mm, memory_hotplug: add nid parameter to arch_remove_memory
[sfrench/cifs-2.6.git] / arch / x86 / mm / init_32.c
1 /*
2  *
3  *  Copyright (C) 1995  Linus Torvalds
4  *
5  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6  */
7
8 #include <linux/signal.h>
9 #include <linux/sched.h>
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/types.h>
14 #include <linux/ptrace.h>
15 #include <linux/mman.h>
16 #include <linux/mm.h>
17 #include <linux/hugetlb.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/highmem.h>
22 #include <linux/pagemap.h>
23 #include <linux/pci.h>
24 #include <linux/pfn.h>
25 #include <linux/poison.h>
26 #include <linux/memblock.h>
27 #include <linux/proc_fs.h>
28 #include <linux/memory_hotplug.h>
29 #include <linux/initrd.h>
30 #include <linux/cpumask.h>
31 #include <linux/gfp.h>
32
33 #include <asm/asm.h>
34 #include <asm/bios_ebda.h>
35 #include <asm/processor.h>
36 #include <linux/uaccess.h>
37 #include <asm/pgtable.h>
38 #include <asm/dma.h>
39 #include <asm/fixmap.h>
40 #include <asm/e820/api.h>
41 #include <asm/apic.h>
42 #include <asm/bugs.h>
43 #include <asm/tlb.h>
44 #include <asm/tlbflush.h>
45 #include <asm/olpc_ofw.h>
46 #include <asm/pgalloc.h>
47 #include <asm/sections.h>
48 #include <asm/paravirt.h>
49 #include <asm/setup.h>
50 #include <asm/set_memory.h>
51 #include <asm/page_types.h>
52 #include <asm/cpu_entry_area.h>
53 #include <asm/init.h>
54
55 #include "mm_internal.h"
56
57 unsigned long highstart_pfn, highend_pfn;
58
59 bool __read_mostly __vmalloc_start_set = false;
60
61 /*
62  * Creates a middle page table and puts a pointer to it in the
63  * given global directory entry. This only returns the gd entry
64  * in non-PAE compilation mode, since the middle layer is folded.
65  */
66 static pmd_t * __init one_md_table_init(pgd_t *pgd)
67 {
68         p4d_t *p4d;
69         pud_t *pud;
70         pmd_t *pmd_table;
71
72 #ifdef CONFIG_X86_PAE
73         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
74                 pmd_table = (pmd_t *)alloc_low_page();
75                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
76                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
77                 p4d = p4d_offset(pgd, 0);
78                 pud = pud_offset(p4d, 0);
79                 BUG_ON(pmd_table != pmd_offset(pud, 0));
80
81                 return pmd_table;
82         }
83 #endif
84         p4d = p4d_offset(pgd, 0);
85         pud = pud_offset(p4d, 0);
86         pmd_table = pmd_offset(pud, 0);
87
88         return pmd_table;
89 }
90
91 /*
92  * Create a page table and place a pointer to it in a middle page
93  * directory entry:
94  */
95 static pte_t * __init one_page_table_init(pmd_t *pmd)
96 {
97         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
98                 pte_t *page_table = (pte_t *)alloc_low_page();
99
100                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
101                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
102                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
103         }
104
105         return pte_offset_kernel(pmd, 0);
106 }
107
108 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
109 {
110         int pgd_idx = pgd_index(vaddr);
111         int pmd_idx = pmd_index(vaddr);
112
113         return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
114 }
115
116 pte_t * __init populate_extra_pte(unsigned long vaddr)
117 {
118         int pte_idx = pte_index(vaddr);
119         pmd_t *pmd;
120
121         pmd = populate_extra_pmd(vaddr);
122         return one_page_table_init(pmd) + pte_idx;
123 }
124
125 static unsigned long __init
126 page_table_range_init_count(unsigned long start, unsigned long end)
127 {
128         unsigned long count = 0;
129 #ifdef CONFIG_HIGHMEM
130         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
131         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
132         int pgd_idx, pmd_idx;
133         unsigned long vaddr;
134
135         if (pmd_idx_kmap_begin == pmd_idx_kmap_end)
136                 return 0;
137
138         vaddr = start;
139         pgd_idx = pgd_index(vaddr);
140         pmd_idx = pmd_index(vaddr);
141
142         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {
143                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
144                                                         pmd_idx++) {
145                         if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin &&
146                             (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end)
147                                 count++;
148                         vaddr += PMD_SIZE;
149                 }
150                 pmd_idx = 0;
151         }
152 #endif
153         return count;
154 }
155
156 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
157                                            unsigned long vaddr, pte_t *lastpte,
158                                            void **adr)
159 {
160 #ifdef CONFIG_HIGHMEM
161         /*
162          * Something (early fixmap) may already have put a pte
163          * page here, which causes the page table allocation
164          * to become nonlinear. Attempt to fix it, and if it
165          * is still nonlinear then we have to bug.
