xref: /openbmc/linux/arch/arm/mm/init.c (revision 45f6d7e0)
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 
37 static unsigned long phys_initrd_start __initdata = 0;
38 static unsigned long phys_initrd_size __initdata = 0;
39 
40 static 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 }
54 early_param("initrd", early_initrd);
55 
56 static 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 
67 static 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
77 void __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  */
89 struct meminfo meminfo;
90 
91 void 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 
135 static 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 
162 static 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 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
216 	unsigned long dma_size)
217 {
218 	if (size[0] <= dma_size)
219 		return;
220 
221 	size[ZONE_NORMAL] = size[0] - dma_size;
222 	size[ZONE_DMA] = dma_size;
223 	hole[ZONE_NORMAL] = hole[0];
224 	hole[ZONE_DMA] = 0;
225 }
226 #endif
227 
228 static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
229 	unsigned long max_high)
230 {
231 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
232 	struct memblock_region *reg;
233 
234 	/*
235 	 * initialise the zones.
236 	 */
237 	memset(zone_size, 0, sizeof(zone_size));
238 
239 	/*
240 	 * The memory size has already been determined.  If we need
241 	 * to do anything fancy with the allocation of this memory
242 	 * to the zones, now is the time to do it.
243 	 */
244 	zone_size[0] = max_low - min;
245 #ifdef CONFIG_HIGHMEM
246 	zone_size[ZONE_HIGHMEM] = max_high - max_low;
247 #endif
248 
249 	/*
250 	 * Calculate the size of the holes.
251 	 *  holes = node_size - sum(bank_sizes)
252 	 */
253 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
254 	for_each_memblock(memory, reg) {
255 		unsigned long start = memblock_region_memory_base_pfn(reg);
256 		unsigned long end = memblock_region_memory_end_pfn(reg);
257 
258 		if (start < max_low) {
259 			unsigned long low_end = min(end, max_low);
260 			zhole_size[0] -= low_end - start;
261 		}
262 #ifdef CONFIG_HIGHMEM
263 		if (end > max_low) {
264 			unsigned long high_start = max(start, max_low);
265 			zhole_size[ZONE_HIGHMEM] -= end - high_start;
266 		}
267 #endif
268 	}
269 
270 #ifdef ARM_DMA_ZONE_SIZE
271 #ifndef CONFIG_ZONE_DMA
272 #error ARM_DMA_ZONE_SIZE set but no DMA zone to limit allocations
273 #endif
274 
275 	/*
276 	 * Adjust the sizes according to any special requirements for
277 	 * this machine type.
278 	 */
279 	arm_adjust_dma_zone(zone_size, zhole_size,
280 		ARM_DMA_ZONE_SIZE >> PAGE_SHIFT);
281 #endif
282 
283 	free_area_init_node(0, zone_size, min, zhole_size);
284 }
285 
286 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
287 int pfn_valid(unsigned long pfn)
288 {
289 	return memblock_is_memory(pfn << PAGE_SHIFT);
290 }
291 EXPORT_SYMBOL(pfn_valid);
292 #endif
293 
294 #ifndef CONFIG_SPARSEMEM
295 static void arm_memory_present(void)
296 {
297 }
298 #else
299 static void arm_memory_present(void)
300 {
301 	struct memblock_region *reg;
302 
303 	for_each_memblock(memory, reg)
304 		memory_present(0, memblock_region_memory_base_pfn(reg),
305 			       memblock_region_memory_end_pfn(reg));
306 }
307 #endif
308 
309 static int __init meminfo_cmp(const void *_a, const void *_b)
310 {
311 	const struct membank *a = _a, *b = _b;
312 	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
313 	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
314 }
315 
316 void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
317 {
318 	int i;
319 
320 	sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
321 
322 	memblock_init();
323 	for (i = 0; i < mi->nr_banks; i++)
324 		memblock_add(mi->bank[i].start, mi->bank[i].size);
325 
326 	/* Register the kernel text, kernel data and initrd with memblock. */
327 #ifdef CONFIG_XIP_KERNEL
328 	memblock_reserve(__pa(_sdata), _end - _sdata);
