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[PATCH] i386: romsignature/checksum cleanup
[linux-2.6/verdex.git] / arch / i386 / kernel / e820.c
blob70f39560846aa3bcd27bb52fe426a766a441479e
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 #include <asm/setup.h>
18
19 #ifdef CONFIG_EFI
20 int efi_enabled = 0;
21 EXPORT_SYMBOL(efi_enabled);
22 #endif
23
24 struct e820map e820;
25 struct change_member {
26 struct e820entry *pbios; /* pointer to original bios entry */
27 unsigned long long addr; /* address for this change point */
28 };
29 static struct change_member change_point_list[2*E820MAX] __initdata;
30 static struct change_member *change_point[2*E820MAX] __initdata;
31 static struct e820entry *overlap_list[E820MAX] __initdata;
32 static struct e820entry new_bios[E820MAX] __initdata;
33 /* For PCI or other memory-mapped resources */
34 unsigned long pci_mem_start = 0x10000000;
35 #ifdef CONFIG_PCI
36 EXPORT_SYMBOL(pci_mem_start);
37 #endif
38 extern int user_defined_memmap;
39 struct resource data_resource = {
40 .name = "Kernel data",
41 .start = 0,
42 .end = 0,
43 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
44 };
45
46 struct resource code_resource = {
47 .name = "Kernel code",
48 .start = 0,
49 .end = 0,
50 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
51 };
52
53 static struct resource system_rom_resource = {
54 .name = "System ROM",
55 .start = 0xf0000,
56 .end = 0xfffff,
57 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
58 };
59
60 static struct resource extension_rom_resource = {
61 .name = "Extension ROM",
62 .start = 0xe0000,
63 .end = 0xeffff,
64 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
65 };
66
67 static struct resource adapter_rom_resources[] = { {
68 .name = "Adapter ROM",
69 .start = 0xc8000,
70 .end = 0,
71 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
72 }, {
73 .name = "Adapter ROM",
74 .start = 0,
75 .end = 0,
76 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
77 }, {
78 .name = "Adapter ROM",
79 .start = 0,
80 .end = 0,
81 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
82 }, {
83 .name = "Adapter ROM",
84 .start = 0,
85 .end = 0,
86 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
87 }, {
88 .name = "Adapter ROM",
89 .start = 0,
90 .end = 0,
91 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
92 }, {
93 .name = "Adapter ROM",
94 .start = 0,
95 .end = 0,
96 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
97 } };
98
99 static struct resource video_rom_resource = {
100 .name = "Video ROM",
101 .start = 0xc0000,
102 .end = 0xc7fff,
103 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
104 };
105
106 static struct resource video_ram_resource = {
107 .name = "Video RAM area",
108 .start = 0xa0000,
109 .end = 0xbffff,
110 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
111 };
112
113 static struct resource standard_io_resources[] = { {
114 .name = "dma1",
115 .start = 0x0000,
116 .end = 0x001f,
117 .flags = IORESOURCE_BUSY | IORESOURCE_IO
118 }, {
119 .name = "pic1",
120 .start = 0x0020,
121 .end = 0x0021,
122 .flags = IORESOURCE_BUSY | IORESOURCE_IO
123 }, {
124 .name = "timer0",
125 .start = 0x0040,
126 .end = 0x0043,
127 .flags = IORESOURCE_BUSY | IORESOURCE_IO
128 }, {
129 .name = "timer1",
130 .start = 0x0050,
131 .end = 0x0053,
132 .flags = IORESOURCE_BUSY | IORESOURCE_IO
133 }, {
134 .name = "keyboard",
135 .start = 0x0060,
136 .end = 0x006f,
137 .flags = IORESOURCE_BUSY | IORESOURCE_IO
138 }, {
139 .name = "dma page reg",
140 .start = 0x0080,
141 .end = 0x008f,
142 .flags = IORESOURCE_BUSY | IORESOURCE_IO
143 }, {
144 .name = "pic2",
145 .start = 0x00a0,
146 .end = 0x00a1,
147 .flags = IORESOURCE_BUSY | IORESOURCE_IO
148 }, {
149 .name = "dma2",
150 .start = 0x00c0,
