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/crash_dump.h>
15 #include <linux/export.h>
16 #include <linux/bootmem.h>
17 #include <linux/pfn.h>
18 #include <linux/suspend.h>
19 #include <linux/acpi.h>
20 #include <linux/firmware-map.h>
21 #include <linux/memblock.h>
22 #include <linux/sort.h>
25 #include <asm/proto.h>
26 #include <asm/setup.h>
29 * The e820 map is the map that gets modified e.g. with command line parameters
30 * and that is also registered with modifications in the kernel resource tree
31 * with the iomem_resource as parent.
33 * The e820_saved is directly saved after the BIOS-provided memory map is
34 * copied. It doesn't get modified afterwards. It's registered for the
35 * /sys/firmware/memmap interface.
37 * That memory map is not modified and is used as base for kexec. The kexec'd
38 * kernel should get the same memory map as the firmware provides. Then the
39 * user can e.g. boot the original kernel with mem=1G while still booting the
40 * next kernel with full memory.
43 struct e820map e820_saved
;
45 /* For PCI or other memory-mapped resources */
46 unsigned long pci_mem_start
= 0xaeedbabe;
48 EXPORT_SYMBOL(pci_mem_start
);
52 * This function checks if any part of the range <start,end> is mapped
56 e820_any_mapped(u64 start
, u64 end
, unsigned type
)
60 for (i
= 0; i
< e820
.nr_map
; i
++) {
61 struct e820entry
*ei
= &e820
.map
[i
];
63 if (type
&& ei
->type
!= type
)
65 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
71 EXPORT_SYMBOL_GPL(e820_any_mapped
);
74 * This function checks if the entire range <start,end> is mapped with type.
76 * Note: this function only works correct if the e820 table is sorted and
77 * not-overlapping, which is the case
79 int __init
e820_all_mapped(u64 start
, u64 end
, unsigned type
)
83 for (i
= 0; i
< e820
.nr_map
; i
++) {
84 struct e820entry
*ei
= &e820
.map
[i
];
86 if (type
&& ei
->type
!= type
)
88 /* is the region (part) in overlap with the current region ?*/
89 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
92 /* if the region is at the beginning of <start,end> we move
93 * start to the end of the region since it's ok until there
95 if (ei
->addr
<= start
)
96 start
= ei
->addr
+ ei
->size
;
98 * if start is now at or beyond end, we're done, full
108 * Add a memory region to the kernel e820 map.
110 static void __init
__e820_add_region(struct e820map
*e820x
, u64 start
, u64 size
,
113 int x
= e820x
->nr_map
;
115 if (x
>= ARRAY_SIZE(e820x
->map
)) {
116 printk(KERN_ERR
"e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
117 (unsigned long long) start
,
118 (unsigned long long) (start
+ size
- 1));
122 e820x
->map
[x
].addr
= start
;
123 e820x
->map
[x
].size
= size
;
124 e820x
->map
[x
].type
= type
;
128 void __init
e820_add_region(u64 start
, u64 size
, int type
)
130 __e820_add_region(&e820
, start
, size
, type
);
133 static void __init
e820_print_type(u32 type
)
137 case E820_RESERVED_KERN
:
138 printk(KERN_CONT
"usable");
141 printk(KERN_CONT
"reserved");
144 printk(KERN_CONT
"ACPI data");
147 printk(KERN_CONT
"ACPI NVS");
150 printk(KERN_CONT
"unusable");
153 printk(KERN_CONT
"type %u", type
);
158 void __init
e820_print_map(char *who
)
162 for (i
= 0; i
< e820
.nr_map
; i
++) {
163 printk(KERN_INFO
"%s: [mem %#018Lx-%#018Lx] ", who
,
164 (unsigned long long) e820
.map
[i
].addr
,
166 (e820
.map
[i
].addr
+ e820
.map
[i
].size
- 1));
167 e820_print_type(e820
.map
[i
].type
);
168 printk(KERN_CONT
"\n");
173 * Sanitize the BIOS e820 map.
