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RT-AC66 3.0.0.4.374.130 core
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / arch / i386 / kernel / e820.c
blob9645bb51f76a38c01a8c250d087ee46de44ceb0c
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 const unsigned short * const ptr = (const unsigned short *)rom;
165 unsigned short sig;
166
167 return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
168 }
169
170 static int __init romchecksum(const unsigned char *rom, unsigned long length)
171 {
172 unsigned char sum, c;
173
174 for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
175 sum += c;
176 return !length && !sum;
177 }
178
179 static void __init probe_roms(void)
180 {
181 const unsigned char *rom;
182 unsigned long start, length, upper;
183 unsigned char c;
184 int i;
185
186 /* video rom */
187 upper = adapter_rom_resources[0].start;
188 for (start = video_rom_resource.start; start < upper; start += 2048) {
189 rom = isa_bus_to_virt(start);
190 if (!romsignature(rom))
191 continue;
192
193 video_rom_resource.start = start;
194
195 if (probe_kernel_address(rom + 2, c) != 0)
196 continue;
197
198 /* 0 < length <= 0x7f * 512, historically */
199 length = c * 512;
200
201 /* if checksum okay, trust length byte */
202 if (length && romchecksum(rom, length))
203 video_rom_resource.end = start + length - 1;
204
205 request_resource(&iomem_resource, &video_rom_resource);
206 break;
207 }
208
209 start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
210 if (start < upper)
211 start = upper;
212
213 /* system rom */
214 request_resource(&iomem_resource, &system_rom_resource);
215 upper = system_rom_resource.start;
216
217 /* check for extension rom (ignore length byte!) */
218 rom = isa_bus_to_virt(extension_rom_resource.start);
219 if (romsignature(rom)) {
220 length = extension_rom_resource.end - extension_rom_resource.start + 1;
221 if (romchecksum(rom, length)) {
222 request_resource(&iomem_resource, &extension_rom_resource);
223 upper = extension_rom_resource.start;
224 }
225 }
226
227 /* check for adapter roms on 2k boundaries */
228 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
229 rom = isa_bus_to_virt(start);
230 if (!romsignature(rom))
231 continue;
232
233 if (probe_kernel_address(rom + 2, c) != 0)
234 continue;
235
236 /* 0 < length <= 0x7f * 512, historically */
237 length = c * 512;
238
239 /* but accept any length that fits if checksum okay */
240 if (!length || start + length > upper || !romchecksum(rom, length))
241 continue;
242
243 adapter_rom_resources[i].start = start;
244 adapter_rom_resources[i].end = start + length - 1;
245 request_resource(&iomem_resource, &adapter_rom_resources[i]);
246
247 start = adapter_rom_resources[i++].end & ~2047UL;
248 }
249 }
250
251 /*
252 * Request address space for all standard RAM and ROM resources
253 * and also for regions reported as reserved by the e820.
254 */
255 static void __init
256 legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
257 {
258 int i;
259
260 probe_roms();
261 for (i = 0; i < e820.nr_map; i++) {
262 struct resource *res;
263 #ifndef CONFIG_RESOURCES_64BIT
264 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
265 continue;
266 #endif
267 res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
268 switch (e820.map[i].type) {
269 case E820_RAM: res->name = "System RAM"; break;
270 case E820_ACPI: res->name = "ACPI Tables"; break;
271 case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
272 default: res->name = "reserved";
273 }
274 res->start = e820.map[i].addr;
275 res->end = res->start + e820.map[i].size - 1;
276 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
277 if (request_resource(&iomem_resource, res)) {
278 kfree(res);
279 continue;
280 }
281 if (e820.map[i].type == E820_RAM) {
282 /*
283 * We don't know which RAM region contains kernel data,
284 * so we try it repeatedly and let the resource manager
285 * test it.
