Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / arch / ia64 / mm / init.c
1 /*
2  * Initialize MMU support.
3  *
4  * Copyright (C) 1998-2003 Hewlett-Packard Co
5  *      David Mosberger-Tang <davidm@hpl.hp.com>
6  */
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9
10 #include <linux/bootmem.h>
11 #include <linux/efi.h>
12 #include <linux/elf.h>
13 #include <linux/mm.h>
14 #include <linux/mmzone.h>
15 #include <linux/module.h>
16 #include <linux/personality.h>
17 #include <linux/reboot.h>
18 #include <linux/slab.h>
19 #include <linux/swap.h>
20 #include <linux/proc_fs.h>
21 #include <linux/bitops.h>
22 #include <linux/kexec.h>
23
24 #include <asm/a.out.h>
25 #include <asm/dma.h>
26 #include <asm/ia32.h>
27 #include <asm/io.h>
28 #include <asm/machvec.h>
29 #include <asm/numa.h>
30 #include <asm/patch.h>
31 #include <asm/pgalloc.h>
32 #include <asm/sal.h>
33 #include <asm/sections.h>
34 #include <asm/system.h>
35 #include <asm/tlb.h>
36 #include <asm/uaccess.h>
37 #include <asm/unistd.h>
38 #include <asm/mca.h>
39
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41
42 DEFINE_PER_CPU(unsigned long *, __pgtable_quicklist);
43 DEFINE_PER_CPU(long, __pgtable_quicklist_size);
44
45 extern void ia64_tlb_init (void);
46
47 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
48
49 #ifdef CONFIG_VIRTUAL_MEM_MAP
50 unsigned long vmalloc_end = VMALLOC_END_INIT;
51 EXPORT_SYMBOL(vmalloc_end);
52 struct page *vmem_map;
53 EXPORT_SYMBOL(vmem_map);
54 #endif
55
56 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
57 EXPORT_SYMBOL(zero_page_memmap_ptr);
58
59 #define MIN_PGT_PAGES                   25UL
60 #define MAX_PGT_FREES_PER_PASS          16L
61 #define PGT_FRACTION_OF_NODE_MEM        16
62
63 static inline long
64 max_pgt_pages(void)
65 {
66         u64 node_free_pages, max_pgt_pages;
67
68 #ifndef CONFIG_NUMA
69         node_free_pages = nr_free_pages();
70 #else
71         node_free_pages = node_page_state(numa_node_id(), NR_FREE_PAGES);
72 #endif
73         max_pgt_pages = node_free_pages / PGT_FRACTION_OF_NODE_MEM;
74         max_pgt_pages = max(max_pgt_pages, MIN_PGT_PAGES);
75         return max_pgt_pages;
76 }
77
78 static inline long
79 min_pages_to_free(void)
80 {
81         long pages_to_free;
82
83         pages_to_free = pgtable_quicklist_size - max_pgt_pages();
84         pages_to_free = min(pages_to_free, MAX_PGT_FREES_PER_PASS);
85         return pages_to_free;
86 }
87
88 void
89 check_pgt_cache(void)
90 {
91         long pages_to_free;
92
93         if (unlikely(pgtable_quicklist_size <= MIN_PGT_PAGES))
94                 return;
95
96         preempt_disable();
97         while (unlikely((pages_to_free = min_pages_to_free()) > 0)) {
98                 while (pages_to_free--) {
99                         free_page((unsigned long)pgtable_quicklist_alloc());
100                 }
101                 preempt_enable();
102                 preempt_disable();
103         }
104         preempt_enable();
105 }
106
107 void
108 lazy_mmu_prot_update (pte_t pte)
109 {
110         unsigned long addr;
111         struct page *page;
112         unsigned long order;
113
114         if (!pte_exec(pte))
115                 return;                         /* not an executable page... */
116
117         page = pte_page(pte);
118         addr = (unsigned long) page_address(page);
119
120         if (test_bit(PG_arch_1, &page->flags))
121                 return;                         /* i-cache is already coherent with d-cache */
122
123         if (PageCompound(page)) {
124                 order = (unsigned long) (page[1].lru.prev);
125                 flush_icache_range(addr, addr + (1UL << order << PAGE_SHIFT));
126         }
127         else
128                 flush_icache_range(addr, addr + PAGE_SIZE);
129         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
130 }
131
132 /*
133  * Since DMA is i-cache coherent, any (complete) pages that were written via
134  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
135  * flush them when they get mapped into an executable vm-area.
