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1da177e4 | 1 | /* |
41151e77 | 2 | * PPC Huge TLB Page Support for Kernel. |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2003 David Gibson, IBM Corporation. | |
41151e77 | 5 | * Copyright (C) 2011 Becky Bruce, Freescale Semiconductor |
1da177e4 LT |
6 | * |
7 | * Based on the IA-32 version: | |
8 | * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> | |
9 | */ | |
10 | ||
1da177e4 | 11 | #include <linux/mm.h> |
883a3e52 | 12 | #include <linux/io.h> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1da177e4 | 14 | #include <linux/hugetlb.h> |
342d3db7 | 15 | #include <linux/export.h> |
41151e77 BB |
16 | #include <linux/of_fdt.h> |
17 | #include <linux/memblock.h> | |
18 | #include <linux/bootmem.h> | |
13020be8 | 19 | #include <linux/moduleparam.h> |
883a3e52 | 20 | #include <asm/pgtable.h> |
1da177e4 LT |
21 | #include <asm/pgalloc.h> |
22 | #include <asm/tlb.h> | |
41151e77 | 23 | #include <asm/setup.h> |
29409997 AK |
24 | #include <asm/hugetlb.h> |
25 | ||
26 | #ifdef CONFIG_HUGETLB_PAGE | |
1da177e4 | 27 | |
91224346 | 28 | #define PAGE_SHIFT_64K 16 |
4b914286 CL |
29 | #define PAGE_SHIFT_512K 19 |
30 | #define PAGE_SHIFT_8M 23 | |
91224346 JT |
31 | #define PAGE_SHIFT_16M 24 |
32 | #define PAGE_SHIFT_16G 34 | |
4ec161cf | 33 | |
41151e77 | 34 | unsigned int HPAGE_SHIFT; |
ec4b2c0c | 35 | |
41151e77 BB |
36 | /* |
37 | * Tracks gpages after the device tree is scanned and before the | |
a6146888 BB |
38 | * huge_boot_pages list is ready. On non-Freescale implementations, this is |
39 | * just used to track 16G pages and so is a single array. FSL-based | |
40 | * implementations may have more than one gpage size, so we need multiple | |
41 | * arrays | |
41151e77 | 42 | */ |
4b914286 | 43 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
41151e77 BB |
44 | #define MAX_NUMBER_GPAGES 128 |
45 | struct psize_gpages { | |
46 | u64 gpage_list[MAX_NUMBER_GPAGES]; | |
47 | unsigned int nr_gpages; | |
48 | }; | |
49 | static struct psize_gpages gpage_freearray[MMU_PAGE_COUNT]; | |
881fde1d BB |
50 | #else |
51 | #define MAX_NUMBER_GPAGES 1024 | |
52 | static u64 gpage_freearray[MAX_NUMBER_GPAGES]; | |
53 | static unsigned nr_gpages; | |
41151e77 | 54 | #endif |
f10a04c0 | 55 | |
a4fe3ce7 DG |
56 | #define hugepd_none(hpd) ((hpd).pd == 0) |
57 | ||
a4fe3ce7 DG |
58 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) |
59 | { | |
12bc9f6f | 60 | /* Only called for hugetlbfs pages, hence can ignore THP */ |
891121e6 | 61 | return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL); |
a4fe3ce7 DG |
62 | } |
63 | ||
f10a04c0 | 64 | static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, |
a4fe3ce7 | 65 | unsigned long address, unsigned pdshift, unsigned pshift) |
f10a04c0 | 66 | { |
41151e77 BB |
67 | struct kmem_cache *cachep; |
68 | pte_t *new; | |
41151e77 | 69 | int i; |
03bb2d65 CL |
70 | int num_hugepd; |
71 | ||
72 | if (pshift >= pdshift) { | |
73 | cachep = hugepte_cache; | |
74 | num_hugepd = 1 << (pshift - pdshift); | |
75 | } else { | |
76 | cachep = PGT_CACHE(pdshift - pshift); | |
77 | num_hugepd = 1; | |
78 | } | |
41151e77 | 79 | |
2379a23e | 80 | new = kmem_cache_zalloc(cachep, GFP_KERNEL); |
f10a04c0 | 81 | |
a4fe3ce7 DG |
82 | BUG_ON(pshift > HUGEPD_SHIFT_MASK); |
83 | BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK); | |
84 | ||
f10a04c0 DG |
85 | if (! new) |
86 | return -ENOMEM; | |
87 | ||
0eab46be SB |
88 | /* |
89 | * Make sure other cpus find the hugepd set only after a | |
90 | * properly initialized page table is visible to them. | |
91 | * For more details look for comment in __pte_alloc(). | |
92 | */ | |
93 | smp_wmb(); | |
94 | ||
f10a04c0 | 95 | spin_lock(&mm->page_table_lock); |
03bb2d65 | 96 | |
41151e77 BB |
97 | /* |
98 | * We have multiple higher-level entries that point to the same | |
99 | * actual pte location. Fill in each as we go and backtrack on error. | |
100 | * We need all of these so the DTLB pgtable walk code can find the | |
101 | * right higher-level entry without knowing if it's a hugepage or not. | |
102 | */ | |
103 | for (i = 0; i < num_hugepd; i++, hpdp++) { | |
104 | if (unlikely(!hugepd_none(*hpdp))) | |
105 | break; | |
106 | else | |
03bb2d65 CL |
107 | #ifdef CONFIG_PPC_BOOK3S_64 |
108 | hpdp->pd = __pa(new) | | |
109 | (shift_to_mmu_psize(pshift) << 2); | |
4b914286 CL |
110 | #elif defined(CONFIG_PPC_8xx) |
111 | hpdp->pd = __pa(new) | | |
112 | (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M : | |
113 | _PMD_PAGE_512K) | | |
114 | _PMD_PRESENT; | |
03bb2d65 | 115 | #else |
cf9427b8 | 116 | /* We use the old format for PPC_FSL_BOOK3E */ |
41151e77 | 117 | hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift; |
03bb2d65 | 118 | #endif |
41151e77 BB |
119 | } |
120 | /* If we bailed from the for loop early, an error occurred, clean up */ | |