151 .end = 0x00df,
152 .flags = IORESOURCE_BUSY | IORESOURCE_IO
153 }, {
154 .name = "fpu",
155 .start = 0x00f0,
156 .end = 0x00ff,
157 .flags = IORESOURCE_BUSY | IORESOURCE_IO
158 } };
159
160 #define ROMSIGNATURE 0xaa55
161
162 static int __init romsignature(const unsigned char *rom)
163 {
164 unsigned short sig;
165
166 return probe_kernel_address((const unsigned short *)rom, sig) == 0 &&
167 sig == ROMSIGNATURE;
168 }
169
170 static int __init romchecksum(unsigned char *rom, unsigned long length)
171 {
172 unsigned char sum;
173
174 for (sum = 0; length; length--)
175 sum += *rom++;
176 return sum == 0;
177 }
178
179 static void __init probe_roms(void)
180 {
181 unsigned long start, length, upper;
182 unsigned char *rom;
183 int i;
184
185 /* video rom */
186 upper = adapter_rom_resources[0].start;
187 for (start = video_rom_resource.start; start < upper; start += 2048) {
188 rom = isa_bus_to_virt(start);
189 if (!romsignature(rom))
190 continue;
191
192 video_rom_resource.start = start;
193
194 /* 0 < length <= 0x7f * 512, historically */
195 length = rom[2] * 512;
196
197 /* if checksum okay, trust length byte */
198 if (length && romchecksum(rom, length))
199 video_rom_resource.end = start + length - 1;
200
201 request_resource(&iomem_resource, &video_rom_resource);
202 break;
203 }
204
205 start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
206 if (start < upper)
207 start = upper;
208
209 /* system rom */
210 request_resource(&iomem_resource, &system_rom_resource);
211 upper = system_rom_resource.start;
212
213 /* check for extension rom (ignore length byte!) */
214 rom = isa_bus_to_virt(extension_rom_resource.start);
215 if (romsignature(rom)) {
216 length = extension_rom_resource.end - extension_rom_resource.start + 1;
217 if (romchecksum(rom, length)) {
218 request_resource(&iomem_resource, &extension_rom_resource);
219 upper = extension_rom_resource.start;
220 }
221 }
222
223 /* check for adapter roms on 2k boundaries */
224 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
225 rom = isa_bus_to_virt(start);
226 if (!romsignature(rom))
227 continue;
228
229 /* 0 < length <= 0x7f * 512, historically */
230 length = rom[2] * 512;
231
232 /* but accept any length that fits if checksum okay */
233 if (!length || start + length > upper || !romchecksum(rom, length))
234 continue;
235
236 adapter_rom_resources[i].start = start;
237 adapter_rom_resources[i].end = start + length - 1;
238 request_resource(&iomem_resource, &adapter_rom_resources[i]);
239
240 start = adapter_rom_resources[i++].end & ~2047UL;
241 }
242 }
243
244 /*
245 * Request address space for all standard RAM and ROM resources
246 * and also for regions reported as reserved by the e820.
247 */
248 static void __init
249 legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
250 {
251 int i;
252
253 probe_roms();
254 for (i = 0; i < e820.nr_map; i++) {
255 struct resource *res;
256 #ifndef CONFIG_RESOURCES_64BIT
257 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
258 continue;
259 #endif
260 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
261 switch (e820.map[i].type) {
262 case E820_RAM: res->name = "System RAM"; break;
263 case E820_ACPI: res->name = "ACPI Tables"; break;
264 case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
265 default: res->name = "reserved";
266 }
267 res->start = e820.map[i].addr;
268 res->end = res->start + e820.map[i].size - 1;
269 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
270 if (request_resource(&iomem_resource, res)) {
271 kfree(res);
272 continue;
273 }
274 if (e820.map[i].type == E820_RAM) {
275 /*
276 * We don't know which RAM region contains kernel data,
277 * so we try it repeatedly and let the resource manager
278 * test it.