175 * Some e820 responses include overlapping entries. The following
176 * replaces the original e820 map with a new one, removing overlaps,
177 * and resolving conflicting memory types in favor of highest
180 * The input parameter biosmap points to an array of 'struct
181 * e820entry' which on entry has elements in the range [0, *pnr_map)
182 * valid, and which has space for up to max_nr_map entries.
183 * On return, the resulting sanitized e820 map entries will be in
184 * overwritten in the same location, starting at biosmap.
186 * The integer pointed to by pnr_map must be valid on entry (the
187 * current number of valid entries located at biosmap) and will
188 * be updated on return, with the new number of valid entries
189 * (something no more than max_nr_map.)
191 * The return value from sanitize_e820_map() is zero if it
192 * successfully 'sanitized' the map entries passed in, and is -1
193 * if it did nothing, which can happen if either of (1) it was
194 * only passed one map entry, or (2) any of the input map entries
195 * were invalid (start + size < start, meaning that the size was
196 * so big the described memory range wrapped around through zero.)
198 * Visually we're performing the following
199 * (1,2,3,4 = memory types)...
201 * Sample memory map (w/overlaps):
202 * ____22__________________
203 * ______________________4_
204 * ____1111________________
205 * _44_____________________
206 * 11111111________________
207 * ____________________33__
208 * ___________44___________
209 * __________33333_________
210 * ______________22________
211 * ___________________2222_
212 * _________111111111______
213 * _____________________11_
214 * _________________4______
216 * Sanitized equivalent (no overlap):
217 * 1_______________________
218 * _44_____________________
219 * ___1____________________
220 * ____22__________________
221 * ______11________________
222 * _________1______________
223 * __________3_____________
224 * ___________44___________
225 * _____________33_________
226 * _______________2________
227 * ________________1_______
228 * _________________4______
229 * ___________________2____
230 * ____________________33__
231 * ______________________4_
233 struct change_member
{
234 struct e820entry
*pbios
; /* pointer to original bios entry */
235 unsigned long long addr
; /* address for this change point */
238 static int __init
cpcompare(const void *a
, const void *b
)
240 struct change_member
* const *app
= a
, * const *bpp
= b
;
241 const struct change_member
*ap
= *app
, *bp
= *bpp
;
244 * Inputs are pointers to two elements of change_point[]. If their
245 * addresses are unequal, their difference dominates. If the addresses
246 * are equal, then consider one that represents the end of its region
247 * to be greater than one that does not.
249 if (ap
->addr
!= bp
->addr
)
250 return ap
->addr
> bp
->addr
? 1 : -1;
252 return (ap
->addr
!= ap
->pbios
->addr
) - (bp
->addr
!= bp
->pbios
->addr
);
255 int __init
sanitize_e820_map(struct e820entry
*biosmap
, int max_nr_map
,
258 static struct change_member change_point_list
[2*E820_X_MAX
] __initdata
;
259 static struct change_member
*change_point
[2*E820_X_MAX
] __initdata
;
260 static struct e820entry
*overlap_list
[E820_X_MAX
] __initdata
;
261 static struct e820entry new_bios
[E820_X_MAX
] __initdata
;
262 unsigned long current_type
, last_type
;
263 unsigned long long last_addr
;
267 int old_nr
, new_nr
, chg_nr
;
270 /* if there's only one memory region, don't bother */
275 BUG_ON(old_nr