329 #else
330 	memblock_reserve(__pa(_stext), _end - _stext);
331 #endif
332 #ifdef CONFIG_BLK_DEV_INITRD
333 	if (phys_initrd_size &&
334 	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
335 		pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region - disabling initrd\n",
336 		       phys_initrd_start, phys_initrd_size);
337 		phys_initrd_start = phys_initrd_size = 0;
338 	}
339 	if (phys_initrd_size) {
340 		memblock_reserve(phys_initrd_start, phys_initrd_size);
341 
342 		/* Now convert initrd to virtual addresses */
343 		initrd_start = __phys_to_virt(phys_initrd_start);
344 		initrd_end = initrd_start + phys_initrd_size;
345 	}
346 #endif
347 
348 	arm_mm_memblock_reserve();
349 	arm_dt_memblock_reserve();
350 
351 	/* reserve any platform specific memblock areas */
352 	if (mdesc->reserve)
353 		mdesc->reserve();
354 
355 	memblock_analyze();
356 	memblock_dump_all();
357 }
358 
359 void __init bootmem_init(void)
360 {
361 	unsigned long min, max_low, max_high;
362 
363 	max_low = max_high = 0;
364 
365 	find_limits(&min, &max_low, &max_high);
366 
367 	arm_bootmem_init(min, max_low);
368 
369 	/*
370 	 * Sparsemem tries to allocate bootmem in memory_present(),
371 	 * so must be done after the fixed reservations
372 	 */
373 	arm_memory_present();
374 
375 	/*
376 	 * sparse_init() needs the bootmem allocator up and running.
377 	 */
378 	sparse_init();
379 
380 	/*
381 	 * Now free the memory - free_area_init_node needs
382 	 * the sparse mem_map arrays initialized by sparse_init()
383 	 * for memmap_init_zone(), otherwise all PFNs are invalid.
384 	 */
385 	arm_bootmem_free(min, max_low, max_high);
386 
387 	high_memory = __va(((phys_addr_t)max_low << PAGE_SHIFT) - 1) + 1;
388 
389 	/*
390 	 * This doesn't seem to be used by the Linux memory manager any
391 	 * more, but is used by ll_rw_block.  If we can get rid of it, we
392 	 * also get rid of some of the stuff above as well.
393 	 *
394 	 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
395 	 * the system, not the maximum PFN.
396 	 */
397 	max_low_pfn = max_low - PHYS_PFN_OFFSET;
398 	max_pfn = max_high - PHYS_PFN_OFFSET;
399 }
400 
401 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
402 {
403 	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
404 
405 	for (; pfn < end; pfn++) {
406 		struct page *page = pfn_to_page(pfn);
407 		ClearPageReserved(page);
408 		init_page_count(page);
409 		__free_page(page);
410 		pages++;
411 	}
412 
413 	if (size && s)
414 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
415 
416 	return pages;
417 }
418 
419 static inline void
420 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
421 {
422 	struct page *start_pg, *end_pg;
423 	unsigned long pg, pgend;
424 
425 	/*
426 	 * Convert start_pfn/end_pfn to a struct page pointer.
427 	 */
428 	start_pg = pfn_to_page(start_pfn - 1) + 1;
429 	end_pg = pfn_to_page(end_pfn - 1) + 1;
430 
431 	/*
432 	 * Convert to physical addresses, and
433 	 * round start upwards and end downwards.
434 	 */
435 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
436 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
437 
438 	/*
439 	 * If there are free pages between these,
440 	 * free the section of the memmap array.
441 	 */
442 	if (pg < pgend)
443 		free_bootmem(pg, pgend - pg);
444 }
445 
446 /*
447  * The mem_map array can get very big.  Free the unused area of the memory map.
448  */
449 static void __init free_unused_memmap(struct meminfo *mi)
450 {
451 	unsigned long bank_start, prev_bank_end = 0;
452 	unsigned int i;
453 
454 	/*
455 	 * This relies on each bank being in address order.
456 	 * The banks are sorted previously in bootmem_init().
457 	 */
458 	for_each_bank(i, mi) {
459 		struct membank *bank = &mi->bank[i];
460 
461 		bank_start = bank_pfn_start(bank);
462 
463 #ifdef CONFIG_SPARSEMEM
464 		/*
465 		 * Take care not to free memmap entries that don't exist
466 		 * due to SPARSEMEM sections which aren't present.
