2 * Handle the memory map.
3 * The functions here do the job until bootmem takes over.
5 * Getting sanitize_e820_map() in sync with i386 version by applying change:
6 * - Provisions for empty E820 memory regions (reported by certain BIOSes).
7 * Alex Achenbach <xela@slit.de>, December 2002.
8 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/bootmem.h>
15 #include <linux/ioport.h>
16 #include <linux/string.h>
17 #include <linux/kexec.h>
18 #include <linux/module.h>
20 #include <asm/pgtable.h>
23 #include <asm/proto.h>
24 #include <asm/bootsetup.h>
25 #include <asm/sections.h>
27 struct e820map e820 __initdata
;
30 * PFN of last memory page.
32 unsigned long end_pfn
;
33 EXPORT_SYMBOL(end_pfn
);
36 * end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
37 * The direct mapping extends to end_pfn_map, so that we can directly access
38 * apertures, ACPI and other tables without having to play with fixmaps.
40 unsigned long end_pfn_map
;
43 * Last pfn which the user wants to use.
45 static unsigned long __initdata end_user_pfn
= MAXMEM
>>PAGE_SHIFT
;
47 extern struct resource code_resource
, data_resource
;
49 /* Check for some hardcoded bad areas that early boot is not allowed to touch */
50 static inline int bad_addr(unsigned long *addrp
, unsigned long size
)
52 unsigned long addr
= *addrp
, last
= addr
+ size
;
54 /* various gunk below that needed for SMP startup */
60 /* direct mapping tables of the kernel */
61 if (last
>= table_start
<<PAGE_SHIFT
&& addr
< table_end
<<PAGE_SHIFT
) {
62 *addrp
= table_end
<< PAGE_SHIFT
;
67 #ifdef CONFIG_BLK_DEV_INITRD
68 if (LOADER_TYPE
&& INITRD_START
&& last
>= INITRD_START
&&
69 addr
< INITRD_START
+INITRD_SIZE
) {
70 *addrp
= INITRD_START
+ INITRD_SIZE
;
74 /* kernel code + 640k memory hole (later should not be needed, but
75 be paranoid for now) */
76 if (last
>= 640*1024 && addr
< 1024*1024) {
80 if (last
>= __pa_symbol(&_text
) && last
< __pa_symbol(&_end
)) {
81 *addrp
= __pa_symbol(&_end
);
85 if (last
>= ebda_addr
&& addr
< ebda_addr
+ ebda_size
) {
86 *addrp
= ebda_addr
+ ebda_size
;
90 /* XXX ramdisk image here? */
95 * This function checks if any part of the range <start,end> is mapped
99 e820_any_mapped(unsigned long start
, unsigned long end
, unsigned type
)
102 for (i
= 0; i
< e820
.nr_map
; i
++) {
103 struct e820entry
*ei
= &e820
.map
[i
];
104 if (type
&& ei
->type
!= type
)
106 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
114 * This function checks if the entire range <start,end> is mapped with type.
116 * Note: this function only works correct if the e820 table is sorted and
117 * not-overlapping, which is the case
119 int __init
e820_all_mapped(unsigned long start
, unsigned long end
, unsigned type
)
122 for (i
= 0; i
< e820
.nr_map
; i
++) {
123 struct e820entry
*ei
= &e820
.map
[i
];
124 if (type
&& ei
->type
!= type
)
126 /* is the region (part) in overlap with the current region ?*/
127 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
130 /* if the region is at the beginning of <start,end> we move
131 * start to the end of the region since it's ok until there
133 if (ei
->addr
<= start
)
134 start
= ei
->addr
+ ei
->size
;
135 /* if start is now at or beyond end, we're done, full coverage */
137 return 1; /* we're done */
143 * Find a free area in a specific range.
145 unsigned long __init
find_e820_area(unsigned long start
, unsigned long end
, unsigned size
)
148 for (i
= 0; i
< e820
.nr_map
; i
++) {
149 struct e820entry
*ei
= &e820
.map
[i
];
150 unsigned long addr
= ei
->addr
, last
;
151 if (ei
->type
!= E820_RAM
)
155 if (addr
> ei
->addr
+ ei
->size
)
157 while (bad_addr(&addr
, size
) && addr
+size
<= ei
->addr
+ei
->size
)
160 if (last
> ei
->addr
+ ei
->size
)
170 * Free bootmem based on the e820 table for a node.
