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 <linux/suspend.h>
21 #include <linux/pfn.h>
23 #include <asm/pgtable.h>
26 #include <asm/proto.h>
27 #include <asm/setup.h>
28 #include <asm/sections.h>
29 #include <asm/kdebug.h>
30 #include <asm/trampoline.h>
35 * PFN of last memory page.
37 unsigned long end_pfn
;
40 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
41 * The direct mapping extends to max_pfn_mapped, so that we can directly access
42 * apertures, ACPI and other tables without having to play with fixmaps.
44 unsigned long max_pfn_mapped
;
47 * Last pfn which the user wants to use.
49 static unsigned long __initdata end_user_pfn
= MAXMEM
>>PAGE_SHIFT
;
52 * Early reserved memory areas.
54 #define MAX_EARLY_RES 20
57 unsigned long start
, end
;
60 static struct early_res early_res
[MAX_EARLY_RES
] __initdata
= {
61 { 0, PAGE_SIZE
, "BIOS data page" }, /* BIOS data page */
62 #ifdef CONFIG_X86_TRAMPOLINE
63 { TRAMPOLINE_BASE
, TRAMPOLINE_BASE
+ 2 * PAGE_SIZE
, "TRAMPOLINE" },
68 void __init
reserve_early(unsigned long start
, unsigned long end
, char *name
)
72 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
74 if (end
> r
->start
&& start
< r
->end
)
75 panic("Overlapping early reservations %lx-%lx %s to %lx-%lx %s\n",
76 start
, end
- 1, name
?name
:"", r
->start
, r
->end
- 1, r
->name
);
78 if (i
>= MAX_EARLY_RES
)
79 panic("Too many early reservations");
84 strncpy(r
->name
, name
, sizeof(r
->name
) - 1);
87 void __init
free_early(unsigned long start
, unsigned long end
)
92 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
94 if (start
== r
->start
&& end
== r
->end
)
97 if (i
>= MAX_EARLY_RES
|| !early_res
[i
].end
)
98 panic("free_early on not reserved area: %lx-%lx!", start
, end
);
100 for (j
= i
+ 1; j
< MAX_EARLY_RES
&& early_res
[j
].end
; j
++)
103 memcpy(&early_res
[i
], &early_res
[i
+ 1],
104 (j
- 1 - i
) * sizeof(struct early_res
));
106 early_res
[j
- 1].end
= 0;
109 void __init
early_res_to_bootmem(void)
112 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
113 struct early_res
*r
= &early_res
[i
];
114 printk(KERN_INFO
"early res: %d [%lx-%lx] %s\n", i
,
115 r
->start
, r
->end
- 1, r
->name
);
116 reserve_bootmem_generic(r
->start
, r
->end
- r
->start
);
120 /* Check for already reserved areas */
121 static inline int __init
122 bad_addr(unsigned long *addrp
, unsigned long size
, unsigned long align
)
125 unsigned long addr
= *addrp
, last
;
129 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
130 struct early_res
*r
= &early_res
[i
];
131 if (last
>= r
->start
&& addr
< r
->end
) {
132 *addrp
= addr
= round_up(r
->end
, align
);
140 /* Check for already reserved areas */
141 static inline int __init
142 bad_addr_size(unsigned long *addrp
, unsigned long *sizep
, unsigned long align
)
145 unsigned long addr
= *addrp
, last
;
146 unsigned long size
= *sizep
;
150 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
151 struct early_res
*r
= &early_res
[i
];
152 if (last
> r
->start
&& addr
< r
->start
) {
153 size
= r
->start
- addr
;
157 if (last
> r
->end
&& addr
< r
->end
) {
158 addr
= round_up(r
->end
, align
);
163 if (last
<= r
->end
&& addr
>= r
->start
) {
175 * This function checks if any part of the range <start,end> is mapped
179 e820_any_mapped(unsigned long start
, unsigned long end
, unsigned type
)
183 for (i
= 0; i
< e820
.nr_map
; i
++) {
184 struct e820entry
*ei
= &e820
.map
[i
];
186 if (type
&& ei
->type
!= type
)
188 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
194 EXPORT_SYMBOL_GPL(e820_any_mapped
);
197 * This function checks if the entire range <start,end> is mapped with type.
