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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * TILE Huge TLB Page Support for Kernel. | |
15 | * Taken from i386 hugetlb implementation: | |
16 | * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> | |
17 | */ | |
18 | ||
19 | #include <linux/init.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/hugetlb.h> | |
23 | #include <linux/pagemap.h> | |
867e359b CM |
24 | #include <linux/slab.h> |
25 | #include <linux/err.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/mman.h> | |
28 | #include <asm/tlb.h> | |
29 | #include <asm/tlbflush.h> | |
621b1955 CM |
30 | #include <asm/setup.h> |
31 | ||
32 | #ifdef CONFIG_HUGETLB_SUPER_PAGES | |
33 | ||
34 | /* | |
35 | * Provide an additional huge page size (in addition to the regular default | |
36 | * huge page size) if no "hugepagesz" arguments are specified. | |
37 | * Note that it must be smaller than the default huge page size so | |
38 | * that it's possible to allocate them on demand from the buddy allocator. | |
39 | * You can change this to 64K (on a 16K build), 256K, 1M, or 4M, | |
40 | * or not define it at all. | |
41 | */ | |
42 | #define ADDITIONAL_HUGE_SIZE (1024 * 1024UL) | |
43 | ||
44 | /* "Extra" page-size multipliers, one per level of the page table. */ | |
45 | int huge_shift[HUGE_SHIFT_ENTRIES] = { | |
46 | #ifdef ADDITIONAL_HUGE_SIZE | |
47 | #define ADDITIONAL_HUGE_SHIFT __builtin_ctzl(ADDITIONAL_HUGE_SIZE / PAGE_SIZE) | |
48 | [HUGE_SHIFT_PAGE] = ADDITIONAL_HUGE_SHIFT | |
49 | #endif | |
50 | }; | |
51 | ||
621b1955 | 52 | #endif |
867e359b CM |
53 | |
54 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
55 | unsigned long addr, unsigned long sz) | |
56 | { | |
57 | pgd_t *pgd; | |
58 | pud_t *pud; | |
867e359b | 59 | |
621b1955 | 60 | addr &= -sz; /* Mask off any low bits in the address. */ |
867e359b CM |
61 | |
62 | pgd = pgd_offset(mm, addr); | |
63 | pud = pud_alloc(mm, pgd, addr); | |
867e359b | 64 | |
621b1955 CM |
65 | #ifdef CONFIG_HUGETLB_SUPER_PAGES |
66 | if (sz >= PGDIR_SIZE) { | |
67 | BUG_ON(sz != PGDIR_SIZE && | |
68 | sz != PGDIR_SIZE << huge_shift[HUGE_SHIFT_PGDIR]); | |
69 | return (pte_t *)pud; | |
70 | } else { | |
71 | pmd_t *pmd = pmd_alloc(mm, pud, addr); | |
72 | if (sz >= PMD_SIZE) { | |
73 | BUG_ON(sz != PMD_SIZE && | |
74 | sz != (PMD_SIZE << huge_shift[HUGE_SHIFT_PMD])); | |
75 | return (pte_t *)pmd; | |
76 | } | |
77 | else { | |
78 | if (sz != PAGE_SIZE << huge_shift[HUGE_SHIFT_PAGE]) | |
79 | panic("Unexpected page size %#lx\n", sz); | |
a0bd12d7 | 80 | return pte_alloc_map(mm, NULL, pmd, addr); |
621b1955 CM |
81 | } |
82 | } | |
83 | #else | |
84 | BUG_ON(sz != PMD_SIZE); | |
85 | return (pte_t *) pmd_alloc(mm, pud, addr); | |
86 | #endif | |
867e359b CM |
87 | } |
88 | ||
621b1955 | 89 | static pte_t *get_pte(pte_t *base, int index, int level) |
867e359b | 90 | { |
621b1955 CM |
91 | pte_t *ptep = base + index; |
92 | #ifdef CONFIG_HUGETLB_SUPER_PAGES | |
93 | if (!pte_present(*ptep) && huge_shift[level] != 0) { | |
94 | unsigned long mask = -1UL << huge_shift[level]; | |
95 | pte_t *super_ptep = base + (index & mask); | |
96 | pte_t pte = *super_ptep; | |
97 | if (pte_present(pte) && pte_super(pte)) | |
