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
38extern void ia64_tlb_init (void);
39
40unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
41
42#ifdef CONFIG_VIRTUAL_MEM_MAP
43unsigned long VMALLOC_END = VMALLOC_END_INIT;
44EXPORT_SYMBOL(VMALLOC_END);
45struct page *vmem_map;
46EXPORT_SYMBOL(vmem_map);
47#endif
48
49struct page *zero_page_memmap_ptr;	/* map entry for zero page */
50EXPORT_SYMBOL(zero_page_memmap_ptr);
51
52void
53__ia64_sync_icache_dcache (pte_t pte)
54{
55	unsigned long addr;
56	struct page *page;
57
58	page = pte_page(pte);
59	addr = (unsigned long) page_address(page);
60
61	if (test_bit(PG_arch_1, &page->flags))
62		return;				/* i-cache is already coherent with d-cache */
63
64	flush_icache_range(addr, addr + (PAGE_SIZE << compound_order(page)));
65	set_bit(PG_arch_1, &page->flags);	/* mark page as clean */
66}
67
68/*
69 * Since DMA is i-cache coherent, any (complete) pages that were written via
70 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
71 * flush them when they get mapped into an executable vm-area.
72 */
73void
74dma_mark_clean(void *addr, size_t size)
75{
76	unsigned long pg_addr, end;
77
78	pg_addr = PAGE_ALIGN((unsigned long) addr);
79	end = (unsigned long) addr + size;
80	while (pg_addr + PAGE_SIZE <= end) {
81		struct page *page = virt_to_page(pg_addr);
82		set_bit(PG_arch_1, &page->flags);
83		pg_addr += PAGE_SIZE;
84	}
85}
86
87inline void
88ia64_set_rbs_bot (void)
89{
90	unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
91
92	if (stack_size > MAX_USER_STACK_SIZE)
93		stack_size = MAX_USER_STACK_SIZE;
94	current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
95}
96
97/*
98 * This performs some platform-dependent address space initialization.
99 * On IA-64, we want to setup the VM area for the register backing
100 * store (which grows upwards) and install the gateway page which is
101 * used for signal trampolines, etc.
102 */
103void
104ia64_init_addr_space (void)
105{
106	struct vm_area_struct *vma;
107
108	ia64_set_rbs_bot();
109
110	/*
111	 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
112	 * the problem.  When the process attempts to write to the register backing store
113	 * for the first time, it will get a SEGFAULT in this case.
114	 */
115	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
116	if (vma) {
117		INIT_LIST_HEAD(&vma->anon_vma_chain);
118		vma->vm_mm = current->mm;
119		vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
120		vma->vm_end = vma->vm_start + PAGE_SIZE;
121		vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
122		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
123		down_write(&current->mm->mmap_sem);
124		if (insert_vm_struct(current->mm, vma)) {
125			up_write(&current->mm->mmap_sem);
126			kmem_cache_free(vm_area_cachep, vma);
127			return;
128		}
129		up_write(&current->mm->mmap_sem);
130	}
131
132	/* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
133	if (!(current->personality & MMAP_PAGE_ZERO)) {
134		vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
135		if (vma) {
136			INIT_LIST_HEAD(&vma->anon_vma_chain);
137			vma->vm_mm = current->mm;
138			vma->vm_end = PAGE_SIZE;
139			vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
140			vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
141					VM_DONTEXPAND | VM_DONTDUMP;
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	free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
157			   -1, "unused kernel");
158}
159
160void __init
161free_initrd_mem (unsigned long start, unsigned long end)
162{
163	/*
164	 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
165	 * Thus EFI and the kernel may have different page sizes. It is
166	 * therefore possible to have the initrd share the same page as
167	 * the end of the kernel (given current setup).
