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1/*
2 * SPARC64 Huge TLB page support.
3 *
4 * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
5 */
6
7#include <linux/fs.h>
8#include <linux/mm.h>
9#include <linux/hugetlb.h>
10#include <linux/pagemap.h>
11#include <linux/sysctl.h>
12
13#include <asm/mman.h>
14#include <asm/pgalloc.h>
15#include <asm/tlb.h>
16#include <asm/tlbflush.h>
17#include <asm/cacheflush.h>
18#include <asm/mmu_context.h>
19
20/* Slightly simplified from the non-hugepage variant because by
21 * definition we don't have to worry about any page coloring stuff
22 */
23
24static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
25 unsigned long addr,
26 unsigned long len,
27 unsigned long pgoff,
28 unsigned long flags)
29{
30 unsigned long task_size = TASK_SIZE;
31 struct vm_unmapped_area_info info;
32
33 if (test_thread_flag(TIF_32BIT))
34 task_size = STACK_TOP32;
35
36 info.flags = 0;
37 info.length = len;
38 info.low_limit = TASK_UNMAPPED_BASE;
39 info.high_limit = min(task_size, VA_EXCLUDE_START);
40 info.align_mask = PAGE_MASK & ~HPAGE_MASK;
41 info.align_offset = 0;
42 addr = vm_unmapped_area(&info);
43
44 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
45 VM_BUG_ON(addr != -ENOMEM);
46 info.low_limit = VA_EXCLUDE_END;
47 info.high_limit = task_size;
48 addr = vm_unmapped_area(&info);
49 }
50
51 return addr;
52}
53
54static unsigned long
55hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
56 const unsigned long len,
57 const unsigned long pgoff,
58 const unsigned long flags)
59{
60 struct mm_struct *mm = current->mm;
61 unsigned long addr = addr0;
62 struct vm_unmapped_area_info info;
63
64 /* This should only ever run for 32-bit processes. */
65 BUG_ON(!test_thread_flag(TIF_32BIT));
66
67 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
68 info.length = len;
69 info.low_limit = PAGE_SIZE;
70 info.high_limit = mm->mmap_base;
71 info.align_mask = PAGE_MASK & ~HPAGE_MASK;
72 info.align_offset = 0;
73 addr = vm_unmapped_area(&info);
74
75 /*
76 * A failed mmap() very likely causes application failure,
77 * so fall back to the bottom-up function here. This scenario
78 * can happen with large stack limits and large mmap()
79 * allocations.
80 */
81 if (addr & ~PAGE_MASK) {
82 VM_BUG_ON(addr != -ENOMEM);
83 info.flags = 0;
84 info.low_limit = TASK_UNMAPPED_BASE;
85 info.high_limit = STACK_TOP32;
86 addr = vm_unmapped_area(&info);
87 }
88
89 return addr;
90}
91
92unsigned long
93hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
94 unsigned long len, unsigned long pgoff, unsigned long flags)
95{
96 struct mm_struct *mm = current->mm;
97 struct vm_area_struct *vma;
98 unsigned long task_size = TASK_SIZE;
99
100 if (test_thread_flag(TIF_32BIT))
101 task_size = STACK_TOP32;
102
103 if (len & ~HPAGE_MASK)
104 return -EINVAL;
105 if (len > task_size)
106 return -ENOMEM;
107
108 if (flags & MAP_FIXED) {
109 if (prepare_hugepage_range(file, addr, len))
110 return -EINVAL;
111 return addr;
112 }
113
114 if (addr) {
115 addr = ALIGN(addr, HPAGE_SIZE);
116 vma = find_vma(mm, addr);
117 if (task_size - len >= addr &&
118 (!vma || addr + len <= vma->vm_start))
119 return addr;
120 }
121 if (mm->get_unmapped_area == arch_get_unmapped_area)
122 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
123 pgoff, flags);
124 else
125 return hugetlb_get_unmapped_area_topdown(file, addr, len,
126 pgoff, flags);
127}
128
129pte_t *huge_pte_alloc(struct mm_struct *mm,
130 unsigned long addr, unsigned long sz)
131{
132 pgd_t *pgd;
133 pud_t *pud;
134 pmd_t *pmd;
135 pte_t *pte = NULL;
136
137 /* We must align the address, because our caller will run
138 * set_huge_pte_at() on whatever we return, which writes out
139 * all of the sub-ptes for the hugepage range. So we have
140 * to give it the first such sub-pte.