98 | ptep = super_ptep; | |
867e359b | 99 | } |
621b1955 CM |
100 | #endif |
101 | return ptep; | |
867e359b CM |
102 | } |
103 | ||
621b1955 | 104 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) |
867e359b | 105 | { |
621b1955 CM |
106 | pgd_t *pgd; |
107 | pud_t *pud; | |
108 | pmd_t *pmd; | |
109 | #ifdef CONFIG_HUGETLB_SUPER_PAGES | |
110 | pte_t *pte; | |
111 | #endif | |
867e359b | 112 | |
621b1955 CM |
113 | /* Get the top-level page table entry. */ |
114 | pgd = (pgd_t *)get_pte((pte_t *)mm->pgd, pgd_index(addr), 0); | |
867e359b | 115 | |
621b1955 CM |
116 | /* We don't have four levels. */ |
117 | pud = pud_offset(pgd, addr); | |
118 | #ifndef __PAGETABLE_PUD_FOLDED | |
119 | # error support fourth page table level | |
120 | #endif | |
a0bd12d7 CM |
121 | if (!pud_present(*pud)) |
122 | return NULL; | |
867e359b | 123 | |
621b1955 CM |
124 | /* Check for an L0 huge PTE, if we have three levels. */ |
125 | #ifndef __PAGETABLE_PMD_FOLDED | |
126 | if (pud_huge(*pud)) | |
127 | return (pte_t *)pud; | |
867e359b | 128 | |
621b1955 CM |
129 | pmd = (pmd_t *)get_pte((pte_t *)pud_page_vaddr(*pud), |
130 | pmd_index(addr), 1); | |
131 | if (!pmd_present(*pmd)) | |
132 | return NULL; | |
133 | #else | |
134 | pmd = pmd_offset(pud, addr); | |
135 | #endif | |
867e359b | 136 | |
621b1955 CM |
137 | /* Check for an L1 huge PTE. */ |
138 | if (pmd_huge(*pmd)) | |
139 | return (pte_t *)pmd; | |
140 | ||
141 | #ifdef CONFIG_HUGETLB_SUPER_PAGES | |
142 | /* Check for an L2 huge PTE. */ | |
143 | pte = get_pte((pte_t *)pmd_page_vaddr(*pmd), pte_index(addr), 2); | |
144 | if (!pte_present(*pte)) | |
145 | return NULL; | |
146 | if (pte_super(*pte)) | |
147 | return pte; | |
148 | #endif | |
867e359b | 149 | |
867e359b CM |
150 | return NULL; |
151 | } | |
152 | ||
867e359b CM |
153 | struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, |
154 | int write) | |
155 | { | |
156 | return ERR_PTR(-EINVAL); | |
157 | } | |
158 | ||
159 | int pmd_huge(pmd_t pmd) | |
160 | { | |
161 | return !!(pmd_val(pmd) & _PAGE_HUGE_PAGE); | |
162 | } | |
163 | ||
164 | int pud_huge(pud_t pud) | |
165 | { | |
166 | return !!(pud_val(pud) & _PAGE_HUGE_PAGE); | |
167 | } | |
168 | ||
169 | struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, | |
170 | pmd_t *pmd, int write) | |
171 | { | |
172 | struct page *page; | |
173 | ||
174 | page = pte_page(*(pte_t *)pmd); | |
175 | if (page) | |
176 | page += ((address & ~PMD_MASK) >> PAGE_SHIFT); | |
177 | return page; | |
178 | } | |
179 | ||
180 | struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
181 | pud_t *pud, int write) | |
182 | { | |
183 | struct page *page; | |
184 | ||
185 | page = pte_page(*(pte_t *)pud); | |
186 | if (page) | |
187 | page += ((address & ~PUD_MASK) >> PAGE_SHIFT); | |
188 | return page; | |
189 | } | |
190 | ||
191 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
192 | { | |
193 | return 0; | |
194 | } | |
195 | ||
867e359b CM |
196 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA |
197 | static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, | |
198 | unsigned long addr, unsigned long len, | |
199 | unsigned long pgoff, unsigned long flags) | |
200 | { | |