166          */
167         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
168         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
169
170         if (pmd_idx_kmap_begin != pmd_idx_kmap_end
171             && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
172             && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) {
173                 pte_t *newpte;
174                 int i;
175
176                 BUG_ON(after_bootmem);
177                 newpte = *adr;
178                 for (i = 0; i < PTRS_PER_PTE; i++)
179                         set_pte(newpte + i, pte[i]);
180                 *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE);
181
182                 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
183                 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
184                 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
185                 __flush_tlb_all();
186
187                 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
188                 pte = newpte;
189         }
190         BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
191                && vaddr > fix_to_virt(FIX_KMAP_END)
192                && lastpte && lastpte + PTRS_PER_PTE != pte);
193 #endif
194         return pte;
195 }
196
197 /*
198  * This function initializes a certain range of kernel virtual memory
199  * with new bootmem page tables, everywhere page tables are missing in
200  * the given range.
201  *
202  * NOTE: The pagetables are allocated contiguous on the physical space
203  * so we can cache the place of the first one and move around without
204  * checking the pgd every time.
205  */
206 static void __init
207 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
208 {
209         int pgd_idx, pmd_idx;
210         unsigned long vaddr;
211         pgd_t *pgd;
212         pmd_t *pmd;
213         pte_t *pte = NULL;
214         unsigned long count = page_table_range_init_count(start, end);
215         void *adr = NULL;
216
217         if (count)
218                 adr = alloc_low_pages(count);
219
220         vaddr = start;
221         pgd_idx = pgd_index(vaddr);
222         pmd_idx = pmd_index(vaddr);
223         pgd = pgd_base + pgd_idx;
224
225         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
226                 pmd = one_md_table_init(pgd);
227                 pmd = pmd + pmd_index(vaddr);
228                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
229                                                         pmd++, pmd_idx++) {
230                         pte = page_table_kmap_check(one_page_table_init(pmd),
231                                                     pmd, vaddr, pte, &adr);
232
233                         vaddr += PMD_SIZE;
234                 }
235                 pmd_idx = 0;
236         }
237 }
238
239 static inline int is_kernel_text(unsigned long addr)
240 {
241         if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
242                 return 1;
243         return 0;
244 }
245
246 /*
247  * This maps the physical memory to kernel virtual address space, a total
248  * of max_low_pfn pages, by creating page tables starting from address
249  * PAGE_OFFSET:
250  */
251 unsigned long __init
252 kernel_physical_mapping_init(unsigned long start,
253                              unsigned long end,
254                              unsigned long page_size_mask)
255 {
256         int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
257         unsigned long last_map_addr = end;
258         unsigned long start_pfn, end_pfn;
259         pgd_t *pgd_base = swapper_pg_dir;
260         int pgd_idx, pmd_idx, pte_ofs;
261         unsigned long pfn;
262         pgd_t *pgd;
263         pmd_t *pmd;
264         pte_t *pte;
265         unsigned pages_2m, pages_4k;
266         int mapping_iter;
267
268         start_pfn = start >> PAGE_SHIFT;
269         end_pfn = end >> PAGE_SHIFT;
270
271         /*
272          * First iteration will setup identity mapping using large/small pages
273          * based on use_pse, with other attributes same as set by
274          * the early code in head_32.S
275          *
276          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
277          * as desired for the kernel identity mapping.