141 */
142 addr &= HPAGE_MASK;
143
144 pgd = pgd_offset(mm, addr);
145 pud = pud_alloc(mm, pgd, addr);
146 if (pud) {
147 pmd = pmd_alloc(mm, pud, addr);
148 if (pmd)
149 pte = pte_alloc_map(mm, NULL, pmd, addr);
150 }
151 return pte;
152}
153
154pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
155{
156 pgd_t *pgd;
157 pud_t *pud;
158 pmd_t *pmd;
159 pte_t *pte = NULL;
160
161 addr &= HPAGE_MASK;
162
163 pgd = pgd_offset(mm, addr);
164 if (!pgd_none(*pgd)) {
165 pud = pud_offset(pgd, addr);
166 if (!pud_none(*pud)) {
167 pmd = pmd_offset(pud, addr);
168 if (!pmd_none(*pmd))
169 pte = pte_offset_map(pmd, addr);
170 }
171 }
172 return pte;
173}
174
175int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
176{
177 return 0;
178}
179
180void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
181 pte_t *ptep, pte_t entry)
182{
183 int i;
184
185 if (!pte_present(*ptep) && pte_present(entry))
186 mm->context.huge_pte_count++;
187
188 addr &= HPAGE_MASK;
189 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
190 set_pte_at(mm, addr, ptep, entry);
191 ptep++;
192 addr += PAGE_SIZE;
193 pte_val(entry) += PAGE_SIZE;
194 }
195}
196
197pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
198 pte_t *ptep)
199{
200 pte_t entry;
201 int i;
202
203 entry = *ptep;
204 if (pte_present(entry))
205 mm->context.huge_pte_count--;
206
207 addr &= HPAGE_MASK;
208
209 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
210 pte_clear(mm, addr, ptep);
211 addr += PAGE_SIZE;
212 ptep++;
213 }
214
215 return entry;
216}
217
218struct page *follow_huge_addr(struct mm_struct *mm,
219 unsigned long address, int write)
220{
221 return ERR_PTR(-EINVAL);
222}
223
224int pmd_huge(pmd_t pmd)
225{
226 return 0;
227}
228
229int pud_huge(pud_t pud)
230{
231 return 0;
232}
233
234int pmd_huge_support(void)
235{
236 return 0;
237}
238
239struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
240 pmd_t *pmd, int write)
241{
242 return NULL;
243}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SPARC64 Huge TLB page support.
4 *
5 * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
6 */
7
8#include <linux/fs.h>
9#include <linux/mm.h>
10#include <linux/sched/mm.h>
11#include <linux/hugetlb.h>
12#include <linux/pagemap.h>
13#include <linux/sysctl.h>
14
15#include <asm/mman.h>
16#include <asm/pgalloc.h>
17#include <asm/tlb.h>
18#include <asm/tlbflush.h>
19#include <asm/cacheflush.h>
20#include <asm/mmu_context.h>
21
22/* Slightly simplified from the non-hugepage variant because by
23 * definition we don't have to worry about any page coloring stuff
24 */
25
26static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
27 unsigned long addr,
28 unsigned long len,
29 unsigned long pgoff,
30 unsigned long flags)
31{
32 struct hstate *h = hstate_file(filp);
33 unsigned long task_size = TASK_SIZE;
34 struct vm_unmapped_area_info info;
35
36 if (test_thread_flag(TIF_32BIT))
37 task_size = STACK_TOP32;
38
39 info.flags = 0;
40 info.length = len;
41 info.low_limit = TASK_UNMAPPED_BASE;
42 info.high_limit = min(task_size, VA_EXCLUDE_START);
43 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
44 info.align_offset = 0;
45 addr = vm_unmapped_area(&info);
46
47 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
48 VM_BUG_ON(addr != -ENOMEM);
49 info.low_limit = VA_EXCLUDE_END;
50 info.high_limit = task_size;
51 addr = vm_unmapped_area(&info);
52 }
53
54 return addr;
55}
56
57static unsigned long
58hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
59 const unsigned long len,
60 const unsigned long pgoff,
61 const unsigned long flags)
62{
63 struct hstate *h = hstate_file(filp);
64 struct mm_struct *mm = current->mm;
65 unsigned long addr = addr0;
66 struct vm_unmapped_area_info info;
67
68 /* This should only ever run for 32-bit processes. */
69 BUG_ON(!test_thread_flag(TIF_32BIT));
70
71 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
72 info.length = len;
73 info.low_limit = PAGE_SIZE;
74 info.high_limit = mm->mmap_base;
75 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
76 info.align_offset = 0;
77 addr = vm_unmapped_area(&info);
78
79 /*
80 * A failed mmap() very likely causes application failure,
81 * so fall back to the bottom-up function here. This scenario
82 * can happen with large stack limits and large mmap()
83 * allocations.
