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/pfn.h>
21 #include <linux/suspend.h>
23 #include <asm/pgtable.h>
26 #include <asm/proto.h>
27 #include <asm/setup.h>
28 #include <asm/trampoline.h>
32 /* For PCI or other memory-mapped resources */
33 unsigned long pci_mem_start
= 0xaeedbabe;
35 EXPORT_SYMBOL(pci_mem_start
);
39 * This function checks if any part of the range <start,end> is mapped
43 e820_any_mapped(u64 start
, u64 end
, unsigned type
)
47 for (i
= 0; i
< e820
.nr_map
; i
++) {
48 struct e820entry
*ei
= &e820
.map
[i
];
50 if (type
&& ei
->type
!= type
)
52 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
58 EXPORT_SYMBOL_GPL(e820_any_mapped
);
61 * This function checks if the entire range <start,end> is mapped with type.
63 * Note: this function only works correct if the e820 table is sorted and
64 * not-overlapping, which is the case
66 int __init
e820_all_mapped(u64 start
, u64 end
, unsigned type
)
70 for (i
= 0; i
< e820
.nr_map
; i
++) {
71 struct e820entry
*ei
= &e820
.map
[i
];
73 if (type
&& ei
->type
!= type
)
75 /* is the region (part) in overlap with the current region ?*/
76 if (ei
->addr
>= end
|| ei
->addr
+ ei
->size
<= start
)
79 /* if the region is at the beginning of <start,end> we move
80 * start to the end of the region since it's ok until there
82 if (ei
->addr
<= start
)
83 start
= ei
->addr
+ ei
->size
;
85 * if start is now at or beyond end, we're done, full
95 * Add a memory region to the kernel e820 map.
97 void __init
add_memory_region(u64 start
, u64 size
, int type
)
101 if (x
== ARRAY_SIZE(e820
.map
)) {
102 printk(KERN_ERR
"Ooops! Too many entries in the memory map!\n");
106 e820
.map
[x
].addr
= start
;
107 e820
.map
[x
].size
= size
;
108 e820
.map
[x
].type
= type
;
112 void __init
e820_print_map(char *who
)
116 for (i
= 0; i
< e820
.nr_map
; i
++) {
117 printk(KERN_INFO
" %s: %016Lx - %016Lx ", who
,
118 (unsigned long long) e820
.map
[i
].addr
,
120 (e820
.map
[i
].addr
+ e820
.map
[i
].size
));
121 switch (e820
.map
[i
].type
) {
123 printk(KERN_CONT
"(usable)\n");
126 printk(KERN_CONT
"(reserved)\n");
129 printk(KERN_CONT
"(ACPI data)\n");
132 printk(KERN_CONT
"(ACPI NVS)\n");
135 printk(KERN_CONT
"type %u\n", e820
.map
[i
].type
);
142 * Sanitize the BIOS e820 map.
144 * Some e820 responses include overlapping entries. The following
145 * replaces the original e820 map with a new one, removing overlaps,
146 * and resolving conflicting memory types in favor of highest
149 * The input parameter biosmap points to an array of 'struct
150 * e820entry' which on entry has elements in the range [0, *pnr_map)
151 * valid, and which has space for up to max_nr_map entries.
152 * On return, the resulting sanitized e820 map entries will be in
153 * overwritten in the same location, starting at biosmap.
155 * The integer pointed to by pnr_map must be valid on entry (the
156 * current number of valid entries located at biosmap) and will
157 * be updated on return, with the new number of valid entries
158 * (something no more than max_nr_map.)
160 * The return value from sanitize_e820_map() is zero if it
161 * successfully 'sanitized' the map entries passed in, and is -1
162 * if it did nothing, which can happen if either of (1) it was
163 * only passed one map entry, or (2) any of the input map entries
164 * were invalid (start + size < start, meaning that the size was
165 * so big the described memory range wrapped around through zero.)