467 		 */
468 		bank_start = min(bank_start,
469 				 ALIGN(prev_bank_end, PAGES_PER_SECTION));
470 #endif
471 		/*
472 		 * If we had a previous bank, and there is a space
473 		 * between the current bank and the previous, free it.
474 		 */
475 		if (prev_bank_end && prev_bank_end < bank_start)
476 			free_memmap(prev_bank_end, bank_start);
477 
478 		/*
479 		 * Align up here since the VM subsystem insists that the
480 		 * memmap entries are valid from the bank end aligned to
481 		 * MAX_ORDER_NR_PAGES.
482 		 */
483 		prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
484 	}
485 
486 #ifdef CONFIG_SPARSEMEM
487 	if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
488 		free_memmap(prev_bank_end,
489 			    ALIGN(prev_bank_end, PAGES_PER_SECTION));
490 #endif
491 }
492 
493 static void __init free_highpages(void)
494 {
495 #ifdef CONFIG_HIGHMEM
496 	unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
497 	struct memblock_region *mem, *res;
498 
499 	/* set highmem page free */
500 	for_each_memblock(memory, mem) {
501 		unsigned long start = memblock_region_memory_base_pfn(mem);
502 		unsigned long end = memblock_region_memory_end_pfn(mem);
503 
504 		/* Ignore complete lowmem entries */
505 		if (end <= max_low)
506 			continue;
507 
508 		/* Truncate partial highmem entries */
509 		if (start < max_low)
510 			start = max_low;
511 
512 		/* Find and exclude any reserved regions */
513 		for_each_memblock(reserved, res) {
514 			unsigned long res_start, res_end;
515 
516 			res_start = memblock_region_reserved_base_pfn(res);
517 			res_end = memblock_region_reserved_end_pfn(res);
518 
519 			if (res_end < start)
520 				continue;
521 			if (res_start < start)
522 				res_start = start;
523 			if (res_start > end)
524 				res_start = end;
525 			if (res_end > end)
526 				res_end = end;
527 			if (res_start != start)
528 				totalhigh_pages += free_area(start, res_start,
529 							     NULL);
530 			start = res_end;
531 			if (start == end)
532 				break;
533 		}
534 
535 		/* And now free anything which remains */
536 		if (start < end)
537 			totalhigh_pages += free_area(start, end, NULL);
538 	}
539 	totalram_pages += totalhigh_pages;
540 #endif
541 }
542 
543 /*
544  * mem_init() marks the free areas in the mem_map and tells us how much
545  * memory is free.  This is done after various parts of the system have
546  * claimed their memory after the kernel image.
547  */
548 void __init mem_init(void)
549 {
550 	unsigned long reserved_pages, free_pages;
551 	struct memblock_region *reg;
552 	int i;
553 #ifdef CONFIG_HAVE_TCM
554 	/* These pointers are filled in on TCM detection */
555 	extern u32 dtcm_end;
556 	extern u32 itcm_end;
557 #endif
558 
559 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
560 
561 	/* this will put all unused low memory onto the freelists */
562 	free_unused_memmap(&meminfo);
563 
564 	totalram_pages += free_all_bootmem();
565 
566 #ifdef CONFIG_SA1111
567 	/* now that our DMA memory is actually so designated, we can free it */
568 	totalram_pages += free_area(PHYS_PFN_OFFSET,
569 				    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
570 #endif
571 
572 	free_highpages();
573 
574 	reserved_pages = free_pages = 0;
575 
576 	for_each_bank(i, &meminfo) {
577 		struct membank *bank = &meminfo.bank[i];
578 		unsigned int pfn1, pfn2;
579 		struct page *page, *end;
580 
581 		pfn1 = bank_pfn_start(bank);
582 		pfn2 = bank_pfn_end(bank);
583 
584 		page = pfn_to_page(pfn1);
585 		end  = pfn_to_page(pfn2 - 1) + 1;
586 
587 		do {
588 			if (PageReserved(page))
589 				reserved_pages++;
590 			else if (!page_count(page))
591 				free_pages++;
592 			page++;
593 		} while (page < end);
594 	}
595 
596 	/*
597 	 * Since our memory may not be contiguous, calculate the
598 	 * real number of pages we have in this system
599 	 */
600 	printk(KERN_INFO "Memory:");
601 	num_physpages = 0;
602 	for_each_memblock(memory, reg) {
603 		unsigned long pages = memblock_region_memory_end_pfn(reg) -
604 			memblock_region_memory_base_pfn(reg);
605 		num_physpages += pages;