84 */
85 if (addr & ~PAGE_MASK) {
86 VM_BUG_ON(addr != -ENOMEM);
87 info.flags = 0;
88 info.low_limit = TASK_UNMAPPED_BASE;
89 info.high_limit = STACK_TOP32;
90 addr = vm_unmapped_area(&info);
91 }
92
93 return addr;
94}
95
96unsigned long
97hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
98 unsigned long len, unsigned long pgoff, unsigned long flags)
99{
100 struct hstate *h = hstate_file(file);
101 struct mm_struct *mm = current->mm;
102 struct vm_area_struct *vma;
103 unsigned long task_size = TASK_SIZE;
104
105 if (test_thread_flag(TIF_32BIT))
106 task_size = STACK_TOP32;
107
108 if (len & ~huge_page_mask(h))
109 return -EINVAL;
110 if (len > task_size)
111 return -ENOMEM;
112
113 if (flags & MAP_FIXED) {
114 if (prepare_hugepage_range(file, addr, len))
115 return -EINVAL;
116 return addr;
117 }
118
119 if (addr) {
120 addr = ALIGN(addr, huge_page_size(h));
121 vma = find_vma(mm, addr);
122 if (task_size - len >= addr &&
123 (!vma || addr + len <= vm_start_gap(vma)))
124 return addr;
125 }
126 if (mm->get_unmapped_area == arch_get_unmapped_area)
127 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
128 pgoff, flags);
129 else
130 return hugetlb_get_unmapped_area_topdown(file, addr, len,
131 pgoff, flags);
132}
133
134static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
135{
136 return entry;
137}
138
139static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
140{
141 unsigned long hugepage_size = _PAGE_SZ4MB_4V;
142
143 pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;
144
145 switch (shift) {
146 case HPAGE_16GB_SHIFT:
147 hugepage_size = _PAGE_SZ16GB_4V;
148 pte_val(entry) |= _PAGE_PUD_HUGE;
149 break;
150 case HPAGE_2GB_SHIFT:
151 hugepage_size = _PAGE_SZ2GB_4V;
152 pte_val(entry) |= _PAGE_PMD_HUGE;
153 break;
154 case HPAGE_256MB_SHIFT:
155 hugepage_size = _PAGE_SZ256MB_4V;
156 pte_val(entry) |= _PAGE_PMD_HUGE;
157 break;
158 case HPAGE_SHIFT:
159 pte_val(entry) |= _PAGE_PMD_HUGE;
160 break;
161 case HPAGE_64K_SHIFT:
162 hugepage_size = _PAGE_SZ64K_4V;
163 break;
164 default:
165 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift);
166 }
167
168 pte_val(entry) = pte_val(entry) | hugepage_size;
169 return entry;
170}
171
172static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift)
173{
174 if (tlb_type == hypervisor)
175 return sun4v_hugepage_shift_to_tte(entry, shift);
176 else
177 return sun4u_hugepage_shift_to_tte(entry, shift);
178}
179
180pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
181 struct page *page, int writeable)
182{
183 unsigned int shift = huge_page_shift(hstate_vma(vma));
184 pte_t pte;
185
186 pte = hugepage_shift_to_tte(entry, shift);
187
188#ifdef CONFIG_SPARC64
189 /* If this vma has ADI enabled on it, turn on TTE.mcd
190 */
191 if (vma->vm_flags & VM_SPARC_ADI)
192 return pte_mkmcd(pte);
193 else
194 return pte_mknotmcd(pte);
195#else
196 return pte;
197#endif
198}
199
200static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
201{
202 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
203 unsigned int shift;
204
205 switch (tte_szbits) {
206 case _PAGE_SZ16GB_4V:
207 shift = HPAGE_16GB_SHIFT;
208 break;
209 case _PAGE_SZ2GB_4V:
210 shift = HPAGE_2GB_SHIFT;
211 break;
212 case _PAGE_SZ256MB_4V:
213 shift = HPAGE_256MB_SHIFT;
214 break;
215 case _PAGE_SZ4MB_4V:
216 shift = REAL_HPAGE_SHIFT;
217 break;
218 case _PAGE_SZ64K_4V:
219 shift = HPAGE_64K_SHIFT;
220 break;
221 default:
222 shift = PAGE_SHIFT;
223 break;
224 }
225 return shift;