136  */
137 void
138 dma_mark_clean(void *addr, size_t size)
139 {
140         unsigned long pg_addr, end;
141
142         pg_addr = PAGE_ALIGN((unsigned long) addr);
143         end = (unsigned long) addr + size;
144         while (pg_addr + PAGE_SIZE <= end) {
145                 struct page *page = virt_to_page(pg_addr);
146                 set_bit(PG_arch_1, &page->flags);
147                 pg_addr += PAGE_SIZE;
148         }
149 }
150
151 inline void
152 ia64_set_rbs_bot (void)
153 {
154         unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
155
156         if (stack_size > MAX_USER_STACK_SIZE)
157                 stack_size = MAX_USER_STACK_SIZE;
158         current->thread.rbs_bot = STACK_TOP - stack_size;
159 }
160
161 /*
162  * This performs some platform-dependent address space initialization.
163  * On IA-64, we want to setup the VM area for the register backing
164  * store (which grows upwards) and install the gateway page which is
165  * used for signal trampolines, etc.
166  */
167 void
168 ia64_init_addr_space (void)
169 {
170         struct vm_area_struct *vma;
171
172         ia64_set_rbs_bot();
173
174         /*
175          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
176          * the problem.  When the process attempts to write to the register backing store
177          * for the first time, it will get a SEGFAULT in this case.
178          */
179         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
180         if (vma) {
181                 vma->vm_mm = current->mm;
182                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
183                 vma->vm_end = vma->vm_start + PAGE_SIZE;
184                 vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
185                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
186                 down_write(&current->mm->mmap_sem);
187                 if (insert_vm_struct(current->mm, vma)) {
188                         up_write(&current->mm->mmap_sem);
189                         kmem_cache_free(vm_area_cachep, vma);
190                         return;
191                 }
192                 up_write(&current->mm->mmap_sem);
193         }
194
195         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
196         if (!(current->personality & MMAP_PAGE_ZERO)) {
197                 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
198                 if (vma) {
199                         vma->vm_mm = current->mm;
200                         vma->vm_end = PAGE_SIZE;
201                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
202                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
203                         down_write(&current->mm->mmap_sem);
204                         if (insert_vm_struct(current->mm, vma)) {
205                                 up_write(&current->mm->mmap_sem);
206                                 kmem_cache_free(vm_area_cachep, vma);
207                                 return;
208                         }
209                         up_write(&current->mm->mmap_sem);
210                 }
211         }
212 }
213
214 void
215 free_initmem (void)
216 {
217         unsigned long addr, eaddr;
218
219         addr = (unsigned long) ia64_imva(__init_begin);
220         eaddr = (unsigned long) ia64_imva(__init_end);
221         while (addr < eaddr) {
222                 ClearPageReserved(virt_to_page(addr));
223                 init_page_count(virt_to_page(addr));
224                 free_page(addr);
225                 ++totalram_pages;
226                 addr += PAGE_SIZE;
227         }
228         printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
229                (__init_end - __init_begin) >> 10);
230 }
231
232 void __init
233 free_initrd_mem (unsigned long start, unsigned long end)
234 {
235         struct page *page;
236         /*
237          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
238          * Thus EFI and the kernel may have different page sizes. It is
239          * therefore possible to have the initrd share the same page as
240          * the end of the kernel (given current setup).
