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[linux-3.10.git] / arch / x86_64 / kernel / e820.c
1 /* 
2  * Handle the memory map.
3  * The functions here do the job until bootmem takes over.
4  * $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $
5  */
6 #include <linux/config.h>
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/init.h>
10 #include <linux/bootmem.h>
11 #include <linux/ioport.h>
12 #include <linux/string.h>
13 #include <asm/page.h>
14 #include <asm/e820.h>
15 #include <asm/proto.h>
16 #include <asm/bootsetup.h>
17
18 extern char _end[];
19
20 /* 
21  * PFN of last memory page.
22  */
23 unsigned long end_pfn; 
24
25 /* 
26  * end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
27  * The direct mapping extends to end_pfn_map, so that we can directly access
28  * apertures, ACPI and other tables without having to play with fixmaps.
29  */ 
30 unsigned long end_pfn_map; 
31
32 /* 
33  * Last pfn which the user wants to use.
34  */
35 unsigned long end_user_pfn = MAXMEM>>PAGE_SHIFT;  
36
37 extern struct resource code_resource, data_resource;
38
39 /* Check for some hardcoded bad areas that early boot is not allowed to touch */ 
40 static inline int bad_addr(unsigned long *addrp, unsigned long size)
41
42         unsigned long addr = *addrp, last = addr + size; 
43
44         /* various gunk below that needed for SMP startup */
45         if (addr < 0x8000) { 
46                 *addrp = 0x8000;
47                 return 1; 
48         }
49
50         /* direct mapping tables of the kernel */
51         if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) { 
52                 *addrp = table_end << PAGE_SHIFT; 
53                 return 1;
54         } 
55
56         /* initrd */ 
57 #ifdef CONFIG_BLK_DEV_INITRD
58         if (LOADER_TYPE && INITRD_START && last >= INITRD_START && 
59             addr < INITRD_START+INITRD_SIZE) { 
60                 *addrp = INITRD_START + INITRD_SIZE; 
61                 return 1;
62         } 
63 #endif
64         /* kernel code + 640k memory hole (later should not be needed, but 
65            be paranoid for now) */
66         if (last >= 640*1024 && addr < __pa_symbol(&_end)) { 
67                 *addrp = __pa_symbol(&_end);
68                 return 1;
69         }
70         /* XXX ramdisk image here? */ 
71         return 0;
72
73
74 int __init e820_mapped(unsigned long start, unsigned long end, unsigned type) 
75
76         int i;
77         for (i = 0; i < e820.nr_map; i++) { 
78                 struct e820entry *ei = &e820.map[i]; 
79                 if (type && ei->type != type) 
80                         continue;
81                 if (ei->addr >= end || ei->addr + ei->size < start) 
82                         continue; 
83                 return 1; 
84         } 
85         return 0;
86 }
87
88 /* 
89  * Find a free area in a specific range. 
90  */ 
91 unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size) 
92
93         int i; 
94         for (i = 0; i < e820.nr_map; i++) { 
95                 struct e820entry *ei = &e820.map[i]; 
96                 unsigned long addr = ei->addr, last; 
97                 if (ei->type != E820_RAM) 
98                         continue; 
99                 if (addr < start) 
100                         addr = start;
101                 if (addr > ei->addr + ei->size) 
102                         continue; 
103                 while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
104                         ;
105                 last = addr + size;
106                 if (last > ei->addr + ei->size)
107                         continue;
108                 if (last > end) 
109                         continue;
110                 return addr; 
111         } 
112         return -1UL;            
113
114
115 /* 
116  * Free bootmem based on the e820 table for a node.
