2 * linux/arch/arm/mm/init.c
4 * Copyright (C) 1995-2005 Russell King
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.
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/ptrace.h>
13 #include <linux/swap.h>
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/mman.h>
17 #include <linux/nodemask.h>
18 #include <linux/initrd.h>
20 #include <asm/mach-types.h>
21 #include <asm/setup.h>
22 #include <asm/sizes.h>
25 #include <asm/mach/arch.h>
26 #include <asm/mach/map.h>
28 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
30 extern pgd_t swapper_pg_dir
[PTRS_PER_PGD
];
31 extern void _stext
, _text
, _etext
, __data_start
, _end
, __init_begin
, __init_end
;
32 extern unsigned long phys_initrd_start
;
33 extern unsigned long phys_initrd_size
;
36 * The sole use of this is to pass memory configuration
37 * data from paging_init to mem_init.
39 static struct meminfo meminfo __initdata
= { 0, };
42 * empty_zero_page is a special page that is used for
43 * zero-initialized data and COW.
45 struct page
*empty_zero_page
;
49 int free
= 0, total
= 0, reserved
= 0;
50 int shared
= 0, cached
= 0, slab
= 0, node
;
52 printk("Mem-info:\n");
54 printk("Free swap: %6ldkB\n", nr_swap_pages
<<(PAGE_SHIFT
-10));
56 for_each_online_node(node
) {
57 struct page
*page
, *end
;
59 page
= NODE_MEM_MAP(node
);
60 end
= page
+ NODE_DATA(node
)->node_spanned_pages
;
64 if (PageReserved(page
))
66 else if (PageSwapCache(page
))
68 else if (PageSlab(page
))
70 else if (!page_count(page
))
73 shared
+= page_count(page
) - 1;
78 printk("%d pages of RAM\n", total
);
79 printk("%d free pages\n", free
);
80 printk("%d reserved pages\n", reserved
);
81 printk("%d slab pages\n", slab
);
82 printk("%d pages shared\n", shared
);
83 printk("%d pages swap cached\n", cached
);
86 static inline pmd_t
*pmd_off(pgd_t
*pgd
, unsigned long virt
)
88 return pmd_offset(pgd
, virt
);
91 static inline pmd_t
*pmd_off_k(unsigned long virt
)
93 return pmd_off(pgd_offset_k(virt
), virt
);
96 #define for_each_nodebank(iter,mi,no) \
97 for (iter = 0; iter < mi->nr_banks; iter++) \
98 if (mi->bank[iter].node == no)
101 * FIXME: We really want to avoid allocating the bootmap bitmap
102 * over the top of the initrd. Hopefully, this is located towards
103 * the start of a bank, so if we allocate the bootmap bitmap at
104 * the end, we won't clash.
106 static unsigned int __init
107 find_bootmap_pfn(int node
, struct meminfo
*mi
, unsigned int bootmap_pages
)
109 unsigned int start_pfn
, bank
, bootmap_pfn
;
111 start_pfn
= PAGE_ALIGN(__pa(&_end
)) >> PAGE_SHIFT
;
114 for_each_nodebank(bank
, mi
, node
) {
115 unsigned int start
, end
;
117 start
= mi
->bank
[bank
].start
>> PAGE_SHIFT
;
118 end
= (mi
->bank
[bank
].size
+
119 mi
->bank
[bank
].start
) >> PAGE_SHIFT
;
124 if (start
< start_pfn
)
130 if (end
- start
>= bootmap_pages
) {
136 if (bootmap_pfn
== 0)
142 static int __init
check_initrd(struct meminfo
*mi
)
144 int initrd_node
= -2;
145 #ifdef CONFIG_BLK_DEV_INITRD
146 unsigned long end
= phys_initrd_start
+ phys_initrd_size
;
149 * Make sure that the initrd is within a valid area of
152 if (phys_initrd_size
) {
157 for (i
= 0; i
< mi
->nr_banks
; i
++) {
158 unsigned long bank_end
;
160 bank_end
= mi
->bank
[i
].start
+ mi
->bank
[i
].size
;
162 if (mi
->bank
[i
].start
<= phys_initrd_start
&&
164 initrd_node
= mi
->bank
[i
].node
;
168 if (initrd_node
== -1) {
169 printk(KERN_ERR
"initrd (0x%08lx - 0x%08lx) extends beyond "
170 "physical memory - disabling initrd\n",
171 phys_initrd_start
, end
);
172 phys_initrd_start
= phys_initrd_size
= 0;
180 * Reserve the various regions of node 0
182 static __init
void reserve_node_zero(pg_data_t
*pgdat
)
184 unsigned long res_size
= 0;
187 * Register the kernel text and data with bootmem.