168	 *
169	 * To avoid freeing/using the wrong page (kernel sized) we:
170	 *	- align up the beginning of initrd
171	 *	- align down the end of initrd
172	 *
173	 *  |             |
174	 *  |=============| a000
175	 *  |             |
176	 *  |             |
177	 *  |             | 9000
178	 *  |/////////////|
179	 *  |/////////////|
180	 *  |=============| 8000
181	 *  |///INITRD////|
182	 *  |/////////////|
183	 *  |/////////////| 7000
184	 *  |             |
185	 *  |KKKKKKKKKKKKK|
186	 *  |=============| 6000
187	 *  |KKKKKKKKKKKKK|
188	 *  |KKKKKKKKKKKKK|
189	 *  K=kernel using 8KB pages
190	 *
191	 * In this example, we must free page 8000 ONLY. So we must align up
192	 * initrd_start and keep initrd_end as is.
193	 */
194	start = PAGE_ALIGN(start);
195	end = end & PAGE_MASK;
196
197	if (start < end)
198		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
199
200	for (; start < end; start += PAGE_SIZE) {
201		if (!virt_addr_valid(start))
202			continue;
203		free_reserved_page(virt_to_page(start));
204	}
205}
206
207/*
208 * This installs a clean page in the kernel's page table.
209 */
210static struct page * __init
211put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
212{
213	pgd_t *pgd;
214	pud_t *pud;
215	pmd_t *pmd;
216	pte_t *pte;
217
218	pgd = pgd_offset_k(address);		/* note: this is NOT pgd_offset()! */
219
220	{
221		pud = pud_alloc(&init_mm, pgd, address);
222		if (!pud)
223			goto out;
224		pmd = pmd_alloc(&init_mm, pud, address);
225		if (!pmd)
226			goto out;
227		pte = pte_alloc_kernel(pmd, address);
228		if (!pte)
229			goto out;
230		if (!pte_none(*pte))
231			goto out;
232		set_pte(pte, mk_pte(page, pgprot));
233	}
234  out:
235	/* no need for flush_tlb */
236	return page;
237}
238
239static void __init
240setup_gate (void)
241{
242	struct page *page;
243
244	/*
245	 * Map the gate page twice: once read-only to export the ELF
246	 * headers etc. and once execute-only page to enable
247	 * privilege-promotion via "epc":
248	 */
249	page = virt_to_page(ia64_imva(__start_gate_section));
250	put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
251#ifdef HAVE_BUGGY_SEGREL
252	page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
253	put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
254#else
255	put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
256	/* Fill in the holes (if any) with read-only zero pages: */
257	{
258		unsigned long addr;
259
260		for (addr = GATE_ADDR + PAGE_SIZE;
261		     addr < GATE_ADDR + PERCPU_PAGE_SIZE;
262		     addr += PAGE_SIZE)
263		{
264			put_kernel_page(ZERO_PAGE(0), addr,
265					PAGE_READONLY);
266			put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
267					PAGE_READONLY);
268		}
269	}
270#endif
271	ia64_patch_gate();
272}
273
274static struct vm_area_struct gate_vma;
275
276static int __init gate_vma_init(void)
277{
278	gate_vma.vm_mm = NULL;
279	gate_vma.vm_start = FIXADDR_USER_START;
280	gate_vma.vm_end = FIXADDR_USER_END;
281	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
282	gate_vma.vm_page_prot = __P101;
283
284	return 0;
285}
286__initcall(gate_vma_init);
287
288struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
289{
290	return &gate_vma;
291}
292
293int in_gate_area_no_mm(unsigned long addr)
294{
295	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
296		return 1;
297	return 0;
298}
299
300int in_gate_area(struct mm_struct *mm, unsigned long addr)
301{
302	return in_gate_area_no_mm(addr);
303}
304
305void ia64_mmu_init(void *my_cpu_data)
306{
307	unsigned long pta, impl_va_bits;
308	extern void tlb_init(void);
309
310#ifdef CONFIG_DISABLE_VHPT
311#	define VHPT_ENABLE_BIT	0
312#else
313#	define VHPT_ENABLE_BIT	1
314#endif
315
316	/*
317	 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
318	 * address space.  The IA-64 architecture guarantees that at least 50 bits of
319	 * virtual address space are implemented but if we pick a large enough page size
320	 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
321	 * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
322	 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
323	 * problem in practice.  Alternatively, we could truncate the top of the mapped
324	 * address space to not permit mappings that would overlap with the VMLPT.