199 * Note: this function only works correct if the e820 table is sorted and
200 * not-overlapping, which is the case
202 int __init
e820_all_mapped(unsigned long start
, unsigned long end
,
207 for (i
= 0; i
< e820
.nr_map
; i
++) {
208 struct e820entry
*ei
= &e820
.map
[i
];
210 if (type
&& ei
->type
!= type
)
212 /* is the region (part) in overlap with the current region ?*/
213 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
216 /* if the region is at the beginning of <start,end> we move
217 * start to the end of the region since it's ok until there
219 if (ei
->addr
<= start
)
220 start
= ei
->addr
+ ei
->size
;
222 * if start is now at or beyond end, we're done, full
232 * Find a free area with specified alignment in a specific range.
234 unsigned long __init
find_e820_area(unsigned long start
, unsigned long end
,
235 unsigned long size
, unsigned long align
)
239 for (i
= 0; i
< e820
.nr_map
; i
++) {
240 struct e820entry
*ei
= &e820
.map
[i
];
241 unsigned long addr
, last
;
242 unsigned long ei_last
;
244 if (ei
->type
!= E820_RAM
)
246 addr
= round_up(ei
->addr
, align
);
247 ei_last
= ei
->addr
+ ei
->size
;
249 addr
= round_up(start
, align
);
252 while (bad_addr(&addr
, size
, align
) && addr
+size
<= ei_last
)
265 * Find next free range after *start
267 unsigned long __init
find_e820_area_size(unsigned long start
,
268 unsigned long *sizep
,
273 for (i
= 0; i
< e820
.nr_map
; i
++) {
274 struct e820entry
*ei
= &e820
.map
[i
];
275 unsigned long addr
, last
;
276 unsigned long ei_last
;
278 if (ei
->type
!= E820_RAM
)
280 addr
= round_up(ei
->addr
, align
);
281 ei_last
= ei
->addr
+ ei
->size
;
283 addr
= round_up(start
, align
);
286 *sizep
= ei_last
- addr
;
287 while (bad_addr_size(&addr
, sizep
, align
) &&
288 addr
+ *sizep
<= ei_last
)
290 last
= addr
+ *sizep
;
299 * Find the highest page frame number we have available
301 unsigned long __init
e820_end_of_ram(void)
303 unsigned long end_pfn
;
305 end_pfn
= find_max_pfn_with_active_regions();
307 if (end_pfn
> max_pfn_mapped
)
308 max_pfn_mapped
= end_pfn
;
309 if (max_pfn_mapped
> MAXMEM
>>PAGE_SHIFT
)
310 max_pfn_mapped
= MAXMEM
>>PAGE_SHIFT
;
311 if (end_pfn
> end_user_pfn
)
312 end_pfn
= end_user_pfn
;
313 if (end_pfn
> max_pfn_mapped
)
314 end_pfn
= max_pfn_mapped
;
316 printk(KERN_INFO
"max_pfn_mapped = %lu\n", max_pfn_mapped
);
321 * Mark e820 reserved areas as busy for the resource manager.
323 void __init
e820_reserve_resources(void)
326 struct resource
*res
;
328 res
= alloc_bootmem_low(sizeof(struct resource
) * e820
.nr_map
);
329 for (i
= 0; i
< e820
.nr_map
; i
++) {
330 switch (e820
.map
[i
].type
) {
331 case E820_RAM
: res
->name
= "System RAM"; break;
332 case E820_ACPI
: res
->name
= "ACPI Tables"; break;
333 case E820_NVS
: res
->name
= "ACPI Non-volatile Storage"; break;
334 default: res
->name
= "reserved";
336 res
->start
= e820
.map
[i
].addr
;
337 res
->end
= res
->start
+ e820
.map
[i
].size
- 1;
338 res
->flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
339 insert_resource(&iomem_resource
, res
);
345 * Find the ranges of physical addresses that do not correspond to
346 * e820 RAM areas and mark the corresponding pages as nosave for software
347 * suspend and suspend to RAM.
349 * This function requires the e820 map to be sorted and without any
350 * overlapping entries and assumes the first e820 area to be RAM.