172 void __init
e820_bootmem_free(pg_data_t
*pgdat
, unsigned long start
,unsigned long end
)
175 for (i
= 0; i
< e820
.nr_map
; i
++) {
176 struct e820entry
*ei
= &e820
.map
[i
];
177 unsigned long last
, addr
;
179 if (ei
->type
!= E820_RAM
||
180 ei
->addr
+ei
->size
<= start
||
184 addr
= round_up(ei
->addr
, PAGE_SIZE
);
188 last
= round_down(ei
->addr
+ ei
->size
, PAGE_SIZE
);
192 if (last
> addr
&& last
-addr
>= PAGE_SIZE
)
193 free_bootmem_node(pgdat
, addr
, last
-addr
);
198 * Find the highest page frame number we have available
200 unsigned long __init
e820_end_of_ram(void)
203 unsigned long end_pfn
= 0;
205 for (i
= 0; i
< e820
.nr_map
; i
++) {
206 struct e820entry
*ei
= &e820
.map
[i
];
207 unsigned long start
, end
;
209 start
= round_up(ei
->addr
, PAGE_SIZE
);
210 end
= round_down(ei
->addr
+ ei
->size
, PAGE_SIZE
);
213 if (ei
->type
== E820_RAM
) {
214 if (end
> end_pfn
<<PAGE_SHIFT
)
215 end_pfn
= end
>>PAGE_SHIFT
;
217 if (end
> end_pfn_map
<<PAGE_SHIFT
)
218 end_pfn_map
= end
>>PAGE_SHIFT
;
222 if (end_pfn
> end_pfn_map
)
223 end_pfn_map
= end_pfn
;
224 if (end_pfn_map
> MAXMEM
>>PAGE_SHIFT
)
225 end_pfn_map
= MAXMEM
>>PAGE_SHIFT
;
226 if (end_pfn
> end_user_pfn
)
227 end_pfn
= end_user_pfn
;
228 if (end_pfn
> end_pfn_map
)
229 end_pfn
= end_pfn_map
;
235 * Compute how much memory is missing in a range.
236 * Unlike the other functions in this file the arguments are in page numbers.
239 e820_hole_size(unsigned long start_pfn
, unsigned long end_pfn
)
241 unsigned long ram
= 0;
242 unsigned long start
= start_pfn
<< PAGE_SHIFT
;
243 unsigned long end
= end_pfn
<< PAGE_SHIFT
;
245 for (i
= 0; i
< e820
.nr_map
; i
++) {
246 struct e820entry
*ei
= &e820
.map
[i
];
247 unsigned long last
, addr
;
249 if (ei
->type
!= E820_RAM
||
250 ei
->addr
+ei
->size
<= start
||
254 addr
= round_up(ei
->addr
, PAGE_SIZE
);
258 last
= round_down(ei
->addr
+ ei
->size
, PAGE_SIZE
);
265 return ((end
- start
) - ram
) >> PAGE_SHIFT
;
269 * Mark e820 reserved areas as busy for the resource manager.
271 void __init
e820_reserve_resources(void)
274 for (i
= 0; i
< e820
.nr_map
; i
++) {
275 struct resource
*res
;
276 res
= alloc_bootmem_low(sizeof(struct resource
));
277 switch (e820
.map
[i
].type
) {
278 case E820_RAM
: res
->name
= "System RAM"; break;
279 case E820_ACPI
: res
->name
= "ACPI Tables"; break;
280 case E820_NVS
: res
->name
= "ACPI Non-volatile Storage"; break;
281 default: res
->name
= "reserved";
283 res
->start
= e820
.map
[i
].addr
;
284 res
->end
= res
->start
+ e820
.map
[i
].size
- 1;
285 res
->flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
286 request_resource(&iomem_resource
, res
);
287 if (e820
.map
[i
].type
== E820_RAM
) {
289 * We don't know which RAM region contains kernel data,
290 * so we try it repeatedly and let the resource manager
293 request_resource(res
, &code_resource
);
294 request_resource(res
, &data_resource
);
296 request_resource(res
, &crashk_res
);
303 * Add a memory region to the kernel e820 map.