279 */
280 request_resource(res, code_resource);
281 request_resource(res, data_resource);
282 #ifdef CONFIG_KEXEC
283 request_resource(res, &crashk_res);
284 #endif
285 }
286 }
287 }
288
289 /*
290 * Request address space for all standard resources
291 *
292 * This is called just before pcibios_init(), which is also a
293 * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
294 */
295 static int __init request_standard_resources(void)
296 {
297 int i;
298
299 printk("Setting up standard PCI resources\n");
300 if (efi_enabled)
301 efi_initialize_iomem_resources(&code_resource, &data_resource);
302 else
303 legacy_init_iomem_resources(&code_resource, &data_resource);
304
305 /* EFI systems may still have VGA */
306 request_resource(&iomem_resource, &video_ram_resource);
307
308 /* request I/O space for devices used on all i[345]86 PCs */
309 for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
310 request_resource(&ioport_resource, &standard_io_resources[i]);
311 return 0;
312 }
313
314 subsys_initcall(request_standard_resources);
315
316 void __init add_memory_region(unsigned long long start,
317 unsigned long long size, int type)
318 {
319 int x;
320
321 if (!efi_enabled) {
322 x = e820.nr_map;
323
324 if (x == E820MAX) {
325 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
326 return;
327 }
328
329 e820.map[x].addr = start;
330 e820.map[x].size = size;
331 e820.map[x].type = type;
332 e820.nr_map++;
333 }
334 } /* add_memory_region */
335
336 /*
337 * Sanitize the BIOS e820 map.
338 *
339 * Some e820 responses include overlapping entries. The following
340 * replaces the original e820 map with a new one, removing overlaps.
341 *
342 */
343 int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
344 {
345 struct change_member *change_tmp;
346 unsigned long current_type, last_type;
347 unsigned long long last_addr;
348 int chgidx, still_changing;
349 int overlap_entries;
350 int new_bios_entry;
351 int old_nr, new_nr, chg_nr;
352 int i;
353
354 /*
355 Visually we're performing the following (1,2,3,4 = memory types)...
356
357 Sample memory map (w/overlaps):
358 ____22__________________
359 ______________________4_
360 ____1111________________
361 _44_____________________
362 11111111________________
363 ____________________33__
364 ___________44___________
365 __________33333_________
366 ______________22________
367 ___________________2222_
368 _________111111111______
369 _____________________11_
370 _________________4______
371
372 Sanitized equivalent (no overlap):
373 1_______________________
374 _44_____________________
375 ___1____________________
376 ____22__________________
377 ______11________________
378 _________1______________
379 __________3_____________
380 ___________44___________
381 _____________33_________
382 _______________2________
383 ________________1_______
384 _________________4______
385 ___________________2____
386 ____________________33__
387 ______________________4_
388 */
389 printk("sanitize start\n");
390 /* if there's only one memory region, don't bother */
391 if (*pnr_map < 2) {
392 printk("sanitize bail 0\n");
393 return -1;
394 }
395
396 old_nr = *pnr_map;
397
398 /* bail out if we find any unreasonable addresses in bios map */
399 for (i=0; i<old_nr; i++)
400 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
401 printk("sanitize bail 1\n");
402 return -1;
403 }
404
405 /* create pointers for initial change-point information (for sorting) */
406 for (i=0; i < 2*old_nr; i++)
407 change_point[i] = &change_point_list[i];
408
409 /* record all known change-points (starting and ending addresses),
410 omitting those that are for empty memory regions */
411 chgidx = 0;
412 for (i=0; i < old_nr; i++) {
413 if (biosmap[i].size != 0) {
414 change_point[chgidx]->addr = biosmap[i].addr;
415 change_point[chgidx++]->pbios = &biosmap[i];
416 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
417 change_point[chgidx++]->pbios = &biosmap[i];
418 }
419 }
420 chg_nr = chgidx; /* true number of change-points */
421
422 /* sort change-point list by memory addresses (low -> high) */
423 still_changing = 1;
424 while (still_changing) {
425 still_changing = 0;
426 for (i=1; i < chg_nr; i++) {
427 /* if <current_addr> > <last_addr>, swap */
428 /* or, if current=<start_addr> & last=<end_addr>, swap */
429 if ((change_point[i]->addr < change_point[i-1]->addr) ||
430 ((change_point[i]->addr == change_point[i-1]->addr) &&
