xref: /openbmc/linux/arch/arm/mm/init.c (revision 1dbd30e9)
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/highmem.h>
19 #include <linux/gfp.h>
20 
21 #include <asm/mach-types.h>
22 #include <asm/sections.h>
23 #include <asm/setup.h>
24 #include <asm/sizes.h>
25 #include <asm/tlb.h>
26 #include <asm/fixmap.h>
27 
28 #include <asm/mach/arch.h>
29 #include <asm/mach/map.h>
30 
31 #include "mm.h"
32 
33 static unsigned long phys_initrd_start __initdata = 0;
34 static unsigned long phys_initrd_size __initdata = 0;
35 
36 static int __init early_initrd(char *p)
37 {
38 	unsigned long start, size;
39 	char *endp;
40 
41 	start = memparse(p, &endp);
42 	if (*endp == ',') {
43 		size = memparse(endp + 1, NULL);
44 
45 		phys_initrd_start = start;
46 		phys_initrd_size = size;
47 	}
48 	return 0;
49 }
50 early_param("initrd", early_initrd);
51 
52 static int __init parse_tag_initrd(const struct tag *tag)
53 {
54 	printk(KERN_WARNING "ATAG_INITRD is deprecated; "
55 		"please update your bootloader.\n");
56 	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
57 	phys_initrd_size = tag->u.initrd.size;
58 	return 0;
59 }
60 
61 __tagtable(ATAG_INITRD, parse_tag_initrd);
62 
63 static int __init parse_tag_initrd2(const struct tag *tag)
64 {
65 	phys_initrd_start = tag->u.initrd.start;
66 	phys_initrd_size = tag->u.initrd.size;
67 	return 0;
68 }
69 
70 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
71 
72 /*
73  * This keeps memory configuration data used by a couple memory
74  * initialization functions, as well as show_mem() for the skipping
75  * of holes in the memory map.  It is populated by arm_add_memory().
76  */
77 struct meminfo meminfo;
78 
79 void show_mem(void)
80 {
81 	int free = 0, total = 0, reserved = 0;
82 	int shared = 0, cached = 0, slab = 0, node, i;
83 	struct meminfo * mi = &meminfo;
84 
85 	printk("Mem-info:\n");
86 	show_free_areas();
87 	for_each_online_node(node) {
88 		for_each_nodebank (i,mi,node) {
89 			struct membank *bank = &mi->bank[i];
90 			unsigned int pfn1, pfn2;
91 			struct page *page, *end;
92 
93 			pfn1 = bank_pfn_start(bank);
94 			pfn2 = bank_pfn_end(bank);
95 
96 			page = pfn_to_page(pfn1);
97 			end  = pfn_to_page(pfn2 - 1) + 1;
98 
99 			do {
100 				total++;
101 				if (PageReserved(page))
102 					reserved++;
103 				else if (PageSwapCache(page))
104 					cached++;
105 				else if (PageSlab(page))
106 					slab++;
107 				else if (!page_count(page))
108 					free++;
109 				else
110 					shared += page_count(page) - 1;
111 				page++;
112 			} while (page < end);
113 		}
114 	}
115 
116 	printk("%d pages of RAM\n", total);
117 	printk("%d free pages\n", free);
118 	printk("%d reserved pages\n", reserved);
119 	printk("%d slab pages\n", slab);
120 	printk("%d pages shared\n", shared);
121 	printk("%d pages swap cached\n", cached);
122 }
123 
124 static void __init find_node_limits(int node, struct meminfo *mi,
125 	unsigned long *min, unsigned long *max_low, unsigned long *max_high)
126 {
127 	int i;
128 
129 	*min = -1UL;
130 	*max_low = *max_high = 0;
131 
132 	for_each_nodebank(i, mi, node) {
133 		struct membank *bank = &mi->bank[i];
134 		unsigned long start, end;
135 
136 		start = bank_pfn_start(bank);
137 		end = bank_pfn_end(bank);
138 
139 		if (*min > start)
140 			*min = start;
141 		if (*max_high < end)
142 			*max_high = end;
143 		if (bank->highmem)
144 			continue;
145 		if (*max_low < end)
146 			*max_low = end;
147 	}
148 }
149 
150 /*
151  * FIXME: We really want to avoid allocating the bootmap bitmap
152  * over the top of the initrd.  Hopefully, this is located towards
153  * the start of a bank, so if we allocate the bootmap bitmap at
154  * the end, we won't clash.