352 void __init
e820_mark_nosave_regions(void)
357 paddr
= round_down(e820
.map
[0].addr
+ e820
.map
[0].size
, PAGE_SIZE
);
358 for (i
= 1; i
< e820
.nr_map
; i
++) {
359 struct e820entry
*ei
= &e820
.map
[i
];
361 if (paddr
< ei
->addr
)
362 register_nosave_region(PFN_DOWN(paddr
),
365 paddr
= round_down(ei
->addr
+ ei
->size
, PAGE_SIZE
);
366 if (ei
->type
!= E820_RAM
)
367 register_nosave_region(PFN_UP(ei
->addr
),
370 if (paddr
>= (end_pfn
<< PAGE_SHIFT
))
376 * Finds an active region in the address range from start_pfn to end_pfn and
377 * returns its range in ei_startpfn and ei_endpfn for the e820 entry.
379 static int __init
e820_find_active_region(const struct e820entry
*ei
,
380 unsigned long start_pfn
,
381 unsigned long end_pfn
,
382 unsigned long *ei_startpfn
,
383 unsigned long *ei_endpfn
)
385 *ei_startpfn
= round_up(ei
->addr
, PAGE_SIZE
) >> PAGE_SHIFT
;
386 *ei_endpfn
= round_down(ei
->addr
+ ei
->size
, PAGE_SIZE
) >> PAGE_SHIFT
;
388 /* Skip map entries smaller than a page */
389 if (*ei_startpfn
>= *ei_endpfn
)
392 /* Check if max_pfn_mapped should be updated */
393 if (ei
->type
!= E820_RAM
&& *ei_endpfn
> max_pfn_mapped
)
394 max_pfn_mapped
= *ei_endpfn
;
396 /* Skip if map is outside the node */
397 if (ei
->type
!= E820_RAM
|| *ei_endpfn
<= start_pfn
||
398 *ei_startpfn
>= end_pfn
)
401 /* Check for overlaps */
402 if (*ei_startpfn
< start_pfn
)
403 *ei_startpfn
= start_pfn
;
404 if (*ei_endpfn
> end_pfn
)
405 *ei_endpfn
= end_pfn
;
407 /* Obey end_user_pfn to save on memmap */
408 if (*ei_startpfn
>= end_user_pfn
)
410 if (*ei_endpfn
> end_user_pfn
)
411 *ei_endpfn
= end_user_pfn
;
416 /* Walk the e820 map and register active regions within a node */
418 e820_register_active_regions(int nid
, unsigned long start_pfn
,
419 unsigned long end_pfn
)
421 unsigned long ei_startpfn
;
422 unsigned long ei_endpfn
;
425 for (i
= 0; i
< e820
.nr_map
; i
++)
426 if (e820_find_active_region(&e820
.map
[i
],
428 &ei_startpfn
, &ei_endpfn
))
429 add_active_range(nid
, ei_startpfn
, ei_endpfn
);
433 * Add a memory region to the kernel e820 map.
435 void __init
add_memory_region(unsigned long start
, unsigned long size
, int type
)
440 printk(KERN_ERR
"Ooops! Too many entries in the memory map!\n");
444 e820
.map
[x
].addr
= start
;
445 e820
.map
[x
].size
= size
;
446 e820
.map
[x
].type
= type
;
451 * Find the hole size (in bytes) in the memory range.
452 * @start: starting address of the memory range to scan
453 * @end: ending address of the memory range to scan
455 unsigned long __init
e820_hole_size(unsigned long start
, unsigned long end
)
457 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
458 unsigned long end_pfn
= end
>> PAGE_SHIFT
;
459 unsigned long ei_startpfn
, ei_endpfn
, ram
= 0;
462 for (i
= 0; i
< e820
.nr_map
; i
++) {
463 if (e820_find_active_region(&e820
.map
[i
],
465 &ei_startpfn
, &ei_endpfn
))
466 ram
+= ei_endpfn
- ei_startpfn
;
468 return end
- start
- (ram
<< PAGE_SHIFT
);
471 static void __init
e820_print_map(char *who
)
475 for (i
= 0; i
< e820
.nr_map
; i
++) {
476 printk(KERN_INFO
" %s: %016Lx - %016Lx ", who
,
477 (unsigned long long) e820
.map
[i
].addr
,
479 (e820
.map
[i
].addr
+ e820
.map
[i
].size
));
480 switch (e820
.map
[i
].type
) {
482 printk(KERN_CONT
"(usable)\n");
485 printk(KERN_CONT
"(reserved)\n");
488 printk(KERN_CONT
"(ACPI data)\n");
491 printk(KERN_CONT
"(ACPI NVS)\n");
494 printk(KERN_CONT
"type %u\n", e820
.map
[i
].type
);
501 * Sanitize the BIOS e820 map.