117  */
118 void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end)
119 {
120         int i;
121         for (i = 0; i < e820.nr_map; i++) {
122                 struct e820entry *ei = &e820.map[i]; 
123                 unsigned long last, addr;
124
125                 if (ei->type != E820_RAM || 
126                     ei->addr+ei->size <= start || 
127                     ei->addr > end)
128                         continue;
129
130                 addr = round_up(ei->addr, PAGE_SIZE);
131                 if (addr < start) 
132                         addr = start;
133
134                 last = round_down(ei->addr + ei->size, PAGE_SIZE); 
135                 if (last >= end)
136                         last = end; 
137
138                 if (last > addr && last-addr >= PAGE_SIZE)
139                         free_bootmem_node(pgdat, addr, last-addr);
140         }
141 }
142
143 /*
144  * Find the highest page frame number we have available
145  */
146 unsigned long __init e820_end_of_ram(void)
147 {
148         int i;
149         unsigned long end_pfn = 0;
150         
151         for (i = 0; i < e820.nr_map; i++) {
152                 struct e820entry *ei = &e820.map[i]; 
153                 unsigned long start, end;
154
155                 start = round_up(ei->addr, PAGE_SIZE); 
156                 end = round_down(ei->addr + ei->size, PAGE_SIZE); 
157                 if (start >= end)
158                         continue;
159                 if (ei->type == E820_RAM) { 
160                 if (end > end_pfn<<PAGE_SHIFT)
161                         end_pfn = end>>PAGE_SHIFT;
162                 } else { 
163                         if (end > end_pfn_map<<PAGE_SHIFT) 
164                                 end_pfn_map = end>>PAGE_SHIFT;
165                 } 
166         }
167
168         if (end_pfn > end_pfn_map) 
169                 end_pfn_map = end_pfn;
170         if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
171                 end_pfn_map = MAXMEM>>PAGE_SHIFT;
172         if (end_pfn > end_user_pfn)
173                 end_pfn = end_user_pfn;
174         if (end_pfn > end_pfn_map) 
175                 end_pfn = end_pfn_map; 
176
177         return end_pfn; 
178 }
179
180 /* 
181  * Mark e820 reserved areas as busy for the resource manager.
182  */
183 void __init e820_reserve_resources(void)
184 {
185         int i;
186         for (i = 0; i < e820.nr_map; i++) {
187                 struct resource *res;
188                 if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
189                         continue;
190                 res = alloc_bootmem_low(sizeof(struct resource));
191                 switch (e820.map[i].type) {
192                 case E820_RAM:  res->name = "System RAM"; break;
193                 case E820_ACPI: res->name = "ACPI Tables"; break;
194                 case E820_NVS:  res->name = "ACPI Non-volatile Storage"; break;
195                 default:        res->name = "reserved";
196                 }
197                 res->start = e820.map[i].addr;
198                 res->end = res->start + e820.map[i].size - 1;
199                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
200                 request_resource(&iomem_resource, res);
201                 if (e820.map[i].type == E820_RAM) {
202                         /*
203                          *  We don't know which RAM region contains kernel data,
204                          *  so we try it repeatedly and let the resource manager
205                          *  test it.
206                          */
207                         request_resource(res, &code_resource);
208                         request_resource(res, &data_resource);
209                 }
210         }
211 }
212
213 /* 
214  * Add a memory region to the kernel e820 map.
215  */ 
216 void __init add_memory_region(unsigned long start, unsigned long size, int type)
217 {
218         int x = e820.nr_map;
219
220         if (x == E820MAX) {
221                 printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
222                 return;
223         }
224
225         e820.map[x].addr = start;
226         e820.map[x].size = size;
227         e820.map[x].type = type;
228         e820.nr_map++;
229 }
230
231 void __init e820_print_map(char *who)
232 {
233         int i;
234
235         for (i = 0; i < e820.nr_map; i++) {
236                 printk(" %s: %016Lx - %016Lx ", who,
237                         (unsigned long long) e820.map[i].addr,
238                         (unsigned long long) (e820.map[i].addr + e820.map[i].size));
239                 switch (e820.map[i].type) {
240                 case E820_RAM:  printk("(usable)\n");
241                                 break;
242                 case E820_RESERVED:
243                                 printk("(reserved)\n");
244                                 break;
245                 case E820_ACPI:
246                                 printk("(ACPI data)\n");
247                                 break;
248                 case E820_NVS:
249                                 printk("(ACPI NVS)\n");
250                                 break;
251                 default:        printk("type %u\n", e820.map[i].type);
252                                 break;
253                 }
254         }
255 }
256
257 /*
258  * Sanitize the BIOS e820 map.
259  *
260  * Some e820 responses include overlapping entries.  The following 
261  * replaces the original e820 map with a new one, removing overlaps.