> max_nr_map
);
277 /* bail out if we find any unreasonable addresses in bios map */
278 for (i
= 0; i
< old_nr
; i
++)
279 if (biosmap
[i
].addr
+ biosmap
[i
].size
< biosmap
[i
].addr
)
282 /* create pointers for initial change-point information (for sorting) */
283 for (i
= 0; i
< 2 * old_nr
; i
++)
284 change_point
[i
] = &change_point_list
[i
];
286 /* record all known change-points (starting and ending addresses),
287 omitting those that are for empty memory regions */
289 for (i
= 0; i
< old_nr
; i
++) {
290 if (biosmap
[i
].size
!= 0) {
291 change_point
[chgidx
]->addr
= biosmap
[i
].addr
;
292 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
293 change_point
[chgidx
]->addr
= biosmap
[i
].addr
+
295 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
300 /* sort change-point list by memory addresses (low -> high) */
301 sort(change_point
, chg_nr
, sizeof *change_point
, cpcompare
, NULL
);
303 /* create a new bios memory map, removing overlaps */
304 overlap_entries
= 0; /* number of entries in the overlap table */
305 new_bios_entry
= 0; /* index for creating new bios map entries */
306 last_type
= 0; /* start with undefined memory type */
307 last_addr
= 0; /* start with 0 as last starting address */
309 /* loop through change-points, determining affect on the new bios map */
310 for (chgidx
= 0; chgidx
< chg_nr
; chgidx
++) {
311 /* keep track of all overlapping bios entries */
312 if (change_point
[chgidx
]->addr
==
313 change_point
[chgidx
]->pbios
->addr
) {
315 * add map entry to overlap list (> 1 entry
316 * implies an overlap)
318 overlap_list
[overlap_entries
++] =
319 change_point
[chgidx
]->pbios
;
322 * remove entry from list (order independent,
325 for (i
= 0; i
< overlap_entries
; i
++) {
326 if (overlap_list
[i
] ==
327 change_point
[chgidx
]->pbios
)
329 overlap_list
[overlap_entries
-1];
334 * if there are overlapping entries, decide which
335 * "type" to use (larger value takes precedence --
336 * 1=usable, 2,3,4,4+=unusable)
339 for (i
= 0; i
< overlap_entries
; i
++)
340 if (overlap_list
[i
]->type
> current_type
)
341 current_type
= overlap_list
[i
]->type
;
343 * continue building up new bios map based on this
346 if (current_type
!= last_type
) {
347 if (last_type
!= 0) {
348 new_bios
[new_bios_entry
].size
=
349 change_point
[chgidx
]->addr
- last_addr
;
351 * move forward only if the new size
354 if (new_bios
[new_bios_entry
].size
!= 0)
356 * no more space left for new
359 if (++new_bios_entry
>= max_nr_map
)
362 if (current_type
!= 0) {
363 new_bios
[new_bios_entry
].addr
=
364 change_point
[chgidx
]->addr
;
365 new_bios
[new_bios_entry
].type
= current_type
;
366 last_addr
= change_point
[chgidx
]->addr
;
368 last_type
= current_type
;
371 /* retain count for new bios entries */
372 new_nr
= new_bios_entry
;
374 /* copy new bios mapping into original location */
375 memcpy(biosmap
, new_bios
, new_nr
* sizeof(struct e820entry
));
381 static int __init
__append_e820_map(struct e820entry
*biosmap
, int nr_map
)
384 u64 start
= biosmap
->addr
;
385 u64 size
= biosmap
->size
;
386 u64 end
= start
+ size
;
387 u32 type
= biosmap
->type
;
389 /* Overflow in 64 bits? Ignore the memory map. */
393 e820_add_region(start
, size
, type
);
402 * Copy the BIOS e820 map into a safe place.
404 * Sanity-check it while we're at it..
406 * If we're lucky and live on a modern system, the setup code
407 * will have given us a memory map that we can use to properly
408 * set up memory. If we aren't, we'll fake a memory map.