305 void __init
add_memory_region(unsigned long start
, unsigned long size
, int type
)
310 printk(KERN_ERR
"Ooops! Too many entries in the memory map!\n");
314 e820
.map
[x
].addr
= start
;
315 e820
.map
[x
].size
= size
;
316 e820
.map
[x
].type
= type
;
320 void __init
e820_print_map(char *who
)
324 for (i
= 0; i
< e820
.nr_map
; i
++) {
325 printk(" %s: %016Lx - %016Lx ", who
,
326 (unsigned long long) e820
.map
[i
].addr
,
327 (unsigned long long) (e820
.map
[i
].addr
+ e820
.map
[i
].size
));
328 switch (e820
.map
[i
].type
) {
329 case E820_RAM
: printk("(usable)\n");
332 printk("(reserved)\n");
335 printk("(ACPI data)\n");
338 printk("(ACPI NVS)\n");
340 default: printk("type %u\n", e820
.map
[i
].type
);
347 * Sanitize the BIOS e820 map.
349 * Some e820 responses include overlapping entries. The following
350 * replaces the original e820 map with a new one, removing overlaps.
353 static int __init
sanitize_e820_map(struct e820entry
* biosmap
, char * pnr_map
)
355 struct change_member
{
356 struct e820entry
*pbios
; /* pointer to original bios entry */
357 unsigned long long addr
; /* address for this change point */
359 static struct change_member change_point_list
[2*E820MAX
] __initdata
;
360 static struct change_member
*change_point
[2*E820MAX
] __initdata
;
361 static struct e820entry
*overlap_list
[E820MAX
] __initdata
;
362 static struct e820entry new_bios
[E820MAX
] __initdata
;
363 struct change_member
*change_tmp
;
364 unsigned long current_type
, last_type
;
365 unsigned long long last_addr
;
366 int chgidx
, still_changing
;
369 int old_nr
, new_nr
, chg_nr
;
373 Visually we're performing the following (1,2,3,4 = memory types)...
375 Sample memory map (w/overlaps):
376 ____22__________________
377 ______________________4_
378 ____1111________________
379 _44_____________________
380 11111111________________
381 ____________________33__
382 ___________44___________
383 __________33333_________
384 ______________22________
385 ___________________2222_
386 _________111111111______
387 _____________________11_
388 _________________4______
390 Sanitized equivalent (no overlap):
391 1_______________________
392 _44_____________________
393 ___1____________________
394 ____22__________________
395 ______11________________
396 _________1______________
397 __________3_____________
398 ___________44___________
399 _____________33_________
400 _______________2________
401 ________________1_______
402 _________________4______
403 ___________________2____
404 ____________________33__
405 ______________________4_
408 /* if there's only one memory region, don't bother */
414 /* bail out if we find any unreasonable addresses in bios map */
415 for (i
=0; i
<old_nr
; i
++)
416 if (biosmap
[i
].addr
+ biosmap
[i
].size
< biosmap
[i
].addr
)
419 /* create pointers for initial change-point information (for sorting) */
420 for (i
=0; i
< 2*old_nr
; i
++)
421 change_point
[i
] = &change_point_list
[i
];
423 /* record all known change-points (starting and ending addresses),
424 omitting those that are for empty memory regions */
426 for (i
=0; i
< old_nr
; i
++) {
427 if (biosmap
[i
].size
!= 0) {
428 change_point
[chgidx
]->addr
= biosmap
[i
].addr
;
429 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
430 change_point
[chgidx
]->addr
= biosmap
[i
].addr
+ biosmap
[i
].size
;
431 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
436 /* sort change-point list by memory addresses (low -> high) */
438 while (still_changing
) {
440 for (i
=1; i
< chg_nr
; i
++) {
441 /* if <current_addr> > <last_addr>, swap */