121 | if (i < num_hugepd) { | |
122 | for (i = i - 1 ; i >= 0; i--, hpdp--) | |
123 | hpdp->pd = 0; | |
124 | kmem_cache_free(cachep, new); | |
125 | } | |
f10a04c0 DG |
126 | spin_unlock(&mm->page_table_lock); |
127 | return 0; | |
128 | } | |
129 | ||
a1cd5419 BB |
130 | /* |
131 | * These macros define how to determine which level of the page table holds | |
132 | * the hpdp. | |
133 | */ | |
4b914286 | 134 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
a1cd5419 BB |
135 | #define HUGEPD_PGD_SHIFT PGDIR_SHIFT |
136 | #define HUGEPD_PUD_SHIFT PUD_SHIFT | |
137 | #else | |
138 | #define HUGEPD_PGD_SHIFT PUD_SHIFT | |
139 | #define HUGEPD_PUD_SHIFT PMD_SHIFT | |
140 | #endif | |
141 | ||
e2b3d202 AK |
142 | /* |
143 | * At this point we do the placement change only for BOOK3S 64. This would | |
144 | * possibly work on other subarchs. | |
145 | */ | |
146 | pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz) | |
147 | { | |
148 | pgd_t *pg; | |
149 | pud_t *pu; | |
150 | pmd_t *pm; | |
151 | hugepd_t *hpdp = NULL; | |
152 | unsigned pshift = __ffs(sz); | |
153 | unsigned pdshift = PGDIR_SHIFT; | |
154 | ||
155 | addr &= ~(sz-1); | |
156 | pg = pgd_offset(mm, addr); | |
157 | ||
03bb2d65 | 158 | #ifdef CONFIG_PPC_BOOK3S_64 |
e2b3d202 AK |
159 | if (pshift == PGDIR_SHIFT) |
160 | /* 16GB huge page */ | |
161 | return (pte_t *) pg; | |
162 | else if (pshift > PUD_SHIFT) | |
163 | /* | |
164 | * We need to use hugepd table | |
165 | */ | |
166 | hpdp = (hugepd_t *)pg; | |
167 | else { | |
168 | pdshift = PUD_SHIFT; | |
169 | pu = pud_alloc(mm, pg, addr); | |
170 | if (pshift == PUD_SHIFT) | |
171 | return (pte_t *)pu; | |
172 | else if (pshift > PMD_SHIFT) | |
173 | hpdp = (hugepd_t *)pu; | |
174 | else { | |
175 | pdshift = PMD_SHIFT; | |
176 | pm = pmd_alloc(mm, pu, addr); | |
177 | if (pshift == PMD_SHIFT) | |
178 | /* 16MB hugepage */ | |
179 | return (pte_t *)pm; | |
180 | else | |
181 | hpdp = (hugepd_t *)pm; | |
182 | } | |
183 | } | |
e2b3d202 | 184 | #else |
a1cd5419 | 185 | if (pshift >= HUGEPD_PGD_SHIFT) { |
a4fe3ce7 DG |
186 | hpdp = (hugepd_t *)pg; |
187 | } else { | |
188 | pdshift = PUD_SHIFT; | |
189 | pu = pud_alloc(mm, pg, addr); | |
a1cd5419 | 190 | if (pshift >= HUGEPD_PUD_SHIFT) { |
a4fe3ce7 DG |
191 | hpdp = (hugepd_t *)pu; |
192 | } else { | |
193 | pdshift = PMD_SHIFT; | |
194 | pm = pmd_alloc(mm, pu, addr); | |
195 | hpdp = (hugepd_t *)pm; | |
196 | } | |
197 | } | |
03bb2d65 | 198 | #endif |
a4fe3ce7 DG |
199 | if (!hpdp) |
200 | return NULL; | |
201 | ||
202 | BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp)); | |
203 | ||
204 | if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift)) | |
205 | return NULL; | |
206 | ||
b30e7590 | 207 | return hugepte_offset(*hpdp, addr, pdshift); |
4ec161cf | 208 | } |
4ec161cf | 209 | |
4b914286 | 210 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
658013e9 | 211 | /* Build list of addresses of gigantic pages. This function is used in early |
14ed7409 | 212 | * boot before the buddy allocator is setup. |
658013e9 | 213 | */ |
41151e77 BB |
214 | void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages) |
215 | { | |
216 | unsigned int idx = shift_to_mmu_psize(__ffs(page_size)); | |
217 | int i; | |
218 | ||
219 | if (addr == 0) | |
220 | return; | |
221 | ||
222 | gpage_freearray[idx].nr_gpages = number_of_pages; | |
223 | ||
224 | for (i = 0; i < number_of_pages; i++) { | |
225 | gpage_freearray[idx].gpage_list[i] = addr; | |
226 | addr += page_size; | |
227 | } | |
228 | } | |
229 | ||
230 | /* | |
231 | * Moves the gigantic page addresses from the temporary list to the | |
232 | * huge_boot_pages list. | |
233 | */ | |
234 | int alloc_bootmem_huge_page(struct hstate *hstate) | |
235 | { | |
236 | struct huge_bootmem_page *m; | |
2415cf12 | 237 | int idx = shift_to_mmu_psize(huge_page_shift(hstate)); |
41151e77 BB |
238 | int nr_gpages = gpage_freearray[idx].nr_gpages; |
239 | ||
240 | if (nr_gpages == 0) | |
241 | return 0; | |
242 | ||
243 | #ifdef CONFIG_HIGHMEM | |
244 | /* | |
245 | * If gpages can be in highmem we can't use the trick of storing the | |
246 | * data structure in the page; allocate space for this | |
247 | */ | |
e39f223f | 248 | m = memblock_virt_alloc(sizeof(struct huge_bootmem_page), 0); |
41151e77 BB |
249 | m->phys = gpage_freearray[idx].gpage_list[--nr_gpages]; |
250 | #else | |
251 | m = phys_to_virt(gpage_freearray[idx].gpage_list[--nr_gpages]); | |
252 | #endif | |
253 | ||
254 | list_add(&m->list, &huge_boot_pages); | |
255 | gpage_freearray[idx].nr_gpages = nr_gpages; | |
256 | gpage_freearray[idx].gpage_list[nr_gpages] = 0; | |
257 | m->hstate = hstate; | |
258 | ||
259 | return 1; | |
260 | } | |
261 | /* | |
262 | * Scan the command line hugepagesz= options for gigantic pages; store those in | |