503 * Some e820 responses include overlapping entries. The following
504 * replaces the original e820 map with a new one, removing overlaps.
507 static int __init
sanitize_e820_map(struct e820entry
*biosmap
, char *pnr_map
)
509 struct change_member
{
510 struct e820entry
*pbios
; /* pointer to original bios entry */
511 unsigned long long addr
; /* address for this change point */
513 static struct change_member change_point_list
[2*E820MAX
] __initdata
;
514 static struct change_member
*change_point
[2*E820MAX
] __initdata
;
515 static struct e820entry
*overlap_list
[E820MAX
] __initdata
;
516 static struct e820entry new_bios
[E820MAX
] __initdata
;
517 struct change_member
*change_tmp
;
518 unsigned long current_type
, last_type
;
519 unsigned long long last_addr
;
520 int chgidx
, still_changing
;
523 int old_nr
, new_nr
, chg_nr
;
527 Visually we're performing the following
528 (1,2,3,4 = memory types)...
530 Sample memory map (w/overlaps):
531 ____22__________________
532 ______________________4_
533 ____1111________________
534 _44_____________________
535 11111111________________
536 ____________________33__
537 ___________44___________
538 __________33333_________
539 ______________22________
540 ___________________2222_
541 _________111111111______
542 _____________________11_
543 _________________4______
545 Sanitized equivalent (no overlap):
546 1_______________________
547 _44_____________________
548 ___1____________________
549 ____22__________________
550 ______11________________
551 _________1______________
552 __________3_____________
553 ___________44___________
554 _____________33_________
555 _______________2________
556 ________________1_______
557 _________________4______
558 ___________________2____
559 ____________________33__
560 ______________________4_
563 /* if there's only one memory region, don't bother */
569 /* bail out if we find any unreasonable addresses in bios map */
570 for (i
= 0; i
< old_nr
; i
++)
571 if (biosmap
[i
].addr
+ biosmap
[i
].size
< biosmap
[i
].addr
)
574 /* create pointers for initial change-point information (for sorting) */
575 for (i
= 0; i
< 2 * old_nr
; i
++)
576 change_point
[i
] = &change_point_list
[i
];
578 /* record all known change-points (starting and ending addresses),
579 omitting those that are for empty memory regions */
581 for (i
= 0; i
< old_nr
; i
++) {
582 if (biosmap
[i
].size
!= 0) {
583 change_point
[chgidx
]->addr
= biosmap
[i
].addr
;
584 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
585 change_point
[chgidx
]->addr
= biosmap
[i
].addr
+
587 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
592 /* sort change-point list by memory addresses (low -> high) */
594 while (still_changing
) {
596 for (i
= 1; i
< chg_nr
; i
++) {
597 unsigned long long curaddr
, lastaddr
;
598 unsigned long long curpbaddr
, lastpbaddr
;
600 curaddr
= change_point
[i
]->addr
;
601 lastaddr
= change_point
[i
- 1]->addr
;
602 curpbaddr
= change_point
[i
]->pbios
->addr
;
603 lastpbaddr
= change_point
[i
- 1]->pbios
->addr
;
606 * swap entries, when:
608 * curaddr > lastaddr or
609 * curaddr == lastaddr and curaddr == curpbaddr and