278          *
279          * This two pass mechanism conforms to the TLB app note which says:
280          *
281          *     "Software should not write to a paging-structure entry in a way
282          *      that would change, for any linear address, both the page size
283          *      and either the page frame or attributes."
284          */
285         mapping_iter = 1;
286
287         if (!boot_cpu_has(X86_FEATURE_PSE))
288                 use_pse = 0;
289
290 repeat:
291         pages_2m = pages_4k = 0;
292         pfn = start_pfn;
293         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
294         pgd = pgd_base + pgd_idx;
295         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
296                 pmd = one_md_table_init(pgd);
297
298                 if (pfn >= end_pfn)
299                         continue;
300 #ifdef CONFIG_X86_PAE
301                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
302                 pmd += pmd_idx;
303 #else
304                 pmd_idx = 0;
305 #endif
306                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
307                      pmd++, pmd_idx++) {
308                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
309
310                         /*
311                          * Map with big pages if possible, otherwise
312                          * create normal page tables:
313                          */
314                         if (use_pse) {
315                                 unsigned int addr2;
316                                 pgprot_t prot = PAGE_KERNEL_LARGE;
317                                 /*
318                                  * first pass will use the same initial
319                                  * identity mapping attribute + _PAGE_PSE.
320                                  */
321                                 pgprot_t init_prot =
322                                         __pgprot(PTE_IDENT_ATTR |
323                                                  _PAGE_PSE);
324
325                                 pfn &= PMD_MASK >> PAGE_SHIFT;
326                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
327                                         PAGE_OFFSET + PAGE_SIZE-1;
328
329                                 if (is_kernel_text(addr) ||
330                                     is_kernel_text(addr2))
331                                         prot = PAGE_KERNEL_LARGE_EXEC;
332
333                                 pages_2m++;
334                                 if (mapping_iter == 1)
335                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
336                                 else
337                                         set_pmd(pmd, pfn_pmd(pfn, prot));
338
339                                 pfn += PTRS_PER_PTE;
340                                 continue;
341                         }
342                         pte = one_page_table_init(pmd);
343
344                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
345                         pte += pte_ofs;
346                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
347                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
348                                 pgprot_t prot = PAGE_KERNEL;
349                                 /*
350                                  * first pass will use the same initial
351                                  * identity mapping attribute.
352                                  */
353                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
354
355                                 if (is_kernel_text(addr))
356                                         prot = PAGE_KERNEL_EXEC;
357
358                                 pages_4k++;
359                                 if (mapping_iter == 1) {
360                                         set_pte(pte, pfn_pte(pfn, init_prot));
361                                         last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
362                                 } else
363                                         set_pte(pte, pfn_pte(pfn, prot));
364                         }
365                 }
366         }
367         if (mapping_iter == 1) {
368                 /*
369                  * update direct mapping page count only in the first
370                  * iteration.
371                  */
372                 update_page_count(PG_LEVEL_2M, pages_2m);
373                 update_page_count(PG_LEVEL_4K, pages_4k);
374
375                 /*
376                  * local global flush tlb, which will flush the previous
377                  * mappings present in both small and large page TLB's.
378                  */
379                 __flush_tlb_all();
380
381                 /*
382                  * Second iteration will set the actual desired PTE attributes.