442 /* or, if current=<start_addr> & last=<end_addr>, swap */
443 if ((change_point
[i
]->addr
< change_point
[i
-1]->addr
) ||
444 ((change_point
[i
]->addr
== change_point
[i
-1]->addr
) &&
445 (change_point
[i
]->addr
== change_point
[i
]->pbios
->addr
) &&
446 (change_point
[i
-1]->addr
!= change_point
[i
-1]->pbios
->addr
))
449 change_tmp
= change_point
[i
];
450 change_point
[i
] = change_point
[i
-1];
451 change_point
[i
-1] = change_tmp
;
457 /* create a new bios memory map, removing overlaps */
458 overlap_entries
=0; /* number of entries in the overlap table */
459 new_bios_entry
=0; /* index for creating new bios map entries */
460 last_type
= 0; /* start with undefined memory type */
461 last_addr
= 0; /* start with 0 as last starting address */
462 /* loop through change-points, determining affect on the new bios map */
463 for (chgidx
=0; chgidx
< chg_nr
; chgidx
++)
465 /* keep track of all overlapping bios entries */
466 if (change_point
[chgidx
]->addr
== change_point
[chgidx
]->pbios
->addr
)
468 /* add map entry to overlap list (> 1 entry implies an overlap) */
469 overlap_list
[overlap_entries
++]=change_point
[chgidx
]->pbios
;
473 /* remove entry from list (order independent, so swap with last) */
474 for (i
=0; i
<overlap_entries
; i
++)
476 if (overlap_list
[i
] == change_point
[chgidx
]->pbios
)
477 overlap_list
[i
] = overlap_list
[overlap_entries
-1];
481 /* if there are overlapping entries, decide which "type" to use */
482 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
484 for (i
=0; i
<overlap_entries
; i
++)
485 if (overlap_list
[i
]->type
> current_type
)
486 current_type
= overlap_list
[i
]->type
;
487 /* continue building up new bios map based on this information */
488 if (current_type
!= last_type
) {
489 if (last_type
!= 0) {
490 new_bios
[new_bios_entry
].size
=
491 change_point
[chgidx
]->addr
- last_addr
;
492 /* move forward only if the new size was non-zero */
493 if (new_bios
[new_bios_entry
].size
!= 0)
494 if (++new_bios_entry
>= E820MAX
)
495 break; /* no more space left for new bios entries */
497 if (current_type
!= 0) {
498 new_bios
[new_bios_entry
].addr
= change_point
[chgidx
]->addr
;
499 new_bios
[new_bios_entry
].type
= current_type
;
500 last_addr
=change_point
[chgidx
]->addr
;
502 last_type
= current_type
;
505 new_nr
= new_bios_entry
; /* retain count for new bios entries */
507 /* copy new bios mapping into original location */
508 memcpy(biosmap
, new_bios
, new_nr
*sizeof(struct e820entry
));
515 * Copy the BIOS e820 map into a safe place.
517 * Sanity-check it while we're at it..
519 * If we're lucky and live on a modern system, the setup code
520 * will have given us a memory map that we can use to properly
521 * set up memory. If we aren't, we'll fake a memory map.
523 * We check to see that the memory map contains at least 2 elements
524 * before we'll use it, because the detection code in setup.S may
525 * not be perfect and most every PC known to man has two memory
526 * regions: one from 0 to 640k, and one from 1mb up. (The IBM
527 * thinkpad 560x, for example, does not cooperate with the memory
530 static int __init
copy_e820_map(struct e820entry
* biosmap
, int nr_map
)
532 /* Only one memory region (or negative)? Ignore it */
537 unsigned long start
= biosmap
->addr
;
538 unsigned long size
= biosmap
->size
;
539 unsigned long end
= start
+ size
;
540 unsigned long type
= biosmap
->type
;
542 /* Overflow in 64 bits? Ignore the memory map. */
547 * Some BIOSes claim RAM in the 640k - 1M region.
548 * Not right. Fix it up.