410 static int __init
append_e820_map(struct e820entry
*biosmap
, int nr_map
)
412 /* Only one memory region (or negative)? Ignore it */
416 return __append_e820_map(biosmap
, nr_map
);
419 static u64 __init
__e820_update_range(struct e820map
*e820x
, u64 start
,
420 u64 size
, unsigned old_type
,
425 u64 real_updated_size
= 0;
427 BUG_ON(old_type
== new_type
);
429 if (size
> (ULLONG_MAX
- start
))
430 size
= ULLONG_MAX
- start
;
433 printk(KERN_DEBUG
"e820: update [mem %#010Lx-%#010Lx] ",
434 (unsigned long long) start
, (unsigned long long) (end
- 1));
435 e820_print_type(old_type
);
436 printk(KERN_CONT
" ==> ");
437 e820_print_type(new_type
);
438 printk(KERN_CONT
"\n");
440 for (i
= 0; i
< e820x
->nr_map
; i
++) {
441 struct e820entry
*ei
= &e820x
->map
[i
];
442 u64 final_start
, final_end
;
445 if (ei
->type
!= old_type
)
448 ei_end
= ei
->addr
+ ei
->size
;
449 /* totally covered by new range? */
450 if (ei
->addr
>= start
&& ei_end
<= end
) {
452 real_updated_size
+= ei
->size
;
456 /* new range is totally covered? */
457 if (ei
->addr
< start
&& ei_end
> end
) {
458 __e820_add_region(e820x
, start
, size
, new_type
);
459 __e820_add_region(e820x
, end
, ei_end
- end
, ei
->type
);
460 ei
->size
= start
- ei
->addr
;
461 real_updated_size
+= size
;
465 /* partially covered */
466 final_start
= max(start
, ei
->addr
);
467 final_end
= min(end
, ei_end
);
468 if (final_start
>= final_end
)
471 __e820_add_region(e820x
, final_start
, final_end
- final_start
,
474 real_updated_size
+= final_end
- final_start
;
477 * left range could be head or tail, so need to update
480 ei
->size
-= final_end
- final_start
;
481 if (ei
->addr
< final_start
)
483 ei
->addr
= final_end
;
485 return real_updated_size
;
488 u64 __init
e820_update_range(u64 start
, u64 size
, unsigned old_type
,
491 return __e820_update_range(&e820
, start
, size
, old_type
, new_type
);
494 static u64 __init
e820_update_range_saved(u64 start
, u64 size
,
495 unsigned old_type
, unsigned new_type
)
497 return __e820_update_range(&e820_saved
, start
, size
, old_type
,
501 /* make e820 not cover the range */
502 u64 __init
e820_remove_range(u64 start
, u64 size
, unsigned old_type
,
507 u64 real_removed_size
= 0;
509 if (size
> (ULLONG_MAX
- start
))
510 size
= ULLONG_MAX
- start
;
513 printk(KERN_DEBUG
"e820: remove [mem %#010Lx-%#010Lx] ",
514 (unsigned long long) start
, (unsigned long long) (end
- 1));
516 e820_print_type(old_type
);
517 printk(KERN_CONT
"\n");
519 for (i
= 0; i
< e820
.nr_map
; i
++) {
520 struct e820entry
*ei
= &e820
.map
[i
];
521 u64 final_start
, final_end
;
524 if (checktype
&& ei
->type
!= old_type
)
527 ei_end
= ei
->addr
+ ei
->size
;
528 /* totally covered? */
529 if (ei
->addr
>= start
&& ei_end
<= end
) {
530 real_removed_size
+= ei
->size
;
531 memset(ei
, 0, sizeof(struct e820entry
));
535 /* new range is totally covered? */
536 if (ei
->addr
< start
&& ei_end
> end
) {
537 e820_add_region(end
, ei_end
- end
, ei
->type
);
538 ei
->size
= start
- ei
->addr
;
539 real_removed_size
+= size
;
543 /* partially covered */
544 final_start
= max(start
, ei
->addr
);
545 final_end
= min(end
, ei_end
);
546 if (final_start
>= final_end
)
548 real_removed_size
+= final_end
- final_start
;
551 * left range could be head or tail, so need to update
554 ei
->size
-= final_end
- final_start
;
555 if (ei
->addr
< final_start
)
557 ei
->addr
= final_end
;
559 return real_removed_size
;
562 void __init
update_e820(void)
566 nr_map
= e820
.nr_map
;
567 if (sanitize_e820_map(e820
.map
, ARRAY_SIZE(e820
.map
), &nr_map
))
569 e820
.nr_map
= nr_map
;
570 printk(KERN_INFO
"e820: modified physical RAM map:\n");
571 e820_print_map("modified");
573 static void __init
update_e820_saved(void)
577 nr_map
= e820_saved
.nr_map
;
578 if (sanitize_e820_map(e820_saved
.map
, ARRAY_SIZE(e820_saved
.map
), &nr_map
))
580 e820_saved
.nr_map
= nr_map
;
582 #define MAX_GAP_END 0x100000000ull
584 * Search for a gap in the e820 memory space from start_addr to end_addr.