431 (change_point[i]->addr == change_point[i]->pbios->addr) &&
432 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
433 )
434 {
435 change_tmp = change_point[i];
436 change_point[i] = change_point[i-1];
437 change_point[i-1] = change_tmp;
438 still_changing=1;
439 }
440 }
441 }
442
443 /* create a new bios memory map, removing overlaps */
444 overlap_entries=0; /* number of entries in the overlap table */
445 new_bios_entry=0; /* index for creating new bios map entries */
446 last_type = 0; /* start with undefined memory type */
447 last_addr = 0; /* start with 0 as last starting address */
448 /* loop through change-points, determining affect on the new bios map */
449 for (chgidx=0; chgidx < chg_nr; chgidx++)
450 {
451 /* keep track of all overlapping bios entries */
452 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
453 {
454 /* add map entry to overlap list (> 1 entry implies an overlap) */
455 overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
456 }
457 else
458 {
459 /* remove entry from list (order independent, so swap with last) */
460 for (i=0; i<overlap_entries; i++)
461 {
462 if (overlap_list[i] == change_point[chgidx]->pbios)
463 overlap_list[i] = overlap_list[overlap_entries-1];
464 }
465 overlap_entries--;
466 }
467 /* if there are overlapping entries, decide which "type" to use */
468 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
469 current_type = 0;
470 for (i=0; i<overlap_entries; i++)
471 if (overlap_list[i]->type > current_type)
472 current_type = overlap_list[i]->type;
473 /* continue building up new bios map based on this information */
474 if (current_type != last_type) {
475 if (last_type != 0) {
476 new_bios[new_bios_entry].size =
477 change_point[chgidx]->addr - last_addr;
478 /* move forward only if the new size was non-zero */
479 if (new_bios[new_bios_entry].size != 0)
480 if (++new_bios_entry >= E820MAX)
481 break; /* no more space left for new bios entries */
482 }
483 if (current_type != 0) {
484 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
485 new_bios[new_bios_entry].type = current_type;
486 last_addr=change_point[chgidx]->addr;
487 }
488 last_type = current_type;
489 }
490 }
491 new_nr = new_bios_entry; /* retain count for new bios entries */
492
493 /* copy new bios mapping into original location */
494 memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
495 *pnr_map = new_nr;
496
497 printk("sanitize end\n");
498 return 0;
499 }
500
501 /*
502 * Copy the BIOS e820 map into a safe place.
503 *
504 * Sanity-check it while we're at it..
505 *
506 * If we're lucky and live on a modern system, the setup code
507 * will have given us a memory map that we can use to properly
508 * set up memory. If we aren't, we'll fake a memory map.
509 *
510 * We check to see that the memory map contains at least 2 elements
511 * before we'll use it, because the detection code in setup.S may
512 * not be perfect and most every PC known to man has two memory
513 * regions: one from 0 to 640k, and one from 1mb up. (The IBM
514 * thinkpad 560x, for example, does not cooperate with the memory
515 * detection code.)
516 */
517 int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
518 {
519 /* Only one memory region (or negative)? Ignore it */
520 if (nr_map < 2)
521 return -1;
522
523 do {
524 unsigned long long start = biosmap->addr;
525 unsigned long long size = biosmap->size;
526 unsigned long long end = start + size;
527 unsigned long type = biosmap->type;
528 printk("copy_e820_map() start: %016Lx size: %016Lx end: %016Lx type: %ld\n", start, size, end, type);
529
530 /* Overflow in 64 bits? Ignore the memory map. */
531 if (start > end)
532 return -1;
533
534 /*
535 * Some BIOSes claim RAM in the 640k - 1M region.
536 * Not right. Fix it up.
537 */
538 if (type == E820_RAM) {
539 printk("copy_e820_map() type is E820_RAM\n");
540 if (start < 0x100000ULL && end > 0xA0000ULL) {
541 printk("copy_e820_map() lies in range...\n");
542 if (start < 0xA0000ULL) {
543 printk("copy_e820_map() start < 0xA0000ULL\n");
544 add_memory_region(start, 0xA0000ULL-start, type);
545 }
546 if (end <= 0x100000ULL) {
547 printk("copy_e820_map() end <= 0x100000ULL\n");
548 continue;
549 }
550 start = 0x100000ULL;
551 size = end - start;
552 }
553 }
554 add_memory_region(start, size, type);
555 } while (biosmap++,--nr_map);
556 return 0;
557 }
558
559 /*
560 * Callback for efi_memory_walk.