262  *
263  */
264 static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
265 {
266         struct change_member {
267                 struct e820entry *pbios; /* pointer to original bios entry */
268                 unsigned long long addr; /* address for this change point */
269         };
270         static struct change_member change_point_list[2*E820MAX] __initdata;
271         static struct change_member *change_point[2*E820MAX] __initdata;
272         static struct e820entry *overlap_list[E820MAX] __initdata;
273         static struct e820entry new_bios[E820MAX] __initdata;
274         struct change_member *change_tmp;
275         unsigned long current_type, last_type;
276         unsigned long long last_addr;
277         int chgidx, still_changing;
278         int overlap_entries;
279         int new_bios_entry;
280         int old_nr, new_nr;
281         int i;
282
283         /*
284                 Visually we're performing the following (1,2,3,4 = memory types)...
285
286                 Sample memory map (w/overlaps):
287                    ____22__________________
288                    ______________________4_
289                    ____1111________________
290                    _44_____________________
291                    11111111________________
292                    ____________________33__
293                    ___________44___________
294                    __________33333_________
295                    ______________22________
296                    ___________________2222_
297                    _________111111111______
298                    _____________________11_
299                    _________________4______
300
301                 Sanitized equivalent (no overlap):
302                    1_______________________
303                    _44_____________________
304                    ___1____________________
305                    ____22__________________
306                    ______11________________
307                    _________1______________
308                    __________3_____________
309                    ___________44___________
310                    _____________33_________
311                    _______________2________
312                    ________________1_______
313                    _________________4______
314                    ___________________2____
315                    ____________________33__
316                    ______________________4_
317         */
318
319         /* if there's only one memory region, don't bother */
320         if (*pnr_map < 2)
321                 return -1;
322
323         old_nr = *pnr_map;
324
325         /* bail out if we find any unreasonable addresses in bios map */
326         for (i=0; i<old_nr; i++)
327                 if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
328                         return -1;
329
330         /* create pointers for initial change-point information (for sorting) */
331         for (i=0; i < 2*old_nr; i++)
332                 change_point[i] = &change_point_list[i];
333
334         /* record all known change-points (starting and ending addresses) */
335         chgidx = 0;
336         for (i=0; i < old_nr; i++)      {
337                 change_point[chgidx]->addr = biosmap[i].addr;
338                 change_point[chgidx++]->pbios = &biosmap[i];
339                 change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
340                 change_point[chgidx++]->pbios = &biosmap[i];
341         }
342
343         /* sort change-point list by memory addresses (low -> high) */
344         still_changing = 1;
345         while (still_changing)  {
346                 still_changing = 0;
347                 for (i=1; i < 2*old_nr; i++)  {
348                         /* if <current_addr> > <last_addr>, swap */
349                         /* or, if current=<start_addr> & last=<end_addr>, swap */
350                         if ((change_point[i]->addr < change_point[i-1]->addr) ||
351                                 ((change_point[i]->addr == change_point[i-1]->addr) &&
352                                  (change_point[i]->addr == change_point[i]->pbios->addr) &&
353                                  (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
354                            )
355                         {
356                                 change_tmp = change_point[i];
357                                 change_point[i] = change_point[i-1];
358                                 change_point[i-1] = change_tmp;
359                                 still_changing=1;
360                         }
361                 }
362         }
363
364         /* create a new bios memory map, removing overlaps */
365         overlap_entries=0;       /* number of entries in the overlap table */
366         new_bios_entry=0;        /* index for creating new bios map entries */
367         last_type = 0;           /* start with undefined memory type */
368         last_addr = 0;           /* start with 0 as last starting address */
369         /* loop through change-points, determining affect on the new bios map */
370         for (chgidx=0; chgidx < 2*old_nr; chgidx++)
371         {
372                 /* keep track of all overlapping bios entries */
373                 if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
374                 {
375                         /* add map entry to overlap list (> 1 entry implies an overlap) */
376                         overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
377                 }
378                 else
379                 {
380                         /* remove entry from list (order independent, so swap with last) */
381                         for (i=0; i<overlap_entries; i++)
382                         {
383                                 if (overlap_list[i] == change_point[chgidx]->pbios)
384                                         overlap_list[i] = overlap_list[overlap_entries-1];
385                         }
386                         overlap_entries--;
387                 }
388                 /* if there are overlapping entries, decide which "type" to use */
389                 /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
390                 current_type = 0;
391                 for (i=0; i<overlap_entries; i++)
392                         if (overlap_list[i]->type > current_type)
393                                 current_type = overlap_list[i]->type;
394                 /* continue building up new bios map based on this information */
395                 if (current_type != last_type)  {
396                         if (last_type != 0)      {
397                                 new_bios[new_bios_entry].size =
398                                         change_point[chgidx]->addr - last_addr;
399                                 /* move forward only if the new size was non-zero */
400                                 if (new_bios[new_bios_entry].size != 0)
401                                         if (++new_bios_entry >= E820MAX)
402                                                 break;  /* no more space left for new bios entries */
403                         }
404                         if (current_type != 0)  {
405                                 new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
406                                 new_bios[new_bios_entry].type = current_type;
407                                 last_addr=change_point[chgidx]->addr;
408                         }
409                         last_type = current_type;
410                 }
411         }
412         new_nr = new_bios_entry;   /* retain count for new bios entries */
413
414         /* copy new bios mapping into original location */
415         memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
416         *pnr_map = new_nr;
417
418         return 0;
419 }
420
421 /*
422  * Copy the BIOS e820 map into a safe place.