263 | * a list that we use to allocate the memory once all options are parsed. | |
264 | */ | |
265 | ||
266 | unsigned long gpage_npages[MMU_PAGE_COUNT]; | |
267 | ||
89528127 | 268 | static int __init do_gpage_early_setup(char *param, char *val, |
ecc86170 | 269 | const char *unused, void *arg) |
41151e77 BB |
270 | { |
271 | static phys_addr_t size; | |
272 | unsigned long npages; | |
273 | ||
274 | /* | |
275 | * The hugepagesz and hugepages cmdline options are interleaved. We | |
276 | * use the size variable to keep track of whether or not this was done | |
277 | * properly and skip over instances where it is incorrect. Other | |
278 | * command-line parsing code will issue warnings, so we don't need to. | |
279 | * | |
280 | */ | |
281 | if ((strcmp(param, "default_hugepagesz") == 0) || | |
282 | (strcmp(param, "hugepagesz") == 0)) { | |
283 | size = memparse(val, NULL); | |
284 | } else if (strcmp(param, "hugepages") == 0) { | |
285 | if (size != 0) { | |
286 | if (sscanf(val, "%lu", &npages) <= 0) | |
287 | npages = 0; | |
c4f3eb5f JY |
288 | if (npages > MAX_NUMBER_GPAGES) { |
289 | pr_warn("MMU: %lu pages requested for page " | |
03bb2d65 | 290 | #ifdef CONFIG_PHYS_ADDR_T_64BIT |
c4f3eb5f | 291 | "size %llu KB, limiting to " |
03bb2d65 CL |
292 | #else |
293 | "size %u KB, limiting to " | |
294 | #endif | |
c4f3eb5f JY |
295 | __stringify(MAX_NUMBER_GPAGES) "\n", |
296 | npages, size / 1024); | |
297 | npages = MAX_NUMBER_GPAGES; | |
298 | } | |
41151e77 BB |
299 | gpage_npages[shift_to_mmu_psize(__ffs(size))] = npages; |
300 | size = 0; | |
301 | } | |
302 | } | |
303 | return 0; | |
304 | } | |
305 | ||
306 | ||
307 | /* | |
308 | * This function allocates physical space for pages that are larger than the | |
309 | * buddy allocator can handle. We want to allocate these in highmem because | |
310 | * the amount of lowmem is limited. This means that this function MUST be | |
311 | * called before lowmem_end_addr is set up in MMU_init() in order for the lmb | |
312 | * allocate to grab highmem. | |
313 | */ | |
314 | void __init reserve_hugetlb_gpages(void) | |
315 | { | |
316 | static __initdata char cmdline[COMMAND_LINE_SIZE]; | |
317 | phys_addr_t size, base; | |
318 | int i; | |
319 | ||
320 | strlcpy(cmdline, boot_command_line, COMMAND_LINE_SIZE); | |
026cee00 | 321 | parse_args("hugetlb gpages", cmdline, NULL, 0, 0, 0, |
ecc86170 | 322 | NULL, &do_gpage_early_setup); |
41151e77 BB |
323 | |
324 | /* | |
325 | * Walk gpage list in reverse, allocating larger page sizes first. | |
326 | * Skip over unsupported sizes, or sizes that have 0 gpages allocated. | |
327 | * When we reach the point in the list where pages are no longer | |
328 | * considered gpages, we're done. | |
329 | */ | |
330 | for (i = MMU_PAGE_COUNT-1; i >= 0; i--) { | |
331 | if (mmu_psize_defs[i].shift == 0 || gpage_npages[i] == 0) | |
332 | continue; | |
333 | else if (mmu_psize_to_shift(i) < (MAX_ORDER + PAGE_SHIFT)) | |
334 | break; | |
335 | ||
336 | size = (phys_addr_t)(1ULL << mmu_psize_to_shift(i)); | |
337 | base = memblock_alloc_base(size * gpage_npages[i], size, | |
338 | MEMBLOCK_ALLOC_ANYWHERE); | |
339 | add_gpage(base, size, gpage_npages[i]); | |
340 | } | |
341 | } | |
342 | ||
881fde1d | 343 | #else /* !PPC_FSL_BOOK3E */ |
41151e77 BB |
344 | |
345 | /* Build list of addresses of gigantic pages. This function is used in early | |
14ed7409 | 346 | * boot before the buddy allocator is setup. |
41151e77 BB |
347 | */ |
348 | void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages) | |
658013e9 JT |
349 | { |
350 | if (!addr) | |
351 | return; | |
352 | while (number_of_pages > 0) { | |
353 | gpage_freearray[nr_gpages] = addr; | |
354 | nr_gpages++; | |
355 | number_of_pages--; | |
356 | addr += page_size; | |
357 | } | |
358 | } | |
359 | ||
ec4b2c0c | 360 | /* Moves the gigantic page addresses from the temporary list to the |
0d9ea754 JT |
361 | * huge_boot_pages list. |
362 | */ | |
363 | int alloc_bootmem_huge_page(struct hstate *hstate) | |
ec4b2c0c JT |
364 | { |
365 | struct huge_bootmem_page *m; | |
366 | if (nr_gpages == 0) | |
367 | return 0; | |
368 | m = phys_to_virt(gpage_freearray[--nr_gpages]); | |
369 | gpage_freearray[nr_gpages] = 0; | |
370 | list_add(&m->list, &huge_boot_pages); | |
0d9ea754 | 371 | m->hstate = hstate; |
ec4b2c0c JT |
372 | return 1; |
373 | } | |
41151e77 | 374 | #endif |
ec4b2c0c | 375 | |
4b914286 | 376 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
41151e77 BB |
377 | #define HUGEPD_FREELIST_SIZE \ |
378 | ((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t)) | |
379 | ||
380 | struct hugepd_freelist { | |
381 | struct rcu_head rcu; | |
382 | unsigned int index; | |
383 | void *ptes[0]; | |
384 | }; | |
385 | ||
386 | static DEFINE_PER_CPU(struct hugepd_freelist *, hugepd_freelist_cur); | |
387 | ||