155  */
156 static unsigned int __init
157 find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
158 {
159 	unsigned int start_pfn, i, bootmap_pfn;
160 
161 	start_pfn   = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
162 	bootmap_pfn = 0;
163 
164 	for_each_nodebank(i, mi, node) {
165 		struct membank *bank = &mi->bank[i];
166 		unsigned int start, end;
167 
168 		start = bank_pfn_start(bank);
169 		end   = bank_pfn_end(bank);
170 
171 		if (end < start_pfn)
172 			continue;
173 
174 		if (start < start_pfn)
175 			start = start_pfn;
176 
177 		if (end <= start)
178 			continue;
179 
180 		if (end - start >= bootmap_pages) {
181 			bootmap_pfn = start;
182 			break;
183 		}
184 	}
185 
186 	if (bootmap_pfn == 0)
187 		BUG();
188 
189 	return bootmap_pfn;
190 }
191 
192 static int __init check_initrd(struct meminfo *mi)
193 {
194 	int initrd_node = -2;
195 #ifdef CONFIG_BLK_DEV_INITRD
196 	unsigned long end = phys_initrd_start + phys_initrd_size;
197 
198 	/*
199 	 * Make sure that the initrd is within a valid area of
200 	 * memory.
201 	 */
202 	if (phys_initrd_size) {
203 		unsigned int i;
204 
205 		initrd_node = -1;
206 
207 		for (i = 0; i < mi->nr_banks; i++) {
208 			struct membank *bank = &mi->bank[i];
209 			if (bank_phys_start(bank) <= phys_initrd_start &&
210 			    end <= bank_phys_end(bank))
211 				initrd_node = bank->node;
212 		}
213 	}
214 
215 	if (initrd_node == -1) {
216 		printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
217 		       "physical memory - disabling initrd\n",
218 		       phys_initrd_start, phys_initrd_size);
219 		phys_initrd_start = phys_initrd_size = 0;
220 	}
221 #endif
222 
223 	return initrd_node;
224 }
225 
226 static void __init bootmem_init_node(int node, struct meminfo *mi,
227 	unsigned long start_pfn, unsigned long end_pfn)
228 {
229 	unsigned long boot_pfn;
230 	unsigned int boot_pages;
231 	pg_data_t *pgdat;
232 	int i;
233 
234 	/*
235 	 * Allocate the bootmem bitmap page.
236 	 */
237 	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
238 	boot_pfn = find_bootmap_pfn(node, mi, boot_pages);
239 
240 	/*
241 	 * Initialise the bootmem allocator for this node, handing the
242 	 * memory banks over to bootmem.
243 	 */
244 	node_set_online(node);
245 	pgdat = NODE_DATA(node);
246 	init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);
247 
248 	for_each_nodebank(i, mi, node) {
249 		struct membank *bank = &mi->bank[i];
250 		if (!bank->highmem)
251 			free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
252 	}
253 
254 	/*
255 	 * Reserve the bootmem bitmap for this node.
256 	 */
257 	reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
258 			     boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
259 }
260 
261 static void __init bootmem_reserve_initrd(int node)
262 {
263 #ifdef CONFIG_BLK_DEV_INITRD
264 	pg_data_t *pgdat = NODE_DATA(node);
265 	int res;
266 
267 	res = reserve_bootmem_node(pgdat, phys_initrd_start,
268 			     phys_initrd_size, BOOTMEM_EXCLUSIVE);
269 
270 	if (res == 0) {
271 		initrd_start = __phys_to_virt(phys_initrd_start);
272 		initrd_end = initrd_start + phys_initrd_size;
273 	} else {
274 		printk(KERN_ERR
275 			"INITRD: 0x%08lx+0x%08lx overlaps in-use "
276 			"memory region - disabling initrd\n",
277 			phys_initrd_start, phys_initrd_size);
278 	}
279 #endif
280 }
281 
282 static void __init bootmem_free_node(int node, struct meminfo *mi)
283 {
284 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
285 	unsigned long min, max_low, max_high;
286 	int i;
287 
288 	find_node_limits(node, mi, &min, &max_low, &max_high);
289 
290 	/*
291 	 * initialise the zones within this node.
292 	 */
293 	memset(zone_size, 0, sizeof(zone_size));
294 
295 	/*
296 	 * The size of this node has already been determined.  If we need
297 	 * to do anything fancy with the allocation of this memory to the
298 	 * zones, now is the time to do it.
299 	 */
300 	zone_size[0] = max_low - min;
301 #ifdef CONFIG_HIGHMEM
302 	zone_size[ZONE_HIGHMEM] = max_high - max_low;
303 #endif
304 
305 	/*
306 	 * For each bank in this node, calculate the size of the holes.