383                  */
384                 mapping_iter = 2;
385                 goto repeat;
386         }
387         return last_map_addr;
388 }
389
390 pte_t *kmap_pte;
391
392 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
393 {
394         pgd_t *pgd = pgd_offset_k(vaddr);
395         p4d_t *p4d = p4d_offset(pgd, vaddr);
396         pud_t *pud = pud_offset(p4d, vaddr);
397         pmd_t *pmd = pmd_offset(pud, vaddr);
398         return pte_offset_kernel(pmd, vaddr);
399 }
400
401 static void __init kmap_init(void)
402 {
403         unsigned long kmap_vstart;
404
405         /*
406          * Cache the first kmap pte:
407          */
408         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
409         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
410 }
411
412 #ifdef CONFIG_HIGHMEM
413 static void __init permanent_kmaps_init(pgd_t *pgd_base)
414 {
415         unsigned long vaddr;
416         pgd_t *pgd;
417         p4d_t *p4d;
418         pud_t *pud;
419         pmd_t *pmd;
420         pte_t *pte;
421
422         vaddr = PKMAP_BASE;
423         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
424
425         pgd = swapper_pg_dir + pgd_index(vaddr);
426         p4d = p4d_offset(pgd, vaddr);
427         pud = pud_offset(p4d, vaddr);
428         pmd = pmd_offset(pud, vaddr);
429         pte = pte_offset_kernel(pmd, vaddr);
430         pkmap_page_table = pte;
431 }
432
433 void __init add_highpages_with_active_regions(int nid,
434                          unsigned long start_pfn, unsigned long end_pfn)
435 {
436         phys_addr_t start, end;
437         u64 i;
438
439         for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) {
440                 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
441                                             start_pfn, end_pfn);
442                 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
443                                               start_pfn, end_pfn);
444                 for ( ; pfn < e_pfn; pfn++)
445                         if (pfn_valid(pfn))
446                                 free_highmem_page(pfn_to_page(pfn));
447         }
448 }
449 #else
450 static inline void permanent_kmaps_init(pgd_t *pgd_base)
451 {
452 }
453 #endif /* CONFIG_HIGHMEM */
454
455 void __init sync_initial_page_table(void)
456 {
457         clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
458                         swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
459                         KERNEL_PGD_PTRS);
460
461         /*
462          * sync back low identity map too.  It is used for example
463          * in the 32-bit EFI stub.
464          */
465         clone_pgd_range(initial_page_table,
466                         swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
467                         min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
468 }
469
470 void __init native_pagetable_init(void)
471 {
472         unsigned long pfn, va;
473         pgd_t *pgd, *base = swapper_pg_dir;
474         p4d_t *p4d;
475         pud_t *pud;
476         pmd_t *pmd;
477         pte_t *pte;
478
479         /*
480          * Remove any mappings which extend past the end of physical
481          * memory from the boot time page table.
482          * In virtual address space, we should have at least two pages
483          * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
484          * definition. And max_low_pfn is set to VMALLOC_END physical
485          * address. If initial memory mapping is doing right job, we
486          * should have pte used near max_low_pfn or one pmd is not present.
487          */
488         for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
489                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
490                 pgd = base + pgd_index(va);
491                 if (!pgd_present(*pgd))
492                         break;
493
494                 p4d = p4d_offset(pgd, va);
495                 pud = pud_offset(p4d, va);
496                 pmd = pmd_offset(pud, va);
497                 if (!pmd_present(*pmd))
498                         break;
499
500                 /* should not be large page here */
501                 if (pmd_large(*pmd)) {
502                         pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
503                                 pfn, pmd, __pa(pmd));
504                         BUG_ON(1);
505                 }
506
507                 pte = pte_offset_kernel(pmd, va);
508                 if (!pte_present(*pte))
509                         break;
510
511                 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
512                                 pfn, pmd, __pa(pmd), pte, __pa(pte));
513                 pte_clear(NULL, va, pte);
514         }
515         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
516         paging_init();
517 }
518
519 /*
520  * Build a proper pagetable for the kernel mappings.  Up until this
521  * point, we've been running on some set of pagetables constructed by
522  * the boot process.
523  *
524  * If we're booting on native hardware, this will be a pagetable
525  * constructed in arch/x86/kernel/head_32.S.  The root of the
526  * pagetable will be swapper_pg_dir.
527  *
528  * If we're booting paravirtualized under a hypervisor, then there are
529  * more options: we may already be running PAE, and the pagetable may
530  * or may not be based in swapper_pg_dir.  In any case,
531  * paravirt_pagetable_init() will set up swapper_pg_dir
532  * appropriately for the rest of the initialization to work.