241          *
242          * To avoid freeing/using the wrong page (kernel sized) we:
243          *      - align up the beginning of initrd
244          *      - align down the end of initrd
245          *
246          *  |             |
247          *  |=============| a000
248          *  |             |
249          *  |             |
250          *  |             | 9000
251          *  |/////////////|
252          *  |/////////////|
253          *  |=============| 8000
254          *  |///INITRD////|
255          *  |/////////////|
256          *  |/////////////| 7000
257          *  |             |
258          *  |KKKKKKKKKKKKK|
259          *  |=============| 6000
260          *  |KKKKKKKKKKKKK|
261          *  |KKKKKKKKKKKKK|
262          *  K=kernel using 8KB pages
263          *
264          * In this example, we must free page 8000 ONLY. So we must align up
265          * initrd_start and keep initrd_end as is.
266          */
267         start = PAGE_ALIGN(start);
268         end = end & PAGE_MASK;
269
270         if (start < end)
271                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
272
273         for (; start < end; start += PAGE_SIZE) {
274                 if (!virt_addr_valid(start))
275                         continue;
276                 page = virt_to_page(start);
277                 ClearPageReserved(page);
278                 init_page_count(page);
279                 free_page(start);
280                 ++totalram_pages;
281         }
282 }
283
284 /*
285  * This installs a clean page in the kernel's page table.
286  */
287 static struct page * __init
288 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
289 {
290         pgd_t *pgd;
291         pud_t *pud;
292         pmd_t *pmd;
293         pte_t *pte;
294
295         if (!PageReserved(page))
296                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
297                        page_address(page));
298
299         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
300
301         {
302                 pud = pud_alloc(&init_mm, pgd, address);
303                 if (!pud)
304                         goto out;
305                 pmd = pmd_alloc(&init_mm, pud, address);
306                 if (!pmd)
307                         goto out;
308                 pte = pte_alloc_kernel(pmd, address);
309                 if (!pte)
310                         goto out;
311                 if (!pte_none(*pte))
312                         goto out;
313                 set_pte(pte, mk_pte(page, pgprot));
314         }
315   out:
316         /* no need for flush_tlb */
317         return page;
318 }
319
320 static void __init
321 setup_gate (void)
322 {
323         struct page *page;
324
325         /*
326          * Map the gate page twice: once read-only to export the ELF
327          * headers etc. and once execute-only page to enable
328          * privilege-promotion via "epc":
329          */
330         page = virt_to_page(ia64_imva(__start_gate_section));
331         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
332 #ifdef HAVE_BUGGY_SEGREL
333         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
334         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
335 #else
336         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
337         /* Fill in the holes (if any) with read-only zero pages: */
338         {
339                 unsigned long addr;
340
341                 for (addr = GATE_ADDR + PAGE_SIZE;
342                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
343                      addr += PAGE_SIZE)
344                 {
345                         put_kernel_page(ZERO_PAGE(0), addr,
346                                         PAGE_READONLY);
347                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
348                                         PAGE_READONLY);
349                 }
350         }
351 #endif
352         ia64_patch_gate();
353 }
354
355 void __devinit
356 ia64_mmu_init (void *my_cpu_data)
357 {
358         unsigned long psr, pta, impl_va_bits;
359         extern void __devinit tlb_init (void);
360
361 #ifdef CONFIG_DISABLE_VHPT
362 #       define VHPT_ENABLE_BIT  0
363 #else
364 #       define VHPT_ENABLE_BIT  1
365 #endif
366
367         /* Pin mapping for percpu area into TLB */
368         psr = ia64_clear_ic();
369         ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR,
370                  pte_val(pfn_pte(__pa(my_cpu_data) >> PAGE_SHIFT, PAGE_KERNEL)),
371                  PERCPU_PAGE_SHIFT);
372
373         ia64_set_psr(psr);
374         ia64_srlz_i();
375
376         /*
377          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
378          * address space.  The IA-64 architecture guarantees that at least 50 bits of
379          * virtual address space are implemented but if we pick a large enough page size
380          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
381          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
382          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
383          * problem in practice.  Alternatively, we could truncate the top of the mapped
384          * address space to not permit mappings that would overlap with the VMLPT.