606 		printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
607 	}
608 	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
609 
610 	printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
611 		nr_free_pages() << (PAGE_SHIFT-10),
612 		free_pages << (PAGE_SHIFT-10),
613 		reserved_pages << (PAGE_SHIFT-10),
614 		totalhigh_pages << (PAGE_SHIFT-10));
615 
616 #define MLK(b, t) b, t, ((t) - (b)) >> 10
617 #define MLM(b, t) b, t, ((t) - (b)) >> 20
618 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
619 
620 	printk(KERN_NOTICE "Virtual kernel memory layout:\n"
621 			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
622 #ifdef CONFIG_HAVE_TCM
623 			"    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
624 			"    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
625 #endif
626 			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
627 #ifdef CONFIG_MMU
628 			"    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
629 #endif
630 			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
631 			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
632 #ifdef CONFIG_HIGHMEM
633 			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
634 #endif
635 			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
636 			"      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
637 			"      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
638 			"      .data : 0x%p" " - 0x%p" "   (%4d kB)\n"
639 			"       .bss : 0x%p" " - 0x%p" "   (%4d kB)\n",
640 
641 			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
642 				(PAGE_SIZE)),
643 #ifdef CONFIG_HAVE_TCM
644 			MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
645 			MLK(ITCM_OFFSET, (unsigned long) itcm_end),
646 #endif
647 			MLK(FIXADDR_START, FIXADDR_TOP),
648 #ifdef CONFIG_MMU
649 			MLM(CONSISTENT_BASE, CONSISTENT_END),
650 #endif
651 			MLM(VMALLOC_START, VMALLOC_END),
652 			MLM(PAGE_OFFSET, (unsigned long)high_memory),
653 #ifdef CONFIG_HIGHMEM
654 			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
655 				(PAGE_SIZE)),
656 #endif
657 			MLM(MODULES_VADDR, MODULES_END),
658 
659 			MLK_ROUNDUP(__init_begin, __init_end),
660 			MLK_ROUNDUP(_text, _etext),
661 			MLK_ROUNDUP(_sdata, _edata),
662 			MLK_ROUNDUP(__bss_start, __bss_stop));
663 
664 #undef MLK
665 #undef MLM
666 #undef MLK_ROUNDUP
667 
668 	/*
669 	 * Check boundaries twice: Some fundamental inconsistencies can
670 	 * be detected at build time already.
671 	 */
672 #ifdef CONFIG_MMU
673 	BUILD_BUG_ON(VMALLOC_END			> CONSISTENT_BASE);
674 	BUG_ON(VMALLOC_END				> CONSISTENT_BASE);
675 
676 	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
677 	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
678 #endif
679 
680 #ifdef CONFIG_HIGHMEM
681 	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
682 	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
683 #endif
684 
685 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
686 		extern int sysctl_overcommit_memory;
687 		/*
688 		 * On a machine this small we won't get
689 		 * anywhere without overcommit, so turn
690 		 * it on by default.
691 		 */
692 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
693 	}
694 }
695 
696 void free_initmem(void)
697 {
698 #ifdef CONFIG_HAVE_TCM
699 	extern char __tcm_start, __tcm_end;
700 
701 	totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
702 				    __phys_to_pfn(__pa(&__tcm_end)),
703 				    "TCM link");
704 #endif
705 
706 	if (!machine_is_integrator() && !machine_is_cintegrator())
707 		totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
708 					    __phys_to_pfn(__pa(__init_end)),
709 					    "init");
710 }
711 
712 #ifdef CONFIG_BLK_DEV_INITRD
713 
714 static int keep_initrd;
715 
716 void free_initrd_mem(unsigned long start, unsigned long end)
717 {
718 	if (!keep_initrd)
719 		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
720 					    __phys_to_pfn(__pa(end)),
721 					    "initrd");
722 }
723 
724 static int __init keepinitrd_setup(char *__unused)
725 {
726 	keep_initrd = 1;
727 	return 1;
728 }
729 
730 __setup("keepinitrd", keepinitrd_setup);
731 #endif
732