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-rw-r--r--arch/i386/kernel/e820.c894
1 files changed, 894 insertions, 0 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
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index 000000000000..2f7d0a92fd7c
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+++ b/arch/i386/kernel/e820.c
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1#include <linux/kernel.h>
2#include <linux/types.h>
3#include <linux/init.h>
4#include <linux/bootmem.h>
5#include <linux/ioport.h>
6#include <linux/string.h>
7#include <linux/kexec.h>
8#include <linux/module.h>
9#include <linux/mm.h>
10#include <linux/efi.h>
11#include <linux/pfn.h>
12#include <linux/uaccess.h>
13
14#include <asm/pgtable.h>
15#include <asm/page.h>
16#include <asm/e820.h>
17
18#ifdef CONFIG_EFI
19int efi_enabled = 0;
20EXPORT_SYMBOL(efi_enabled);
21#endif
22
23struct e820map e820;
24struct change_member {
25 struct e820entry *pbios; /* pointer to original bios entry */
26 unsigned long long addr; /* address for this change point */
27};
28static struct change_member change_point_list[2*E820MAX] __initdata;
29static struct change_member *change_point[2*E820MAX] __initdata;
30static struct e820entry *overlap_list[E820MAX] __initdata;
31static struct e820entry new_bios[E820MAX] __initdata;
32/* For PCI or other memory-mapped resources */
33unsigned long pci_mem_start = 0x10000000;
34#ifdef CONFIG_PCI
35EXPORT_SYMBOL(pci_mem_start);
36#endif
37extern int user_defined_memmap;
38struct resource data_resource = {
39 .name = "Kernel data",
40 .start = 0,
41 .end = 0,
42 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
43};
44
45struct resource code_resource = {
46 .name = "Kernel code",
47 .start = 0,
48 .end = 0,
49 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
50};
51
52static struct resource system_rom_resource = {
53 .name = "System ROM",
54 .start = 0xf0000,
55 .end = 0xfffff,
56 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
57};
58
59static struct resource extension_rom_resource = {
60 .name = "Extension ROM",
61 .start = 0xe0000,
62 .end = 0xeffff,
63 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
64};
65
66static struct resource adapter_rom_resources[] = { {
67 .name = "Adapter ROM",
68 .start = 0xc8000,
69 .end = 0,
70 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
71}, {
72 .name = "Adapter ROM",
73 .start = 0,
74 .end = 0,
75 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
76}, {
77 .name = "Adapter ROM",
78 .start = 0,
79 .end = 0,
80 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
81}, {
82 .name = "Adapter ROM",
83 .start = 0,
84 .end = 0,
85 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
86}, {
87 .name = "Adapter ROM",
88 .start = 0,
89 .end = 0,
90 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
91}, {
92 .name = "Adapter ROM",
93 .start = 0,
94 .end = 0,
95 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
96} };
97
98static struct resource video_rom_resource = {
99 .name = "Video ROM",
100 .start = 0xc0000,
101 .end = 0xc7fff,
102 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
103};
104
105static struct resource video_ram_resource = {
106 .name = "Video RAM area",
107 .start = 0xa0000,
108 .end = 0xbffff,
109 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
110};
111
112static struct resource standard_io_resources[] = { {
113 .name = "dma1",
114 .start = 0x0000,
115 .end = 0x001f,
116 .flags = IORESOURCE_BUSY | IORESOURCE_IO
117}, {
118 .name = "pic1",
119 .start = 0x0020,
120 .end = 0x0021,
121 .flags = IORESOURCE_BUSY | IORESOURCE_IO
122}, {
123 .name = "timer0",
124 .start = 0x0040,
125 .end = 0x0043,
126 .flags = IORESOURCE_BUSY | IORESOURCE_IO
127}, {
128 .name = "timer1",
129 .start = 0x0050,
130 .end = 0x0053,
131 .flags = IORESOURCE_BUSY | IORESOURCE_IO
132}, {
133 .name = "keyboard",
134 .start = 0x0060,
135 .end = 0x006f,
136 .flags = IORESOURCE_BUSY | IORESOURCE_IO
137}, {
138 .name = "dma page reg",