201 | struct hstate *h = hstate_file(file); | |
dd529596 ML |
202 | struct vm_unmapped_area_info info; |
203 | ||
204 | info.flags = 0; | |
205 | info.length = len; | |
206 | info.low_limit = TASK_UNMAPPED_BASE; | |
207 | info.high_limit = TASK_SIZE; | |
208 | info.align_mask = PAGE_MASK & ~huge_page_mask(h); | |
209 | info.align_offset = 0; | |
210 | return vm_unmapped_area(&info); | |
867e359b CM |
211 | } |
212 | ||
213 | static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, | |
214 | unsigned long addr0, unsigned long len, | |
215 | unsigned long pgoff, unsigned long flags) | |
216 | { | |
217 | struct hstate *h = hstate_file(file); | |
dd529596 ML |
218 | struct vm_unmapped_area_info info; |
219 | unsigned long addr; | |
867e359b | 220 | |
dd529596 ML |
221 | info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
222 | info.length = len; | |
223 | info.low_limit = PAGE_SIZE; | |
224 | info.high_limit = current->mm->mmap_base; | |
225 | info.align_mask = PAGE_MASK & ~huge_page_mask(h); | |
226 | info.align_offset = 0; | |
227 | addr = vm_unmapped_area(&info); | |
867e359b | 228 | |
867e359b CM |
229 | /* |
230 | * A failed mmap() very likely causes application failure, | |
231 | * so fall back to the bottom-up function here. This scenario | |
232 | * can happen with large stack limits and large mmap() | |
233 | * allocations. | |
234 | */ | |
dd529596 ML |
235 | if (addr & ~PAGE_MASK) { |
236 | VM_BUG_ON(addr != -ENOMEM); | |
237 | info.flags = 0; | |
238 | info.low_limit = TASK_UNMAPPED_BASE; | |
239 | info.high_limit = TASK_SIZE; | |
240 | addr = vm_unmapped_area(&info); | |
241 | } | |
867e359b CM |
242 | |
243 | return addr; | |
244 | } | |
245 | ||
246 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
247 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
248 | { | |
249 | struct hstate *h = hstate_file(file); | |
250 | struct mm_struct *mm = current->mm; | |
251 | struct vm_area_struct *vma; | |
252 | ||
253 | if (len & ~huge_page_mask(h)) | |
254 | return -EINVAL; | |
255 | if (len > TASK_SIZE) | |
256 | return -ENOMEM; | |
257 | ||
258 | if (flags & MAP_FIXED) { | |
259 | if (prepare_hugepage_range(file, addr, len)) | |
260 | return -EINVAL; | |
261 | return addr; | |
262 | } | |
263 | ||
264 | if (addr) { | |
265 | addr = ALIGN(addr, huge_page_size(h)); | |
266 | vma = find_vma(mm, addr); | |
267 | if (TASK_SIZE - len >= addr && | |
268 | (!vma || addr + len <= vma->vm_start)) | |
269 | return addr; | |
270 | } | |
271 | if (current->mm->get_unmapped_area == arch_get_unmapped_area) | |
272 | return hugetlb_get_unmapped_area_bottomup(file, addr, len, | |
273 | pgoff, flags); | |
274 | else | |
275 | return hugetlb_get_unmapped_area_topdown(file, addr, len, | |
276 | pgoff, flags); | |
277 | } | |
621b1955 | 278 | #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */ |
867e359b | 279 | |
621b1955 CM |
280 | #ifdef CONFIG_HUGETLB_SUPER_PAGES |
281 | static __init int __setup_hugepagesz(unsigned long ps) | |
867e359b | 282 | { |
621b1955 CM |
283 | int log_ps = __builtin_ctzl(ps); |
284 | int level, base_shift; | |
285 | ||
286 | if ((1UL << log_ps) != ps || (log_ps & 1) != 0) { | |
287 | pr_warn("Not enabling %ld byte huge pages;" | |