388 | static void hugepd_free_rcu_callback(struct rcu_head *head) | |
389 | { | |
390 | struct hugepd_freelist *batch = | |
391 | container_of(head, struct hugepd_freelist, rcu); | |
392 | unsigned int i; | |
393 | ||
394 | for (i = 0; i < batch->index; i++) | |
395 | kmem_cache_free(hugepte_cache, batch->ptes[i]); | |
396 | ||
397 | free_page((unsigned long)batch); | |
398 | } | |
399 | ||
400 | static void hugepd_free(struct mmu_gather *tlb, void *hugepte) | |
401 | { | |
402 | struct hugepd_freelist **batchp; | |
403 | ||
08a5bb29 | 404 | batchp = &get_cpu_var(hugepd_freelist_cur); |
41151e77 BB |
405 | |
406 | if (atomic_read(&tlb->mm->mm_users) < 2 || | |
407 | cpumask_equal(mm_cpumask(tlb->mm), | |
408 | cpumask_of(smp_processor_id()))) { | |
409 | kmem_cache_free(hugepte_cache, hugepte); | |
08a5bb29 | 410 | put_cpu_var(hugepd_freelist_cur); |
41151e77 BB |
411 | return; |
412 | } | |
413 | ||
414 | if (*batchp == NULL) { | |
415 | *batchp = (struct hugepd_freelist *)__get_free_page(GFP_ATOMIC); | |
416 | (*batchp)->index = 0; | |
417 | } | |
418 | ||
419 | (*batchp)->ptes[(*batchp)->index++] = hugepte; | |
420 | if ((*batchp)->index == HUGEPD_FREELIST_SIZE) { | |
421 | call_rcu_sched(&(*batchp)->rcu, hugepd_free_rcu_callback); | |
422 | *batchp = NULL; | |
423 | } | |
94b09d75 | 424 | put_cpu_var(hugepd_freelist_cur); |
41151e77 | 425 | } |
03bb2d65 CL |
426 | #else |
427 | static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {} | |
41151e77 BB |
428 | #endif |
429 | ||
a4fe3ce7 DG |
430 | static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift, |
431 | unsigned long start, unsigned long end, | |
432 | unsigned long floor, unsigned long ceiling) | |
f10a04c0 DG |
433 | { |
434 | pte_t *hugepte = hugepd_page(*hpdp); | |
41151e77 BB |
435 | int i; |
436 | ||
a4fe3ce7 | 437 | unsigned long pdmask = ~((1UL << pdshift) - 1); |
41151e77 | 438 | unsigned int num_hugepd = 1; |
03bb2d65 | 439 | unsigned int shift = hugepd_shift(*hpdp); |
41151e77 | 440 | |
881fde1d | 441 | /* Note: On fsl the hpdp may be the first of several */ |
03bb2d65 CL |
442 | if (shift > pdshift) |
443 | num_hugepd = 1 << (shift - pdshift); | |
a4fe3ce7 DG |
444 | |
445 | start &= pdmask; | |
446 | if (start < floor) | |
447 | return; | |
448 | if (ceiling) { | |
449 | ceiling &= pdmask; | |
450 | if (! ceiling) | |
451 | return; | |
452 | } | |
453 | if (end - 1 > ceiling - 1) | |
454 | return; | |
f10a04c0 | 455 | |
41151e77 BB |
456 | for (i = 0; i < num_hugepd; i++, hpdp++) |
457 | hpdp->pd = 0; | |
458 | ||
03bb2d65 CL |
459 | if (shift >= pdshift) |
460 | hugepd_free(tlb, hugepte); | |
461 | else | |
462 | pgtable_free_tlb(tlb, hugepte, pdshift - shift); | |
f10a04c0 DG |
463 | } |
464 | ||
f10a04c0 DG |
465 | static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, |
466 | unsigned long addr, unsigned long end, | |
a4fe3ce7 | 467 | unsigned long floor, unsigned long ceiling) |
f10a04c0 DG |
468 | { |
469 | pmd_t *pmd; | |
470 | unsigned long next; | |
471 | unsigned long start; | |
472 | ||
473 | start = addr; | |
f10a04c0 | 474 | do { |
03bb2d65 CL |
475 | unsigned long more; |
476 | ||
a1cd5419 | 477 | pmd = pmd_offset(pud, addr); |
f10a04c0 | 478 | next = pmd_addr_end(addr, end); |
b30e7590 | 479 | if (!is_hugepd(__hugepd(pmd_val(*pmd)))) { |
8bbd9f04 AK |
480 | /* |
481 | * if it is not hugepd pointer, we should already find | |
482 | * it cleared. | |
483 | */ | |
484 | WARN_ON(!pmd_none_or_clear_bad(pmd)); | |
f10a04c0 | 485 | continue; |
8bbd9f04 | 486 | } |
a1cd5419 BB |
487 | /* |
488 | * Increment next by the size of the huge mapping since | |
489 | * there may be more than one entry at this level for a | |
490 | * single hugepage, but all of them point to | |
491 | * the same kmem cache that holds the hugepte. | |
492 | */ | |
03bb2d65 CL |
493 | more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd)); |
494 | if (more > next) | |
495 | next = more; | |
496 | ||
a4fe3ce7 DG |
497 | free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT, |
498 | addr, next, floor, ceiling); | |
a1cd5419 | 499 | } while (addr = next, addr != end); |
f10a04c0 DG |
500 | |
501 | start &= PUD_MASK; | |
502 | if (start < floor) | |
503 | return; | |
504 | if (ceiling) { | |
505 | ceiling &= PUD_MASK; | |
506 | if (!ceiling) | |
507 | return; | |
1da177e4 | 508 | } |
f10a04c0 DG |
509 | if (end - 1 > ceiling - 1) |
510 | return; | |
1da177e4 | 511 | |
f10a04c0 DG |
512 | pmd = pmd_offset(pud, start); |
513 | pud_clear(pud); | |
9e1b32ca | 514 | pmd_free_tlb(tlb, pmd, start); |
50c6a665 | 515 | mm_dec_nr_pmds(tlb->mm); |
f10a04c0 | 516 | } |
f10a04c0 DG |
517 | |
518 | static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, | |
519 | unsigned long addr, unsigned long end, | |
520 | unsigned long floor, unsigned long ceiling) | |
521 | { | |
522 | pud_t *pud; | |
523 | unsigned long next; | |