586 __init
int e820_search_gap(unsigned long *gapstart
, unsigned long *gapsize
,
587 unsigned long start_addr
, unsigned long long end_addr
)
589 unsigned long long last
;
593 last
= (end_addr
&& end_addr
< MAX_GAP_END
) ? end_addr
: MAX_GAP_END
;
596 unsigned long long start
= e820
.map
[i
].addr
;
597 unsigned long long end
= start
+ e820
.map
[i
].size
;
599 if (end
< start_addr
)
603 * Since "last" is at most 4GB, we know we'll
604 * fit in 32 bits if this condition is true
607 unsigned long gap
= last
- end
;
609 if (gap
>= *gapsize
) {
622 * Search for the biggest gap in the low 32 bits of the e820
623 * memory space. We pass this space to PCI to assign MMIO resources
624 * for hotplug or unconfigured devices in.
625 * Hopefully the BIOS let enough space left.
627 __init
void e820_setup_gap(void)
629 unsigned long gapstart
, gapsize
;
632 gapstart
= 0x10000000;
634 found
= e820_search_gap(&gapstart
, &gapsize
, 0, MAX_GAP_END
);
638 gapstart
= (max_pfn
<< PAGE_SHIFT
) + 1024*1024;
640 "e820: cannot find a gap in the 32bit address range\n"
641 "e820: PCI devices with unassigned 32bit BARs may break!\n");
646 * e820_reserve_resources_late protect stolen RAM already
648 pci_mem_start
= gapstart
;
651 "e820: [mem %#010lx-%#010lx] available for PCI devices\n",
652 gapstart
, gapstart
+ gapsize
- 1);
656 * Because of the size limitation of struct boot_params, only first
657 * 128 E820 memory entries are passed to kernel via
658 * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
659 * linked list of struct setup_data, which is parsed here.
661 void __init
parse_e820_ext(struct setup_data
*sdata
)
664 struct e820entry
*extmap
;
666 entries
= sdata
->len
/ sizeof(struct e820entry
);
667 extmap
= (struct e820entry
*)(sdata
->data
);
668 __append_e820_map(extmap
, entries
);
669 sanitize_e820_map(e820
.map
, ARRAY_SIZE(e820
.map
), &e820
.nr_map
);
670 printk(KERN_INFO
"e820: extended physical RAM map:\n");
671 e820_print_map("extended");
674 #if defined(CONFIG_X86_64) || \
675 (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
677 * Find the ranges of physical addresses that do not correspond to
678 * e820 RAM areas and mark the corresponding pages as nosave for
679 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
681 * This function requires the e820 map to be sorted and without any
682 * overlapping entries and assumes the first e820 area to be RAM.
684 void __init
e820_mark_nosave_regions(unsigned long limit_pfn
)
689 pfn
= PFN_DOWN(e820
.map
[0].addr
+ e820
.map
[0].size
);
690 for (i
= 1; i
< e820
.nr_map
; i
++) {
691 struct e820entry
*ei
= &e820
.map
[i
];
693 if (pfn
< PFN_UP(ei
->addr
))
694 register_nosave_region(pfn
, PFN_UP(ei
->addr
));
696 pfn
= PFN_DOWN(ei
->addr
+ ei
->size
);
697 if (ei
->type
!= E820_RAM
&& ei
->type
!= E820_RESERVED_KERN
)
698 register_nosave_region(PFN_UP(ei
->addr
), pfn
);
700 if (pfn
>= limit_pfn
)
708 * Mark ACPI NVS memory region, so that we can save/restore it during
709 * hibernation and the subsequent resume.