533  *
534  * In general, pagetable_init() assumes that the pagetable may already
535  * be partially populated, and so it avoids stomping on any existing
536  * mappings.
537  */
538 void __init early_ioremap_page_table_range_init(void)
539 {
540         pgd_t *pgd_base = swapper_pg_dir;
541         unsigned long vaddr, end;
542
543         /*
544          * Fixed mappings, only the page table structure has to be
545          * created - mappings will be set by set_fixmap():
546          */
547         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
548         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
549         page_table_range_init(vaddr, end, pgd_base);
550         early_ioremap_reset();
551 }
552
553 static void __init pagetable_init(void)
554 {
555         pgd_t *pgd_base = swapper_pg_dir;
556
557         permanent_kmaps_init(pgd_base);
558 }
559
560 #define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
561 /* Bits supported by the hardware: */
562 pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK;
563 /* Bits allowed in normal kernel mappings: */
564 pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK;
565 EXPORT_SYMBOL_GPL(__supported_pte_mask);
566 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
567 EXPORT_SYMBOL(__default_kernel_pte_mask);
568
569 /* user-defined highmem size */
570 static unsigned int highmem_pages = -1;
571
572 /*
573  * highmem=size forces highmem to be exactly 'size' bytes.
574  * This works even on boxes that have no highmem otherwise.
575  * This also works to reduce highmem size on bigger boxes.
576  */
577 static int __init parse_highmem(char *arg)
578 {
579         if (!arg)
580                 return -EINVAL;
581
582         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
583         return 0;
584 }
585 early_param("highmem", parse_highmem);
586
587 #define MSG_HIGHMEM_TOO_BIG \
588         "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
589
590 #define MSG_LOWMEM_TOO_SMALL \
591         "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
592 /*
593  * All of RAM fits into lowmem - but if user wants highmem
594  * artificially via the highmem=x boot parameter then create
595  * it:
596  */
597 static void __init lowmem_pfn_init(void)
598 {
599         /* max_low_pfn is 0, we already have early_res support */
600         max_low_pfn = max_pfn;
601
602         if (highmem_pages == -1)
603                 highmem_pages = 0;
604 #ifdef CONFIG_HIGHMEM
605         if (highmem_pages >= max_pfn) {
606                 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
607                         pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
608                 highmem_pages = 0;
609         }
610         if (highmem_pages) {
611                 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
612                         printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
613                                 pages_to_mb(highmem_pages));
614                         highmem_pages = 0;
615                 }
616                 max_low_pfn -= highmem_pages;
617         }
618 #else
619         if (highmem_pages)
620                 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
621 #endif
622 }
623
624 #define MSG_HIGHMEM_TOO_SMALL \
625         "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
626
627 #define MSG_HIGHMEM_TRIMMED \
628         "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
629 /*
630  * We have more RAM than fits into lowmem - we try to put it into
631  * highmem, also taking the highmem=x boot parameter into account:
632  */
633 static void __init highmem_pfn_init(void)
634 {
635         max_low_pfn = MAXMEM_PFN;
636
637         if (highmem_pages == -1)
638                 highmem_pages = max_pfn - MAXMEM_PFN;
639
640         if (highmem_pages + MAXMEM_PFN < max_pfn)
641                 max_pfn = MAXMEM_PFN + highmem_pages;
642
643         if (highmem_pages + MAXMEM_PFN > max_pfn) {
644                 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
645                         pages_to_mb(max_pfn - MAXMEM_PFN),
646                         pages_to_mb(highmem_pages));
647                 highmem_pages = 0;
648         }
649 #ifndef CONFIG_HIGHMEM
650         /* Maximum memory usable is what is directly addressable */
651         printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