167 * Visually we're performing the following
168 * (1,2,3,4 = memory types)...
170 * Sample memory map (w/overlaps):
171 * ____22__________________
172 * ______________________4_
173 * ____1111________________
174 * _44_____________________
175 * 11111111________________
176 * ____________________33__
177 * ___________44___________
178 * __________33333_________
179 * ______________22________
180 * ___________________2222_
181 * _________111111111______
182 * _____________________11_
183 * _________________4______
185 * Sanitized equivalent (no overlap):
186 * 1_______________________
187 * _44_____________________
188 * ___1____________________
189 * ____22__________________
190 * ______11________________
191 * _________1______________
192 * __________3_____________
193 * ___________44___________
194 * _____________33_________
195 * _______________2________
196 * ________________1_______
197 * _________________4______
198 * ___________________2____
199 * ____________________33__
200 * ______________________4_
203 int __init
sanitize_e820_map(struct e820entry
*biosmap
, int max_nr_map
,
206 struct change_member
{
207 struct e820entry
*pbios
; /* pointer to original bios entry */
208 unsigned long long addr
; /* address for this change point */
210 static struct change_member change_point_list
[2*E820_X_MAX
] __initdata
;
211 static struct change_member
*change_point
[2*E820_X_MAX
] __initdata
;
212 static struct e820entry
*overlap_list
[E820_X_MAX
] __initdata
;
213 static struct e820entry new_bios
[E820_X_MAX
] __initdata
;
214 struct change_member
*change_tmp
;
215 unsigned long current_type
, last_type
;
216 unsigned long long last_addr
;
217 int chgidx
, still_changing
;
220 int old_nr
, new_nr
, chg_nr
;
223 /* if there's only one memory region, don't bother */
228 BUG_ON(old_nr
> max_nr_map
);
230 /* bail out if we find any unreasonable addresses in bios map */
231 for (i
= 0; i
< old_nr
; i
++)
232 if (biosmap
[i
].addr
+ biosmap
[i
].size
< biosmap
[i
].addr
)
235 /* create pointers for initial change-point information (for sorting) */
236 for (i
= 0; i
< 2 * old_nr
; i
++)
237 change_point
[i
] = &change_point_list
[i
];
239 /* record all known change-points (starting and ending addresses),
240 omitting those that are for empty memory regions */
242 for (i
= 0; i
< old_nr
; i
++) {
243 if (biosmap
[i
].size
!= 0) {
244 change_point
[chgidx
]->addr
= biosmap
[i
].addr
;
245 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
246 change_point
[chgidx
]->addr
= biosmap
[i
].addr
+
248 change_point
[chgidx
++]->pbios
= &biosmap
[i
];
253 /* sort change-point list by memory addresses (low -> high) */
255 while (still_changing
) {
257 for (i
= 1; i
< chg_nr
; i
++) {
258 unsigned long long curaddr
, lastaddr
;
259 unsigned long long curpbaddr
, lastpbaddr
;
261 curaddr
= change_point
[i
]->addr
;
262 lastaddr
= change_point
[i
- 1]->addr
;
263 curpbaddr
= change_point
[i
]->pbios
->addr
;
264 lastpbaddr
= change_point
[i
- 1]->pbios
->addr
;
267 * swap entries, when:
269 * curaddr > lastaddr or
270 * curaddr == lastaddr and curaddr == curpbaddr and
271 * lastaddr != lastpbaddr
273 if (curaddr
< lastaddr
||
274 (curaddr
== lastaddr
&& curaddr
== curpbaddr
&&
275 lastaddr
!= lastpbaddr
)) {
276 change_tmp
= change_point
[i
];
277 change_point
[i
] = change_point
[i
-1];
278 change_point
[i
-1] = change_tmp
;
284 /* create a new bios memory map, removing overlaps */
285 overlap_entries
= 0; /* number of entries in the overlap table */
286 new_bios_entry
= 0; /* index for creating new bios map entries */
287 last_type
= 0; /* start with undefined memory type */