561 */
562 static int __init
563 efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
564 {
565 unsigned long *max_pfn = arg, pfn;
566
567 if (start < end) {
568 pfn = PFN_UP(end -1);
569 if (pfn > *max_pfn)
570 *max_pfn = pfn;
571 }
572 return 0;
573 }
574
575 static int __init
576 efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
577 {
578 memory_present(0, PFN_UP(start), PFN_DOWN(end));
579 return 0;
580 }
581
582 /*
583 * Find the highest page frame number we have available
584 */
585 void __init find_max_pfn(void)
586 {
587 int i;
588
589 max_pfn = 0;
590 if (efi_enabled) {
591 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
592 efi_memmap_walk(efi_memory_present_wrapper, NULL);
593 return;
594 }
595
596 for (i = 0; i < e820.nr_map; i++) {
597 unsigned long start, end;
598 /* RAM? */
599 if (e820.map[i].type != E820_RAM)
600 continue;
601 start = PFN_UP(e820.map[i].addr);
602 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
603 if (start >= end)
604 continue;
605 if (end > max_pfn)
606 max_pfn = end;
607 memory_present(0, start, end);
608 }
609 }
610
611 /*
612 * Free all available memory for boot time allocation. Used
613 * as a callback function by efi_memory_walk()
614 */
615
616 static int __init
617 free_available_memory(unsigned long start, unsigned long end, void *arg)
618 {
619 /* check max_low_pfn */
620 if (start >= (max_low_pfn << PAGE_SHIFT))
621 return 0;
622 if (end >= (max_low_pfn << PAGE_SHIFT))
623 end = max_low_pfn << PAGE_SHIFT;
624 if (start < end)
625 free_bootmem(start, end - start);
626
627 return 0;
628 }
629 /*
630 * Register fully available low RAM pages with the bootmem allocator.
631 */
632 void __init register_bootmem_low_pages(unsigned long max_low_pfn)
633 {
634 int i;
635
636 if (efi_enabled) {
637 efi_memmap_walk(free_available_memory, NULL);
638 return;
639 }
640 for (i = 0; i < e820.nr_map; i++) {
641 unsigned long curr_pfn, last_pfn, size;
642 /*
643 * Reserve usable low memory
644 */
645 if (e820.map[i].type != E820_RAM)
646 continue;
647 /*
648 * We are rounding up the start address of usable memory:
649 */
650 curr_pfn = PFN_UP(e820.map[i].addr);
651 if (curr_pfn >= max_low_pfn)
652 continue;
653 /*
654 * ... and at the end of the usable range downwards:
655 */
656 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
657
658 if (last_pfn > max_low_pfn)
659 last_pfn = max_low_pfn;
660
661 /*
662 * .. finally, did all the rounding and playing
663 * around just make the area go away?
664 */
665 if (last_pfn <= curr_pfn)
666 continue;
667
668 size = last_pfn - curr_pfn;
669 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
670 }
671 }
672
673 void __init e820_register_memory(void)
674 {
675 unsigned long gapstart, gapsize, round;
676 unsigned long long last;
677 int i;
678
679 /*
680 * Search for the bigest gap in the low 32 bits of the e820
681 * memory space.
682 */
683 last = 0x100000000ull;
684 gapstart = 0x10000000;
685 gapsize = 0x400000;
686 i = e820.nr_map;
687 while (--i >= 0) {
688 unsigned long long start = e820.map[i].addr;
689 unsigned long long end = start + e820.map[i].size;
690
691 /*
692 * Since "last" is at most 4GB, we know we'll
693 * fit in 32 bits if this condition is true
694 */
695 if (last > end) {
696 unsigned long gap = last - end;
697
698 if (gap > gapsize) {
699 gapsize = gap;
700 gapstart = end;
701 }
702 }
703 if (start < last)
704 last = start;
705 }
706
707 /*
708 * See how much we want to round up: start off with
709 * rounding to the next 1MB area.