226}
227
228static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
229{
230 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
231 unsigned int shift;
232
233 switch (tte_szbits) {
234 case _PAGE_SZ256MB_4U:
235 shift = HPAGE_256MB_SHIFT;
236 break;
237 case _PAGE_SZ4MB_4U:
238 shift = REAL_HPAGE_SHIFT;
239 break;
240 case _PAGE_SZ64K_4U:
241 shift = HPAGE_64K_SHIFT;
242 break;
243 default:
244 shift = PAGE_SHIFT;
245 break;
246 }
247 return shift;
248}
249
250static unsigned int huge_tte_to_shift(pte_t entry)
251{
252 unsigned long shift;
253
254 if (tlb_type == hypervisor)
255 shift = sun4v_huge_tte_to_shift(entry);
256 else
257 shift = sun4u_huge_tte_to_shift(entry);
258
259 if (shift == PAGE_SHIFT)
260 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
261 pte_val(entry));
262
263 return shift;
264}
265
266static unsigned long huge_tte_to_size(pte_t pte)
267{
268 unsigned long size = 1UL << huge_tte_to_shift(pte);
269
270 if (size == REAL_HPAGE_SIZE)
271 size = HPAGE_SIZE;
272 return size;
273}
274
275pte_t *huge_pte_alloc(struct mm_struct *mm,
276 unsigned long addr, unsigned long sz)
277{
278 pgd_t *pgd;
279 p4d_t *p4d;
280 pud_t *pud;
281 pmd_t *pmd;
282
283 pgd = pgd_offset(mm, addr);
284 p4d = p4d_offset(pgd, addr);
285 pud = pud_alloc(mm, p4d, addr);
286 if (!pud)
287 return NULL;
288 if (sz >= PUD_SIZE)
289 return (pte_t *)pud;
290 pmd = pmd_alloc(mm, pud, addr);
291 if (!pmd)
292 return NULL;
293 if (sz >= PMD_SIZE)
294 return (pte_t *)pmd;
295 return pte_alloc_map(mm, pmd, addr);
296}
297
298pte_t *huge_pte_offset(struct mm_struct *mm,
299 unsigned long addr, unsigned long sz)
300{
301 pgd_t *pgd;
302 p4d_t *p4d;
303 pud_t *pud;
304 pmd_t *pmd;
305
306 pgd = pgd_offset(mm, addr);
307 if (pgd_none(*pgd))
308 return NULL;
309 p4d = p4d_offset(pgd, addr);
310 if (p4d_none(*p4d))
311 return NULL;
312 pud = pud_offset(p4d, addr);
313 if (pud_none(*pud))
314 return NULL;
315 if (is_hugetlb_pud(*pud))
316 return (pte_t *)pud;
317 pmd = pmd_offset(pud, addr);
318 if (pmd_none(*pmd))
319 return NULL;
320 if (is_hugetlb_pmd(*pmd))
321 return (pte_t *)pmd;
322 return pte_offset_map(pmd, addr);
323}
324
325void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
326 pte_t *ptep, pte_t entry)
327{
328 unsigned int nptes, orig_shift, shift;
329 unsigned long i, size;
330 pte_t orig;
331
332 size = huge_tte_to_size(entry);
333
334 shift = PAGE_SHIFT;
335 if (size >= PUD_SIZE)
336 shift = PUD_SHIFT;
337 else if (size >= PMD_SIZE)
338 shift = PMD_SHIFT;
339 else
340 shift = PAGE_SHIFT;
341
342 nptes = size >> shift;
343
344 if (!pte_present(*ptep) && pte_present(entry))
345 mm->context.hugetlb_pte_count += nptes;
346
347 addr &= ~(size - 1);
348 orig = *ptep;
349 orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
350
351 for (i = 0; i < nptes; i++)
352 ptep[i] = __pte(pte_val(entry) + (i << shift));
353
354 maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
355 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
356 if (size == HPAGE_SIZE)
357 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
358 orig_shift);
359}
360
361pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
362 pte_t *ptep)
363{
364 unsigned int i, nptes, orig_shift, shift;
365 unsigned long size;
366 pte_t entry;
367
368 entry = *ptep;
369 size = huge_tte_to_size(entry);
370
371 shift = PAGE_SHIFT;
372 if (size >= PUD_SIZE)
373 shift = PUD_SHIFT;
374 else if (size >= PMD_SIZE)
375 shift = PMD_SHIFT;
376 else