139 .start = 0x0080,
140 .end = 0x008f,
141 .flags = IORESOURCE_BUSY | IORESOURCE_IO
142}, {
143 .name = "pic2",
144 .start = 0x00a0,
145 .end = 0x00a1,
146 .flags = IORESOURCE_BUSY | IORESOURCE_IO
147}, {
148 .name = "dma2",
149 .start = 0x00c0,
150 .end = 0x00df,
151 .flags = IORESOURCE_BUSY | IORESOURCE_IO
152}, {
153 .name = "fpu",
154 .start = 0x00f0,
155 .end = 0x00ff,
156 .flags = IORESOURCE_BUSY | IORESOURCE_IO
157} };
158
159static int romsignature(const unsigned char *x)
160{
161 unsigned short sig;
162 int ret = 0;
163 if (probe_kernel_address((const unsigned short *)x, sig) == 0)
164 ret = (sig == 0xaa55);
165 return ret;
166}
167
168static int __init romchecksum(unsigned char *rom, unsigned long length)
169{
170 unsigned char *p, sum = 0;
171
172 for (p = rom; p < rom + length; p++)
173 sum += *p;
174 return sum == 0;
175}
176
177static void __init probe_roms(void)
178{
179 unsigned long start, length, upper;
180 unsigned char *rom;
181 int i;
182
183 /* video rom */
184 upper = adapter_rom_resources[0].start;
185 for (start = video_rom_resource.start; start < upper; start += 2048) {
186 rom = isa_bus_to_virt(start);
187 if (!romsignature(rom))
188 continue;
189
190 video_rom_resource.start = start;
191
192 /* 0 < length <= 0x7f * 512, historically */
193 length = rom[2] * 512;
194
195 /* if checksum okay, trust length byte */
196 if (length && romchecksum(rom, length))
197 video_rom_resource.end = start + length - 1;
198
199 request_resource(&iomem_resource, &video_rom_resource);
200 break;
201 }
202
203 start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
204 if (start < upper)
205 start = upper;
206
207 /* system rom */
208 request_resource(&iomem_resource, &system_rom_resource);
209 upper = system_rom_resource.start;
210
211 /* check for extension rom (ignore length byte!) */
212 rom = isa_bus_to_virt(extension_rom_resource.start);
213 if (romsignature(rom)) {
214 length = extension_rom_resource.end - extension_rom_resource.start + 1;
215 if (romchecksum(rom, length)) {
216 request_resource(&iomem_resource, &extension_rom_resource);
217 upper = extension_rom_resource.start;
218 }
219 }
220
221 /* check for adapter roms on 2k boundaries */
222 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
223 rom = isa_bus_to_virt(start);
224 if (!romsignature(rom))
225 continue;
226
227 /* 0 < length <= 0x7f * 512, historically */
228 length = rom[2] * 512;
229
230 /* but accept any length that fits if checksum okay */
231 if (!length || start + length > upper || !romchecksum(rom, length))
232 continue;
233
234 adapter_rom_resources[i].start = start;
235 adapter_rom_resources[i].end = start + length - 1;
236 request_resource(&iomem_resource, &adapter_rom_resources[i]);
237
238 start = adapter_rom_resources[i++].end & ~2047UL;
239 }
240}
241
242/*
243 * Request address space for all standard RAM and ROM resources
244 * and also for regions reported as reserved by the e820.
245 */
246static void __init
247legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
248{
249 int i;
250
251 probe_roms();
252 for (i = 0; i < e820.nr_map; i++) {
253 struct resource *res;
254#ifndef CONFIG_RESOURCES_64BIT
255 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
256 continue;
257#endif
258 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
259 switch (e820.map[i].type) {
260 case E820_RAM: res->name = "System RAM"; break;
261 case E820_ACPI: res->name = "ACPI Tables"; break;
262 case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
263 default: res->name = "reserved";
264 }
265 res->start = e820.map[i].addr;
266 res->end = res->start + e820.map[i].size - 1;
267 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
268 if (request_resource(&iomem_resource, res)) {
269 kfree(res);
270 continue;
271 }
272 if (e820.map[i].type == E820_RAM) {
273 /*
274 * We don't know which RAM region contains kernel data,
275 * so we try it repeatedly and let the resource manager
276 * test it.