288 last_addr
= 0; /* start with 0 as last starting address */
290 /* loop through change-points, determining affect on the new bios map */
291 for (chgidx
= 0; chgidx
< chg_nr
; chgidx
++) {
292 /* keep track of all overlapping bios entries */
293 if (change_point
[chgidx
]->addr
==
294 change_point
[chgidx
]->pbios
->addr
) {
296 * add map entry to overlap list (> 1 entry
297 * implies an overlap)
299 overlap_list
[overlap_entries
++] =
300 change_point
[chgidx
]->pbios
;
303 * remove entry from list (order independent,
306 for (i
= 0; i
< overlap_entries
; i
++) {
307 if (overlap_list
[i
] ==
308 change_point
[chgidx
]->pbios
)
310 overlap_list
[overlap_entries
-1];
315 * if there are overlapping entries, decide which
316 * "type" to use (larger value takes precedence --
317 * 1=usable, 2,3,4,4+=unusable)
320 for (i
= 0; i
< overlap_entries
; i
++)
321 if (overlap_list
[i
]->type
> current_type
)
322 current_type
= overlap_list
[i
]->type
;
324 * continue building up new bios map based on this
327 if (current_type
!= last_type
) {
328 if (last_type
!= 0) {
329 new_bios
[new_bios_entry
].size
=
330 change_point
[chgidx
]->addr
- last_addr
;
332 * move forward only if the new size
335 if (new_bios
[new_bios_entry
].size
!= 0)
337 * no more space left for new
340 if (++new_bios_entry
>= max_nr_map
)
343 if (current_type
!= 0) {
344 new_bios
[new_bios_entry
].addr
=
345 change_point
[chgidx
]->addr
;
346 new_bios
[new_bios_entry
].type
= current_type
;
347 last_addr
= change_point
[chgidx
]->addr
;
349 last_type
= current_type
;
352 /* retain count for new bios entries */
353 new_nr
= new_bios_entry
;
355 /* copy new bios mapping into original location */
356 memcpy(biosmap
, new_bios
, new_nr
* sizeof(struct e820entry
));
363 * Copy the BIOS e820 map into a safe place.
365 * Sanity-check it while we're at it..
367 * If we're lucky and live on a modern system, the setup code
368 * will have given us a memory map that we can use to properly
369 * set up memory. If we aren't, we'll fake a memory map.
371 int __init
copy_e820_map(struct e820entry
*biosmap
, int nr_map
)
373 /* Only one memory region (or negative)? Ignore it */
378 u64 start
= biosmap
->addr
;
379 u64 size
= biosmap
->size
;
380 u64 end
= start
+ size
;
381 u32 type
= biosmap
->type
;
383 /* Overflow in 64 bits? Ignore the memory map. */
387 add_memory_region(start
, size
, type
);
388 } while (biosmap
++, --nr_map
);
392 u64 __init
update_memory_range(u64 start
, u64 size
, unsigned old_type
,
396 u64 real_updated_size
= 0;
398 BUG_ON(old_type
== new_type
);
400 for (i
= 0; i
< e820
.nr_map
; i
++) {
401 struct e820entry
*ei
= &e820
.map
[i
];
402 u64 final_start
, final_end
;
403 if (ei
->type
!= old_type
)
405 /* totally covered? */
406 if (ei
->addr
>= start
&&
407 (ei
->addr
+ ei
->size
) <= (start
+ size
)) {
409 real_updated_size
+= ei
->size
;
412 /* partially covered */
413 final_start
= max(start
, ei
->addr
);
414 final_end
= min(start
+ size
, ei
->addr
+ ei
->size
);
415 if (final_start
>= final_end
)
417 add_memory_region(final_start
, final_end
- final_start
,
419 real_updated_size
+= final_end
- final_start
;
421 return real_updated_size
;
424 void __init
update_e820(void)
428 nr_map
= e820
.nr_map
;
429 if (sanitize_e820_map(e820
.map
, ARRAY_SIZE(e820
.map
), &nr_map
))
431 e820
.nr_map
= nr_map
;
432 printk(KERN_INFO
"modified physical RAM map:\n");
433 e820_print_map("modified");
437 * Search for the biggest gap in the low 32 bits of the e820
438 * memory space. We pass this space to PCI to assign MMIO resources
439 * for hotplug or unconfigured devices in.