711 static int __init
e820_mark_nvs_memory(void)
715 for (i
= 0; i
< e820
.nr_map
; i
++) {
716 struct e820entry
*ei
= &e820
.map
[i
];
718 if (ei
->type
== E820_NVS
)
719 acpi_nvs_register(ei
->addr
, ei
->size
);
724 core_initcall(e820_mark_nvs_memory
);
728 * pre allocated 4k and reserved it in memblock and e820_saved
730 u64 __init
early_reserve_e820(u64 size
, u64 align
)
734 addr
= __memblock_alloc_base(size
, align
, MEMBLOCK_ALLOC_ACCESSIBLE
);
736 e820_update_range_saved(addr
, size
, E820_RAM
, E820_RESERVED
);
737 printk(KERN_INFO
"e820: update e820_saved for early_reserve_e820\n");
745 # ifdef CONFIG_X86_PAE
746 # define MAX_ARCH_PFN (1ULL<<(36-PAGE_SHIFT))
748 # define MAX_ARCH_PFN (1ULL<<(32-PAGE_SHIFT))
750 #else /* CONFIG_X86_32 */
751 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
755 * Find the highest page frame number we have available
757 static unsigned long __init
e820_end_pfn(unsigned long limit_pfn
, unsigned type
)
760 unsigned long last_pfn
= 0;
761 unsigned long max_arch_pfn
= MAX_ARCH_PFN
;
763 for (i
= 0; i
< e820
.nr_map
; i
++) {
764 struct e820entry
*ei
= &e820
.map
[i
];
765 unsigned long start_pfn
;
766 unsigned long end_pfn
;
768 if (ei
->type
!= type
)
771 start_pfn
= ei
->addr
>> PAGE_SHIFT
;
772 end_pfn
= (ei
->addr
+ ei
->size
) >> PAGE_SHIFT
;
774 if (start_pfn
>= limit_pfn
)
776 if (end_pfn
> limit_pfn
) {
777 last_pfn
= limit_pfn
;
780 if (end_pfn
> last_pfn
)
784 if (last_pfn
> max_arch_pfn
)
785 last_pfn
= max_arch_pfn
;
787 printk(KERN_INFO
"e820: last_pfn = %#lx max_arch_pfn = %#lx\n",
788 last_pfn
, max_arch_pfn
);
791 unsigned long __init
e820_end_of_ram_pfn(void)
793 return e820_end_pfn(MAX_ARCH_PFN
, E820_RAM
);
796 unsigned long __init
e820_end_of_low_ram_pfn(void)
798 return e820_end_pfn(1UL<<(32 - PAGE_SHIFT
), E820_RAM
);
801 static void early_panic(char *msg
)
807 static int userdef __initdata
;
809 /* "mem=nopentium" disables the 4MB page tables. */
810 static int __init
parse_memopt(char *p
)
817 if (!strcmp(p
, "nopentium")) {
819 setup_clear_cpu_cap(X86_FEATURE_PSE
);
822 printk(KERN_WARNING
"mem=nopentium ignored! (only supported on x86_32)\n");
828 mem_size
= memparse(p
, &p
);
829 /* don't remove all of memory when handling "mem={invalid}" param */
832 e820_remove_range(mem_size
, ULLONG_MAX
- mem_size
, E820_RAM
, 1);
836 early_param("mem", parse_memopt
);
838 static int __init
parse_memmap_opt(char *p
)
841 u64 start_at
, mem_size
;
846 if (!strncmp(p
, "exactmap", 8)) {
847 #ifdef CONFIG_CRASH_DUMP
849 * If we are doing a crash dump, we still need to know
850 * the real mem size before original memory map is
853 saved_max_pfn
= e820_end_of_ram_pfn();
861 mem_size
= memparse(p
, &p
);
867 start_at
= memparse(p
+1, &p
);
868 e820_add_region(start_at
, mem_size
, E820_RAM
);
869 } else if (*p
== '#') {
870 start_at
= memparse(p
+1, &p
);
871 e820_add_region(start_at
, mem_size
, E820_ACPI
);
872 } else if (*p
== '$') {
873 start_at
= memparse(p
+1, &p
);
874 e820_add_region(start_at