277 */
278 request_resource(res, code_resource);
279 request_resource(res, data_resource);
280#ifdef CONFIG_KEXEC
281 request_resource(res, &crashk_res);
282#endif
283 }
284 }
285}
286
287/*
288 * Request address space for all standard resources
289 *
290 * This is called just before pcibios_init(), which is also a
291 * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
292 */
293static int __init request_standard_resources(void)
294{
295 int i;
296
297 printk("Setting up standard PCI resources\n");
298 if (efi_enabled)
299 efi_initialize_iomem_resources(&code_resource, &data_resource);
300 else
301 legacy_init_iomem_resources(&code_resource, &data_resource);
302
303 /* EFI systems may still have VGA */
304 request_resource(&iomem_resource, &video_ram_resource);
305
306 /* request I/O space for devices used on all i[345]86 PCs */
307 for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
308 request_resource(&ioport_resource, &standard_io_resources[i]);
309 return 0;
310}
311
312subsys_initcall(request_standard_resources);
313
314void __init add_memory_region(unsigned long long start,
315 unsigned long long size, int type)
316{
317 int x;
318
319 if (!efi_enabled) {
320 x = e820.nr_map;
321
322 if (x == E820MAX) {
323 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
324 return;
325 }
326
327 e820.map[x].addr = start;
328 e820.map[x].size = size;
329 e820.map[x].type = type;
330 e820.nr_map++;
331 }
332} /* add_memory_region */
333
334/*
335 * Sanitize the BIOS e820 map.
336 *
337 * Some e820 responses include overlapping entries. The following
338 * replaces the original e820 map with a new one, removing overlaps.
339 *
340 */
341int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
342{
343 struct change_member *change_tmp;
344 unsigned long current_type, last_type;
345 unsigned long long last_addr;
346 int chgidx, still_changing;
347 int overlap_entries;
348 int new_bios_entry;
349 int old_nr, new_nr, chg_nr;
350 int i;
351
352 /*
353 Visually we're performing the following (1,2,3,4 = memory types)...
354
355 Sample memory map (w/overlaps):
356 ____22__________________
357 ______________________4_
358 ____1111________________
359 _44_____________________
360 11111111________________
361 ____________________33__
362 ___________44___________
363 __________33333_________
364 ______________22________
365 ___________________2222_
366 _________111111111______
367 _____________________11_
368 _________________4______
369
370 Sanitized equivalent (no overlap):
371 1_______________________
372 _44_____________________
373 ___1____________________
374 ____22__________________
375 ______11________________
376 _________1______________
377 __________3_____________
378 ___________44___________
379 _____________33_________
380 _______________2________
381 ________________1_______
382 _________________4______
383 ___________________2____
384 ____________________33__
385 ______________________4_
386 */
387 printk("sanitize start\n");
388 /* if there's only one memory region, don't bother */
389 if (*pnr_map < 2) {
390 printk("sanitize bail 0\n");
391 return -1;
392 }
393
394 old_nr = *pnr_map;
395
396 /* bail out if we find any unreasonable addresses in bios map */
397 for (i=0; i<old_nr; i++)
398 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
399 printk("sanitize bail 1\n");
400 return -1;
401 }
402
403 /* create pointers for initial change-point information (for sorting) */
404 for (i=0; i < 2*old_nr; i++)
405 change_point[i] = &change_point_list[i];
406
407 /* record all known change-points (starting and ending addresses),
408 omitting those that are for empty memory regions */
409 chgidx = 0;
410 for (i=0; i < old_nr; i++) {
411 if (biosmap[i].size != 0) {
412 change_point[chgidx]->addr = biosmap[i].addr;
413 change_point[chgidx++]->pbios = &biosmap[i];
414 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
415 change_point[chgidx++]->pbios = &biosmap[i];
416 }
417 }
418 chg_nr = chgidx; /* true number of change-points */
419
420 /* sort change-point list by memory addresses (low -> high) */
421 still_changing = 1;
422 while (still_changing) {
423 still_changing = 0;
424 for (i=1; i < chg_nr; i++) {
425 /* if <current_addr> > <last_addr>, swap */
426 /* or, if current=<start_addr> & last=<end_addr>, swap */
427 if ((change_point[i]->addr < change_point[i-1]->addr) ||
428 ((change_point[i]->addr == change_point[i-1]->addr) &&