385          * --davidm 00/12/06
386          */
387 #       define pte_bits                 3
388 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
389         /*
390          * The virtual page table has to cover the entire implemented address space within
391          * a region even though not all of this space may be mappable.  The reason for
392          * this is that the Access bit and Dirty bit fault handlers perform
393          * non-speculative accesses to the virtual page table, so the address range of the
394          * virtual page table itself needs to be covered by virtual page table.
395          */
396 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
397 #       define POW2(n)                  (1ULL << (n))
398
399         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
400
401         if (impl_va_bits < 51 || impl_va_bits > 61)
402                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
403         /*
404          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
405          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
406          * the test makes sure that our mapped space doesn't overlap the
407          * unimplemented hole in the middle of the region.
408          */
409         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
410             (mapped_space_bits > impl_va_bits - 1))
411                 panic("Cannot build a big enough virtual-linear page table"
412                       " to cover mapped address space.\n"
413                       " Try using a smaller page size.\n");
414
415
416         /* place the VMLPT at the end of each page-table mapped region: */
417         pta = POW2(61) - POW2(vmlpt_bits);
418
419         /*
420          * Set the (virtually mapped linear) page table address.  Bit
421          * 8 selects between the short and long format, bits 2-7 the
422          * size of the table, and bit 0 whether the VHPT walker is
423          * enabled.
424          */
425         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
426
427         ia64_tlb_init();
428
429 #ifdef  CONFIG_HUGETLB_PAGE
430         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
431         ia64_srlz_d();
432 #endif
433 }
434
435 #ifdef CONFIG_VIRTUAL_MEM_MAP
436 int vmemmap_find_next_valid_pfn(int node, int i)
437 {
438         unsigned long end_address, hole_next_pfn;
439         unsigned long stop_address;
440         pg_data_t *pgdat = NODE_DATA(node);
441
442         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
443         end_address = PAGE_ALIGN(end_address);
444
445         stop_address = (unsigned long) &vmem_map[
446                 pgdat->node_start_pfn + pgdat->node_spanned_pages];
447
448         do {
449                 pgd_t *pgd;
450                 pud_t *pud;
451                 pmd_t *pmd;
452                 pte_t *pte;
453
454                 pgd = pgd_offset_k(end_address);
455                 if (pgd_none(*pgd)) {
456                         end_address += PGDIR_SIZE;
457                         continue;
458                 }
459
460                 pud = pud_offset(pgd, end_address);
461                 if (pud_none(*pud)) {
462                         end_address += PUD_SIZE;
463                         continue;
464                 }
465
466                 pmd = pmd_offset(pud, end_address);
467                 if (pmd_none(*pmd)) {
468                         end_address += PMD_SIZE;
469                         continue;
470                 }
471
472                 pte = pte_offset_kernel(pmd, end_address);
473 retry_pte:
474                 if (pte_none(*pte)) {
475                         end_address += PAGE_SIZE;
476                         pte++;
477                         if ((end_address < stop_address) &&
478                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
479                                 goto retry_pte;
480                         continue;
481                 }
482                 /* Found next valid vmem_map page */
483                 break;
484         } while (end_address < stop_address);
485
486         end_address = min(end_address, stop_address);
487         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
488         hole_next_pfn = end_address / sizeof(struct page);
489         return hole_next_pfn - pgdat->node_start_pfn;
490 }
491
492 int __init
493 create_mem_map_page_table (u64 start, u64 end, void *arg)
494 {
495         unsigned long address, start_page, end_page;
496         struct page *map_start, *map_end;
497         int node;
498         pgd_t *pgd;
499         pud_t *pud;
500         pmd_t *pmd;
501         pte_t *pte;
502
503         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
504         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
505
506         start_page = (unsigned long) map_start & PAGE_MASK;
507         end_page = PAGE_ALIGN((unsigned long) map_end);
508         node = paddr_to_nid(__pa(start));
509
510         for (address = start_page; address < end_page; address += PAGE_SIZE) {
