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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Initialize MMU support.
4 *
5 * Copyright (C) 1998-2003 Hewlett-Packard Co
6 * David Mosberger-Tang <davidm@hpl.hp.com>
7 */
8#include <linux/kernel.h>
9#include <linux/init.h>
10
11#include <linux/dma-noncoherent.h>
12#include <linux/dmar.h>
13#include <linux/efi.h>
14#include <linux/elf.h>
15#include <linux/memblock.h>
16#include <linux/mm.h>
17#include <linux/sched/signal.h>
18#include <linux/mmzone.h>
19#include <linux/module.h>
20#include <linux/personality.h>
21#include <linux/reboot.h>
22#include <linux/slab.h>
23#include <linux/swap.h>
24#include <linux/proc_fs.h>
25#include <linux/bitops.h>
26#include <linux/kexec.h>
27#include <linux/swiotlb.h>
28
29#include <asm/dma.h>
30#include <asm/io.h>
31#include <asm/numa.h>
32#include <asm/patch.h>
33#include <asm/pgalloc.h>
34#include <asm/sal.h>
35#include <asm/sections.h>
36#include <asm/tlb.h>
37#include <linux/uaccess.h>
38#include <asm/unistd.h>
39#include <asm/mca.h>
40
41extern void ia64_tlb_init (void);
42
43unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
44
45#ifdef CONFIG_VIRTUAL_MEM_MAP
46unsigned long VMALLOC_END = VMALLOC_END_INIT;
47EXPORT_SYMBOL(VMALLOC_END);
48struct page *vmem_map;
49EXPORT_SYMBOL(vmem_map);
50#endif
51
52struct page *zero_page_memmap_ptr; /* map entry for zero page */
53EXPORT_SYMBOL(zero_page_memmap_ptr);
54
55void
56__ia64_sync_icache_dcache (pte_t pte)
57{
58 unsigned long addr;
59 struct page *page;
60
61 page = pte_page(pte);
62 addr = (unsigned long) page_address(page);
63
64 if (test_bit(PG_arch_1, &page->flags))
65 return; /* i-cache is already coherent with d-cache */
66
67 flush_icache_range(addr, addr + page_size(page));
68 set_bit(PG_arch_1, &page->flags); /* mark page as clean */
69}
70
71/*
72 * Since DMA is i-cache coherent, any (complete) pages that were written via
73 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
74 * flush them when they get mapped into an executable vm-area.
75 */
76void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
77 size_t size, enum dma_data_direction dir)
78{
79 unsigned long pfn = PHYS_PFN(paddr);
80
81 do {
82 set_bit(PG_arch_1, &pfn_to_page(pfn)->flags);
83 } while (++pfn <= PHYS_PFN(paddr + size - 1));
84}
85
86inline void
87ia64_set_rbs_bot (void)
88{
89 unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
90
91 if (stack_size > MAX_USER_STACK_SIZE)
92 stack_size = MAX_USER_STACK_SIZE;
93 current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
94}
95
96/*
97 * This performs some platform-dependent address space initialization.
98 * On IA-64, we want to setup the VM area for the register backing
99 * store (which grows upwards) and install the gateway page which is
100 * used for signal trampolines, etc.
101 */
102void
103ia64_init_addr_space (void)
104{
105 struct vm_area_struct *vma;
106
107 ia64_set_rbs_bot();
108
109 /*
110 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
111 * the problem. When the process attempts to write to the register backing store
112 * for the first time, it will get a SEGFAULT in this case.