307 	 *  holes = node_size - sum(bank_sizes_in_node)
308 	 */
309 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
310 	for_each_nodebank(i, mi, node) {
311 		int idx = 0;
312 #ifdef CONFIG_HIGHMEM
313 		if (mi->bank[i].highmem)
314 			idx = ZONE_HIGHMEM;
315 #endif
316 		zhole_size[idx] -= bank_pfn_size(&mi->bank[i]);
317 	}
318 
319 	/*
320 	 * Adjust the sizes according to any special requirements for
321 	 * this machine type.
322 	 */
323 	arch_adjust_zones(node, zone_size, zhole_size);
324 
325 	free_area_init_node(node, zone_size, min, zhole_size);
326 }
327 
328 #ifndef CONFIG_SPARSEMEM
329 int pfn_valid(unsigned long pfn)
330 {
331 	struct meminfo *mi = &meminfo;
332 	unsigned int left = 0, right = mi->nr_banks;
333 
334 	do {
335 		unsigned int mid = (right + left) / 2;
336 		struct membank *bank = &mi->bank[mid];
337 
338 		if (pfn < bank_pfn_start(bank))
339 			right = mid;
340 		else if (pfn >= bank_pfn_end(bank))
341 			left = mid + 1;
342 		else
343 			return 1;
344 	} while (left < right);
345 	return 0;
346 }
347 EXPORT_SYMBOL(pfn_valid);
348 
349 static void arm_memory_present(struct meminfo *mi, int node)
350 {
351 }
352 #else
353 static void arm_memory_present(struct meminfo *mi, int node)
354 {
355 	int i;
356 	for_each_nodebank(i, mi, node) {
357 		struct membank *bank = &mi->bank[i];
358 		memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
359 	}
360 }
361 #endif
362 
363 void __init bootmem_init(void)
364 {
365 	struct meminfo *mi = &meminfo;
366 	unsigned long min, max_low, max_high;
367 	int node, initrd_node;
368 
369 	/*
370 	 * Locate which node contains the ramdisk image, if any.
371 	 */
372 	initrd_node = check_initrd(mi);
373 
374 	max_low = max_high = 0;
375 
376 	/*
377 	 * Run through each node initialising the bootmem allocator.
378 	 */
379 	for_each_node(node) {
380 		unsigned long node_low, node_high;
381 
382 		find_node_limits(node, mi, &min, &node_low, &node_high);
383 
384 		if (node_low > max_low)
385 			max_low = node_low;
386 		if (node_high > max_high)
387 			max_high = node_high;
388 
389 		/*
390 		 * If there is no memory in this node, ignore it.
391 		 * (We can't have nodes which have no lowmem)
392 		 */
393 		if (node_low == 0)
394 			continue;
395 
396 		bootmem_init_node(node, mi, min, node_low);
397 
398 		/*
399 		 * Reserve any special node zero regions.
400 		 */
401 		if (node == 0)
402 			reserve_node_zero(NODE_DATA(node));
403 
404 		/*
405 		 * If the initrd is in this node, reserve its memory.
406 		 */
407 		if (node == initrd_node)
408 			bootmem_reserve_initrd(node);
409 
410 		/*
411 		 * Sparsemem tries to allocate bootmem in memory_present(),
412 		 * so must be done after the fixed reservations
413 		 */
414 		arm_memory_present(mi, node);
415 	}
416 
417 	/*
418 	 * sparse_init() needs the bootmem allocator up and running.
419 	 */
420 	sparse_init();
421 
422 	/*
423 	 * Now free memory in each node - free_area_init_node needs
424 	 * the sparse mem_map arrays initialized by sparse_init()
425 	 * for memmap_init_zone(), otherwise all PFNs are invalid.
426 	 */
427 	for_each_node(node)
428 		bootmem_free_node(node, mi);
429 
430 	high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;
431 
432 	/*
433 	 * This doesn't seem to be used by the Linux memory manager any
434 	 * more, but is used by ll_rw_block.  If we can get rid of it, we
435 	 * also get rid of some of the stuff above as well.
436 	 *
437 	 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
438 	 * the system, not the maximum PFN.