511                 pgd = pgd_offset_k(address);
512                 if (pgd_none(*pgd))
513                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
514                 pud = pud_offset(pgd, address);
515
516                 if (pud_none(*pud))
517                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
518                 pmd = pmd_offset(pud, address);
519
520                 if (pmd_none(*pmd))
521                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
522                 pte = pte_offset_kernel(pmd, address);
523
524                 if (pte_none(*pte))
525                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
526                                              PAGE_KERNEL));
527         }
528         return 0;
529 }
530
531 struct memmap_init_callback_data {
532         struct page *start;
533         struct page *end;
534         int nid;
535         unsigned long zone;
536 };
537
538 static int
539 virtual_memmap_init (u64 start, u64 end, void *arg)
540 {
541         struct memmap_init_callback_data *args;
542         struct page *map_start, *map_end;
543
544         args = (struct memmap_init_callback_data *) arg;
545         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
546         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
547
548         if (map_start < args->start)
549                 map_start = args->start;
550         if (map_end > args->end)
551                 map_end = args->end;
552
553         /*
554          * We have to initialize "out of bounds" struct page elements that fit completely
555          * on the same pages that were allocated for the "in bounds" elements because they
556          * may be referenced later (and found to be "reserved").
557          */
558         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
559         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
560                     / sizeof(struct page));
561
562         if (map_start < map_end)
563                 memmap_init_zone((unsigned long)(map_end - map_start),
564                                  args->nid, args->zone, page_to_pfn(map_start),
565                                  MEMMAP_EARLY);
566         return 0;
567 }
568
569 void
570 memmap_init (unsigned long size, int nid, unsigned long zone,
571              unsigned long start_pfn)
572 {
573         if (!vmem_map)
574                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
575         else {
576                 struct page *start;
577                 struct memmap_init_callback_data args;
578
579                 start = pfn_to_page(start_pfn);
580                 args.start = start;
581                 args.end = start + size;
582                 args.nid = nid;
583                 args.zone = zone;
584
585                 efi_memmap_walk(virtual_memmap_init, &args);
586         }
587 }
588
589 int
590 ia64_pfn_valid (unsigned long pfn)
591 {
592         char byte;
593         struct page *pg = pfn_to_page(pfn);
594
595         return     (__get_user(byte, (char __user *) pg) == 0)
596                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
597                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
598 }
599 EXPORT_SYMBOL(ia64_pfn_valid);
600
601 int __init
602 find_largest_hole (u64 start, u64 end, void *arg)
603 {
604         u64 *max_gap = arg;
605
606         static u64 last_end = PAGE_OFFSET;
607
608         /* NOTE: this algorithm assumes efi memmap table is ordered */
609
610         if (*max_gap < (start - last_end))
611                 *max_gap = start - last_end;
612         last_end = end;
613         return 0;
614 }
615
616 #endif /* CONFIG_VIRTUAL_MEM_MAP */
617
618 int __init
619 register_active_ranges(u64 start, u64 end, void *arg)
620 {
621         int nid = paddr_to_nid(__pa(start));
622
623         if (nid < 0)
624                 nid = 0;
625 #ifdef CONFIG_KEXEC
626         if (start > crashk_res.start && start < crashk_res.end)
627                 start = crashk_res.end;
628         if (end > crashk_res.start && end < crashk_res.end)
629                 end = crashk_res.start;
630 #endif
631
632         if (start < end)
633                 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
634                         __pa(end) >> PAGE_SHIFT);
635         return 0;
636 }
637
638 static int __init
639 count_reserved_pages (u64 start, u64 end, void *arg)
640 {
641         unsigned long num_reserved = 0;
642         unsigned long *count = arg;
643
644         for (; start < end; start += PAGE_SIZE)
645                 if (PageReserved(virt_to_page(start)))
646                         ++num_reserved;
647         *count += num_reserved;
648         return 0;
649 }
650
651 /*
652  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
653  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
654  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
655  * useful for performance testing, but conceivably could also come in handy for debugging
656  * purposes.