113 */
114 vma = vm_area_alloc(current->mm);
115 if (vma) {
116 vma_set_anonymous(vma);
117 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
118 vma->vm_end = vma->vm_start + PAGE_SIZE;
119 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
120 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
121 down_write(¤t->mm->mmap_sem);
122 if (insert_vm_struct(current->mm, vma)) {
123 up_write(¤t->mm->mmap_sem);
124 vm_area_free(vma);
125 return;
126 }
127 up_write(¤t->mm->mmap_sem);
128 }
129
130 /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
131 if (!(current->personality & MMAP_PAGE_ZERO)) {
132 vma = vm_area_alloc(current->mm);
133 if (vma) {
134 vma_set_anonymous(vma);
135 vma->vm_end = PAGE_SIZE;
136 vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
137 vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
138 VM_DONTEXPAND | VM_DONTDUMP;
139 down_write(¤t->mm->mmap_sem);
140 if (insert_vm_struct(current->mm, vma)) {
141 up_write(¤t->mm->mmap_sem);
142 vm_area_free(vma);
143 return;
144 }
145 up_write(¤t->mm->mmap_sem);
146 }
147 }
148}
149
150void
151free_initmem (void)
152{
153 free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
154 -1, "unused kernel");
155}
156
157void __init
158free_initrd_mem (unsigned long start, unsigned long end)
159{
160 /*
161 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
162 * Thus EFI and the kernel may have different page sizes. It is
163 * therefore possible to have the initrd share the same page as
164 * the end of the kernel (given current setup).
165 *
166 * To avoid freeing/using the wrong page (kernel sized) we:
167 * - align up the beginning of initrd
168 * - align down the end of initrd
169 *
170 * | |
171 * |=============| a000
172 * | |
173 * | |
174 * | | 9000
175 * |/////////////|
176 * |/////////////|
177 * |=============| 8000
178 * |///INITRD////|
179 * |/////////////|
180 * |/////////////| 7000
181 * | |
182 * |KKKKKKKKKKKKK|
183 * |=============| 6000
184 * |KKKKKKKKKKKKK|
185 * |KKKKKKKKKKKKK|
186 * K=kernel using 8KB pages
187 *
188 * In this example, we must free page 8000 ONLY. So we must align up
189 * initrd_start and keep initrd_end as is.
190 */
191 start = PAGE_ALIGN(start);
192 end = end & PAGE_MASK;
193
194 if (start < end)
195 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
196
197 for (; start < end; start += PAGE_SIZE) {
198 if (!virt_addr_valid(start))
199 continue;
200 free_reserved_page(virt_to_page(start));
201 }
202}
203
204/*
205 * This installs a clean page in the kernel's page table.
206 */
207static struct page * __init
208put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
209{
210 pgd_t *pgd;
211 pud_t *pud;
212 pmd_t *pmd;
213 pte_t *pte;
214
215 pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */
216
217 {
218 pud = pud_alloc(&init_mm, pgd, address);
219 if (!pud)
220 goto out;
221 pmd = pmd_alloc(&init_mm, pud, address);
222 if (!pmd)
223 goto out;
224 pte = pte_alloc_kernel(pmd, address);
225 if (!pte)
226 goto out;
227 if (!pte_none(*pte))
228 goto out;
229 set_pte(pte, mk_pte(page, pgprot));
230 }
231 out:
232 /* no need for flush_tlb */
233 return page;
234}
235
236static void __init
237setup_gate (void)
238{
239 struct page *page;
240
241 /*
242 * Map the gate page twice: once read-only to export the ELF
243 * headers etc. and once execute-only page to enable
244 * privilege-promotion via "epc":
245 */
246 page = virt_to_page(ia64_imva(__start_gate_section));
247 put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
248#ifdef HAVE_BUGGY_SEGREL
249 page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
250 put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
251#else
252 put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
253 /* Fill in the holes (if any) with read-only zero pages: */
254 {