377 shift = PAGE_SHIFT;
378
379 nptes = size >> shift;
380 orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
381
382 if (pte_present(entry))
383 mm->context.hugetlb_pte_count -= nptes;
384
385 addr &= ~(size - 1);
386 for (i = 0; i < nptes; i++)
387 ptep[i] = __pte(0UL);
388
389 maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
390 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
391 if (size == HPAGE_SIZE)
392 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
393 orig_shift);
394
395 return entry;
396}
397
398int pmd_huge(pmd_t pmd)
399{
400 return !pmd_none(pmd) &&
401 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
402}
403
404int pud_huge(pud_t pud)
405{
406 return !pud_none(pud) &&
407 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
408}
409
410static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
411 unsigned long addr)
412{
413 pgtable_t token = pmd_pgtable(*pmd);
414
415 pmd_clear(pmd);
416 pte_free_tlb(tlb, token, addr);
417 mm_dec_nr_ptes(tlb->mm);
418}
419
420static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
421 unsigned long addr, unsigned long end,
422 unsigned long floor, unsigned long ceiling)
423{
424 pmd_t *pmd;
425 unsigned long next;
426 unsigned long start;
427
428 start = addr;
429 pmd = pmd_offset(pud, addr);
430 do {
431 next = pmd_addr_end(addr, end);
432 if (pmd_none(*pmd))
433 continue;
434 if (is_hugetlb_pmd(*pmd))
435 pmd_clear(pmd);
436 else
437 hugetlb_free_pte_range(tlb, pmd, addr);
438 } while (pmd++, addr = next, addr != end);
439
440 start &= PUD_MASK;
441 if (start < floor)
442 return;
443 if (ceiling) {
444 ceiling &= PUD_MASK;
445 if (!ceiling)
446 return;
447 }
448 if (end - 1 > ceiling - 1)
449 return;
450
451 pmd = pmd_offset(pud, start);
452 pud_clear(pud);
453 pmd_free_tlb(tlb, pmd, start);
454 mm_dec_nr_pmds(tlb->mm);
455}
456
457static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
458 unsigned long addr, unsigned long end,
459 unsigned long floor, unsigned long ceiling)
460{
461 pud_t *pud;
462 unsigned long next;
463 unsigned long start;
464
465 start = addr;
466 pud = pud_offset(p4d, addr);
467 do {
468 next = pud_addr_end(addr, end);
469 if (pud_none_or_clear_bad(pud))
470 continue;
471 if (is_hugetlb_pud(*pud))
472 pud_clear(pud);
473 else
474 hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
475 ceiling);
476 } while (pud++, addr = next, addr != end);
477
478 start &= PGDIR_MASK;
479 if (start < floor)
480 return;
481 if (ceiling) {
482 ceiling &= PGDIR_MASK;
483 if (!ceiling)
484 return;
485 }
486 if (end - 1 > ceiling - 1)
487 return;
488
489 pud = pud_offset(p4d, start);
490 p4d_clear(p4d);
491 pud_free_tlb(tlb, pud, start);
492 mm_dec_nr_puds(tlb->mm);
493}
494
495void hugetlb_free_pgd_range(struct mmu_gather *tlb,
496 unsigned long addr, unsigned long end,
497 unsigned long floor, unsigned long ceiling)
498{
499 pgd_t *pgd;
500 p4d_t *p4d;
501 unsigned long next;
502
503 addr &= PMD_MASK;
504 if (addr < floor) {
505 addr += PMD_SIZE;
506 if (!addr)
507 return;
508 }
509 if (ceiling) {
510 ceiling &= PMD_MASK;
511 if (!ceiling)
512 return;
513 }
514 if (end - 1 > ceiling - 1)
515 end -= PMD_SIZE;
516 if (addr > end - 1)
517 return;
518
519 pgd = pgd_offset(tlb->mm, addr);
520 p4d = p4d_offset(pgd, addr);
521 do {
522 next = p4d_addr_end(addr, end);
523 if (p4d_none_or_clear_bad(p4d))
524 continue;
525 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
526 } while (p4d++, addr = next, addr != end);
527}