652         if (max_pfn > MAX_NONPAE_PFN)
653                 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
654         else
655                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
656         max_pfn = MAXMEM_PFN;
657 #else /* !CONFIG_HIGHMEM */
658 #ifndef CONFIG_HIGHMEM64G
659         if (max_pfn > MAX_NONPAE_PFN) {
660                 max_pfn = MAX_NONPAE_PFN;
661                 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
662         }
663 #endif /* !CONFIG_HIGHMEM64G */
664 #endif /* !CONFIG_HIGHMEM */
665 }
666
667 /*
668  * Determine low and high memory ranges:
669  */
670 void __init find_low_pfn_range(void)
671 {
672         /* it could update max_pfn */
673
674         if (max_pfn <= MAXMEM_PFN)
675                 lowmem_pfn_init();
676         else
677                 highmem_pfn_init();
678 }
679
680 #ifndef CONFIG_NEED_MULTIPLE_NODES
681 void __init initmem_init(void)
682 {
683 #ifdef CONFIG_HIGHMEM
684         highstart_pfn = highend_pfn = max_pfn;
685         if (max_pfn > max_low_pfn)
686                 highstart_pfn = max_low_pfn;
687         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
688                 pages_to_mb(highend_pfn - highstart_pfn));
689         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
690 #else
691         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
692 #endif
693
694         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
695         sparse_memory_present_with_active_regions(0);
696
697 #ifdef CONFIG_FLATMEM
698         max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
699 #endif
700         __vmalloc_start_set = true;
701
702         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
703                         pages_to_mb(max_low_pfn));
704
705         setup_bootmem_allocator();
706 }
707 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
708
709 void __init setup_bootmem_allocator(void)
710 {
711         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
712                  max_pfn_mapped<<PAGE_SHIFT);
713         printk(KERN_INFO "  low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
714 }
715
716 /*
717  * paging_init() sets up the page tables - note that the first 8MB are
718  * already mapped by head.S.
719  *
720  * This routines also unmaps the page at virtual kernel address 0, so
721  * that we can trap those pesky NULL-reference errors in the kernel.
722  */
723 void __init paging_init(void)
724 {
725         pagetable_init();
726
727         __flush_tlb_all();
728
729         kmap_init();
730
731         /*
732          * NOTE: at this point the bootmem allocator is fully available.
733          */
734         olpc_dt_build_devicetree();
735         sparse_memory_present_with_active_regions(MAX_NUMNODES);
736         sparse_init();
737         zone_sizes_init();
738 }
739
740 /*
741  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
742  * and also on some strange 486's. All 586+'s are OK. This used to involve
743  * black magic jumps to work around some nasty CPU bugs, but fortunately the
744  * switch to using exceptions got rid of all that.
745  */
746 static void __init test_wp_bit(void)
747 {
748         char z = 0;
749
750         printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode...");
751
752         __set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO);
753
754         if (probe_kernel_write((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) {
755                 clear_fixmap(FIX_WP_TEST);
756                 printk(KERN_CONT "Ok.\n");
757                 return;
758         }
759
760         printk(KERN_CONT "No.\n");
761         panic("Linux doesn't support CPUs with broken WP.");
762 }
763
764 void __init mem_init(void)
765 {
766         pci_iommu_alloc();
767
768 #ifdef CONFIG_FLATMEM
769         BUG_ON(!mem_map);
770 #endif
771         /*
772          * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
773          * be done before memblock_free_all(). Memblock use free low memory for
774          * temporary data (see find_range_array()) and for this purpose can use
775          * pages that was already passed to the buddy allocator, hence marked as
776          * not accessible in the page tables when compiled with
777          * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
778          * important here.