610 * lastaddr != lastpbaddr
612 if (curaddr
< lastaddr
||
613 (curaddr
== lastaddr
&& curaddr
== curpbaddr
&&
614 lastaddr
!= lastpbaddr
)) {
615 change_tmp
= change_point
[i
];
616 change_point
[i
] = change_point
[i
-1];
617 change_point
[i
-1] = change_tmp
;
623 /* create a new bios memory map, removing overlaps */
624 overlap_entries
= 0; /* number of entries in the overlap table */
625 new_bios_entry
= 0; /* index for creating new bios map entries */
626 last_type
= 0; /* start with undefined memory type */
627 last_addr
= 0; /* start with 0 as last starting address */
629 /* loop through change-points, determining affect on the new bios map */
630 for (chgidx
= 0; chgidx
< chg_nr
; chgidx
++) {
631 /* keep track of all overlapping bios entries */
632 if (change_point
[chgidx
]->addr
==
633 change_point
[chgidx
]->pbios
->addr
) {
635 * add map entry to overlap list (> 1 entry
636 * implies an overlap)
638 overlap_list
[overlap_entries
++] =
639 change_point
[chgidx
]->pbios
;
642 * remove entry from list (order independent,
645 for (i
= 0; i
< overlap_entries
; i
++) {
646 if (overlap_list
[i
] ==
647 change_point
[chgidx
]->pbios
)
649 overlap_list
[overlap_entries
-1];
654 * if there are overlapping entries, decide which
655 * "type" to use (larger value takes precedence --
656 * 1=usable, 2,3,4,4+=unusable)
659 for (i
= 0; i
< overlap_entries
; i
++)
660 if (overlap_list
[i
]->type
> current_type
)
661 current_type
= overlap_list
[i
]->type
;
663 * continue building up new bios map based on this
666 if (current_type
!= last_type
) {
667 if (last_type
!= 0) {
668 new_bios
[new_bios_entry
].size
=
669 change_point
[chgidx
]->addr
- last_addr
;
671 * move forward only if the new size
674 if (new_bios
[new_bios_entry
].size
!= 0)
676 * no more space left for new
679 if (++new_bios_entry
>= E820MAX
)
682 if (current_type
!= 0) {
683 new_bios
[new_bios_entry
].addr
=
684 change_point
[chgidx
]->addr
;
685 new_bios
[new_bios_entry
].type
= current_type
;
686 last_addr
= change_point
[chgidx
]->addr
;
688 last_type
= current_type
;
691 /* retain count for new bios entries */
692 new_nr
= new_bios_entry
;
694 /* copy new bios mapping into original location */
695 memcpy(biosmap
, new_bios
, new_nr
* sizeof(struct e820entry
));
702 * Copy the BIOS e820 map into a safe place.
704 * Sanity-check it while we're at it..
706 * If we're lucky and live on a modern system, the setup code
707 * will have given us a memory map that we can use to properly
708 * set up memory. If we aren't, we'll fake a memory map.
710 static int __init
copy_e820_map(struct e820entry
*biosmap
, int nr_map
)
712 /* Only one memory region (or negative)? Ignore it */
717 u64 start
= biosmap
->addr
;
718 u64 size
= biosmap
->size
;
719 u64 end
= start
+ size
;
720 u32 type
= biosmap
->type
;
722 /* Overflow in 64 bits? Ignore the memory map. */
726 add_memory_region(start
, size
, type
);
727 } while (biosmap
++, --nr_map
);
731 static void early_panic(char *msg
)
737 /* We're not void only for x86 32-bit compat */
738 char * __init
machine_specific_memory_setup(void)
740 char *who
= "BIOS-e820";
742 * Try to copy the BIOS-supplied E820-map.
