Linux Audio

Check our new training course

Loading...
  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/memblock.h>
 14#include <linux/mm.h>
 15#include <linux/mmzone.h>
 16#include <linux/module.h>
 17#include <linux/personality.h>
 18#include <linux/reboot.h>
 19#include <linux/slab.h>
 20#include <linux/swap.h>
 21#include <linux/proc_fs.h>
 22#include <linux/bitops.h>
 23#include <linux/kexec.h>
 24
 25#include <asm/dma.h>
 26#include <asm/io.h>
 27#include <asm/machvec.h>
 28#include <asm/numa.h>
 29#include <asm/patch.h>
 30#include <asm/pgalloc.h>
 31#include <asm/sal.h>
 32#include <asm/sections.h>
 33#include <asm/tlb.h>
 34#include <asm/uaccess.h>
 35#include <asm/unistd.h>
 36#include <asm/mca.h>
 37#include <asm/paravirt.h>
 38
 39extern void ia64_tlb_init (void);
 40
 41unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
 42
 43#ifdef CONFIG_VIRTUAL_MEM_MAP
 44unsigned long VMALLOC_END = VMALLOC_END_INIT;
 45EXPORT_SYMBOL(VMALLOC_END);
 46struct page *vmem_map;
 47EXPORT_SYMBOL(vmem_map);
 48#endif
 49
 50struct page *zero_page_memmap_ptr;	/* map entry for zero page */
 51EXPORT_SYMBOL(zero_page_memmap_ptr);
 52
 53void
 54__ia64_sync_icache_dcache (pte_t pte)
 55{
 56	unsigned long addr;
 57	struct page *page;
 58
 59	page = pte_page(pte);
 60	addr = (unsigned long) page_address(page);
 61
 62	if (test_bit(PG_arch_1, &page->flags))
 63		return;				/* i-cache is already coherent with d-cache */
 64
 65	flush_icache_range(addr, addr + (PAGE_SIZE << compound_order(page)));
 66	set_bit(PG_arch_1, &page->flags);	/* mark page as clean */
 67}
 68
 69/*
 70 * Since DMA is i-cache coherent, any (complete) pages that were written via
 71 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
 72 * flush them when they get mapped into an executable vm-area.
 73 */
 74void
 75dma_mark_clean(void *addr, size_t size)
 76{
 77	unsigned long pg_addr, end;
 78
 79	pg_addr = PAGE_ALIGN((unsigned long) addr);
 80	end = (unsigned long) addr + size;
 81	while (pg_addr + PAGE_SIZE <= end) {
 82		struct page *page = virt_to_page(pg_addr);
 83		set_bit(PG_arch_1, &page->flags);
 84		pg_addr += PAGE_SIZE;
 85	}
 86}
 87
 88inline void
 89ia64_set_rbs_bot (void)
 90{
 91	unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
 92
 93	if (stack_size > MAX_USER_STACK_SIZE)
 94		stack_size = MAX_USER_STACK_SIZE;
 95	current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
 96}
 97
 98/*
 99 * This performs some platform-dependent address space initialization.
100 * On IA-64, we want to setup the VM area for the register backing
101 * store (which grows upwards) and install the gateway page which is
102 * used for signal trampolines, etc.
103 */
104void
105ia64_init_addr_space (void)
106{
107	struct vm_area_struct *vma;
108
109	ia64_set_rbs_bot();
110
111	/*
112	 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
113	 * the problem.  When the process attempts to write to the register backing store
114	 * for the first time, it will get a SEGFAULT in this case.