, mem_size
, E820_RESERVED
);
876 e820_remove_range(mem_size
, ULLONG_MAX
- mem_size
, E820_RAM
, 1);
878 return *p
== '\0' ? 0 : -EINVAL
;
880 early_param("memmap", parse_memmap_opt
);
882 void __init
finish_e820_parsing(void)
885 u32 nr
= e820
.nr_map
;
887 if (sanitize_e820_map(e820
.map
, ARRAY_SIZE(e820
.map
), &nr
) < 0)
888 early_panic("Invalid user supplied memory map");
891 printk(KERN_INFO
"e820: user-defined physical RAM map:\n");
892 e820_print_map("user");
896 static inline const char *e820_type_to_string(int e820_type
)
899 case E820_RESERVED_KERN
:
900 case E820_RAM
: return "System RAM";
901 case E820_ACPI
: return "ACPI Tables";
902 case E820_NVS
: return "ACPI Non-volatile Storage";
903 case E820_UNUSABLE
: return "Unusable memory";
904 default: return "reserved";
909 * Mark e820 reserved areas as busy for the resource manager.
911 static struct resource __initdata
*e820_res
;
912 void __init
e820_reserve_resources(void)
915 struct resource
*res
;
918 res
= alloc_bootmem(sizeof(struct resource
) * e820
.nr_map
);
920 for (i
= 0; i
< e820
.nr_map
; i
++) {
921 end
= e820
.map
[i
].addr
+ e820
.map
[i
].size
- 1;
922 if (end
!= (resource_size_t
)end
) {
926 res
->name
= e820_type_to_string(e820
.map
[i
].type
);
927 res
->start
= e820
.map
[i
].addr
;
930 res
->flags
= IORESOURCE_MEM
;
933 * don't register the region that could be conflicted with
934 * pci device BAR resource and insert them later in
935 * pcibios_resource_survey()
937 if (e820
.map
[i
].type
!= E820_RESERVED
|| res
->start
< (1ULL<<20)) {
938 res
->flags
|= IORESOURCE_BUSY
;
939 insert_resource(&iomem_resource
, res
);
944 for (i
= 0; i
< e820_saved
.nr_map
; i
++) {
945 struct e820entry
*entry
= &e820_saved
.map
[i
];
946 firmware_map_add_early(entry
->addr
,
947 entry
->addr
+ entry
->size
,
948 e820_type_to_string(entry
->type
));
952 /* How much should we pad RAM ending depending on where it is? */
953 static unsigned long ram_alignment(resource_size_t pos
)
955 unsigned long mb
= pos
>> 20;
957 /* To 64kB in the first megabyte */
961 /* To 1MB in the first 16MB */
965 /* To 64MB for anything above that */
969 #define MAX_RESOURCE_SIZE ((resource_size_t)-1)
971 void __init
e820_reserve_resources_late(void)
974 struct resource
*res
;
977 for (i
= 0; i
< e820
.nr_map
; i
++) {
978 if (!res
->parent
&& res
->end
)
979 insert_resource_expand_to_fit(&iomem_resource
, res
);
984 * Try to bump up RAM regions to reasonable boundaries to
987 for (i
= 0; i
< e820
.nr_map
; i
++) {
988 struct e820entry
*entry
= &e820
.map
[i
];
991 if (entry
->type
!= E820_RAM
)
993 start
= entry
->addr
+ entry
->size
;
994 end
= round_up(start
, ram_alignment(start
)) - 1;
995 if (end
> MAX_RESOURCE_SIZE
)
996 end
= MAX_RESOURCE_SIZE
;
1000 "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n",
1002 reserve_region_with_split(&iomem_resource
, start
, end
,
1007 char *__init
default_machine_specific_memory_setup(void)
1009 char *who
= "BIOS-e820";
1012 * Try to copy the BIOS-supplied E820-map.