550 * This should be removed on Hammer which is supposed to not
551 * have non e820 covered ISA mappings there, but I had some strange
552 * problems so it stays for now. -AK
554 if (type
== E820_RAM
) {
555 if (start
< 0x100000ULL
&& end
> 0xA0000ULL
) {
556 if (start
< 0xA0000ULL
)
557 add_memory_region(start
, 0xA0000ULL
-start
, type
);
558 if (end
<= 0x100000ULL
)
565 add_memory_region(start
, size
, type
);
566 } while (biosmap
++,--nr_map
);
570 void __init
setup_memory_region(void)
572 char *who
= "BIOS-e820";
575 * Try to copy the BIOS-supplied E820-map.
577 * Otherwise fake a memory map; one section from 0k->640k,
578 * the next section from 1mb->appropriate_mem_k
580 sanitize_e820_map(E820_MAP
, &E820_MAP_NR
);
581 if (copy_e820_map(E820_MAP
, E820_MAP_NR
) < 0) {
582 unsigned long mem_size
;
584 /* compare results from other methods and take the greater */
585 if (ALT_MEM_K
< EXT_MEM_K
) {
586 mem_size
= EXT_MEM_K
;
589 mem_size
= ALT_MEM_K
;
594 add_memory_region(0, LOWMEMSIZE(), E820_RAM
);
595 add_memory_region(HIGH_MEMORY
, mem_size
<< 10, E820_RAM
);
597 printk(KERN_INFO
"BIOS-provided physical RAM map:\n");
601 static int __init
parse_memopt(char *p
)
605 end_user_pfn
= memparse(p
, &p
);
606 end_user_pfn
>>= PAGE_SHIFT
;
609 early_param("mem", parse_memopt
);
611 static int userdef __initdata
;
613 static int __init
parse_memmap_opt(char *p
)
616 unsigned long long start_at
, mem_size
;
618 if (!strcmp(p
, "exactmap")) {
619 #ifdef CONFIG_CRASH_DUMP
620 /* If we are doing a crash dump, we
621 * still need to know the real mem
622 * size before original memory map is
625 saved_max_pfn
= e820_end_of_ram();
634 mem_size
= memparse(p
, &p
);
638 start_at
= memparse(p
+1, &p
);
639 add_memory_region(start_at
, mem_size
, E820_RAM
);
640 } else if (*p
== '#') {
641 start_at
= memparse(p
+1, &p
);
642 add_memory_region(start_at
, mem_size
, E820_ACPI
);
643 } else if (*p
== '$') {
644 start_at
= memparse(p
+1, &p
);
645 add_memory_region(start_at
, mem_size
, E820_RESERVED
);
647 end_user_pfn
= (mem_size
>> PAGE_SHIFT
);
649 return *p
== '\0' ? 0 : -EINVAL
;
651 early_param("memmap", parse_memmap_opt
);
653 void finish_e820_parsing(void)
656 printk(KERN_INFO
"user-defined physical RAM map:\n");
657 e820_print_map("user");
661 unsigned long pci_mem_start
= 0xaeedbabe;
662 EXPORT_SYMBOL(pci_mem_start
);
665 * Search for the biggest gap in the low 32 bits of the e820
666 * memory space. We pass this space to PCI to assign MMIO resources
667 * for hotplug or unconfigured devices in.
668 * Hopefully the BIOS let enough space left.
670 __init
void e820_setup_gap(void)
672 unsigned long gapstart
, gapsize
, round
;
677 last
= 0x100000000ull
;
678 gapstart
= 0x10000000;
682 unsigned long long start
= e820
.map
[i
].addr
;
683 unsigned long long end
= start
+ e820
.map
[i
].size
;
686 * Since "last" is at most 4GB, we know we'll
687 * fit in 32 bits if this condition is true
690 unsigned long gap
= last
- end
;
703 gapstart
= (end_pfn
<< PAGE_SHIFT
) + 1024*1024;
704 printk(KERN_ERR
"PCI: Warning: Cannot find a gap in the 32bit address range\n"
705 KERN_ERR
"PCI: Unassigned devices with 32bit resource registers may break!\n");
709 * See how much we want to round up: start off with
710 * rounding to the next 1MB area.
713 while ((gapsize
>> 4) > round
)
715 /* Fun with two's complement */
716 pci_mem_start
= (gapstart
+ round
) & -round
;
718 printk(KERN_INFO
"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
719 pci_mem_start
, gapstart
, gapsize
);