188 * Note that this can only be in node 0.
190 #ifdef CONFIG_XIP_KERNEL
191 reserve_bootmem_node(pgdat
, __pa(&__data_start
), &_end
- &__data_start
);
193 reserve_bootmem_node(pgdat
, __pa(&_stext
), &_end
- &_stext
);
197 * Reserve the page tables. These are already in use,
198 * and can only be in node 0.
200 reserve_bootmem_node(pgdat
, __pa(swapper_pg_dir
),
201 PTRS_PER_PGD
* sizeof(pgd_t
));
204 * Hmm... This should go elsewhere, but we really really need to
205 * stop things allocating the low memory; ideally we need a better
206 * implementation of GFP_DMA which does not assume that DMA-able
207 * memory starts at zero.
209 if (machine_is_integrator() || machine_is_cintegrator())
210 res_size
= __pa(swapper_pg_dir
) - PHYS_OFFSET
;
213 * These should likewise go elsewhere. They pre-reserve the
214 * screen memory region at the start of main system memory.
216 if (machine_is_edb7211())
217 res_size
= 0x00020000;
218 if (machine_is_p720t())
219 res_size
= 0x00014000;
223 * Because of the SA1111 DMA bug, we want to preserve our
224 * precious DMA-able memory...
226 res_size
= __pa(swapper_pg_dir
) - PHYS_OFFSET
;
229 reserve_bootmem_node(pgdat
, PHYS_OFFSET
, res_size
);
232 void __init
build_mem_type_table(void);
233 void __init
create_mapping(struct map_desc
*md
);
235 static unsigned long __init
236 bootmem_init_node(int node
, int initrd_node
, struct meminfo
*mi
)
238 unsigned long zone_size
[MAX_NR_ZONES
], zhole_size
[MAX_NR_ZONES
];
239 unsigned long start_pfn
, end_pfn
, boot_pfn
;
240 unsigned int boot_pages
;
248 * Calculate the pfn range, and map the memory banks for this node.
250 for_each_nodebank(i
, mi
, node
) {
251 unsigned long start
, end
;
254 start
= mi
->bank
[i
].start
>> PAGE_SHIFT
;
255 end
= (mi
->bank
[i
].start
+ mi
->bank
[i
].size
) >> PAGE_SHIFT
;
257 if (start_pfn
> start
)
262 map
.pfn
= __phys_to_pfn(mi
->bank
[i
].start
);
263 map
.virtual = __phys_to_virt(mi
->bank
[i
].start
);
264 map
.length
= mi
->bank
[i
].size
;
265 map
.type
= MT_MEMORY
;
267 create_mapping(&map
);
271 * If there is no memory in this node, ignore it.
277 * Allocate the bootmem bitmap page.
279 boot_pages
= bootmem_bootmap_pages(end_pfn
- start_pfn
);
280 boot_pfn
= find_bootmap_pfn(node
, mi
, boot_pages
);
283 * Initialise the bootmem allocator for this node, handing the
284 * memory banks over to bootmem.
286 node_set_online(node
);
287 pgdat
= NODE_DATA(node
);
288 init_bootmem_node(pgdat
, boot_pfn
, start_pfn
, end_pfn
);
290 for_each_nodebank(i
, mi
, node
)
291 free_bootmem_node(pgdat
, mi
->bank
[i
].start
, mi
->bank
[i
].size
);
294 * Reserve the bootmem bitmap for this node.