440 * Hopefully the BIOS let enough space left.
442 __init
void e820_setup_gap(void)
444 unsigned long gapstart
, gapsize
, round
;
445 unsigned long long last
;
449 last
= 0x100000000ull
;
450 gapstart
= 0x10000000;
454 unsigned long long start
= e820
.map
[i
].addr
;
455 unsigned long long end
= start
+ e820
.map
[i
].size
;
458 * Since "last" is at most 4GB, we know we'll
459 * fit in 32 bits if this condition is true
462 unsigned long gap
= last
- end
;
476 gapstart
= (end_pfn
<< PAGE_SHIFT
) + 1024*1024;
477 printk(KERN_ERR
"PCI: Warning: Cannot find a gap in the 32bit "
479 KERN_ERR
"PCI: Unassigned devices with 32bit resource "
480 "registers may break!\n");
485 * See how much we want to round up: start off with
486 * rounding to the next 1MB area.
489 while ((gapsize
>> 4) > round
)
491 /* Fun with two's complement */
492 pci_mem_start
= (gapstart
+ round
) & -round
;
495 "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
496 pci_mem_start
, gapstart
, gapsize
);
499 #if defined(CONFIG_X86_64) || \
500 (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
502 * Find the ranges of physical addresses that do not correspond to
503 * e820 RAM areas and mark the corresponding pages as nosave for
504 * hibernation (32 bit) or software suspend and suspend to RAM (64 bit).
506 * This function requires the e820 map to be sorted and without any
507 * overlapping entries and assumes the first e820 area to be RAM.
509 void __init
e820_mark_nosave_regions(unsigned long limit_pfn
)
514 pfn
= PFN_DOWN(e820
.map
[0].addr
+ e820
.map
[0].size
);
515 for (i
= 1; i
< e820
.nr_map
; i
++) {
516 struct e820entry
*ei
= &e820
.map
[i
];
518 if (pfn
< PFN_UP(ei
->addr
))
519 register_nosave_region(pfn
, PFN_UP(ei
->addr
));
521 pfn
= PFN_DOWN(ei
->addr
+ ei
->size
);
522 if (ei
->type
!= E820_RAM
)
523 register_nosave_region(PFN_UP(ei
->addr
), pfn
);
525 if (pfn
>= limit_pfn
)
532 * Early reserved memory areas.
