perms[i].prot : perms[i].clear, mm);
688	}
689
690}
691
692static void update_sections_early(struct section_perm perms[], int n)
693{
694	struct task_struct *t, *s;
695
696	read_lock(&tasklist_lock);
697	for_each_process(t) {
698		if (t->flags & PF_KTHREAD)
699			continue;
700		for_each_thread(t, s)
701			set_section_perms(perms, n, true, s->mm);
702	}
703	read_unlock(&tasklist_lock);
704	set_section_perms(perms, n, true, current->active_mm);
705	set_section_perms(perms, n, true, &init_mm);
706}
707
708int __fix_kernmem_perms(void *unused)
709{
710	update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
711	return 0;
712}
713
714void fix_kernmem_perms(void)
715{
716	stop_machine(__fix_kernmem_perms, NULL, NULL);
717}
718
719int __mark_rodata_ro(void *unused)
720{
721	update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
722	return 0;
723}
724
725void mark_rodata_ro(void)
726{
727	stop_machine(__mark_rodata_ro, NULL, NULL);
728}
729
730void set_kernel_text_rw(void)
731{
732	set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
733				current->active_mm);
734}
735
736void set_kernel_text_ro(void)
737{
738	set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
739				current->active_mm);
740}
741
742#else
743static inline void fix_kernmem_perms(void) { }
744#endif /* CONFIG_DEBUG_RODATA */
745
746void free_tcmmem(void)
747{
748#ifdef CONFIG_HAVE_TCM
749	extern char __tcm_start, __tcm_end;
750
751	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
752	free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 
 
753#endif
754}
755
756void free_initmem(void)
757{
758	fix_kernmem_perms();
759	free_tcmmem();
760
761	poison_init_mem(__init_begin, __init_end - __init_begin);
762	if (!machine_is_integrator() && !machine_is_cintegrator())
763		free_initmem_default(-1);
 
 
764}
765
766#ifdef CONFIG_BLK_DEV_INITRD
767
768static int keep_initrd;
769
770void free_initrd_mem(unsigned long start, unsigned long end)
771{
772	if (!keep_initrd) {
773		if (start == initrd_start)
774			start = round_down(start, PAGE_SIZE);
775		if (end == initrd_end)
776			end = round_up(end, PAGE_SIZE);
777
778		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
779		free_reserved_area((void *)start, (void *)end, -1, "initrd");
 
 
780	}
781}
782
783static int __init keepinitrd_setup(char *__unused)
784{
785	keep_initrd = 1;
786	return 1;
787}
788
789__setup("keepinitrd", keepinitrd_setup);
790#endif