115	 */
116	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
117	if (vma) {
118		INIT_LIST_HEAD(&vma->anon_vma_chain);
119		vma->vm_mm = current->mm;
120		vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
121		vma->vm_end = vma->vm_start + PAGE_SIZE;
122		vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
123		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
124		down_write(&current->mm->mmap_sem);
125		if (insert_vm_struct(current->mm, vma)) {
126			up_write(&current->mm->mmap_sem);
127			kmem_cache_free(vm_area_cachep, vma);
128			return;
129		}
130		up_write(&current->mm->mmap_sem);
131	}
132
133	/* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
134	if (!(current->personality & MMAP_PAGE_ZERO)) {
135		vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
136		if (vma) {
137			INIT_LIST_HEAD(&vma->anon_vma_chain);
138			vma->vm_mm = current->mm;
139			vma->vm_end = PAGE_SIZE;
140			vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
141			vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
142			down_write(&current->mm->mmap_sem);
143			if (insert_vm_struct(current->mm, vma)) {
144				up_write(&current->mm->mmap_sem);
145				kmem_cache_free(vm_area_cachep, vma);
146				return;
147			}
148			up_write(&current->mm->mmap_sem);
149		}
150	}
151}
152
153void
154free_initmem (void)
155{
156	unsigned long addr, eaddr;
157
158	addr = (unsigned long) ia64_imva(__init_begin);
159	eaddr = (unsigned long) ia64_imva(__init_end);
160	while (addr < eaddr) {
161		ClearPageReserved(virt_to_page(addr));
162		init_page_count(virt_to_page(addr));
163		free_page(addr);
164		++totalram_pages;
165		addr += PAGE_SIZE;
166	}
167	printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
168	       (__init_end - __init_begin) >> 10);
169}
170
171void __init
172free_initrd_mem (unsigned long start, unsigned long end)
173{
174	struct page *page;
175	/*
176	 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
177	 * Thus EFI and the kernel may have different page sizes. It is
178	 * therefore possible to have the initrd share the same page as
179	 * the end of the kernel (given current setup).
180	 *
181	 * To avoid freeing/using the wrong page (kernel sized) we:
182	 *	- align up the beginning of initrd
183	 *	- align down the end of initrd
184	 *
185	 *  |             |
186	 *  |=============| a000
187	 *  |             |
188	 *  |             |
189	 *  |             | 9000
190	 *  |/////////////|
191	 *  |/////////////|
192	 *  |=============| 8000
193	 *  |///INITRD////|
194	 *  |/////////////|
195	 *  |/////////////| 7000
196	 *  |             |
197	 *  |KKKKKKKKKKKKK|
198	 *  |=============| 6000
199	 *  |KKKKKKKKKKKKK|
200	 *  |KKKKKKKKKKKKK|
201	 *  K=kernel using 8KB pages
202	 *
203	 * In this example, we must free page 8000 ONLY. So we must align up
204	 * initrd_start and keep initrd_end as is.
205	 */
206	start = PAGE_ALIGN(start);
207	end = end & PAGE_MASK;
208
209	if (start < end)
210		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
211
212	for (; start < end; start += PAGE_SIZE) {
213		if (!virt_addr_valid(start))
214			continue;
215		page = virt_to_page(start);
216		ClearPageReserved(page);
217		init_page_count(page);
218		free_page(start);
219		++totalram_pages;
220	}
221}
222
223/*
224 * This installs a clean page in the kernel's page table.
225 */
226static struct page * __init
227put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
228{
229	pgd_t *pgd;
230	pud_t *pud;
231	pmd_t *pmd;
232	pte_t *pte;
233
234	if (!PageReserved(page))
235		printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
236		       page_address(page));
237
238	pgd = pgd_offset_k(address);		/* note: this is NOT pgd_offset()! */
239
240	{
241		pud = pud_alloc(&init_mm, pgd, address);
242		if (!pud)
243			goto out;
244		pmd = pmd_alloc(&init_mm, pud, address);
245		if (!pmd)
246			goto out;
247		pte = pte_alloc_kernel(pmd, address);
248		if (!pte)
249			goto out;
250		if (!pte_none(*pte))
251			goto out;
252		set_pte(pte, mk_pte(page, pgprot));
253	}
254  out:
255	/* no need for flush_tlb */
256	return page;
257}
258
259static void __init
260setup_gate (void)
261{
262	void *gate_section;
263	struct page *page;
264
265	/*
266	 * Map the gate page twice: once read-only to export the ELF
267	 * headers etc. and once execute-only page to enable
268	 * privilege-promotion via "epc":
269	 */
270	gate_section = paravirt_get_gate_section();
271	page = virt_to_page(ia64_imva(gate_section));
272	put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
273#ifdef HAVE_BUGGY_SEGREL
274	page = virt_to_page(ia64_imva(gate_section + PAGE_SIZE));
275	put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
276#else
277	put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
278	/* Fill in the holes (if any) with read-only zero pages: */
279	{
280		unsigned long addr;
281
282		for (addr = GATE_ADDR + PAGE_SIZE;
283		     addr < GATE_ADDR + PERCPU_PAGE_SIZE;
284		     addr += PAGE_SIZE)
285		{
286			put_kernel_page(ZERO_PAGE(0), addr,
287					PAGE_READONLY);
288			put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
289					PAGE_READONLY);
290		}
291	}
292#endif
293	ia64_patch_gate();
294}
295
296void __devinit
297ia64_mmu_init (void *my_cpu_data)
298{
299	unsigned long pta, impl_va_bits;
300	extern void __devinit tlb_init (void);
301
302#ifdef CONFIG_DISABLE_VHPT
303#	define VHPT_ENABLE_BIT	0
304#else
305#	define VHPT_ENABLE_BIT	1
306#endif
307
308	/*
309	 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
310	 * address space.  The IA-64 architecture guarantees that at least 50 bits of
311	 * virtual address space are implemented but if we pick a large enough page size
312	 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
313	 * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
314	 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
315	 * problem in practice.  Alternatively, we could truncate the top of the mapped
316	 * address space to not permit mappings that would overlap with the VMLPT.