1014 * Otherwise fake a memory map; one section from 0k->640k,
1015 * the next section from 1mb->appropriate_mem_k
1017 new_nr
= boot_params
.e820_entries
;
1018 sanitize_e820_map(boot_params
.e820_map
,
1019 ARRAY_SIZE(boot_params
.e820_map
),
1021 boot_params
.e820_entries
= new_nr
;
1022 if (append_e820_map(boot_params
.e820_map
, boot_params
.e820_entries
)
1026 /* compare results from other methods and take the greater */
1027 if (boot_params
.alt_mem_k
1028 < boot_params
.screen_info
.ext_mem_k
) {
1029 mem_size
= boot_params
.screen_info
.ext_mem_k
;
1032 mem_size
= boot_params
.alt_mem_k
;
1037 e820_add_region(0, LOWMEMSIZE(), E820_RAM
);
1038 e820_add_region(HIGH_MEMORY
, mem_size
<< 10, E820_RAM
);
1041 /* In case someone cares... */
1045 void __init
setup_memory_map(void)
1049 who
= x86_init
.resources
.memory_setup();
1050 memcpy(&e820_saved
, &e820
, sizeof(struct e820map
));
1051 printk(KERN_INFO
"e820: BIOS-provided physical RAM map:\n");
1052 e820_print_map(who
);
1055 void __init
memblock_x86_fill(void)
1061 * EFI may have more than 128 entries
1062 * We are safe to enable resizing, beause memblock_x86_fill()
1063 * is rather later for x86
1065 memblock_allow_resize();
1067 for (i
= 0; i
< e820
.nr_map
; i
++) {
1068 struct e820entry
*ei
= &e820
.map
[i
];
1070 end
= ei
->addr
+ ei
->size
;
1071 if (end
!= (resource_size_t
)end
)
1074 if (ei
->type
!= E820_RAM
&& ei
->type
!= E820_RESERVED_KERN
)
1077 memblock_add(ei
->addr
, ei
->size
);
1080 /* throw away partial pages */
1081 memblock_trim_memory(PAGE_SIZE
);
1083 memblock_dump_all();
1086 void __init
memblock_find_dma_reserve(void)
1088 #ifdef CONFIG_X86_64
1089 u64 nr_pages
= 0, nr_free_pages
= 0;
1090 unsigned long start_pfn
, end_pfn
;
1091 phys_addr_t start
, end
;
1096 * need to find out used area below MAX_DMA_PFN
1097 * need to use memblock to get free size in [0, MAX_DMA_PFN]
1098 * at first, and assume boot_mem will not take below MAX_DMA_PFN
1100 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, NULL
) {
1101 start_pfn
= min_t(unsigned long, start_pfn
, MAX_DMA_PFN
);
1102 end_pfn
= min_t(unsigned long, end_pfn
, MAX_DMA_PFN
);
1103 nr_pages
+= end_pfn
- start_pfn
;
1106 for_each_free_mem_range(u
, MAX_NUMNODES
, &start
, &end
, NULL
) {
1107 start_pfn
= min_t(unsigned long, PFN_UP(start
), MAX_DMA_PFN
);
1108 end_pfn
= min_t(unsigned long, PFN_DOWN(end
), MAX_DMA_PFN
);
1109 if (start_pfn
< end_pfn
)
1110 nr_free_pages
+= end_pfn
- start_pfn
;
1113 set_dma_reserve(nr_pages
- nr_free_pages
);