286 */
287 request_resource(res, code_resource);
288 request_resource(res, data_resource);
289 #ifdef CONFIG_KEXEC
290 request_resource(res, &crashk_res);
291 #endif
292 }
293 }
294 }
295
296 /*
297 * Request address space for all standard resources
298 *
299 * This is called just before pcibios_init(), which is also a
300 * subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
301 */
302 static int __init request_standard_resources(void)
303 {
304 int i;
305
306 printk("Setting up standard PCI resources\n");
307 if (efi_enabled)
308 efi_initialize_iomem_resources(&code_resource, &data_resource);
309 else
310 legacy_init_iomem_resources(&code_resource, &data_resource);
311
312 /* EFI systems may still have VGA */
313 request_resource(&iomem_resource, &video_ram_resource);
314
315 /* request I/O space for devices used on all i[345]86 PCs */
316 for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
317 request_resource(&ioport_resource, &standard_io_resources[i]);
318 return 0;
319 }
320
321 subsys_initcall(request_standard_resources);
322
323 void __init add_memory_region(unsigned long long start,
324 unsigned long long size, int type)
325 {
326 int x;
327
328 if (!efi_enabled) {
329 x = e820.nr_map;
330
331 if (x == E820MAX) {
332 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
333 return;
334 }
335
336 e820.map[x].addr = start;
337 e820.map[x].size = size;
338 e820.map[x].type = type;
339 e820.nr_map++;
340 }
341 } /* add_memory_region */
342
343 /*
344 * Sanitize the BIOS e820 map.
345 *
346 * Some e820 responses include overlapping entries. The following
347 * replaces the original e820 map with a new one, removing overlaps.
348 *
349 */
350 int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
351 {
352 struct change_member *change_tmp;
353 unsigned long current_type, last_type;
354 unsigned long long last_addr;
355 int chgidx, still_changing;
356 int overlap_entries;
357 int new_bios_entry;
358 int old_nr, new_nr, chg_nr;
359 int i;
360
361 /*
362 Visually we're performing the following (1,2,3,4 = memory types)...
363
364 Sample memory map (w/overlaps):
365 ____22__________________
366 ______________________4_
367 ____1111________________
368 _44_____________________
369 11111111________________
370 ____________________33__
371 ___________44___________
372 __________33333_________
373 ______________22________
374 ___________________2222_
375 _________111111111______
376 _____________________11_
377 _________________4______
378
379 Sanitized equivalent (no overlap):
380 1_______________________
381 _44_____________________
382 ___1____________________
383 ____22__________________
384 ______11________________
385 _________1______________
386 __________3_____________
387 ___________44___________
388 _____________33_________
389 _______________2________
390 ________________1_______
391 _________________4______
392 ___________________2____
393 ____________________33__
394 ______________________4_
395 */
396 /* if there's only one memory region, don't bother */
397 if (*pnr_map < 2) {
398 return -1;
399 }
400
401 old_nr = *pnr_map;
402
403 /* bail out if we find any unreasonable addresses in bios map */
404 for (i=0; i<old_nr; i++)
405 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) {
406 return -1;
407 }
408
409 /* create pointers for initial change-point information (for sorting) */
410 for (i=0; i < 2*old_nr; i++)
411 change_point[i] = &change_point_list[i];
412
413 /* record all known change-points (starting and ending addresses),
414 omitting those that are for empty memory regions */
415 chgidx = 0;
416 for (i=0; i < old_nr; i++) {
417 if (biosmap[i].size != 0) {
418 change_point[chgidx]->addr = biosmap[i].addr;
419 change_point[chgidx++]->pbios = &biosmap[i];
420 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
421 change_point[chgidx++]->pbios = &biosmap[i];
422 }
423 }
424 chg_nr = chgidx; /* true number of change-points */
425
426 /* sort change-point list by memory addresses (low -> high) */
427 still_changing = 1;
428 while (still_changing) {
429 still_changing = 0;
430 for (i=1; i < chg_nr; i++) {
431 /* if <current_addr> > <last_addr>, swap */
432 /* or, if current=<start_addr> & last=<end_addr>, swap */
433 if ((change_point[i]->addr < change_point[i-1]->addr) ||
434 ((change_point[i]->addr == change_point[i-1]->addr) &&
435 (change_point[i]->addr == change_point[i]->pbios->addr) &&
436 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
437 )
438 {
439 change_tmp = change_point[i];
440 change_point[i] = change_point[i-1];
441 change_point[i-1] = change_tmp;
442 still_changing=1;
443 }
444 }
445 }
446
447 /* create a new bios memory map, removing overlaps */
448 overlap_entries=0; /* number of entries in the overlap table */
449 new_bios_entry=0; /* index for creating new bios map entries */
450 last_type = 0; /* start with undefined memory type */
451 last_addr = 0; /* start with 0 as last starting address */
452 /* loop through change-points, determining affect on the new bios map */