317	 * --davidm 00/12/06
318	 */
319#	define pte_bits			3
320#	define mapped_space_bits	(3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
321	/*
322	 * The virtual page table has to cover the entire implemented address space within
323	 * a region even though not all of this space may be mappable.  The reason for
324	 * this is that the Access bit and Dirty bit fault handlers perform
325	 * non-speculative accesses to the virtual page table, so the address range of the
326	 * virtual page table itself needs to be covered by virtual page table.
327	 */
328#	define vmlpt_bits		(impl_va_bits - PAGE_SHIFT + pte_bits)
329#	define POW2(n)			(1ULL << (n))
330
331	impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
332
333	if (impl_va_bits < 51 || impl_va_bits > 61)
334		panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
335	/*
336	 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
337	 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
338	 * the test makes sure that our mapped space doesn't overlap the
339	 * unimplemented hole in the middle of the region.
340	 */
341	if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
342	    (mapped_space_bits > impl_va_bits - 1))
343		panic("Cannot build a big enough virtual-linear page table"
344		      " to cover mapped address space.\n"
345		      " Try using a smaller page size.\n");
346
347
348	/* place the VMLPT at the end of each page-table mapped region: */
349	pta = POW2(61) - POW2(vmlpt_bits);
350
351	/*
352	 * Set the (virtually mapped linear) page table address.  Bit
353	 * 8 selects between the short and long format, bits 2-7 the
354	 * size of the table, and bit 0 whether the VHPT walker is
355	 * enabled.
356	 */
357	ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
358
359	ia64_tlb_init();
360
361#ifdef	CONFIG_HUGETLB_PAGE
362	ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
363	ia64_srlz_d();
364#endif
365}
366
367#ifdef CONFIG_VIRTUAL_MEM_MAP
368int vmemmap_find_next_valid_pfn(int node, int i)
369{
370	unsigned long end_address, hole_next_pfn;
371	unsigned long stop_address;
372	pg_data_t *pgdat = NODE_DATA(node);
373
374	end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
375	end_address = PAGE_ALIGN(end_address);
376
377	stop_address = (unsigned long) &vmem_map[
378		pgdat->node_start_pfn + pgdat->node_spanned_pages];
379
380	do {
381		pgd_t *pgd;
382		pud_t *pud;
383		pmd_t *pmd;
384		pte_t *pte;
385
386		pgd = pgd_offset_k(end_address);
387		if (pgd_none(*pgd)) {
388			end_address += PGDIR_SIZE;
389			continue;
390		}
391
392		pud = pud_offset(pgd, end_address);
393		if (pud_none(*pud)) {
394			end_address += PUD_SIZE;
395			continue;
396		}
397
398		pmd = pmd_offset(pud, end_address);
399		if (pmd_none(*pmd)) {
400			end_address += PMD_SIZE;
401			continue;
402		}
403
404		pte = pte_offset_kernel(pmd, end_address);
405retry_pte:
406		if (pte_none(*pte)) {
407			end_address += PAGE_SIZE;
408			pte++;
409			if ((end_address < stop_address) &&
410			    (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
411				goto retry_pte;
412			continue;
413		}
414		/* Found next valid vmem_map page */
415		break;
416	} while (end_address < stop_address);
417
418	end_address = min(end_address, stop_address);
419	end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
420	hole_next_pfn = end_address / sizeof(struct page);
421	return hole_next_pfn - pgdat->node_start_pfn;
422}
423
424int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
425{
426	unsigned long address, start_page, end_page;
427	struct page *map_start, *map_end;
428	int node;
429	pgd_t *pgd;
430	pud_t *pud;
431	pmd_t *pmd;
432	pte_t *pte;
433
434	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
435	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
436
437	start_page = (unsigned long) map_start & PAGE_MASK;
438	end_page = PAGE_ALIGN((unsigned long) map_end);
439	node = paddr_to_nid(__pa(start));
440
441	for (address = start_page; address < end_page; address += PAGE_SIZE) {
442		pgd = pgd_offset_k(address);
443		if (pgd_none(*pgd))
444			pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
445		pud = pud_offset(pgd, address);
446
447		if (pud_none(*pud))
448			pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