439 	 */
440 	max_low_pfn = max_low - PHYS_PFN_OFFSET;
441 	max_pfn = max_high - PHYS_PFN_OFFSET;
442 }
443 
444 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
445 {
446 	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
447 
448 	for (; pfn < end; pfn++) {
449 		struct page *page = pfn_to_page(pfn);
450 		ClearPageReserved(page);
451 		init_page_count(page);
452 		__free_page(page);
453 		pages++;
454 	}
455 
456 	if (size && s)
457 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
458 
459 	return pages;
460 }
461 
462 static inline void
463 free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
464 {
465 	struct page *start_pg, *end_pg;
466 	unsigned long pg, pgend;
467 
468 	/*
469 	 * Convert start_pfn/end_pfn to a struct page pointer.
470 	 */
471 	start_pg = pfn_to_page(start_pfn - 1) + 1;
472 	end_pg = pfn_to_page(end_pfn);
473 
474 	/*
475 	 * Convert to physical addresses, and
476 	 * round start upwards and end downwards.
477 	 */
478 	pg = PAGE_ALIGN(__pa(start_pg));
479 	pgend = __pa(end_pg) & PAGE_MASK;
480 
481 	/*
482 	 * If there are free pages between these,
483 	 * free the section of the memmap array.
484 	 */
485 	if (pg < pgend)
486 		free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
487 }
488 
489 /*
490  * The mem_map array can get very big.  Free the unused area of the memory map.
491  */
492 static void __init free_unused_memmap_node(int node, struct meminfo *mi)
493 {
494 	unsigned long bank_start, prev_bank_end = 0;
495 	unsigned int i;
496 
497 	/*
498 	 * [FIXME] This relies on each bank being in address order.  This
499 	 * may not be the case, especially if the user has provided the
500 	 * information on the command line.
501 	 */
502 	for_each_nodebank(i, mi, node) {
503 		struct membank *bank = &mi->bank[i];
504 
505 		bank_start = bank_pfn_start(bank);
506 		if (bank_start < prev_bank_end) {
507 			printk(KERN_ERR "MEM: unordered memory banks.  "
508 				"Not freeing memmap.\n");
509 			break;
510 		}
511 
512 		/*
513 		 * If we had a previous bank, and there is a space
514 		 * between the current bank and the previous, free it.
515 		 */
516 		if (prev_bank_end && prev_bank_end != bank_start)
517 			free_memmap(node, prev_bank_end, bank_start);
518 
519 		prev_bank_end = bank_pfn_end(bank);
520 	}
521 }
522 
523 /*
524  * mem_init() marks the free areas in the mem_map and tells us how much
525  * memory is free.  This is done after various parts of the system have
526  * claimed their memory after the kernel image.
527  */
528 void __init mem_init(void)
529 {
530 	unsigned long reserved_pages, free_pages;
531 	int i, node;
532 #ifdef CONFIG_HAVE_TCM
533 	/* These pointers are filled in on TCM detection */
534 	extern u32 dtcm_end;
535 	extern u32 itcm_end;
536 #endif
537 
538 #ifndef CONFIG_DISCONTIGMEM
539 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
540 #endif
541 
542 	/* this will put all unused low memory onto the freelists */
543 	for_each_online_node(node) {
544 		pg_data_t *pgdat = NODE_DATA(node);
545 
546 		free_unused_memmap_node(node, &meminfo);
547 
548 		if (pgdat->node_spanned_pages != 0)
549 			totalram_pages += free_all_bootmem_node(pgdat);
550 	}
551 
552 #ifdef CONFIG_SA1111
553 	/* now that our DMA memory is actually so designated, we can free it */
554 	totalram_pages += free_area(PHYS_PFN_OFFSET,
555 				    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
556 #endif
557 
558 #ifdef CONFIG_HIGHMEM
559 	/* set highmem page free */
560 	for_each_online_node(node) {
561 		for_each_nodebank (i, &meminfo, node) {
562 			unsigned long start = bank_pfn_start(&meminfo.bank[i]);
563 			unsigned long end = bank_pfn_end(&meminfo.bank[i]);
564 			if (start >= max_low_pfn + PHYS_PFN_OFFSET)
565 				totalhigh_pages += free_area(start, end, NULL);
566 		}
567 	}
568 	totalram_pages += totalhigh_pages;
569 #endif
570 
571 	reserved_pages = free_pages = 0;
572 
573 	for_each_online_node(node) {
574 		for_each_nodebank(i, &meminfo, node) {
575 			struct membank *bank = &meminfo.bank[i];
576 			unsigned int pfn1, pfn2;
577 			struct page *page, *end;
578 
579 			pfn1 = bank_pfn_start(bank);
580 			pfn2 = bank_pfn_end(bank);
581 
582 			page = pfn_to_page(pfn1);
583 			end  = pfn_to_page(pfn2 - 1) + 1;
584 
585 			do {
586 				if (PageReserved(page))
587 					reserved_pages++;
588 				else if (!page_count(page))
589 					free_pages++;