255 unsigned long addr;
256
257 for (addr = GATE_ADDR + PAGE_SIZE;
258 addr < GATE_ADDR + PERCPU_PAGE_SIZE;
259 addr += PAGE_SIZE)
260 {
261 put_kernel_page(ZERO_PAGE(0), addr,
262 PAGE_READONLY);
263 put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
264 PAGE_READONLY);
265 }
266 }
267#endif
268 ia64_patch_gate();
269}
270
271static struct vm_area_struct gate_vma;
272
273static int __init gate_vma_init(void)
274{
275 vma_init(&gate_vma, NULL);
276 gate_vma.vm_start = FIXADDR_USER_START;
277 gate_vma.vm_end = FIXADDR_USER_END;
278 gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
279 gate_vma.vm_page_prot = __P101;
280
281 return 0;
282}
283__initcall(gate_vma_init);
284
285struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
286{
287 return &gate_vma;
288}
289
290int in_gate_area_no_mm(unsigned long addr)
291{
292 if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
293 return 1;
294 return 0;
295}
296
297int in_gate_area(struct mm_struct *mm, unsigned long addr)
298{
299 return in_gate_area_no_mm(addr);
300}
301
302void ia64_mmu_init(void *my_cpu_data)
303{
304 unsigned long pta, impl_va_bits;
305 extern void tlb_init(void);
306
307#ifdef CONFIG_DISABLE_VHPT
308# define VHPT_ENABLE_BIT 0
309#else
310# define VHPT_ENABLE_BIT 1
311#endif
312
313 /*
314 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
315 * address space. The IA-64 architecture guarantees that at least 50 bits of
316 * virtual address space are implemented but if we pick a large enough page size
317 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
318 * VMLPT. I assume that once we run on machines big enough to warrant 64KB pages,
319 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
320 * problem in practice. Alternatively, we could truncate the top of the mapped
321 * address space to not permit mappings that would overlap with the VMLPT.
322 * --davidm 00/12/06
323 */
324# define pte_bits 3
325# define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
326 /*
327 * The virtual page table has to cover the entire implemented address space within
328 * a region even though not all of this space may be mappable. The reason for
329 * this is that the Access bit and Dirty bit fault handlers perform
330 * non-speculative accesses to the virtual page table, so the address range of the
331 * virtual page table itself needs to be covered by virtual page table.
332 */
333# define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits)
334# define POW2(n) (1ULL << (n))
335
336 impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
337
338 if (impl_va_bits < 51 || impl_va_bits > 61)
339 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
340 /*
341 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
342 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
343 * the test makes sure that our mapped space doesn't overlap the
344 * unimplemented hole in the middle of the region.
345 */
346 if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
347 (mapped_space_bits > impl_va_bits - 1))
348 panic("Cannot build a big enough virtual-linear page table"
349 " to cover mapped address space.\n"
350 " Try using a smaller page size.\n");
351
352
353 /* place the VMLPT at the end of each page-table mapped region: */
354 pta = POW2(61) - POW2(vmlpt_bits);
355
356 /*
357 * Set the (virtually mapped linear) page table address. Bit
358 * 8 selects between the short and long format, bits 2-7 the
359 * size of the table, and bit 0 whether the VHPT walker is
360 * enabled.
361 */
362 ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
363
364 ia64_tlb_init();
365
366#ifdef CONFIG_HUGETLB_PAGE
367 ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
368 ia64_srlz_d();
369#endif
370}
371
372#ifdef CONFIG_VIRTUAL_MEM_MAP
373int vmemmap_find_next_valid_pfn(int node, int i)