534 #define MAX_EARLY_RES 20
540 static struct early_res early_res
[MAX_EARLY_RES
] __initdata
= {
541 { 0, PAGE_SIZE
, "BIOS data page" }, /* BIOS data page */
542 #if defined(CONFIG_X86_64) && defined(CONFIG_X86_TRAMPOLINE)
543 { TRAMPOLINE_BASE
, TRAMPOLINE_BASE
+ 2 * PAGE_SIZE
, "TRAMPOLINE" },
545 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
547 * But first pinch a few for the stack/trampoline stuff
548 * FIXME: Don't need the extra page at 4K, but need to fix
549 * trampoline before removing it. (see the GDT stuff)
551 { PAGE_SIZE
, PAGE_SIZE
+ PAGE_SIZE
, "EX TRAMPOLINE" },
553 * Has to be in very low memory so we can execute
556 { TRAMPOLINE_BASE
, TRAMPOLINE_BASE
+ PAGE_SIZE
, "TRAMPOLINE" },
561 void __init
reserve_early(u64 start
, u64 end
, char *name
)
565 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
567 if (end
> r
->start
&& start
< r
->end
)
568 panic("Overlapping early reservations %llx-%llx %s to %llx-%llx %s\n",
569 start
, end
- 1, name
?name
:"", r
->start
,
570 r
->end
- 1, r
->name
);
572 if (i
>= MAX_EARLY_RES
)
573 panic("Too many early reservations");
578 strncpy(r
->name
, name
, sizeof(r
->name
) - 1);
581 void __init
free_early(u64 start
, u64 end
)
586 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
588 if (start
== r
->start
&& end
== r
->end
)
591 if (i
>= MAX_EARLY_RES
|| !early_res
[i
].end
)
592 panic("free_early on not reserved area: %llx-%llx!",
595 for (j
= i
+ 1; j
< MAX_EARLY_RES
&& early_res
[j
].end
; j
++)
598 memmove(&early_res
[i
], &early_res
[i
+ 1],
599 (j
- 1 - i
) * sizeof(struct early_res
));
601 early_res
[j
- 1].end
= 0;
604 void __init
early_res_to_bootmem(u64 start
, u64 end
)
607 u64 final_start
, final_end
;
608 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
609 struct early_res
*r
= &early_res
[i
];
610 final_start
= max(start
, r
->start
);
611 final_end
= min(end
, r
->end
);
612 if (final_start
>= final_end
)
614 printk(KERN_INFO
" early res: %d [%llx-%llx] %s\n", i
,
615 final_start
, final_end
- 1, r
->name
);
617 reserve_bootmem_generic(final_start
, final_end
- final_start
);
619 reserve_bootmem(final_start
, final_end
- final_start
,
625 /* Check for already reserved areas */
626 static inline int __init
bad_addr(u64
*addrp
, u64 size
, u64 align
)
629 u64 addr
= *addrp
, last
;
633 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
634 struct early_res
*r
= &early_res
[i
];
635 if (last
>= r
->start
&& addr
< r
->end
) {
636 *addrp
= addr
= round_up(r
->end
, align
);
644 /* Check for already reserved areas */
645 static inline int __init
bad_addr_size(u64
*addrp
, u64
*sizep
, u64 align
)
648 u64 addr
= *addrp
, last
;
653 for (i
= 0; i
< MAX_EARLY_RES
&& early_res
[i
].end
; i
++) {
654 struct early_res
*r
= &early_res
[i
];
655 if (last
> r
->start
&& addr
< r
->start
) {
656 size
= r
->start
- addr
;
660 if (last
> r
->end
&& addr
< r
->end
) {
661 addr
= round_up(r
->end
, align
);
666 if (last
<= r
->end
&& addr
>= r
->start
) {
679 * Find a free area with specified alignment in a specific range.
681 u64 __init
find_e820_area(u64 start
, u64 end
, u64 size
, u64 align
)
685 for (i
= 0; i
< e820
.nr_map
; i
++) {
686 struct e820entry
*ei
= &e820
.map
[i
];
690 if (ei
->type
!= E820_RAM
)
692 addr
= round_up(ei
->addr
, align
);
693 ei_last
= ei
->addr
+ ei
->size
;
695 addr
= round_up(start
, align
);
698 while (bad_addr(&addr
, size
, align
) && addr
+size
<= ei_last
)
711 * Find next free range after *start
713 u64 __init
find_e820_area_size(u64 start
, u64
*sizep
, u64 align
)
717 for (i
= 0; i
< e820
.nr_map
; i
++) {
718 struct e820entry
*ei
= &e820
.map
[i
];
722 if (ei
->type
!= E820_RAM
)
724 addr
= round_up(ei
->addr
, align
);
725 ei_last
= ei
->addr
+ ei
->size
;
727 addr
= round_up(start
, align
);
730 *sizep
= ei_last
- addr
;
731 while (bad_addr_size(&addr
, sizep
, align
) &&
732 addr
+ *sizep
<= ei_last
)
734 last
= addr
+ *sizep
;