296 reserve_bootmem_node(pgdat
, boot_pfn
<< PAGE_SHIFT
,
297 boot_pages
<< PAGE_SHIFT
);
299 #ifdef CONFIG_BLK_DEV_INITRD
301 * If the initrd is in this node, reserve its memory.
303 if (node
== initrd_node
) {
304 reserve_bootmem_node(pgdat
, phys_initrd_start
,
306 initrd_start
= __phys_to_virt(phys_initrd_start
);
307 initrd_end
= initrd_start
+ phys_initrd_size
;
312 * Finally, reserve any node zero regions.
315 reserve_node_zero(pgdat
);
318 * initialise the zones within this node.
320 memset(zone_size
, 0, sizeof(zone_size
));
321 memset(zhole_size
, 0, sizeof(zhole_size
));
324 * The size of this node has already been determined. If we need
325 * to do anything fancy with the allocation of this memory to the
326 * zones, now is the time to do it.
328 zone_size
[0] = end_pfn
- start_pfn
;
331 * For each bank in this node, calculate the size of the holes.
332 * holes = node_size - sum(bank_sizes_in_node)
334 zhole_size
[0] = zone_size
[0];
335 for_each_nodebank(i
, mi
, node
)
336 zhole_size
[0] -= mi
->bank
[i
].size
>> PAGE_SHIFT
;
339 * Adjust the sizes according to any special requirements for
342 arch_adjust_zones(node
, zone_size
, zhole_size
);
344 free_area_init_node(node
, pgdat
, zone_size
, start_pfn
, zhole_size
);
349 static void __init
bootmem_init(struct meminfo
*mi
)
351 unsigned long addr
, memend_pfn
= 0;
352 int node
, initrd_node
, i
;
355 * Invalidate the node number for empty or invalid memory banks
357 for (i
= 0; i
< mi
->nr_banks
; i
++)
358 if (mi
->bank
[i
].size
== 0 || mi
->bank
[i
].node
>= MAX_NUMNODES
)
359 mi
->bank
[i
].node
= -1;
361 memcpy(&meminfo
, mi
, sizeof(meminfo
));
364 * Clear out all the mappings below the kernel image.
366 for (addr
= 0; addr
< MODULE_START
; addr
+= PGDIR_SIZE
)
367 pmd_clear(pmd_off_k(addr
));
368 #ifdef CONFIG_XIP_KERNEL
369 /* The XIP kernel is mapped in the module area -- skip over it */
370 addr
= ((unsigned long)&_etext
+ PGDIR_SIZE
- 1) & PGDIR_MASK
;
372 for ( ; addr
< PAGE_OFFSET
; addr
+= PGDIR_SIZE
)
373 pmd_clear(pmd_off_k(addr
));
376 * Clear out all the kernel space mappings, except for the first
377 * memory bank, up to the end of the vmalloc region.
379 for (addr
= __phys_to_virt(mi
->bank
[0].start
+ mi
->bank
[0].size
);
380 addr
< VMALLOC_END
; addr
+= PGDIR_SIZE
)
381 pmd_clear(pmd_off_k(addr
));
384 * Locate which node contains the ramdisk image, if any.
386 initrd_node
= check_initrd(mi
);
389 * Run through each node initialising the bootmem allocator.
391 for_each_node(node
) {
392 unsigned long end_pfn
;
394 end_pfn
= bootmem_init_node(node
, initrd_node
, mi
);
397 * Remember the highest memory PFN.
399 if (end_pfn
> memend_pfn
)
400 memend_pfn
= end_pfn
;
403 high_memory
= __va(memend_pfn
<< PAGE_SHIFT
);
406 * This doesn't seem to be used by the Linux memory manager any
407 * more, but is used by ll_rw_block. If we can get rid of it, we
408 * also get rid of some of the stuff above as well.
410 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
411 * the system, not the maximum PFN.
413 max_pfn
= max_low_pfn
= memend_pfn
- PHYS_PFN_OFFSET
;
417 * Set up device the mappings. Since we clear out the page tables for all
418 * mappings above VMALLOC_END, we will remove any debug device mappings.