374{
375 unsigned long end_address, hole_next_pfn;
376 unsigned long stop_address;
377 pg_data_t *pgdat = NODE_DATA(node);
378
379 end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
380 end_address = PAGE_ALIGN(end_address);
381 stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
382
383 do {
384 pgd_t *pgd;
385 pud_t *pud;
386 pmd_t *pmd;
387 pte_t *pte;
388
389 pgd = pgd_offset_k(end_address);
390 if (pgd_none(*pgd)) {
391 end_address += PGDIR_SIZE;
392 continue;
393 }
394
395 pud = pud_offset(pgd, end_address);
396 if (pud_none(*pud)) {
397 end_address += PUD_SIZE;
398 continue;
399 }
400
401 pmd = pmd_offset(pud, end_address);
402 if (pmd_none(*pmd)) {
403 end_address += PMD_SIZE;
404 continue;
405 }
406
407 pte = pte_offset_kernel(pmd, end_address);
408retry_pte:
409 if (pte_none(*pte)) {
410 end_address += PAGE_SIZE;
411 pte++;
412 if ((end_address < stop_address) &&
413 (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
414 goto retry_pte;
415 continue;
416 }
417 /* Found next valid vmem_map page */
418 break;
419 } while (end_address < stop_address);
420
421 end_address = min(end_address, stop_address);
422 end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
423 hole_next_pfn = end_address / sizeof(struct page);
424 return hole_next_pfn - pgdat->node_start_pfn;
425}
426
427int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
428{
429 unsigned long address, start_page, end_page;
430 struct page *map_start, *map_end;
431 int node;
432 pgd_t *pgd;
433 pud_t *pud;
434 pmd_t *pmd;
435 pte_t *pte;
436
437 map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
438 map_end = vmem_map + (__pa(end) >> PAGE_SHIFT);
439
440 start_page = (unsigned long) map_start & PAGE_MASK;
441 end_page = PAGE_ALIGN((unsigned long) map_end);
442 node = paddr_to_nid(__pa(start));
443
444 for (address = start_page; address < end_page; address += PAGE_SIZE) {
445 pgd = pgd_offset_k(address);
446 if (pgd_none(*pgd)) {
447 pud = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
448 if (!pud)
449 goto err_alloc;
450 pgd_populate(&init_mm, pgd, pud);
451 }
452 pud = pud_offset(pgd, address);
453
454 if (pud_none(*pud)) {
455 pmd = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
456 if (!pmd)
457 goto err_alloc;
458 pud_populate(&init_mm, pud, pmd);
459 }
460 pmd = pmd_offset(pud, address);
461
462 if (pmd_none(*pmd)) {
463 pte = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
464 if (!pte)
465 goto err_alloc;
466 pmd_populate_kernel(&init_mm, pmd, pte);
467 }
468 pte = pte_offset_kernel(pmd, address);
469
470 if (pte_none(*pte)) {
471 void *page = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE,
472 node);
473 if (!page)
474 goto err_alloc;
475 set_pte(pte, pfn_pte(__pa(page) >> PAGE_SHIFT,
476 PAGE_KERNEL));
477 }
478 }
479 return 0;
480
481err_alloc:
482 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d\n",
483 __func__, PAGE_SIZE, PAGE_SIZE, node);
484 return -ENOMEM;
485}
486
487struct memmap_init_callback_data {
488 struct page *start;
489 struct page *end;
490 int nid;
491 unsigned long zone;
492};
493
494static int __meminit
495virtual_memmap_init(u64 start, u64 end, void *arg)
496{
497 struct memmap_init_callback_data *args;
498 struct page *map_start, *map_end;
499
500 args = (struct memmap_init_callback_data *) arg;
501 map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
502 map_end = vmem_map + (__pa(end) >> PAGE_SHIFT);
503
504 if (map_start < args->start)
505 map_start = args->start;
506 if (map_end > args->end)
507 map_end = args->end;
508
509 /*
510 * We have to initialize "out of bounds" struct page elements that fit completely
511 * on the same pages that were allocated for the "in bounds" elements because they
512 * may be referenced later (and found to be "reserved").