524 | unsigned long start; | |
525 | ||
526 | start = addr; | |
f10a04c0 | 527 | do { |
a1cd5419 | 528 | pud = pud_offset(pgd, addr); |
f10a04c0 | 529 | next = pud_addr_end(addr, end); |
b30e7590 | 530 | if (!is_hugepd(__hugepd(pud_val(*pud)))) { |
4ec161cf JT |
531 | if (pud_none_or_clear_bad(pud)) |
532 | continue; | |
0d9ea754 | 533 | hugetlb_free_pmd_range(tlb, pud, addr, next, floor, |
a4fe3ce7 | 534 | ceiling); |
4ec161cf | 535 | } else { |
03bb2d65 | 536 | unsigned long more; |
a1cd5419 BB |
537 | /* |
538 | * Increment next by the size of the huge mapping since | |
539 | * there may be more than one entry at this level for a | |
540 | * single hugepage, but all of them point to | |
541 | * the same kmem cache that holds the hugepte. | |
542 | */ | |
03bb2d65 CL |
543 | more = addr + (1 << hugepd_shift(*(hugepd_t *)pud)); |
544 | if (more > next) | |
545 | next = more; | |
546 | ||
a4fe3ce7 DG |
547 | free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT, |
548 | addr, next, floor, ceiling); | |
4ec161cf | 549 | } |
a1cd5419 | 550 | } while (addr = next, addr != end); |
f10a04c0 DG |
551 | |
552 | start &= PGDIR_MASK; | |
553 | if (start < floor) | |
554 | return; | |
555 | if (ceiling) { | |
556 | ceiling &= PGDIR_MASK; | |
557 | if (!ceiling) | |
558 | return; | |
559 | } | |
560 | if (end - 1 > ceiling - 1) | |
561 | return; | |
562 | ||
563 | pud = pud_offset(pgd, start); | |
564 | pgd_clear(pgd); | |
9e1b32ca | 565 | pud_free_tlb(tlb, pud, start); |
f10a04c0 DG |
566 | } |
567 | ||
568 | /* | |
569 | * This function frees user-level page tables of a process. | |
f10a04c0 | 570 | */ |
42b77728 | 571 | void hugetlb_free_pgd_range(struct mmu_gather *tlb, |
f10a04c0 DG |
572 | unsigned long addr, unsigned long end, |
573 | unsigned long floor, unsigned long ceiling) | |
574 | { | |
575 | pgd_t *pgd; | |
576 | unsigned long next; | |
f10a04c0 DG |
577 | |
578 | /* | |
a4fe3ce7 DG |
579 | * Because there are a number of different possible pagetable |
580 | * layouts for hugepage ranges, we limit knowledge of how | |
581 | * things should be laid out to the allocation path | |
582 | * (huge_pte_alloc(), above). Everything else works out the | |
583 | * structure as it goes from information in the hugepd | |
584 | * pointers. That means that we can't here use the | |
585 | * optimization used in the normal page free_pgd_range(), of | |
586 | * checking whether we're actually covering a large enough | |
587 | * range to have to do anything at the top level of the walk | |
588 | * instead of at the bottom. | |
f10a04c0 | 589 | * |
a4fe3ce7 DG |
590 | * To make sense of this, you should probably go read the big |
591 | * block comment at the top of the normal free_pgd_range(), | |
592 | * too. | |
f10a04c0 | 593 | */ |
f10a04c0 | 594 | |
f10a04c0 | 595 | do { |
f10a04c0 | 596 | next = pgd_addr_end(addr, end); |
41151e77 | 597 | pgd = pgd_offset(tlb->mm, addr); |
b30e7590 | 598 | if (!is_hugepd(__hugepd(pgd_val(*pgd)))) { |
0b26425c DG |
599 | if (pgd_none_or_clear_bad(pgd)) |
600 | continue; | |
601 | hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling); | |
602 | } else { | |
03bb2d65 | 603 | unsigned long more; |
41151e77 BB |
604 | /* |
605 | * Increment next by the size of the huge mapping since | |
881fde1d BB |
606 | * there may be more than one entry at the pgd level |
607 | * for a single hugepage, but all of them point to the | |
608 | * same kmem cache that holds the hugepte. | |
41151e77 | 609 | */ |
03bb2d65 CL |
610 | more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd)); |
611 | if (more > next) | |
612 | next = more; | |
613 | ||
a4fe3ce7 DG |
614 | free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT, |
615 | addr, next, floor, ceiling); | |
0b26425c | 616 | } |
41151e77 | 617 | } while (addr = next, addr != end); |
1da177e4 LT |
618 | } |
619 | ||
691e95fd AK |
620 | /* |
621 | * We are holding mmap_sem, so a parallel huge page collapse cannot run. | |
622 | * To prevent hugepage split, disable irq. | |
623 | */ | |
1da177e4 LT |
624 | struct page * |
625 | follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) | |
626 | { | |
891121e6 | 627 | bool is_thp; |
7b868e81 | 628 | pte_t *ptep, pte; |
a4fe3ce7 | 629 | unsigned shift; |
691e95fd | 630 | unsigned long mask, flags; |
7b868e81 AK |
631 | struct page *page = ERR_PTR(-EINVAL); |
632 | ||
633 | local_irq_save(flags); | |
891121e6 | 634 | ptep = find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift); |
7b868e81 AK |
635 | if (!ptep) |
636 | goto no_page; | |
637 | pte = READ_ONCE(*ptep); | |
12bc9f6f | 638 | /* |
7b868e81 | 639 | * Verify it is a huge page else bail. |
12bc9f6f AK |
640 | * Transparent hugepages are handled by generic code. We can skip them |
641 | * here. | |
642 | */ | |
891121e6 | 643 | if (!shift || is_thp) |