325	 * --davidm 00/12/06
326	 */
327#	define pte_bits			3
328#	define mapped_space_bits	(3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
329	/*
330	 * The virtual page table has to cover the entire implemented address space within
331	 * a region even though not all of this space may be mappable.  The reason for
332	 * this is that the Access bit and Dirty bit fault handlers perform
333	 * non-speculative accesses to the virtual page table, so the address range of the
334	 * virtual page table itself needs to be covered by virtual page table.
335	 */
336#	define vmlpt_bits		(impl_va_bits - PAGE_SHIFT + pte_bits)
337#	define POW2(n)			(1ULL << (n))
338
339	impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
340
341	if (impl_va_bits < 51 || impl_va_bits > 61)
342		panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
343	/*
344	 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
345	 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
346	 * the test makes sure that our mapped space doesn't overlap the
347	 * unimplemented hole in the middle of the region.
348	 */
349	if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
350	    (mapped_space_bits > impl_va_bits - 1))
351		panic("Cannot build a big enough virtual-linear page table"
352		      " to cover mapped address space.\n"
353		      " Try using a smaller page size.\n");
354
355
356	/* place the VMLPT at the end of each page-table mapped region: */
357	pta = POW2(61) - POW2(vmlpt_bits);
358
359	/*
360	 * Set the (virtually mapped linear) page table address.  Bit
361	 * 8 selects between the short and long format, bits 2-7 the
362	 * size of the table, and bit 0 whether the VHPT walker is
363	 * enabled.
364	 */
365	ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
366
367	ia64_tlb_init();
368
369#ifdef	CONFIG_HUGETLB_PAGE
370	ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
371	ia64_srlz_d();
372#endif
373}
374
375#ifdef CONFIG_VIRTUAL_MEM_MAP
376int vmemmap_find_next_valid_pfn(int node, int i)
377{
378	unsigned long end_address, hole_next_pfn;
379	unsigned long stop_address;
380	pg_data_t *pgdat = NODE_DATA(node);
381
382	end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
383	end_address = PAGE_ALIGN(end_address);
384	stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
385
386	do {
387		pgd_t *pgd;
388		pud_t *pud;
389		pmd_t *pmd;
390		pte_t *pte;
391
392		pgd = pgd_offset_k(end_address);
393		if (pgd_none(*pgd)) {
394			end_address += PGDIR_SIZE;
395			continue;
396		}
397
398		pud = pud_offset(pgd, end_address);
399		if (pud_none(*pud)) {
400			end_address += PUD_SIZE;
401			continue;
402		}
403
404		pmd = pmd_offset(pud, end_address);
405		if (pmd_none(*pmd)) {
406			end_address += PMD_SIZE;
407			continue;
408		}
409
410		pte = pte_offset_kernel(pmd, end_address);
411retry_pte:
412		if (pte_none(*pte)) {
413			end_address += PAGE_SIZE;
414			pte++;
415			if ((end_address < stop_address) &&
416			    (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
417				goto retry_pte;
418			continue;
419		}
420		/* Found next valid vmem_map page */
421		break;
422	} while (end_address < stop_address);
423
424	end_address = min(end_address, stop_address);
425	end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
426	hole_next_pfn = end_address / sizeof(struct page);
427	return hole_next_pfn - pgdat->node_start_pfn;
428}
429
430int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
431{
432	unsigned long address, start_page, end_page;
433	struct page *map_start, *map_end;
434	int node;
435	pgd_t *pgd;
436	pud_t *pud;
437	pmd_t *pmd;
438	pte_t *pte;
439
440	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
441	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
442
443	start_page = (unsigned long) map_start & PAGE_MASK;
444	end_page = PAGE_ALIGN((unsigned long) map_end);
445	node = paddr_to_nid(__pa(start));
446
447	for (address = start_page; address < end_page; address += PAGE_SIZE) {
448		pgd = pgd_offset_k(address);
449		if (pgd_none(*pgd))
450			pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
451		pud = pud_offset(pgd, address);
452
453		if (pud_none(*pud))
454			pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
455		pmd = pmd_offset(pud, address);
456
457		if (pmd_none(*pmd))
458			pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
459		pte = pte_offset_kernel(pmd, address);
460
461		if (pte_none(*pte))
462			set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
463					     PAGE_KERNEL));
464	}
465	return 0;
466}
467
468struct memmap_init_callback_data {
469	struct page *start;
470	struct page *end;
471	int nid;
472	unsigned long zone;
473};
474
475static int __meminit
476virtual_memmap_init(u64 start, u64 end, void *arg)
477{
478	struct memmap_init_callback_data *args;
479	struct page *map_start, *map_end;
480
481	args = (struct memmap_init_callback_data *) arg;
482	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
483	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
484
485	if (map_start < args->start)
486		map_start = args->start;
487	if (map_end > args->end)
488		map_end = args->end;
489
490	/*
491	 * We have to initialize "out of bounds" struct page elements that fit completely
492	 * on the same pages that were allocated for the "in bounds" elements because they
493	 * may be referenced later (and found to be "reserved").