513 */
514 map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
515 map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
516 / sizeof(struct page));
517
518 if (map_start < map_end)
519 memmap_init_zone((unsigned long)(map_end - map_start),
520 args->nid, args->zone, page_to_pfn(map_start),
521 MEMMAP_EARLY, NULL);
522 return 0;
523}
524
525void __meminit
526memmap_init (unsigned long size, int nid, unsigned long zone,
527 unsigned long start_pfn)
528{
529 if (!vmem_map) {
530 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY,
531 NULL);
532 } else {
533 struct page *start;
534 struct memmap_init_callback_data args;
535
536 start = pfn_to_page(start_pfn);
537 args.start = start;
538 args.end = start + size;
539 args.nid = nid;
540 args.zone = zone;
541
542 efi_memmap_walk(virtual_memmap_init, &args);
543 }
544}
545
546int
547ia64_pfn_valid (unsigned long pfn)
548{
549 char byte;
550 struct page *pg = pfn_to_page(pfn);
551
552 return (__get_user(byte, (char __user *) pg) == 0)
553 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
554 || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
555}
556EXPORT_SYMBOL(ia64_pfn_valid);
557
558int __init find_largest_hole(u64 start, u64 end, void *arg)
559{
560 u64 *max_gap = arg;
561
562 static u64 last_end = PAGE_OFFSET;
563
564 /* NOTE: this algorithm assumes efi memmap table is ordered */
565
566 if (*max_gap < (start - last_end))
567 *max_gap = start - last_end;
568 last_end = end;
569 return 0;
570}
571
572#endif /* CONFIG_VIRTUAL_MEM_MAP */
573
574int __init register_active_ranges(u64 start, u64 len, int nid)
575{
576 u64 end = start + len;
577
578#ifdef CONFIG_KEXEC
579 if (start > crashk_res.start && start < crashk_res.end)
580 start = crashk_res.end;
581 if (end > crashk_res.start && end < crashk_res.end)
582 end = crashk_res.start;
583#endif
584
585 if (start < end)
586 memblock_add_node(__pa(start), end - start, nid);
587 return 0;
588}
589
590int
591find_max_min_low_pfn (u64 start, u64 end, void *arg)
592{
593 unsigned long pfn_start, pfn_end;
594#ifdef CONFIG_FLATMEM
595 pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
596 pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
597#else
598 pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
599 pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
600#endif
601 min_low_pfn = min(min_low_pfn, pfn_start);
602 max_low_pfn = max(max_low_pfn, pfn_end);
603 return 0;
604}
605
606/*
607 * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
608 * system call handler. When this option is in effect, all fsyscalls will end up bubbling
609 * down into the kernel and calling the normal (heavy-weight) syscall handler. This is
610 * useful for performance testing, but conceivably could also come in handy for debugging
611 * purposes.
612 */
613
614static int nolwsys __initdata;
615
616static int __init
617nolwsys_setup (char *s)
618{
619 nolwsys = 1;
620 return 1;
621}
622
623__setup("nolwsys", nolwsys_setup);
624
625void __init
626mem_init (void)
627{
628 int i;
629
630 BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
631 BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
632 BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
633
634 /*
635 * This needs to be called _after_ the command line has been parsed but
636 * _before_ any drivers that may need the PCI DMA interface are
637 * initialized or bootmem has been freed.
638 */
639#ifdef CONFIG_INTEL_IOMMU
640 detect_intel_iommu();
641 if (!iommu_detected)
642#endif
643#ifdef CONFIG_SWIOTLB
644 swiotlb_init(1);
645#endif
646
647#ifdef CONFIG_FLATMEM
648 BUG_ON(!mem_map);
649#endif
650
651 set_max_mapnr(max_low_pfn);
652 high_memory = __va(max_low_pfn * PAGE_SIZE);
653 memblock_free_all();
654 mem_init_print_info(NULL);
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 fsyscall_table[NR_syscalls];
663 extern unsigned long sys_call_table[NR_syscalls];
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 struct mhp_restrictions *restrictions)
674{
675 unsigned long start_pfn = start >> PAGE_SHIFT;
676 unsigned long nr_pages = size >> PAGE_SHIFT;
677 int ret;
678
679 ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
680 if (ret)
681 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
682 __func__, ret);
683
684 return ret;
685}
686
687void arch_remove_memory(int nid, u64 start, u64 size,
688 struct vmem_altmap *altmap)
689{
690 unsigned long start_pfn = start >> PAGE_SHIFT;
691 unsigned long nr_pages = size >> PAGE_SHIFT;
692 struct zone *zone;
693
694 zone = page_zone(pfn_to_page(start_pfn));
695 __remove_pages(zone, start_pfn, nr_pages, altmap);
696}
697#endif