429 (change_point[i]->addr == change_point[i]->pbios->addr) &&
430 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
431 )
432 {
433 change_tmp = change_point[i];
434 change_point[i] = change_point[i-1];
435 change_point[i-1] = change_tmp;
436 still_changing=1;
437 }
438 }
439 }
440
441 /* create a new bios memory map, removing overlaps */
442 overlap_entries=0; /* number of entries in the overlap table */
443 new_bios_entry=0; /* index for creating new bios map entries */
444 last_type = 0; /* start with undefined memory type */
445 last_addr = 0; /* start with 0 as last starting address */
446 /* loop through change-points, determining affect on the new bios map */
447 for (chgidx=0; chgidx < chg_nr; chgidx++)
448 {
449 /* keep track of all overlapping bios entries */
450 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
451 {
452 /* add map entry to overlap list (> 1 entry implies an overlap) */
453 overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
454 }
455 else
456 {
457 /* remove entry from list (order independent, so swap with last) */
458 for (i=0; i<overlap_entries; i++)
459 {
460 if (overlap_list[i] == change_point[chgidx]->pbios)
461 overlap_list[i] = overlap_list[overlap_entries-1];
462 }
463 overlap_entries--;
464 }
465 /* if there are overlapping entries, decide which "type" to use */
466 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
467 current_type = 0;
468 for (i=0; i<overlap_entries; i++)
469 if (overlap_list[i]->type > current_type)
470 current_type = overlap_list[i]->type;
471 /* continue building up new bios map based on this information */
472 if (current_type != last_type) {
473 if (last_type != 0) {
474 new_bios[new_bios_entry].size =
475 change_point[chgidx]->addr - last_addr;
476 /* move forward only if the new size was non-zero */
477 if (new_bios[new_bios_entry].size != 0)
478 if (++new_bios_entry >= E820MAX)
479 break; /* no more space left for new bios entries */
480 }
481 if (current_type != 0) {
482 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
483 new_bios[new_bios_entry].type = current_type;
484 last_addr=change_point[chgidx]->addr;
485 }
486 last_type = current_type;
487 }
488 }
489 new_nr = new_bios_entry; /* retain count for new bios entries */
490
491 /* copy new bios mapping into original location */
492 memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
493 *pnr_map = new_nr;
494
495 printk("sanitize end\n");
496 return 0;
497}
498
499/*
500 * Copy the BIOS e820 map into a safe place.
501 *
502 * Sanity-check it while we're at it..
503 *
504 * If we're lucky and live on a modern system, the setup code
505 * will have given us a memory map that we can use to properly
506 * set up memory. If we aren't, we'll fake a memory map.
507 *
508 * We check to see that the memory map contains at least 2 elements
509 * before we'll use it, because the detection code in setup.S may
510 * not be perfect and most every PC known to man has two memory
511 * regions: one from 0 to 640k, and one from 1mb up. (The IBM
512 * thinkpad 560x, for example, does not cooperate with the memory
513 * detection code.)
514 */
515int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
516{
517 /* Only one memory region (or negative)? Ignore it */
518 if (nr_map < 2)
519 return -1;
520
521 do {
522 unsigned long long start = biosmap->addr;
523 unsigned long long size = biosmap->size;
524 unsigned long long end = start + size;
525 unsigned long type = biosmap->type;
526 printk("copy_e820_map() start: %016Lx size: %016Lx end: %016Lx type: %ld\n", start, size, end, type);
527
528 /* Overflow in 64 bits? Ignore the memory map. */
529 if (start > end)
530 return -1;
531
532 /*
533 * Some BIOSes claim RAM in the 640k - 1M region.
534 * Not right. Fix it up.
535 */
536 if (type == E820_RAM) {
537 printk("copy_e820_map() type is E820_RAM\n");
538 if (start < 0x100000ULL && end > 0xA0000ULL) {
539 printk("copy_e820_map() lies in range...\n");
540 if (start < 0xA0000ULL) {
541 printk("copy_e820_map() start < 0xA0000ULL\n");
542 add_memory_region(start, 0xA0000ULL-start, type);
543 }
544 if (end <= 0x100000ULL) {
545 printk("copy_e820_map() end <= 0x100000ULL\n");
546 continue;
547 }
548 start = 0x100000ULL;
549 size = end - start;
550 }
551 }
552 add_memory_region(start, size, type);
553 } while (biosmap++,--nr_map);
554 return 0;
555}
556
557/*
558 * Callback for efi_memory_walk.