657  */
658
659 static int nolwsys __initdata;
660
661 static int __init
662 nolwsys_setup (char *s)
663 {
664         nolwsys = 1;
665         return 1;
666 }
667
668 __setup("nolwsys", nolwsys_setup);
669
670 void __init
671 mem_init (void)
672 {
673         long reserved_pages, codesize, datasize, initsize;
674         pg_data_t *pgdat;
675         int i;
676         static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
677
678         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
679         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
680         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
681
682 #ifdef CONFIG_PCI
683         /*
684          * This needs to be called _after_ the command line has been parsed but _before_
685          * any drivers that may need the PCI DMA interface are initialized or bootmem has
686          * been freed.
687          */
688         platform_dma_init();
689 #endif
690
691 #ifdef CONFIG_FLATMEM
692         if (!mem_map)
693                 BUG();
694         max_mapnr = max_low_pfn;
695 #endif
696
697         high_memory = __va(max_low_pfn * PAGE_SIZE);
698
699         kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
700         kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
701         kclist_add(&kcore_kernel, _stext, _end - _stext);
702
703         for_each_online_pgdat(pgdat)
704                 if (pgdat->bdata->node_bootmem_map)
705                         totalram_pages += free_all_bootmem_node(pgdat);
706
707         reserved_pages = 0;
708         efi_memmap_walk(count_reserved_pages, &reserved_pages);
709
710         codesize =  (unsigned long) _etext - (unsigned long) _stext;
711         datasize =  (unsigned long) _edata - (unsigned long) _etext;
712         initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
713
714         printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
715                "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
716                num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
717                reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
718
719
720         /*
721          * For fsyscall entrpoints with no light-weight handler, use the ordinary
722          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
723          * code can tell them apart.
724          */
725         for (i = 0; i < NR_syscalls; ++i) {
726                 extern unsigned long fsyscall_table[NR_syscalls];
727                 extern unsigned long sys_call_table[NR_syscalls];
728
729                 if (!fsyscall_table[i] || nolwsys)
730                         fsyscall_table[i] = sys_call_table[i] | 1;
731         }
732         setup_gate();
733
734 #ifdef CONFIG_IA32_SUPPORT
735         ia32_mem_init();
736 #endif
737 }
738
739 #ifdef CONFIG_MEMORY_HOTPLUG
740 void online_page(struct page *page)
741 {
742         ClearPageReserved(page);
743         init_page_count(page);
744         __free_page(page);
745         totalram_pages++;
746         num_physpages++;
747 }
748
749 int arch_add_memory(int nid, u64 start, u64 size)
750 {
751         pg_data_t *pgdat;
752         struct zone *zone;
753         unsigned long start_pfn = start >> PAGE_SHIFT;
754         unsigned long nr_pages = size >> PAGE_SHIFT;
755         int ret;
756
757         pgdat = NODE_DATA(nid);
758
759         zone = pgdat->node_zones + ZONE_NORMAL;
760         ret = __add_pages(zone, start_pfn, nr_pages);
761
762         if (ret)
763                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
764                        __FUNCTION__,  ret);
765
766         return ret;
767 }
768
769 int remove_memory(u64 start, u64 size)
770 {
771         return -EINVAL;
772 }
773 EXPORT_SYMBOL_GPL(remove_memory);
774 #endif