494	 */
495	map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
496	map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
497		    / sizeof(struct page));
498
499	if (map_start < map_end)
500		memmap_init_zone((unsigned long)(map_end - map_start),
501				 args->nid, args->zone, page_to_pfn(map_start),
502				 MEMMAP_EARLY);
503	return 0;
504}
505
506void __meminit
507memmap_init (unsigned long size, int nid, unsigned long zone,
508	     unsigned long start_pfn)
509{
510	if (!vmem_map)
511		memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
512	else {
513		struct page *start;
514		struct memmap_init_callback_data args;
515
516		start = pfn_to_page(start_pfn);
517		args.start = start;
518		args.end = start + size;
519		args.nid = nid;
520		args.zone = zone;
521
522		efi_memmap_walk(virtual_memmap_init, &args);
523	}
524}
525
526int
527ia64_pfn_valid (unsigned long pfn)
528{
529	char byte;
530	struct page *pg = pfn_to_page(pfn);
531
532	return     (__get_user(byte, (char __user *) pg) == 0)
533		&& ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
534			|| (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
535}
536EXPORT_SYMBOL(ia64_pfn_valid);
537
538int __init find_largest_hole(u64 start, u64 end, void *arg)
539{
540	u64 *max_gap = arg;
541
542	static u64 last_end = PAGE_OFFSET;
543
544	/* NOTE: this algorithm assumes efi memmap table is ordered */
545
546	if (*max_gap < (start - last_end))
547		*max_gap = start - last_end;
548	last_end = end;
549	return 0;
550}
551
552#endif /* CONFIG_VIRTUAL_MEM_MAP */
553
554int __init register_active_ranges(u64 start, u64 len, int nid)
555{
556	u64 end = start + len;
557
558#ifdef CONFIG_KEXEC
559	if (start > crashk_res.start && start < crashk_res.end)
560		start = crashk_res.end;
561	if (end > crashk_res.start && end < crashk_res.end)
562		end = crashk_res.start;
563#endif
564
565	if (start < end)
566		memblock_add_node(__pa(start), end - start, nid);
567	return 0;
568}
569
570int
571find_max_min_low_pfn (u64 start, u64 end, void *arg)
572{
573	unsigned long pfn_start, pfn_end;
574#ifdef CONFIG_FLATMEM
575	pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
576	pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
577#else
578	pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
579	pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
580#endif
581	min_low_pfn = min(min_low_pfn, pfn_start);
582	max_low_pfn = max(max_low_pfn, pfn_end);
583	return 0;
584}
585
586/*
587 * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
588 * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
589 * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
590 * useful for performance testing, but conceivably could also come in handy for debugging
591 * purposes.
592 */
593
594static int nolwsys __initdata;
595
596static int __init
597nolwsys_setup (char *s)
598{
599	nolwsys = 1;
600	return 1;
601}
602
603__setup("nolwsys", nolwsys_setup);
604
605void __init
606mem_init (void)
607{
608	int i;
609
610	BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
611	BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
612	BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
613
614#ifdef CONFIG_PCI
615	/*
616	 * This needs to be called _after_ the command line has been parsed but _before_
617	 * any drivers that may need the PCI DMA interface are initialized or bootmem has
618	 * been freed.