744 * Otherwise fake a memory map; one section from 0k->640k,
745 * the next section from 1mb->appropriate_mem_k
747 sanitize_e820_map(boot_params
.e820_map
, &boot_params
.e820_entries
);
748 if (copy_e820_map(boot_params
.e820_map
, boot_params
.e820_entries
) < 0)
749 early_panic("Cannot find a valid memory map");
750 printk(KERN_INFO
"BIOS-provided physical RAM map:\n");
753 /* In case someone cares... */
757 static int __init
parse_memopt(char *p
)
761 end_user_pfn
= memparse(p
, &p
);
762 end_user_pfn
>>= PAGE_SHIFT
;
765 early_param("mem", parse_memopt
);
767 static int userdef __initdata
;
769 static int __init
parse_memmap_opt(char *p
)
772 unsigned long long start_at
, mem_size
;
774 if (!strcmp(p
, "exactmap")) {
775 #ifdef CONFIG_CRASH_DUMP
777 * If we are doing a crash dump, we still need to know
778 * the real mem size before original memory map is
781 e820_register_active_regions(0, 0, -1UL);
782 saved_max_pfn
= e820_end_of_ram();
783 remove_all_active_ranges();
792 mem_size
= memparse(p
, &p
);
798 start_at
= memparse(p
+1, &p
);
799 add_memory_region(start_at
, mem_size
, E820_RAM
);
800 } else if (*p
== '#') {
801 start_at
= memparse(p
+1, &p
);
802 add_memory_region(start_at
, mem_size
, E820_ACPI
);
803 } else if (*p
== '$') {
804 start_at
= memparse(p
+1, &p
);
805 add_memory_region(start_at
, mem_size
, E820_RESERVED
);
807 end_user_pfn
= (mem_size
>> PAGE_SHIFT
);
809 return *p
== '\0' ? 0 : -EINVAL
;
811 early_param("memmap", parse_memmap_opt
);
813 void __init
finish_e820_parsing(void)
816 char nr
= e820
.nr_map
;
818 if (sanitize_e820_map(e820
.map
, &nr
) < 0)
819 early_panic("Invalid user supplied memory map");
822 printk(KERN_INFO
"user-defined physical RAM map:\n");
823 e820_print_map("user");
827 void __init
update_memory_range(u64 start
, u64 size
, unsigned old_type
,
832 BUG_ON(old_type
== new_type
);
834 for (i
= 0; i
< e820
.nr_map
; i
++) {
835 struct e820entry
*ei
= &e820
.map
[i
];
836 u64 final_start
, final_end
;
837 if (ei
->type
!= old_type
)
839 /* totally covered? */
840 if (ei
->addr
>= start
&& ei
->size
<= size
) {
844 /* partially covered */
845 final_start
= max(start
, ei
->addr
);
846 final_end
= min(start
+ size
, ei
->addr
+ ei
->size
);
847 if (final_start
>= final_end
)
849 add_memory_region(final_start
, final_end
- final_start
,
854 void __init
update_e820(void)
858 nr_map
= e820
.nr_map
;
859 if (sanitize_e820_map(e820
.map
, &nr_map
))
861 e820
.nr_map
= nr_map
;
862 printk(KERN_INFO
"modified physical RAM map:\n");
863 e820_print_map("modified");
866 unsigned long pci_mem_start
= 0xaeedbabe;
867 EXPORT_SYMBOL(pci_mem_start
);
870 * Search for the biggest gap in the low 32 bits of the e820
871 * memory space. We pass this space to PCI to assign MMIO resources
872 * for hotplug or unconfigured devices in.
873 * Hopefully the BIOS let enough space left.
875 __init
void e820_setup_gap(void)
877 unsigned long gapstart
, gapsize
, round
;
882 last
= 0x100000000ull
;
883 gapstart
= 0x10000000;
887 unsigned long long start
= e820
.map
[i
].addr
;
888 unsigned long long end
= start
+ e820
.map
[i
].size
;
891 * Since "last" is at most 4GB, we know we'll
892 * fit in 32 bits if this condition is true
895 unsigned long gap
= last
- end
;
908 gapstart
= (end_pfn
<< PAGE_SHIFT
) + 1024*1024;
909 printk(KERN_ERR
"PCI: Warning: Cannot find a gap in the 32bit "
911 KERN_ERR
"PCI: Unassigned devices with 32bit resource "
912 "registers may break!\n");
916 * See how much we want to round up: start off with
917 * rounding to the next 1MB area.
920 while ((gapsize
>> 4) > round
)
922 /* Fun with two's complement */
923 pci_mem_start
= (gapstart
+ round
) & -round
;
926 "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
927 pci_mem_start
, gapstart
, gapsize
);
930 int __init
arch_get_ram_range(int slot
, u64
*addr
, u64
*size
)
934 if (slot
< 0 || slot
>= e820
.nr_map
)
936 for (i
= slot
; i
< e820
.nr_map
; i
++) {
937 if (e820
.map
[i
].type
!= E820_RAM
)
941 if (i
== e820
.nr_map
|| e820
.map
[i
].addr
> (max_pfn
<< PAGE_SHIFT
))
943 *addr
= e820
.map
[i
].addr
;
944 *size
= min_t(u64
, e820
.map
[i
].size
+ e820
.map
[i
].addr
,
945 max_pfn
<< PAGE_SHIFT
) - *addr
;