7b868e81 | 644 | goto no_page; |
1da177e4 | 645 | |
7b868e81 AK |
646 | if (!pte_present(pte)) { |
647 | page = NULL; | |
648 | goto no_page; | |
691e95fd | 649 | } |
a4fe3ce7 | 650 | mask = (1UL << shift) - 1; |
7b868e81 | 651 | page = pte_page(pte); |
a4fe3ce7 DG |
652 | if (page) |
653 | page += (address & mask) / PAGE_SIZE; | |
1da177e4 | 654 | |
7b868e81 | 655 | no_page: |
691e95fd | 656 | local_irq_restore(flags); |
1da177e4 LT |
657 | return page; |
658 | } | |
659 | ||
1da177e4 LT |
660 | struct page * |
661 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, | |
662 | pmd_t *pmd, int write) | |
663 | { | |
664 | BUG(); | |
665 | return NULL; | |
666 | } | |
667 | ||
61f77eda NH |
668 | struct page * |
669 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
670 | pud_t *pud, int write) | |
671 | { | |
672 | BUG(); | |
673 | return NULL; | |
674 | } | |
675 | ||
39adfa54 DG |
676 | static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end, |
677 | unsigned long sz) | |
678 | { | |
679 | unsigned long __boundary = (addr + sz) & ~(sz-1); | |
680 | return (__boundary - 1 < end - 1) ? __boundary : end; | |
681 | } | |
682 | ||
b30e7590 AK |
683 | int gup_huge_pd(hugepd_t hugepd, unsigned long addr, unsigned pdshift, |
684 | unsigned long end, int write, struct page **pages, int *nr) | |
a4fe3ce7 DG |
685 | { |
686 | pte_t *ptep; | |
b30e7590 | 687 | unsigned long sz = 1UL << hugepd_shift(hugepd); |
39adfa54 | 688 | unsigned long next; |
a4fe3ce7 DG |
689 | |
690 | ptep = hugepte_offset(hugepd, addr, pdshift); | |
691 | do { | |
39adfa54 | 692 | next = hugepte_addr_end(addr, end, sz); |
a4fe3ce7 DG |
693 | if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr)) |
694 | return 0; | |
39adfa54 | 695 | } while (ptep++, addr = next, addr != end); |
a4fe3ce7 DG |
696 | |
697 | return 1; | |
698 | } | |
1da177e4 | 699 | |
76512959 | 700 | #ifdef CONFIG_PPC_MM_SLICES |
1da177e4 LT |
701 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, |
702 | unsigned long len, unsigned long pgoff, | |
703 | unsigned long flags) | |
704 | { | |
0d9ea754 JT |
705 | struct hstate *hstate = hstate_file(file); |
706 | int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate)); | |
48f797de | 707 | |
48483760 AK |
708 | if (radix_enabled()) |
709 | return radix__hugetlb_get_unmapped_area(file, addr, len, | |
710 | pgoff, flags); | |
34d07177 | 711 | return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1); |
1da177e4 | 712 | } |
76512959 | 713 | #endif |
1da177e4 | 714 | |
3340289d MG |
715 | unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) |
716 | { | |
25c29f9e | 717 | #ifdef CONFIG_PPC_MM_SLICES |
3340289d | 718 | unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start); |
2f5f0dfd AK |
719 | /* With radix we don't use slice, so derive it from vma*/ |
720 | if (!radix_enabled()) | |
721 | return 1UL << mmu_psize_to_shift(psize); | |
722 | #endif | |
41151e77 BB |
723 | if (!is_vm_hugetlb_page(vma)) |
724 | return PAGE_SIZE; | |
725 | ||
726 | return huge_page_size(hstate_vma(vma)); | |
41151e77 BB |
727 | } |
728 | ||
729 | static inline bool is_power_of_4(unsigned long x) | |
730 | { | |
731 | if (is_power_of_2(x)) | |
732 | return (__ilog2(x) % 2) ? false : true; | |
733 | return false; | |
3340289d MG |
734 | } |
735 | ||
d1837cba | 736 | static int __init add_huge_page_size(unsigned long long size) |
4ec161cf | 737 | { |
d1837cba DG |
738 | int shift = __ffs(size); |
739 | int mmu_psize; | |
a4fe3ce7 | 740 | |
4ec161cf | 741 | /* Check that it is a page size supported by the hardware and |
d1837cba | 742 | * that it fits within pagetable and slice limits. */ |
03bb2d65 CL |
743 | if (size <= PAGE_SIZE) |
744 | return -EINVAL; | |
4b914286 | 745 | #if defined(CONFIG_PPC_FSL_BOOK3E) |
03bb2d65 | 746 | if (!is_power_of_4(size)) |
41151e77 | 747 | return -EINVAL; |
4b914286 | 748 | #elif !defined(CONFIG_PPC_8xx) |
03bb2d65 | 749 | if (!is_power_of_2(size) || (shift > SLICE_HIGH_SHIFT)) |
d1837cba | 750 | return -EINVAL; |
41151e77 | 751 | #endif |
91224346 | 752 | |
d1837cba DG |
753 | if ((mmu_psize = shift_to_mmu_psize(shift)) < 0) |
754 | return -EINVAL; | |
755 | ||
d1837cba DG |
756 | BUG_ON(mmu_psize_defs[mmu_psize].shift != shift); |
757 | ||
758 | /* Return if huge page size has already been setup */ | |
759 | if (size_to_hstate(size)) | |
760 | return 0; | |
761 | ||
762 | hugetlb_add_hstate(shift - PAGE_SHIFT); | |
763 | ||
764 | return 0; | |
4ec161cf JT |
765 | } |
766 | ||
767 | static int __init hugepage_setup_sz(char *str) | |
768 | { | |
769 | unsigned long long size; | |
4ec161cf JT |
770 | |
771 | size = memparse(str, &str); | |
772 | ||
71bf79cc VT |
773 | if (add_huge_page_size(size) != 0) { |
774 | hugetlb_bad_size(); | |
775 | pr_err("Invalid huge page size specified(%llu)\n", size); | |
776 | } | |
4ec161cf JT |
777 | |
778 | return 1; | |