419 * This means you have to be careful how you debug this function, or any
420 * called function. This means you can't use any function or debugging
421 * method which may touch any device, otherwise the kernel _will_ crash.
423 static void __init
devicemaps_init(struct machine_desc
*mdesc
)
430 * Allocate the vector page early.
432 vectors
= alloc_bootmem_low_pages(PAGE_SIZE
);
435 for (addr
= VMALLOC_END
; addr
; addr
+= PGDIR_SIZE
)
436 pmd_clear(pmd_off_k(addr
));
439 * Map the kernel if it is XIP.
440 * It is always first in the modulearea.
442 #ifdef CONFIG_XIP_KERNEL
443 map
.pfn
= __phys_to_pfn(CONFIG_XIP_PHYS_ADDR
& PGDIR_MASK
);
444 map
.virtual = MODULE_START
;
445 map
.length
= ((unsigned long)&_etext
- map
.virtual + ~PGDIR_MASK
) & PGDIR_MASK
;
447 create_mapping(&map
);
451 * Map the cache flushing regions.
454 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
);
455 map
.virtual = FLUSH_BASE
;
457 map
.type
= MT_CACHECLEAN
;
458 create_mapping(&map
);
460 #ifdef FLUSH_BASE_MINICACHE
461 map
.pfn
= __phys_to_pfn(FLUSH_BASE_PHYS
+ SZ_1M
);
462 map
.virtual = FLUSH_BASE_MINICACHE
;
464 map
.type
= MT_MINICLEAN
;
465 create_mapping(&map
);
469 * Create a mapping for the machine vectors at the high-vectors
470 * location (0xffff0000). If we aren't using high-vectors, also
471 * create a mapping at the low-vectors virtual address.
473 map
.pfn
= __phys_to_pfn(virt_to_phys(vectors
));
474 map
.virtual = 0xffff0000;
475 map
.length
= PAGE_SIZE
;
476 map
.type
= MT_HIGH_VECTORS
;
477 create_mapping(&map
);
479 if (!vectors_high()) {
481 map
.type
= MT_LOW_VECTORS
;
482 create_mapping(&map
);
486 * Ask the machine support to map in the statically mapped devices.
492 * Finally flush the caches and tlb to ensure that we're in a
493 * consistent state wrt the writebuffer. This also ensures that
494 * any write-allocated cache lines in the vector page are written
495 * back. After this point, we can start to touch devices again.
497 local_flush_tlb_all();
502 * paging_init() sets up the page tables, initialises the zone memory
503 * maps, and sets up the zero page, bad page and bad page tables.
505 void __init
paging_init(struct meminfo
*mi
, struct machine_desc
*mdesc
)
509 build_mem_type_table();
511 devicemaps_init(mdesc
);
513 top_pmd
= pmd_off_k(0xffff0000);
516 * allocate the zero page. Note that we count on this going ok.
518 zero_page
= alloc_bootmem_low_pages(PAGE_SIZE
);
519 memzero(zero_page
, PAGE_SIZE
);
520 empty_zero_page
= virt_to_page(zero_page
);
521 flush_dcache_page(empty_zero_page
);
524 static inline void free_area(unsigned long addr
, unsigned long end
, char *s
)
526 unsigned int size
= (end
- addr
) >> 10;
528 for (; addr
< end
; addr
+= PAGE_SIZE
) {
529 struct page
*page
= virt_to_page(addr
);
530 ClearPageReserved(page
);
531 init_page_count(page
);
537 printk(KERN_INFO
"Freeing %s memory: %dK\n", s
, size
);
541 free_memmap(int node
, unsigned long start_pfn
, unsigned long end_pfn
)
543 struct page
*start_pg
, *end_pg
;
544 unsigned long pg
, pgend
;
547 * Convert start_pfn/end_pfn to a struct page pointer.
549 start_pg
= pfn_to_page(start_pfn
);
550 end_pg
= pfn_to_page(end_pfn
);
553 * Convert to physical addresses, and
554 * round start upwards and end downwards.