619	 */
620	platform_dma_init();
621#endif
622
623#ifdef CONFIG_FLATMEM
624	BUG_ON(!mem_map);
625#endif
626
627	set_max_mapnr(max_low_pfn);
628	high_memory = __va(max_low_pfn * PAGE_SIZE);
629	free_all_bootmem();
630	mem_init_print_info(NULL);
631
632	/*
633	 * For fsyscall entrpoints with no light-weight handler, use the ordinary
634	 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
635	 * code can tell them apart.
636	 */
637	for (i = 0; i < NR_syscalls; ++i) {
638		extern unsigned long fsyscall_table[NR_syscalls];
639		extern unsigned long sys_call_table[NR_syscalls];
640
641		if (!fsyscall_table[i] || nolwsys)
642			fsyscall_table[i] = sys_call_table[i] | 1;
643	}
644	setup_gate();
645}
646
647#ifdef CONFIG_MEMORY_HOTPLUG
648int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
649{
650	pg_data_t *pgdat;
651	struct zone *zone;
652	unsigned long start_pfn = start >> PAGE_SHIFT;
653	unsigned long nr_pages = size >> PAGE_SHIFT;
654	int ret;
655
656	pgdat = NODE_DATA(nid);
657
658	zone = pgdat->node_zones +
659		zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
660	ret = __add_pages(nid, zone, start_pfn, nr_pages);
661
662	if (ret)
663		printk("%s: Problem encountered in __add_pages() as ret=%d\n",
664		       __func__,  ret);
665
666	return ret;
667}
668
669#ifdef CONFIG_MEMORY_HOTREMOVE
670int arch_remove_memory(u64 start, u64 size)
671{
672	unsigned long start_pfn = start >> PAGE_SHIFT;
673	unsigned long nr_pages = size >> PAGE_SHIFT;
674	struct zone *zone;
675	int ret;
676
677	zone = page_zone(pfn_to_page(start_pfn));
678	ret = __remove_pages(zone, start_pfn, nr_pages);
679	if (ret)
680		pr_warn("%s: Problem encountered in __remove_pages() as"
681			" ret=%d\n", __func__,  ret);
682
683	return ret;
684}
685#endif
686#endif
687
688/**
689 * show_mem - give short summary of memory stats
690 *
691 * Shows a simple page count of reserved and used pages in the system.
692 * For discontig machines, it does this on a per-pgdat basis.
693 */
694void show_mem(unsigned int filter)
695{
696	int total_reserved = 0;
697	unsigned long total_present = 0;
698	pg_data_t *pgdat;
699
700	printk(KERN_INFO "Mem-info:\n");
701	show_free_areas(filter);
702	printk(KERN_INFO "Node memory in pages:\n");
703	for_each_online_pgdat(pgdat) {
704		unsigned long present;
705		unsigned long flags;
706		int reserved = 0;
707		int nid = pgdat->node_id;
708		int zoneid;
709
710		if (skip_free_areas_node(filter, nid))
711			continue;
712		pgdat_resize_lock(pgdat, &flags);
713
714		for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
715			struct zone *zone = &pgdat->node_zones[zoneid];
716			if (!populated_zone(zone))
717				continue;
718
719			reserved += zone->present_pages - zone->managed_pages;
720		}
721		present = pgdat->node_present_pages;
722
723		pgdat_resize_unlock(pgdat, &flags);
724		total_present += present;
725		total_reserved += reserved;
726		printk(KERN_INFO "Node %4d:  RAM: %11ld, rsvd: %8d, ",
727		       nid, present, reserved);
728	}
729	printk(KERN_INFO "%ld pages of RAM\n", total_present);
730	printk(KERN_INFO "%d reserved pages\n", total_reserved);
731	printk(KERN_INFO "Total of %ld pages in page table cache\n",
732	       quicklist_total_size());
733	printk(KERN_INFO "%ld free buffer pages\n", nr_free_buffer_pages());
734}
735