779 | } | |
780 | __setup("hugepagesz=", hugepage_setup_sz); | |
781 | ||
41151e77 BB |
782 | struct kmem_cache *hugepte_cache; |
783 | static int __init hugetlbpage_init(void) | |
784 | { | |
785 | int psize; | |
786 | ||
4b914286 | 787 | #if !defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_PPC_8xx) |
48483760 | 788 | if (!radix_enabled() && !mmu_has_feature(MMU_FTR_16M_PAGE)) |
f10a04c0 | 789 | return -ENODEV; |
03bb2d65 | 790 | #endif |
d1837cba DG |
791 | for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { |
792 | unsigned shift; | |
793 | unsigned pdshift; | |
0d9ea754 | 794 | |
d1837cba DG |
795 | if (!mmu_psize_defs[psize].shift) |
796 | continue; | |
00df438e | 797 | |
d1837cba DG |
798 | shift = mmu_psize_to_shift(psize); |
799 | ||
800 | if (add_huge_page_size(1ULL << shift) < 0) | |
801 | continue; | |
802 | ||
03bb2d65 | 803 | if (shift < HUGEPD_PUD_SHIFT) |
d1837cba | 804 | pdshift = PMD_SHIFT; |
03bb2d65 | 805 | else if (shift < HUGEPD_PGD_SHIFT) |
d1837cba DG |
806 | pdshift = PUD_SHIFT; |
807 | else | |
808 | pdshift = PGDIR_SHIFT; | |
e2b3d202 AK |
809 | /* |
810 | * if we have pdshift and shift value same, we don't | |
811 | * use pgt cache for hugepd. | |
812 | */ | |
03bb2d65 | 813 | if (pdshift > shift) { |
e2b3d202 AK |
814 | pgtable_cache_add(pdshift - shift, NULL); |
815 | if (!PGT_CACHE(pdshift - shift)) | |
816 | panic("hugetlbpage_init(): could not create " | |
817 | "pgtable cache for %d bit pagesize\n", shift); | |
818 | } | |
4b914286 | 819 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
03bb2d65 CL |
820 | else if (!hugepte_cache) { |
821 | /* | |
822 | * Create a kmem cache for hugeptes. The bottom bits in | |
823 | * the pte have size information encoded in them, so | |
824 | * align them to allow this | |
825 | */ | |
826 | hugepte_cache = kmem_cache_create("hugepte-cache", | |
827 | sizeof(pte_t), | |
828 | HUGEPD_SHIFT_MASK + 1, | |
829 | 0, NULL); | |
830 | if (hugepte_cache == NULL) | |
831 | panic("%s: Unable to create kmem cache " | |
832 | "for hugeptes\n", __func__); | |
833 | ||
834 | } | |
835 | #endif | |
0d9ea754 | 836 | } |
f10a04c0 | 837 | |
4b914286 CL |
838 | #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
839 | /* Default hpage size = 4M on FSL_BOOK3E and 512k on 8xx */ | |
03bb2d65 CL |
840 | if (mmu_psize_defs[MMU_PAGE_4M].shift) |
841 | HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift; | |
4b914286 CL |
842 | else if (mmu_psize_defs[MMU_PAGE_512K].shift) |
843 | HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_512K].shift; | |
03bb2d65 | 844 | #else |
d1837cba DG |
845 | /* Set default large page size. Currently, we pick 16M or 1M |
846 | * depending on what is available | |
847 | */ | |
848 | if (mmu_psize_defs[MMU_PAGE_16M].shift) | |
849 | HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_16M].shift; | |
850 | else if (mmu_psize_defs[MMU_PAGE_1M].shift) | |
851 | HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift; | |
48483760 AK |
852 | else if (mmu_psize_defs[MMU_PAGE_2M].shift) |
853 | HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift; | |
03bb2d65 CL |
854 | #endif |
855 | else | |
856 | panic("%s: Unable to set default huge page size\n", __func__); | |
d1837cba | 857 | |
f10a04c0 DG |
858 | return 0; |
859 | } | |
03bb2d65 | 860 | |
6f114281 | 861 | arch_initcall(hugetlbpage_init); |
0895ecda DG |
862 | |
863 | void flush_dcache_icache_hugepage(struct page *page) | |
864 | { | |
865 | int i; | |
41151e77 | 866 | void *start; |
0895ecda DG |
867 | |
868 | BUG_ON(!PageCompound(page)); | |
869 | ||
41151e77 BB |
870 | for (i = 0; i < (1UL << compound_order(page)); i++) { |
871 | if (!PageHighMem(page)) { | |
872 | __flush_dcache_icache(page_address(page+i)); | |
873 | } else { | |
2480b208 | 874 | start = kmap_atomic(page+i); |
41151e77 | 875 | __flush_dcache_icache(start); |
2480b208 | 876 | kunmap_atomic(start); |
41151e77 BB |
877 | } |
878 | } | |
0895ecda | 879 | } |
29409997 AK |
880 | |
881 | #endif /* CONFIG_HUGETLB_PAGE */ | |
882 | ||
883 | /* | |
884 | * We have 4 cases for pgds and pmds: | |
885 | * (1) invalid (all zeroes) | |
886 | * (2) pointer to next table, as normal; bottom 6 bits == 0 | |
6a119eae AK |
887 | * (3) leaf pte for huge page _PAGE_PTE set |
888 | * (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table | |
0ac52dd7 AK |
889 | * |
890 | * So long as we atomically load page table pointers we are safe against teardown, | |
891 | * we can follow the address down to the the page and take a ref on it. | |
691e95fd AK |
892 | * This function need to be called with interrupts disabled. We use this variant |
893 | * when we have MSR[EE] = 0 but the paca->soft_enabled = 1 | |
29409997 | 894 | */ |
0ac52dd7 | 895 | |
691e95fd | 896 | pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, |
891121e6 | 897 | bool *is_thp, unsigned *shift) |