710 */
711 round = 0x100000;
712 while ((gapsize >> 4) > round)
713 round += round;
714 /* Fun with two's complement */
715 pci_mem_start = (gapstart + round) & -round;
716
717 printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
718 pci_mem_start, gapstart, gapsize);
719 }
720
721 void __init print_memory_map(char *who)
722 {
723 int i;
724
725 for (i = 0; i < e820.nr_map; i++) {
726 printk(" %s: %016Lx - %016Lx ", who,
727 e820.map[i].addr,
728 e820.map[i].addr + e820.map[i].size);
729 switch (e820.map[i].type) {
730 case E820_RAM: printk("(usable)\n");
731 break;
732 case E820_RESERVED:
733 printk("(reserved)\n");
734 break;
735 case E820_ACPI:
736 printk("(ACPI data)\n");
737 break;
738 case E820_NVS:
739 printk("(ACPI NVS)\n");
740 break;
741 default: printk("type %lu\n", e820.map[i].type);
742 break;
743 }
744 }
745 }
746
747 static __init __always_inline void efi_limit_regions(unsigned long long size)
748 {
749 unsigned long long current_addr = 0;
750 efi_memory_desc_t *md, *next_md;
751 void *p, *p1;
752 int i, j;
753
754 j = 0;
755 p1 = memmap.map;
756 for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
757 md = p;
758 next_md = p1;
759 current_addr = md->phys_addr +
760 PFN_PHYS(md->num_pages);
761 if (is_available_memory(md)) {
762 if (md->phys_addr >= size) continue;
763 memcpy(next_md, md, memmap.desc_size);
764 if (current_addr >= size) {
765 next_md->num_pages -=
766 PFN_UP(current_addr-size);
767 }
768 p1 += memmap.desc_size;
769 next_md = p1;
770 j++;
771 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
772 EFI_MEMORY_RUNTIME) {
773 /* In order to make runtime services
774 * available we have to include runtime
775 * memory regions in memory map */
776 memcpy(next_md, md, memmap.desc_size);
777 p1 += memmap.desc_size;
778 next_md = p1;
779 j++;
780 }
781 }
782 memmap.nr_map = j;
783 memmap.map_end = memmap.map +
784 (memmap.nr_map * memmap.desc_size);
785 }
786
787 void __init limit_regions(unsigned long long size)
788 {
789 unsigned long long current_addr;
790 int i;
791
792 print_memory_map("limit_regions start");
793 if (efi_enabled) {
794 efi_limit_regions(size);
795 return;
796 }
797 for (i = 0; i < e820.nr_map; i++) {
798 current_addr = e820.map[i].addr + e820.map[i].size;
799 if (current_addr < size)
800 continue;
801
802 if (e820.map[i].type != E820_RAM)
803 continue;
804
805 if (e820.map[i].addr >= size) {
806 /*
807 * This region starts past the end of the
808 * requested size, skip it completely.
809 */
810 e820.nr_map = i;
811 } else {
812 e820.nr_map = i + 1;
813 e820.map[i].size -= current_addr - size;
814 }
815 print_memory_map("limit_regions endfor");
816 return;
817 }
818 print_memory_map("limit_regions endfunc");
819 }
820
821 /*
822 * This function checks if the entire range <start,end> is mapped with type.
823 *
824 * Note: this function only works correct if the e820 table is sorted and
825 * not-overlapping, which is the case
826 */
827 int __init
828 e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
829 {
830 u64 start = s;
831 u64 end = e;
832 int i;
833 for (i = 0; i < e820.nr_map; i++) {
834 struct e820entry *ei = &e820.map[i];
835 if (type && ei->type != type)
836 continue;
837 /* is the region (part) in overlap with the current region ?*/
838 if (ei->addr >= end || ei->addr + ei->size <= start)
839 continue;
840 /* if the region is at the beginning of <start,end> we move
841 * start to the end of the region since it's ok until there
842 */
843 if (ei->addr <= start)
844 start = ei->addr + ei->size;
845 /* if start is now at or beyond end, we're done, full
846 * coverage */
847 if (start >= end)
848 return 1; /* we're done */
849 }
850 return 0;
851 }
852
853 static int __init parse_memmap(char *arg)
854 {
855 if (!arg)
856 return -EINVAL;
857
858 if (strcmp(arg, "exactmap") == 0) {
859 #ifdef CONFIG_CRASH_DUMP
860 /* If we are doing a crash dump, we
861 * still need to know the real mem
862 * size before original memory map is
863 * reset.
864 */
865 find_max_pfn();
866 saved_max_pfn = max_pfn;
867 #endif
868 e820.nr_map = 0;
869 user_defined_memmap = 1;
870 } else {
871 /* If the user specifies memory size, we
872 * limit the BIOS-provided memory map to
873 * that size. exactmap can be used to specify
874 * the exact map. mem=number can be used to
875 * trim the existing memory map.
876 */
877 unsigned long long start_at, mem_size;
878
879 mem_size = memparse(arg, &arg);
880 if (*arg == '@') {
881 start_at = memparse(arg+1, &arg);
882 add_memory_region(start_at, mem_size, E820_RAM);
883 } else if (*arg == '#') {
884 start_at = memparse(arg+1, &arg);
885 add_memory_region(start_at, mem_size, E820_ACPI);
886 } else if (*arg == '$') {
887 start_at = memparse(arg+1, &arg);
888 add_memory_region(start_at, mem_size, E820_RESERVED);
889 } else {
890 limit_regions(mem_size);
891 user_defined_memmap = 1;
892 }
893 }
894 return 0;
895 }
896 early_param("memmap", parse_memmap);
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