559 */
560static int __init
561efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
562{
563 unsigned long *max_pfn = arg, pfn;
564
565 if (start < end) {
566 pfn = PFN_UP(end -1);
567 if (pfn > *max_pfn)
568 *max_pfn = pfn;
569 }
570 return 0;
571}
572
573static int __init
574efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
575{
576 memory_present(0, PFN_UP(start), PFN_DOWN(end));
577 return 0;
578}
579
580/*
581 * Find the highest page frame number we have available
582 */
583void __init find_max_pfn(void)
584{
585 int i;
586
587 max_pfn = 0;
588 if (efi_enabled) {
589 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
590 efi_memmap_walk(efi_memory_present_wrapper, NULL);
591 return;
592 }
593
594 for (i = 0; i < e820.nr_map; i++) {
595 unsigned long start, end;
596 /* RAM? */
597 if (e820.map[i].type != E820_RAM)
598 continue;
599 start = PFN_UP(e820.map[i].addr);
600 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
601 if (start >= end)
602 continue;
603 if (end > max_pfn)
604 max_pfn = end;
605 memory_present(0, start, end);
606 }
607}
608
609/*
610 * Free all available memory for boot time allocation. Used
611 * as a callback function by efi_memory_walk()
612 */
613
614static int __init
615free_available_memory(unsigned long start, unsigned long end, void *arg)
616{
617 /* check max_low_pfn */
618 if (start >= (max_low_pfn << PAGE_SHIFT))
619 return 0;
620 if (end >= (max_low_pfn << PAGE_SHIFT))
621 end = max_low_pfn << PAGE_SHIFT;
622 if (start < end)
623 free_bootmem(start, end - start);
624
625 return 0;
626}
627/*
628 * Register fully available low RAM pages with the bootmem allocator.
629 */
630void __init register_bootmem_low_pages(unsigned long max_low_pfn)
631{
632 int i;
633
634 if (efi_enabled) {
635 efi_memmap_walk(free_available_memory, NULL);
636 return;
637 }
638 for (i = 0; i < e820.nr_map; i++) {
639 unsigned long curr_pfn, last_pfn, size;
640 /*
641 * Reserve usable low memory
642 */
643 if (e820.map[i].type != E820_RAM)
644 continue;
645 /*
646 * We are rounding up the start address of usable memory:
647 */
648 curr_pfn = PFN_UP(e820.map[i].addr);
649 if (curr_pfn >= max_low_pfn)
650 continue;
651 /*
652 * ... and at the end of the usable range downwards:
653 */
654 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
655
656 if (last_pfn > max_low_pfn)
657 last_pfn = max_low_pfn;
658
659 /*
660 * .. finally, did all the rounding and playing
661 * around just make the area go away?
662 */
663 if (last_pfn <= curr_pfn)
664 continue;
665
666 size = last_pfn - curr_pfn;
667 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
668 }
669}
670
671void __init register_memory(void)
672{
673 unsigned long gapstart, gapsize, round;
674 unsigned long long last;
675 int i;
676
677 /*
678 * Search for the bigest gap in the low 32 bits of the e820
679 * memory space.
680 */
681 last = 0x100000000ull;
682 gapstart = 0x10000000;
683 gapsize = 0x400000;
684 i = e820.nr_map;
685 while (--i >= 0) {
686 unsigned long long start = e820.map[i].addr;
687 unsigned long long end = start + e820.map[i].size;
688
689 /*
690 * Since "last" is at most 4GB, we know we'll
691 * fit in 32 bits if this condition is true
692 */
693 if (last > end) {
694 unsigned long gap = last - end;
695
696 if (gap > gapsize) {
697 gapsize = gap;
698 gapstart = end;
699 }
700 }
701 if (start < last)
702 last = start;
703 }
704
705 /*
706 * See how much we want to round up: start off with
707 * rounding to the next 1MB area.