423  *
424  * Sanity-check it while we're at it..
425  *
426  * If we're lucky and live on a modern system, the setup code
427  * will have given us a memory map that we can use to properly
428  * set up memory.  If we aren't, we'll fake a memory map.
429  *
430  * We check to see that the memory map contains at least 2 elements
431  * before we'll use it, because the detection code in setup.S may
432  * not be perfect and most every PC known to man has two memory
433  * regions: one from 0 to 640k, and one from 1mb up.  (The IBM
434  * thinkpad 560x, for example, does not cooperate with the memory
435  * detection code.)
436  */
437 static int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
438 {
439         /* Only one memory region (or negative)? Ignore it */
440         if (nr_map < 2)
441                 return -1;
442
443         do {
444                 unsigned long start = biosmap->addr;
445                 unsigned long size = biosmap->size;
446                 unsigned long end = start + size;
447                 unsigned long type = biosmap->type;
448
449                 /* Overflow in 64 bits? Ignore the memory map. */
450                 if (start > end)
451                         return -1;
452
453                 /*
454                  * Some BIOSes claim RAM in the 640k - 1M region.
455                  * Not right. Fix it up.
456                  * 
457                  * This should be removed on Hammer which is supposed to not
458                  * have non e820 covered ISA mappings there, but I had some strange
459                  * problems so it stays for now.  -AK
460                  */
461                 if (type == E820_RAM) {
462                         if (start < 0x100000ULL && end > 0xA0000ULL) {
463                                 if (start < 0xA0000ULL)
464                                         add_memory_region(start, 0xA0000ULL-start, type);
465                                 if (end <= 0x100000ULL)
466                                         continue;
467                                 start = 0x100000ULL;
468                                 size = end - start;
469                         }
470                 }
471
472                 add_memory_region(start, size, type);
473         } while (biosmap++,--nr_map);
474         return 0;
475 }
476
477 void __init setup_memory_region(void)
478 {
479         char *who = "BIOS-e820";
480
481         /*
482          * Try to copy the BIOS-supplied E820-map.
483          *
484          * Otherwise fake a memory map; one section from 0k->640k,
485          * the next section from 1mb->appropriate_mem_k
486          */
487         sanitize_e820_map(E820_MAP, &E820_MAP_NR);
488         if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
489                 unsigned long mem_size;
490
491                 /* compare results from other methods and take the greater */
492                 if (ALT_MEM_K < EXT_MEM_K) {
493                         mem_size = EXT_MEM_K;
494                         who = "BIOS-88";
495                 } else {
496                         mem_size = ALT_MEM_K;
497                         who = "BIOS-e801";
498                 }
499
500                 e820.nr_map = 0;
501                 add_memory_region(0, LOWMEMSIZE(), E820_RAM);
502                 add_memory_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
503         }
504         printk(KERN_INFO "BIOS-provided physical RAM map:\n");
505         e820_print_map(who);
506 }
507
508 void __init parse_memopt(char *p, char **from) 
509
510         end_user_pfn = memparse(p, from);
511         end_user_pfn >>= PAGE_SHIFT;    
512
513