590 				page++;
591 			} while (page < end);
592 		}
593 	}
594 
595 	/*
596 	 * Since our memory may not be contiguous, calculate the
597 	 * real number of pages we have in this system
598 	 */
599 	printk(KERN_INFO "Memory:");
600 	num_physpages = 0;
601 	for (i = 0; i < meminfo.nr_banks; i++) {
602 		num_physpages += bank_pfn_size(&meminfo.bank[i]);
603 		printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
604 	}
605 	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
606 
607 	printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
608 		nr_free_pages() << (PAGE_SHIFT-10),
609 		free_pages << (PAGE_SHIFT-10),
610 		reserved_pages << (PAGE_SHIFT-10),
611 		totalhigh_pages << (PAGE_SHIFT-10));
612 
613 #define MLK(b, t) b, t, ((t) - (b)) >> 10
614 #define MLM(b, t) b, t, ((t) - (b)) >> 20
615 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
616 
617 	printk(KERN_NOTICE "Virtual kernel memory layout:\n"
618 			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
619 #ifdef CONFIG_HAVE_TCM
620 			"    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
621 			"    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
622 #endif
623 			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
624 #ifdef CONFIG_MMU
625 			"    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
626 #endif
627 			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
628 			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
629 #ifdef CONFIG_HIGHMEM
630 			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
631 #endif
632 			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
633 			"      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
634 			"      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
635 			"      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",
636 
637 			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
638 				(PAGE_SIZE)),
639 #ifdef CONFIG_HAVE_TCM
640 			MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
641 			MLK(ITCM_OFFSET, (unsigned long) itcm_end),
642 #endif
643 			MLK(FIXADDR_START, FIXADDR_TOP),
644 #ifdef CONFIG_MMU
645 			MLM(CONSISTENT_BASE, CONSISTENT_END),
646 #endif
647 			MLM(VMALLOC_START, VMALLOC_END),
648 			MLM(PAGE_OFFSET, (unsigned long)high_memory),
649 #ifdef CONFIG_HIGHMEM
650 			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
651 				(PAGE_SIZE)),
652 #endif
653 			MLM(MODULES_VADDR, MODULES_END),
654 
655 			MLK_ROUNDUP(__init_begin, __init_end),
656 			MLK_ROUNDUP(_text, _etext),
657 			MLK_ROUNDUP(_data, _edata));
658 
659 #undef MLK
660 #undef MLM
661 #undef MLK_ROUNDUP
662 
663 	/*
664 	 * Check boundaries twice: Some fundamental inconsistencies can
665 	 * be detected at build time already.
666 	 */
667 #ifdef CONFIG_MMU
668 	BUILD_BUG_ON(VMALLOC_END			> CONSISTENT_BASE);
669 	BUG_ON(VMALLOC_END				> CONSISTENT_BASE);
670 
671 	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
672 	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
673 #endif
674 
675 #ifdef CONFIG_HIGHMEM
676 	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
677 	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
678 #endif
679 
680 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
681 		extern int sysctl_overcommit_memory;
682 		/*
683 		 * On a machine this small we won't get
684 		 * anywhere without overcommit, so turn
685 		 * it on by default.
686 		 */
687 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
688 	}
689 }
690 
691 void free_initmem(void)
692 {
693 #ifdef CONFIG_HAVE_TCM
694 	extern char __tcm_start, __tcm_end;
695 
696 	totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
697 				    __phys_to_pfn(__pa(&__tcm_end)),
698 				    "TCM link");
699 #endif
700 
701 	if (!machine_is_integrator() && !machine_is_cintegrator())
702 		totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
703 					    __phys_to_pfn(__pa(__init_end)),
704 					    "init");
705 }
706 
707 #ifdef CONFIG_BLK_DEV_INITRD
708 
709 static int keep_initrd;
710 
711 void free_initrd_mem(unsigned long start, unsigned long end)
712 {
713 	if (!keep_initrd)
714 		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
715 					    __phys_to_pfn(__pa(end)),
716 					    "initrd");
717 }
718 
719 static int __init keepinitrd_setup(char *__unused)
720 {
721 	keep_initrd = 1;
722 	return 1;
723 }
724 
725 __setup("keepinitrd", keepinitrd_setup);
726 #endif
727