288 | " must be a power of four.\n", ps); | |
289 | return -EINVAL; | |
290 | } | |
291 | ||
292 | if (ps > 64*1024*1024*1024UL) { | |
293 | pr_warn("Not enabling %ld MB huge pages;" | |
294 | " largest legal value is 64 GB .\n", ps >> 20); | |
295 | return -EINVAL; | |
296 | } else if (ps >= PUD_SIZE) { | |
297 | static long hv_jpage_size; | |
298 | if (hv_jpage_size == 0) | |
299 | hv_jpage_size = hv_sysconf(HV_SYSCONF_PAGE_SIZE_JUMBO); | |
300 | if (hv_jpage_size != PUD_SIZE) { | |
301 | pr_warn("Not enabling >= %ld MB huge pages:" | |
302 | " hypervisor reports size %ld\n", | |
303 | PUD_SIZE >> 20, hv_jpage_size); | |
304 | return -EINVAL; | |
305 | } | |
306 | level = 0; | |
307 | base_shift = PUD_SHIFT; | |
308 | } else if (ps >= PMD_SIZE) { | |
309 | level = 1; | |
310 | base_shift = PMD_SHIFT; | |
311 | } else if (ps > PAGE_SIZE) { | |
312 | level = 2; | |
313 | base_shift = PAGE_SHIFT; | |
867e359b | 314 | } else { |
621b1955 CM |
315 | pr_err("hugepagesz: huge page size %ld too small\n", ps); |
316 | return -EINVAL; | |
867e359b | 317 | } |
621b1955 CM |
318 | |
319 | if (log_ps != base_shift) { | |
320 | int shift_val = log_ps - base_shift; | |
321 | if (huge_shift[level] != 0) { | |
322 | int old_shift = base_shift + huge_shift[level]; | |
323 | pr_warn("Not enabling %ld MB huge pages;" | |
324 | " already have size %ld MB.\n", | |
325 | ps >> 20, (1UL << old_shift) >> 20); | |
326 | return -EINVAL; | |
327 | } | |
328 | if (hv_set_pte_super_shift(level, shift_val) != 0) { | |
329 | pr_warn("Not enabling %ld MB huge pages;" | |
330 | " no hypervisor support.\n", ps >> 20); | |
331 | return -EINVAL; | |
332 | } | |
333 | printk(KERN_DEBUG "Enabled %ld MB huge pages\n", ps >> 20); | |
334 | huge_shift[level] = shift_val; | |
335 | } | |
336 | ||
337 | hugetlb_add_hstate(log_ps - PAGE_SHIFT); | |
338 | ||
339 | return 0; | |
340 | } | |
341 | ||
342 | static bool saw_hugepagesz; | |
343 | ||
344 | static __init int setup_hugepagesz(char *opt) | |
345 | { | |
346 | if (!saw_hugepagesz) { | |
347 | saw_hugepagesz = true; | |
348 | memset(huge_shift, 0, sizeof(huge_shift)); | |
349 | } | |
350 | return __setup_hugepagesz(memparse(opt, NULL)); | |
867e359b CM |
351 | } |
352 | __setup("hugepagesz=", setup_hugepagesz); | |
353 | ||
621b1955 CM |
354 | #ifdef ADDITIONAL_HUGE_SIZE |
355 | /* | |
356 | * Provide an additional huge page size if no "hugepagesz" args are given. | |
357 | * In that case, all the cores have properly set up their hv super_shift | |
358 | * already, but we need to notify the hugetlb code to enable the | |
359 | * new huge page size from the Linux point of view. | |
360 | */ | |
361 | static __init int add_default_hugepagesz(void) | |
362 | { | |
363 | if (!saw_hugepagesz) { | |
364 | BUILD_BUG_ON(ADDITIONAL_HUGE_SIZE >= PMD_SIZE || | |
365 | ADDITIONAL_HUGE_SIZE <= PAGE_SIZE); | |
366 | BUILD_BUG_ON((PAGE_SIZE << ADDITIONAL_HUGE_SHIFT) != | |
367 | ADDITIONAL_HUGE_SIZE); | |
368 | BUILD_BUG_ON(ADDITIONAL_HUGE_SHIFT & 1); | |
369 | hugetlb_add_hstate(ADDITIONAL_HUGE_SHIFT); | |
370 | } | |
371 | return 0; | |
372 | } | |
373 | arch_initcall(add_default_hugepagesz); | |
374 | #endif | |
375 | ||
376 | #endif /* CONFIG_HUGETLB_SUPER_PAGES */ |