29409997 | 898 | { |
0ac52dd7 AK |
899 | pgd_t pgd, *pgdp; |
900 | pud_t pud, *pudp; | |
901 | pmd_t pmd, *pmdp; | |
29409997 AK |
902 | pte_t *ret_pte; |
903 | hugepd_t *hpdp = NULL; | |
904 | unsigned pdshift = PGDIR_SHIFT; | |
905 | ||
906 | if (shift) | |
907 | *shift = 0; | |
908 | ||
891121e6 AK |
909 | if (is_thp) |
910 | *is_thp = false; | |
911 | ||
0ac52dd7 | 912 | pgdp = pgdir + pgd_index(ea); |
4f9c53c8 | 913 | pgd = READ_ONCE(*pgdp); |
ac52ae47 | 914 | /* |
0ac52dd7 AK |
915 | * Always operate on the local stack value. This make sure the |
916 | * value don't get updated by a parallel THP split/collapse, | |
917 | * page fault or a page unmap. The return pte_t * is still not | |
918 | * stable. So should be checked there for above conditions. | |
ac52ae47 | 919 | */ |
0ac52dd7 | 920 | if (pgd_none(pgd)) |
ac52ae47 | 921 | return NULL; |
0ac52dd7 AK |
922 | else if (pgd_huge(pgd)) { |
923 | ret_pte = (pte_t *) pgdp; | |
29409997 | 924 | goto out; |
b30e7590 | 925 | } else if (is_hugepd(__hugepd(pgd_val(pgd)))) |
0ac52dd7 | 926 | hpdp = (hugepd_t *)&pgd; |
ac52ae47 | 927 | else { |
0ac52dd7 AK |
928 | /* |
929 | * Even if we end up with an unmap, the pgtable will not | |
930 | * be freed, because we do an rcu free and here we are | |
931 | * irq disabled | |
932 | */ | |
29409997 | 933 | pdshift = PUD_SHIFT; |
0ac52dd7 | 934 | pudp = pud_offset(&pgd, ea); |
da1a288d | 935 | pud = READ_ONCE(*pudp); |
29409997 | 936 | |
0ac52dd7 | 937 | if (pud_none(pud)) |
ac52ae47 | 938 | return NULL; |
0ac52dd7 AK |
939 | else if (pud_huge(pud)) { |
940 | ret_pte = (pte_t *) pudp; | |
29409997 | 941 | goto out; |
b30e7590 | 942 | } else if (is_hugepd(__hugepd(pud_val(pud)))) |
0ac52dd7 | 943 | hpdp = (hugepd_t *)&pud; |
ac52ae47 | 944 | else { |
29409997 | 945 | pdshift = PMD_SHIFT; |
0ac52dd7 | 946 | pmdp = pmd_offset(&pud, ea); |
da1a288d | 947 | pmd = READ_ONCE(*pmdp); |
ac52ae47 AK |
948 | /* |
949 | * A hugepage collapse is captured by pmd_none, because | |
950 | * it mark the pmd none and do a hpte invalidate. | |
ac52ae47 | 951 | */ |
7d6e7f7f | 952 | if (pmd_none(pmd)) |
ac52ae47 | 953 | return NULL; |
29409997 | 954 | |
891121e6 AK |
955 | if (pmd_trans_huge(pmd)) { |
956 | if (is_thp) | |
957 | *is_thp = true; | |
958 | ret_pte = (pte_t *) pmdp; | |
959 | goto out; | |
960 | } | |
961 | ||
962 | if (pmd_huge(pmd)) { | |
0ac52dd7 | 963 | ret_pte = (pte_t *) pmdp; |
29409997 | 964 | goto out; |
b30e7590 | 965 | } else if (is_hugepd(__hugepd(pmd_val(pmd)))) |
0ac52dd7 | 966 | hpdp = (hugepd_t *)&pmd; |
ac52ae47 | 967 | else |
0ac52dd7 | 968 | return pte_offset_kernel(&pmd, ea); |
29409997 AK |
969 | } |
970 | } | |
971 | if (!hpdp) | |
972 | return NULL; | |
973 | ||
b30e7590 | 974 | ret_pte = hugepte_offset(*hpdp, ea, pdshift); |
29409997 AK |
975 | pdshift = hugepd_shift(*hpdp); |
976 | out: | |
977 | if (shift) | |
978 | *shift = pdshift; | |
979 | return ret_pte; | |
980 | } | |
691e95fd | 981 | EXPORT_SYMBOL_GPL(__find_linux_pte_or_hugepte); |
29409997 AK |
982 | |
983 | int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, | |
984 | unsigned long end, int write, struct page **pages, int *nr) | |
985 | { | |
986 | unsigned long mask; | |
987 | unsigned long pte_end; | |
ddc58f27 | 988 | struct page *head, *page; |
29409997 AK |
989 | pte_t pte; |
990 | int refs; | |
991 | ||
992 | pte_end = (addr + sz) & ~(sz-1); | |
993 | if (pte_end < end) | |
994 | end = pte_end; | |
995 | ||
4f9c53c8 | 996 | pte = READ_ONCE(*ptep); |
ac29c640 | 997 | mask = _PAGE_PRESENT | _PAGE_READ; |
6b8cb66a CL |
998 | |
999 | /* | |
1000 | * On some CPUs like the 8xx, _PAGE_RW hence _PAGE_WRITE is defined | |
1001 | * as 0 and _PAGE_RO has to be set when a page is not writable | |
1002 | */ | |
29409997 | 1003 | if (write) |
c7d54842 | 1004 | mask |= _PAGE_WRITE; |
6b8cb66a CL |
1005 | else |
1006 | mask |= _PAGE_RO; | |
29409997 AK |
1007 | |
1008 | if ((pte_val(pte) & mask) != mask) | |
1009 | return 0; | |
1010 | ||
1011 | /* hugepages are never "special" */ | |
1012 | VM_BUG_ON(!pfn_valid(pte_pfn(pte))); | |
1013 | ||
1014 | refs = 0; | |
1015 | head = pte_page(pte); | |
1016 | ||
1017 | page = head + ((addr & (sz-1)) >> PAGE_SHIFT); | |
29409997 AK |
1018 | do { |
1019 | VM_BUG_ON(compound_head(page) != head); | |
1020 | pages[*nr] = page; | |
1021 | (*nr)++; | |
1022 | page++; | |
1023 | refs++; | |
1024 | } while (addr += PAGE_SIZE, addr != end); | |
1025 | ||
1026 | if (!page_cache_add_speculative(head, refs)) { | |
1027 | *nr -= refs; | |
1028 | return 0; | |
1029 | } | |
1030 | ||
1031 | if (unlikely(pte_val(pte) != pte_val(*ptep))) { | |
1032 | /* Could be optimized better */ | |
1033 | *nr -= refs; | |
1034 | while (refs--) | |
1035 | put_page(head); | |
1036 | return 0; | |
1037 | } | |
1038 | ||
29409997 AK |
1039 | return 1; |
1040 | } |