708 */
709 round = 0x100000;
710 while ((gapsize >> 4) > round)
711 round += round;
712 /* Fun with two's complement */
713 pci_mem_start = (gapstart + round) & -round;
714
715 printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
716 pci_mem_start, gapstart, gapsize);
717}
718
719void __init print_memory_map(char *who)
720{
721 int i;
722
723 for (i = 0; i < e820.nr_map; i++) {
724 printk(" %s: %016Lx - %016Lx ", who,
725 e820.map[i].addr,
726 e820.map[i].addr + e820.map[i].size);
727 switch (e820.map[i].type) {
728 case E820_RAM: printk("(usable)\n");
729 break;
730 case E820_RESERVED:
731 printk("(reserved)\n");
732 break;
733 case E820_ACPI:
734 printk("(ACPI data)\n");
735 break;
736 case E820_NVS:
737 printk("(ACPI NVS)\n");
738 break;
739 default: printk("type %lu\n", e820.map[i].type);
740 break;
741 }
742 }
743}
744
745static __init __always_inline void efi_limit_regions(unsigned long long size)
746{
747 unsigned long long current_addr = 0;
748 efi_memory_desc_t *md, *next_md;
749 void *p, *p1;
750 int i, j;
751
752 j = 0;
753 p1 = memmap.map;
754 for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
755 md = p;
756 next_md = p1;
757 current_addr = md->phys_addr +
758 PFN_PHYS(md->num_pages);
759 if (is_available_memory(md)) {
760 if (md->phys_addr >= size) continue;
761 memcpy(next_md, md, memmap.desc_size);
762 if (current_addr >= size) {
763 next_md->num_pages -=
764 PFN_UP(current_addr-size);
765 }
766 p1 += memmap.desc_size;
767 next_md = p1;
768 j++;
769 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
770 EFI_MEMORY_RUNTIME) {
771 /* In order to make runtime services
772 * available we have to include runtime
773 * memory regions in memory map */
774 memcpy(next_md, md, memmap.desc_size);
775 p1 += memmap.desc_size;
776 next_md = p1;
777 j++;
778 }
779 }
780 memmap.nr_map = j;
781 memmap.map_end = memmap.map +
782 (memmap.nr_map * memmap.desc_size);
783}
784
785void __init limit_regions(unsigned long long size)
786{
787 unsigned long long current_addr;
788 int i;
789
790 print_memory_map("limit_regions start");
791 if (efi_enabled) {
792 efi_limit_regions(size);
793 return;
794 }
795 for (i = 0; i < e820.nr_map; i++) {
796 current_addr = e820.map[i].addr + e820.map[i].size;
797 if (current_addr < size)
798 continue;
799
800 if (e820.map[i].type != E820_RAM)
801 continue;
802
803 if (e820.map[i].addr >= size) {
804 /*
805 * This region starts past the end of the
806 * requested size, skip it completely.
807 */
808 e820.nr_map = i;
809 } else {
810 e820.nr_map = i + 1;
811 e820.map[i].size -= current_addr - size;
812 }
813 print_memory_map("limit_regions endfor");
814 return;
815 }
816 print_memory_map("limit_regions endfunc");
817}
818
819 /*
820 * This function checks if the entire range <start,end> is mapped with type.
821 *
822 * Note: this function only works correct if the e820 table is sorted and
823 * not-overlapping, which is the case
824 */
825int __init
826e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
827{
828 u64 start = s;
829 u64 end = e;
830 int i;
831 for (i = 0; i < e820.nr_map; i++) {
832 struct e820entry *ei = &e820.map[i];
833 if (type && ei->type != type)
834 continue;
835 /* is the region (part) in overlap with the current region ?*/
836 if (ei->addr >= end || ei->addr + ei->size <= start)
837 continue;
838 /* if the region is at the beginning of <start,end> we move
839 * start to the end of the region since it's ok until there
840 */
841 if (ei->addr <= start)
842 start = ei->addr + ei->size;
843 /* if start is now at or beyond end, we're done, full
844 * coverage */
845 if (start >= end)
846 return 1; /* we're done */
847 }
848 return 0;
849}
850
851static int __init parse_memmap(char *arg)
852{
853 if (!arg)
854 return -EINVAL;
855
856 if (strcmp(arg, "exactmap") == 0) {
857#ifdef CONFIG_CRASH_DUMP
858 /* If we are doing a crash dump, we
859 * still need to know the real mem
860 * size before original memory map is
861 * reset.
862 */
863 find_max_pfn();
864 saved_max_pfn = max_pfn;
865#endif
866 e820.nr_map = 0;
867 user_defined_memmap = 1;
868 } else {
869 /* If the user specifies memory size, we
870 * limit the BIOS-provided memory map to
871 * that size. exactmap can be used to specify
872 * the exact map. mem=number can be used to
873 * trim the existing memory map.
874 */
875 unsigned long long start_at, mem_size;
876
877 mem_size = memparse(arg, &arg);
878 if (*arg == '@') {
879 start_at = memparse(arg+1, &arg);
880 add_memory_region(start_at, mem_size, E820_RAM);
881 } else if (*arg == '#') {
882 start_at = memparse(arg+1, &arg);
883 add_memory_region(start_at, mem_size, E820_ACPI);
884 } else if (*arg == '$') {
885 start_at = memparse(arg+1, &arg);
886 add_memory_region(start_at, mem_size, E820_RESERVED);
887 } else {
888 limit_regions(mem_size);
889 user_defined_memmap = 1;
890 }
891 }
892 return 0;
893}
894early_param("memmap", parse_memmap);
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-10 07:12:43 -0500