449		pmd = pmd_offset(pud, address);
450
451		if (pmd_none(*pmd))
452			pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
453		pte = pte_offset_kernel(pmd, address);
454
455		if (pte_none(*pte))
456			set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
457					     PAGE_KERNEL));
458	}
459	return 0;
460}
461
462struct memmap_init_callback_data {
463	struct page *start;
464	struct page *end;
465	int nid;
466	unsigned long zone;
467};
468
469static int __meminit
470virtual_memmap_init(u64 start, u64 end, void *arg)
471{
472	struct memmap_init_callback_data *args;
473	struct page *map_start, *map_end;
474
475	args = (struct memmap_init_callback_data *) arg;
476	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
477	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
478
479	if (map_start < args->start)
480		map_start = args->start;
481	if (map_end > args->end)
482		map_end = args->end;
483
484	/*
485	 * We have to initialize "out of bounds" struct page elements that fit completely
486	 * on the same pages that were allocated for the "in bounds" elements because they
487	 * may be referenced later (and found to be "reserved").
488	 */
489	map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
490	map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
491		    / sizeof(struct page));
492
493	if (map_start < map_end)
494		memmap_init_zone((unsigned long)(map_end - map_start),
495				 args->nid, args->zone, page_to_pfn(map_start),
496				 MEMMAP_EARLY);
497	return 0;
498}
499
500void __meminit
501memmap_init (unsigned long size, int nid, unsigned long zone,
502	     unsigned long start_pfn)
503{
504	if (!vmem_map)
505		memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
506	else {
507		struct page *start;
508		struct memmap_init_callback_data args;
509
510		start = pfn_to_page(start_pfn);
511		args.start = start;
512		args.end = start + size;
513		args.nid = nid;
514		args.zone = zone;
515
516		efi_memmap_walk(virtual_memmap_init, &args);
517	}
518}
519
520int
521ia64_pfn_valid (unsigned long pfn)
522{
523	char byte;
524	struct page *pg = pfn_to_page(pfn);
525
526	return     (__get_user(byte, (char __user *) pg) == 0)
527		&& ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
528			|| (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
529}
530EXPORT_SYMBOL(ia64_pfn_valid);
531
532int __init find_largest_hole(u64 start, u64 end, void *arg)
533{
534	u64 *max_gap = arg;
535
536	static u64 last_end = PAGE_OFFSET;
537
538	/* NOTE: this algorithm assumes efi memmap table is ordered */
539
540	if (*max_gap < (start - last_end))
541		*max_gap = start - last_end;
542	last_end = end;
543	return 0;
544}
545
546#endif /* CONFIG_VIRTUAL_MEM_MAP */
547
548int __init register_active_ranges(u64 start, u64 len, int nid)
549{
550	u64 end = start + len;
551
552#ifdef CONFIG_KEXEC
553	if (start > crashk_res.start && start < crashk_res.end)
554		start = crashk_res.end;
555	if (end > crashk_res.start && end < crashk_res.end)
556		end = crashk_res.start;
557#endif
558
559	if (start < end)
560		memblock_add_node(__pa(start), end - start, nid);
561	return 0;
562}
563
564static int __init
565count_reserved_pages(u64 start, u64 end, void *arg)
566{
567	unsigned long num_reserved = 0;
568	unsigned long *count = arg;
569
570	for (; start < end; start += PAGE_SIZE)
571		if (PageReserved(virt_to_page(start)))
572			++num_reserved;
573	*count += num_reserved;
574	return 0;
575}
576
577int
578find_max_min_low_pfn (u64 start, u64 end, void *arg)
579{
580	unsigned long pfn_start, pfn_end;
581#ifdef CONFIG_FLATMEM
582	pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
583	pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
584#else
585	pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
586	pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
587#endif
588	min_low_pfn = min(min_low_pfn, pfn_start);
589	max_low_pfn = max(max_low_pfn, pfn_end);
590	return 0;
591}
592
593/*
594 * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
595 * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
596 * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
597 * useful for performance testing, but conceivably could also come in handy for debugging
598 * purposes.