779          */
780         set_highmem_pages_init();
781
782         /* this will put all low memory onto the freelists */
783         memblock_free_all();
784
785         after_bootmem = 1;
786         x86_init.hyper.init_after_bootmem();
787
788         mem_init_print_info(NULL);
789         printk(KERN_INFO "virtual kernel memory layout:\n"
790                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
791                 "  cpu_entry : 0x%08lx - 0x%08lx   (%4ld kB)\n"
792 #ifdef CONFIG_HIGHMEM
793                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
794 #endif
795                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
796                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
797                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
798                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
799                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
800                 FIXADDR_START, FIXADDR_TOP,
801                 (FIXADDR_TOP - FIXADDR_START) >> 10,
802
803                 CPU_ENTRY_AREA_BASE,
804                 CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_MAP_SIZE,
805                 CPU_ENTRY_AREA_MAP_SIZE >> 10,
806
807 #ifdef CONFIG_HIGHMEM
808                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
809                 (LAST_PKMAP*PAGE_SIZE) >> 10,
810 #endif
811
812                 VMALLOC_START, VMALLOC_END,
813                 (VMALLOC_END - VMALLOC_START) >> 20,
814
815                 (unsigned long)__va(0), (unsigned long)high_memory,
816                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
817
818                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
819                 ((unsigned long)&__init_end -
820                  (unsigned long)&__init_begin) >> 10,
821
822                 (unsigned long)&_etext, (unsigned long)&_edata,
823                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
824
825                 (unsigned long)&_text, (unsigned long)&_etext,
826                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
827
828         /*
829          * Check boundaries twice: Some fundamental inconsistencies can
830          * be detected at build time already.
831          */
832 #define __FIXADDR_TOP (-PAGE_SIZE)
833 #ifdef CONFIG_HIGHMEM
834         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
835         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
836 #endif
837 #define high_memory (-128UL << 20)
838         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
839 #undef high_memory
840 #undef __FIXADDR_TOP
841
842 #ifdef CONFIG_HIGHMEM
843         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
844         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
845 #endif
846         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
847         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
848
849         test_wp_bit();
850 }
851
852 #ifdef CONFIG_MEMORY_HOTPLUG
853 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
854                 bool want_memblock)
855 {
856         unsigned long start_pfn = start >> PAGE_SHIFT;
857         unsigned long nr_pages = size >> PAGE_SHIFT;
858
859         return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
860 }
861
862 #ifdef CONFIG_MEMORY_HOTREMOVE
863 int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
864 {
865         unsigned long start_pfn = start >> PAGE_SHIFT;
866         unsigned long nr_pages = size >> PAGE_SHIFT;
867         struct zone *zone;
868
869         zone = page_zone(pfn_to_page(start_pfn));
870         return __remove_pages(zone, start_pfn, nr_pages, altmap);
871 }
872 #endif
873 #endif
874
875 int kernel_set_to_readonly __read_mostly;
876
877 void set_kernel_text_rw(void)
878 {
879         unsigned long start = PFN_ALIGN(_text);
880         unsigned long size = PFN_ALIGN(_etext) - start;
881
882         if (!kernel_set_to_readonly)
883                 return;
884
885         pr_debug("Set kernel text: %lx - %lx for read write\n",
886                  start, start+size);
887
888         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
889 }
890
891 void set_kernel_text_ro(void)
892 {
893         unsigned long start = PFN_ALIGN(_text);
894         unsigned long size = PFN_ALIGN(_etext) - start;
895
896         if (!kernel_set_to_readonly)
897                 return;
898
899         pr_debug("Set kernel text: %lx - %lx for read only\n",
900                  start, start+size);
901
902         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
903 }
904
905 static void mark_nxdata_nx(void)
906 {
907         /*
908          * When this called, init has already been executed and released,
909          * so everything past _etext should be NX.
910          */
911         unsigned long start = PFN_ALIGN(_etext);
912         /*
913          * This comes from is_kernel_text upper limit. Also HPAGE where used:
914          */
915         unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
916
917         if (__supported_pte_mask & _PAGE_NX)
918                 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
919         set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
920 }
921
922 void mark_rodata_ro(void)
923 {
924         unsigned long start = PFN_ALIGN(_text);
925         unsigned long size = (unsigned long)__end_rodata - start;
926
927         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
928         pr_info("Write protecting kernel text and read-only data: %luk\n",
929                 size >> 10);
930
931         kernel_set_to_readonly = 1;
932
933 #ifdef CONFIG_CPA_DEBUG
934         pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
935         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
936
937         pr_info("Testing CPA: write protecting again\n");
938         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
939 #endif
940         mark_nxdata_nx();
941         if (__supported_pte_mask & _PAGE_NX)
942                 debug_checkwx();
943 }