453 for (chgidx=0; chgidx < chg_nr; chgidx++)
454 {
455 /* keep track of all overlapping bios entries */
456 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
457 {
458 /* add map entry to overlap list (> 1 entry implies an overlap) */
459 overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
460 }
461 else
462 {
463 /* remove entry from list (order independent, so swap with last) */
464 for (i=0; i<overlap_entries; i++)
465 {
466 if (overlap_list[i] == change_point[chgidx]->pbios)
467 overlap_list[i] = overlap_list[overlap_entries-1];
468 }
469 overlap_entries--;
470 }
471 /* if there are overlapping entries, decide which "type" to use */
472 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
473 current_type = 0;
474 for (i=0; i<overlap_entries; i++)
475 if (overlap_list[i]->type > current_type)
476 current_type = overlap_list[i]->type;
477 /* continue building up new bios map based on this information */
478 if (current_type != last_type) {
479 if (last_type != 0) {
480 new_bios[new_bios_entry].size =
481 change_point[chgidx]->addr - last_addr;
482 /* move forward only if the new size was non-zero */
483 if (new_bios[new_bios_entry].size != 0)
484 if (++new_bios_entry >= E820MAX)
485 break; /* no more space left for new bios entries */
486 }
487 if (current_type != 0) {
488 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
489 new_bios[new_bios_entry].type = current_type;
490 last_addr=change_point[chgidx]->addr;
491 }
492 last_type = current_type;
493 }
494 }
495 new_nr = new_bios_entry; /* retain count for new bios entries */
496
497 /* copy new bios mapping into original location */
498 memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
499 *pnr_map = new_nr;
500
501 return 0;
502 }
503
504 /*
505 * Copy the BIOS e820 map into a safe place.
506 *
507 * Sanity-check it while we're at it..
508 *
509 * If we're lucky and live on a modern system, the setup code
510 * will have given us a memory map that we can use to properly
511 * set up memory. If we aren't, we'll fake a memory map.
512 *
513 * We check to see that the memory map contains at least 2 elements
514 * before we'll use it, because the detection code in setup.S may
515 * not be perfect and most every PC known to man has two memory
516 * regions: one from 0 to 640k, and one from 1mb up. (The IBM
517 * thinkpad 560x, for example, does not cooperate with the memory
518 * detection code.)
519 */
520 int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
521 {
522 /* Only one memory region (or negative)? Ignore it */
523 if (nr_map < 2)
524 return -1;
525
526 do {
527 unsigned long long start = biosmap->addr;
528 unsigned long long size = biosmap->size;
529 unsigned long long end = start + size;
530 unsigned long type = biosmap->type;
531
532 /* Overflow in 64 bits? Ignore the memory map. */
533 if (start > end)
534 return -1;
535
536 /*
537 * Some BIOSes claim RAM in the 640k - 1M region.
538 * Not right. Fix it up.
539 */
540 if (type == E820_RAM) {
541 if (start < 0x100000ULL && end > 0xA0000ULL) {
542 if (start < 0xA0000ULL)
543 add_memory_region(start, 0xA0000ULL-start, type);
544 if (end <= 0x100000ULL)
545 continue;
546 start = 0x100000ULL;
547 size = end - start;
548 }
549 }
550 add_memory_region(start, size, type);
551 } while (biosmap++,--nr_map);
552 return 0;
553 }
554
555 /*
556 * Callback for efi_memory_walk.
557 */
558 static int __init
559 efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
560 {
561 unsigned long *max_pfn = arg, pfn;
562
563 if (start < end) {
564 pfn = PFN_UP(end -1);
565 if (pfn > *max_pfn)
566 *max_pfn = pfn;
567 }
568 return 0;
569 }
570
571 static int __init
572 efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
573 {
574 memory_present(0, PFN_UP(start), PFN_DOWN(end));
575 return 0;
576 }
577
578 /*
579 * Find the highest page frame number we have available
580 */
581 void __init find_max_pfn(void)
582 {
583 int i;
584
585 max_pfn = 0;
586 if (efi_enabled) {
587 efi_memmap_walk(efi_find_max_pfn, &max_pfn);
588 efi_memmap_walk(efi_memory_present_wrapper, NULL);
589 return;
590 }
591
592 for (i = 0; i < e820.nr_map; i++) {
593 unsigned long start, end;
594 /* RAM? */
595 if (e820.map[i].type != E820_RAM)
596 continue;
597 start = PFN_UP(e820.map[i].addr);
598 end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
599 if (start >= end)
600 continue;
601 if (end > max_pfn)
602 max_pfn = end;
603 memory_present(0, start, end);
604 }
605 }
606
607 /*
608 * Free all available memory for boot time allocation. Used
609 * as a callback function by efi_memory_walk()
610 */
611
612 static int __init
613 free_available_memory(unsigned long start, unsigned long end, void *arg)
614 {
615 /* check max_low_pfn */
616 if (start >= (max_low_pfn << PAGE_SHIFT))
617 return 0;
618 if (end >= (max_low_pfn << PAGE_SHIFT))
619 end = max_low_pfn << PAGE_SHIFT;
620 if (start < end)
621 free_bootmem(start, end - start);
622
623 return 0;
624 }
625 /*
626 * Register fully available low RAM pages with the bootmem allocator.