599 */
600
601static int nolwsys __initdata;
602
603static int __init
604nolwsys_setup (char *s)
605{
606	nolwsys = 1;
607	return 1;
608}
609
610__setup("nolwsys", nolwsys_setup);
611
612void __init
613mem_init (void)
614{
615	long reserved_pages, codesize, datasize, initsize;
616	pg_data_t *pgdat;
617	int i;
618
619	BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
620	BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
621	BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
622
623#ifdef CONFIG_PCI
624	/*
625	 * This needs to be called _after_ the command line has been parsed but _before_
626	 * any drivers that may need the PCI DMA interface are initialized or bootmem has
627	 * been freed.
628	 */
629	platform_dma_init();
630#endif
631
632#ifdef CONFIG_FLATMEM
633	BUG_ON(!mem_map);
634	max_mapnr = max_low_pfn;
635#endif
636
637	high_memory = __va(max_low_pfn * PAGE_SIZE);
638
639	for_each_online_pgdat(pgdat)
640		if (pgdat->bdata->node_bootmem_map)
641			totalram_pages += free_all_bootmem_node(pgdat);
642
643	reserved_pages = 0;
644	efi_memmap_walk(count_reserved_pages, &reserved_pages);
645
646	codesize =  (unsigned long) _etext - (unsigned long) _stext;
647	datasize =  (unsigned long) _edata - (unsigned long) _etext;
648	initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
649
650	printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
651	       "%luk data, %luk init)\n", nr_free_pages() << (PAGE_SHIFT - 10),
652	       num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
653	       reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
654
655
656	/*
657	 * For fsyscall entrpoints with no light-weight handler, use the ordinary
658	 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
659	 * code can tell them apart.
660	 */
661	for (i = 0; i < NR_syscalls; ++i) {
662		extern unsigned long sys_call_table[NR_syscalls];
663		unsigned long *fsyscall_table = paravirt_get_fsyscall_table();
664
665		if (!fsyscall_table[i] || nolwsys)
666			fsyscall_table[i] = sys_call_table[i] | 1;
667	}
668	setup_gate();
669}
670
671#ifdef CONFIG_MEMORY_HOTPLUG
672int arch_add_memory(int nid, u64 start, u64 size)
673{
674	pg_data_t *pgdat;
675	struct zone *zone;
676	unsigned long start_pfn = start >> PAGE_SHIFT;
677	unsigned long nr_pages = size >> PAGE_SHIFT;
678	int ret;
679
680	pgdat = NODE_DATA(nid);
681
682	zone = pgdat->node_zones + ZONE_NORMAL;
683	ret = __add_pages(nid, zone, start_pfn, nr_pages);
684
685	if (ret)
686		printk("%s: Problem encountered in __add_pages() as ret=%d\n",
687		       __func__,  ret);
688
689	return ret;
690}
691#endif
692
693/*
694 * Even when CONFIG_IA32_SUPPORT is not enabled it is
695 * useful to have the Linux/x86 domain registered to
696 * avoid an attempted module load when emulators call
697 * personality(PER_LINUX32). This saves several milliseconds
698 * on each such call.
699 */
700static struct exec_domain ia32_exec_domain;
701
702static int __init
703per_linux32_init(void)
704{
705	ia32_exec_domain.name = "Linux/x86";
706	ia32_exec_domain.handler = NULL;
707	ia32_exec_domain.pers_low = PER_LINUX32;
708	ia32_exec_domain.pers_high = PER_LINUX32;
709	ia32_exec_domain.signal_map = default_exec_domain.signal_map;
710	ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
711	register_exec_domain(&ia32_exec_domain);
712
713	return 0;
714}
715
716__initcall(per_linux32_init);