556 pg
= PAGE_ALIGN(__pa(start_pg
));
557 pgend
= __pa(end_pg
) & PAGE_MASK
;
560 * If there are free pages between these,
561 * free the section of the memmap array.
564 free_bootmem_node(NODE_DATA(node
), pg
, pgend
- pg
);
568 * The mem_map array can get very big. Free the unused area of the memory map.
570 static void __init
free_unused_memmap_node(int node
, struct meminfo
*mi
)
572 unsigned long bank_start
, prev_bank_end
= 0;
576 * [FIXME] This relies on each bank being in address order. This
577 * may not be the case, especially if the user has provided the
578 * information on the command line.
580 for_each_nodebank(i
, mi
, node
) {
581 bank_start
= mi
->bank
[i
].start
>> PAGE_SHIFT
;
582 if (bank_start
< prev_bank_end
) {
583 printk(KERN_ERR
"MEM: unordered memory banks. "
584 "Not freeing memmap.\n");
589 * If we had a previous bank, and there is a space
590 * between the current bank and the previous, free it.
592 if (prev_bank_end
&& prev_bank_end
!= bank_start
)
593 free_memmap(node
, prev_bank_end
, bank_start
);
595 prev_bank_end
= (mi
->bank
[i
].start
+
596 mi
->bank
[i
].size
) >> PAGE_SHIFT
;
601 * mem_init() marks the free areas in the mem_map and tells us how much
602 * memory is free. This is done after various parts of the system have
603 * claimed their memory after the kernel image.
605 void __init
mem_init(void)
607 unsigned int codepages
, datapages
, initpages
;
610 codepages
= &_etext
- &_text
;
611 datapages
= &_end
- &__data_start
;
612 initpages
= &__init_end
- &__init_begin
;
614 #ifndef CONFIG_DISCONTIGMEM
615 max_mapnr
= virt_to_page(high_memory
) - mem_map
;
618 /* this will put all unused low memory onto the freelists */
619 for_each_online_node(node
) {
620 pg_data_t
*pgdat
= NODE_DATA(node
);
622 free_unused_memmap_node(node
, &meminfo
);
624 if (pgdat
->node_spanned_pages
!= 0)
625 totalram_pages
+= free_all_bootmem_node(pgdat
);
629 /* now that our DMA memory is actually so designated, we can free it */
630 free_area(PAGE_OFFSET
, (unsigned long)swapper_pg_dir
, NULL
);
634 * Since our memory may not be contiguous, calculate the
635 * real number of pages we have in this system
637 printk(KERN_INFO
"Memory:");
640 for (i
= 0; i
< meminfo
.nr_banks
; i
++) {
641 num_physpages
+= meminfo
.bank
[i
].size
>> PAGE_SHIFT
;
642 printk(" %ldMB", meminfo
.bank
[i
].size
>> 20);
645 printk(" = %luMB total\n", num_physpages
>> (20 - PAGE_SHIFT
));
646 printk(KERN_NOTICE
"Memory: %luKB available (%dK code, "
647 "%dK data, %dK init)\n",
648 (unsigned long) nr_free_pages() << (PAGE_SHIFT
-10),
649 codepages
>> 10, datapages
>> 10, initpages
>> 10);
651 if (PAGE_SIZE
>= 16384 && num_physpages
<= 128) {
652 extern int sysctl_overcommit_memory
;
654 * On a machine this small we won't get
655 * anywhere without overcommit, so turn
658 sysctl_overcommit_memory
= OVERCOMMIT_ALWAYS
;
662 void free_initmem(void)
664 if (!machine_is_integrator() && !machine_is_cintegrator()) {
665 free_area((unsigned long)(&__init_begin
),
666 (unsigned long)(&__init_end
),
671 #ifdef CONFIG_BLK_DEV_INITRD
673 static int keep_initrd
;
675 void free_initrd_mem(unsigned long start
, unsigned long end
)
678 free_area(start
, end
, "initrd");
681 static int __init
keepinitrd_setup(char *__unused
)
687 __setup("keepinitrd", keepinitrd_setup
);