627 */
628 void __init register_bootmem_low_pages(unsigned long max_low_pfn)
629 {
630 int i;
631
632 if (efi_enabled) {
633 efi_memmap_walk(free_available_memory, NULL);
634 return;
635 }
636 for (i = 0; i < e820.nr_map; i++) {
637 unsigned long curr_pfn, last_pfn, size;
638 /*
639 * Reserve usable low memory
640 */
641 if (e820.map[i].type != E820_RAM)
642 continue;
643 /*
644 * We are rounding up the start address of usable memory:
645 */
646 curr_pfn = PFN_UP(e820.map[i].addr);
647 if (curr_pfn >= max_low_pfn)
648 continue;
649 /*
650 * ... and at the end of the usable range downwards:
651 */
652 last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
653
654 if (last_pfn > max_low_pfn)
655 last_pfn = max_low_pfn;
656
657 /*
658 * .. finally, did all the rounding and playing
659 * around just make the area go away?
660 */
661 if (last_pfn <= curr_pfn)
662 continue;
663
664 size = last_pfn - curr_pfn;
665 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
666 }
667 }
668
669 void __init e820_register_memory(void)
670 {
671 unsigned long gapstart, gapsize, round;
672 unsigned long long last;
673 int i;
674
675 /*
676 * Search for the bigest gap in the low 32 bits of the e820
677 * memory space.
678 */
679 last = 0x100000000ull;
680 gapstart = 0x10000000;
681 gapsize = 0x400000;
682 i = e820.nr_map;
683 while (--i >= 0) {
684 unsigned long long start = e820.map[i].addr;
685 unsigned long long end = start + e820.map[i].size;
686
687 /*
688 * Since "last" is at most 4GB, we know we'll
689 * fit in 32 bits if this condition is true
690 */
691 if (last > end) {
692 unsigned long gap = last - end;
693
694 if (gap > gapsize) {
695 gapsize = gap;
696 gapstart = end;
697 }
698 }
699 if (start < last)
700 last = start;
701 }
702
703 /*
704 * See how much we want to round up: start off with
705 * rounding to the next 1MB area.
706 */
707 round = 0x100000;
708 while ((gapsize >> 4) > round)
709 round += round;
710 /* Fun with two's complement */
711 pci_mem_start = (gapstart + round) & -round;
712
713 printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
714 pci_mem_start, gapstart, gapsize);
715 }
716
717 void __init print_memory_map(char *who)
718 {
719 int i;
720
721 for (i = 0; i < e820.nr_map; i++) {
722 printk(" %s: %016Lx - %016Lx ", who,
723 e820.map[i].addr,
724 e820.map[i].addr + e820.map[i].size);
725 switch (e820.map[i].type) {
726 case E820_RAM: printk("(usable)\n");
727 break;
728 case E820_RESERVED:
729 printk("(reserved)\n");
730 break;
731 case E820_ACPI:
732 printk("(ACPI data)\n");
733 break;
734 case E820_NVS:
735 printk("(ACPI NVS)\n");
736 break;
737 default: printk("type %lu\n", e820.map[i].type);
738 break;
739 }
740 }
741 }
742
743 static __init __always_inline void efi_limit_regions(unsigned long long size)
744 {
745 unsigned long long current_addr = 0;
746 efi_memory_desc_t *md, *next_md;
747 void *p, *p1;
748 int i, j;
749
750 j = 0;
751 p1 = memmap.map;
752 for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
753 md = p;
754 next_md = p1;
755 current_addr = md->phys_addr +
756 PFN_PHYS(md->num_pages);
757 if (is_available_memory(md)) {
758 if (md->phys_addr >= size) continue;
759 memcpy(next_md, md, memmap.desc_size);
760 if (current_addr >= size) {
761 next_md->num_pages -=
762 PFN_UP(current_addr-size);
763 }
764 p1 += memmap.desc_size;
765 next_md = p1;
766 j++;
767 } else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
768 EFI_MEMORY_RUNTIME) {
769 /* In order to make runtime services
770 * available we have to include runtime
771 * memory regions in memory map */
772 memcpy(next_md, md, memmap.desc_size);
773 p1 += memmap.desc_size;
774 next_md = p1;
775 j++;
776 }
777 }
778 memmap.nr_map = j;
779 memmap.map_end = memmap.map +
780 (memmap.nr_map * memmap.desc_size);
781 }
782
783 void __init limit_regions(unsigned long long size)
784 {
785 unsigned long long current_addr;
786 int i;
787
788 print_memory_map("limit_regions start");
789 if (efi_enabled) {
790 efi_limit_regions(size);
791 return;
792 }
793 for (i = 0; i < e820.nr_map; i++) {
794 current_addr = e820.map[i].addr + e820.map[i].size;
795 if (current_addr < size)
796 continue;
797
798 if (e820.map[i].type != E820_RAM)
799 continue;
800
801 if (e820.map[i].addr >= size) {
802 /*
803 * This region starts past the end of the
804 * requested size, skip it completely.
