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