Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[linux-2.6] / arch / i386 / kernel / e820.c
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);