805 */
806 e820.nr_map = i;
807 } else {
808 e820.nr_map = i + 1;
809 e820.map[i].size -= current_addr - size;
810 }
811 print_memory_map("limit_regions endfor");
812 return;
813 }
814 print_memory_map("limit_regions endfunc");
815 }
816
817 /*
818 * This function checks if any part of the range <start,end> is mapped
819 * with type.
820 */
821 int
822 e820_any_mapped(u64 start, u64 end, unsigned type)
823 {
824 int i;
825 for (i = 0; i < e820.nr_map; i++) {
826 const struct e820entry *ei = &e820.map[i];
827 if (type && ei->type != type)
828 continue;
829 if (ei->addr >= end || ei->addr + ei->size <= start)
830 continue;
831 return 1;
832 }
833 return 0;
834 }
835 EXPORT_SYMBOL_GPL(e820_any_mapped);
836
837 /*
838 * This function checks if the entire range <start,end> is mapped with type.
839 *
840 * Note: this function only works correct if the e820 table is sorted and
841 * not-overlapping, which is the case
842 */
843 int __init
844 e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
845 {
846 u64 start = s;
847 u64 end = e;
848 int i;
849 for (i = 0; i < e820.nr_map; i++) {
850 struct e820entry *ei = &e820.map[i];
851 if (type && ei->type != type)
852 continue;
853 /* is the region (part) in overlap with the current region ?*/
854 if (ei->addr >= end || ei->addr + ei->size <= start)
855 continue;
856 /* if the region is at the beginning of <start,end> we move
857 * start to the end of the region since it's ok until there
858 */
859 if (ei->addr <= start)
860 start = ei->addr + ei->size;
861 /* if start is now at or beyond end, we're done, full
862 * coverage */
863 if (start >= end)
864 return 1; /* we're done */
865 }
866 return 0;
867 }
868
869 static int __init parse_memmap(char *arg)
870 {
871 if (!arg)
872 return -EINVAL;
873
874 if (strcmp(arg, "exactmap") == 0) {
875 #ifdef CONFIG_CRASH_DUMP
876 /* If we are doing a crash dump, we
877 * still need to know the real mem
878 * size before original memory map is
879 * reset.
880 */
881 find_max_pfn();
882 saved_max_pfn = max_pfn;
883 #endif
884 e820.nr_map = 0;
885 user_defined_memmap = 1;
886 } else {
887 /* If the user specifies memory size, we
888 * limit the BIOS-provided memory map to
889 * that size. exactmap can be used to specify
890 * the exact map. mem=number can be used to
891 * trim the existing memory map.
892 */
893 unsigned long long start_at, mem_size;
894
895 mem_size = memparse(arg, &arg);
896 if (*arg == '@') {
897 start_at = memparse(arg+1, &arg);
898 add_memory_region(start_at, mem_size, E820_RAM);
899 } else if (*arg == '#') {
900 start_at = memparse(arg+1, &arg);
901 add_memory_region(start_at, mem_size, E820_ACPI);
902 } else if (*arg == '$') {
903 start_at = memparse(arg+1, &arg);
904 add_memory_region(start_at, mem_size, E820_RESERVED);
905 } else {
906 limit_regions(mem_size);
907 user_defined_memmap = 1;
908 }
909 }
910 return 0;
911 }
912 early_param("memmap", parse_memmap);
Tomato firmware and modifications.