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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * IBM System z Huge TLB Page Support for Kernel.
4 *
5 * Copyright IBM Corp. 2007,2020
6 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
7 */
8
9#define KMSG_COMPONENT "hugetlb"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12#include <linux/mm.h>
13#include <linux/hugetlb.h>
14#include <linux/mman.h>
15#include <linux/sched/mm.h>
16#include <linux/security.h>
17
18/*
19 * If the bit selected by single-bit bitmask "a" is set within "x", move
20 * it to the position indicated by single-bit bitmask "b".
21 */
22#define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
23
24static inline unsigned long __pte_to_rste(pte_t pte)
25{
26 unsigned long rste;
27
28 /*
29 * Convert encoding pte bits pmd / pud bits
30 * lIR.uswrdy.p dy..R...I...wr
31 * empty 010.000000.0 -> 00..0...1...00
32 * prot-none, clean, old 111.000000.1 -> 00..1...1...00
33 * prot-none, clean, young 111.000001.1 -> 01..1...1...00
34 * prot-none, dirty, old 111.000010.1 -> 10..1...1...00
35 * prot-none, dirty, young 111.000011.1 -> 11..1...1...00
36 * read-only, clean, old 111.000100.1 -> 00..1...1...01
37 * read-only, clean, young 101.000101.1 -> 01..1...0...01
38 * read-only, dirty, old 111.000110.1 -> 10..1...1...01
39 * read-only, dirty, young 101.000111.1 -> 11..1...0...01
40 * read-write, clean, old 111.001100.1 -> 00..1...1...11
41 * read-write, clean, young 101.001101.1 -> 01..1...0...11
42 * read-write, dirty, old 110.001110.1 -> 10..0...1...11
43 * read-write, dirty, young 100.001111.1 -> 11..0...0...11
44 * HW-bits: R read-only, I invalid
45 * SW-bits: p present, y young, d dirty, r read, w write, s special,
46 * u unused, l large
47 */
48 if (pte_present(pte)) {
49 rste = pte_val(pte) & PAGE_MASK;
50 rste |= move_set_bit(pte_val(pte), _PAGE_READ,
51 _SEGMENT_ENTRY_READ);
52 rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
53 _SEGMENT_ENTRY_WRITE);
54 rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
55 _SEGMENT_ENTRY_INVALID);
56 rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
57 _SEGMENT_ENTRY_PROTECT);
58 rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
59 _SEGMENT_ENTRY_DIRTY);
60 rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
61 _SEGMENT_ENTRY_YOUNG);
62#ifdef CONFIG_MEM_SOFT_DIRTY
63 rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
64 _SEGMENT_ENTRY_SOFT_DIRTY);
65#endif
66 rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC,
67 _SEGMENT_ENTRY_NOEXEC);
68 } else
69 rste = _SEGMENT_ENTRY_EMPTY;
70 return rste;
71}
72
73static inline pte_t __rste_to_pte(unsigned long rste)
74{
75 int present;
76 pte_t pte;
77
78 if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
79 present = pud_present(__pud(rste));
80 else
81 present = pmd_present(__pmd(rste));
82
83 /*
84 * Convert encoding pmd / pud bits pte bits
85 * dy..R...I...wr lIR.uswrdy.p
86 * empty 00..0...1...00 -> 010.000000.0
87 * prot-none, clean, old 00..1...1...00 -> 111.000000.1
88 * prot-none, clean, young 01..1...1...00 -> 111.000001.1
89 * prot-none, dirty, old 10..1...1...00 -> 111.000010.1
90 * prot-none, dirty, young 11..1...1...00 -> 111.000011.1
91 * read-only, clean, old 00..1...1...01 -> 111.000100.1
92 * read-only, clean, young 01..1...0...01 -> 101.000101.1
93 * read-only, dirty, old 10..1...1...01 -> 111.000110.1
94 * read-only, dirty, young 11..1...0...01 -> 101.000111.1
95 * read-write, clean, old 00..1...1...11 -> 111.001100.1
96 * read-write, clean, young 01..1...0...11 -> 101.001101.1
97 * read-write, dirty, old 10..0...1...11 -> 110.001110.1
98 * read-write, dirty, young 11..0...0...11 -> 100.001111.1
99 * HW-bits: R read-only, I invalid
100 * SW-bits: p present, y young, d dirty, r read, w write, s special,
101 * u unused, l large
102 */
103 if (present) {
104 pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
105 pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
106 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
107 _PAGE_READ);
108 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
109 _PAGE_WRITE);
110 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
111 _PAGE_INVALID);
112 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
113 _PAGE_PROTECT);
114 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
115 _PAGE_DIRTY);
116 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
117 _PAGE_YOUNG);
118#ifdef CONFIG_MEM_SOFT_DIRTY
119 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
120 _PAGE_SOFT_DIRTY);
121#endif
122 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
123 _PAGE_NOEXEC);
124 } else
125 pte_val(pte) = _PAGE_INVALID;
126 return pte;
127}
128
129static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
130{
131 struct page *page;
132 unsigned long size, paddr;
133
134 if (!mm_uses_skeys(mm) ||
135 rste & _SEGMENT_ENTRY_INVALID)
136 return;
137
138 if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
139 page = pud_page(__pud(rste));
140 size = PUD_SIZE;
141 paddr = rste & PUD_MASK;
142 } else {
143 page = pmd_page(__pmd(rste));
144 size = PMD_SIZE;
145 paddr = rste & PMD_MASK;
146 }
147
148 if (!test_and_set_bit(PG_arch_1, &page->flags))
149 __storage_key_init_range(paddr, paddr + size - 1);
150}
151
152void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
153 pte_t *ptep, pte_t pte)
154{
155 unsigned long rste;
156
157 rste = __pte_to_rste(pte);
158 if (!MACHINE_HAS_NX)
159 rste &= ~_SEGMENT_ENTRY_NOEXEC;
160
161 /* Set correct table type for 2G hugepages */
162 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
163 if (likely(pte_present(pte)))
164 rste |= _REGION3_ENTRY_LARGE;
165 rste |= _REGION_ENTRY_TYPE_R3;
166 } else if (likely(pte_present(pte)))
167 rste |= _SEGMENT_ENTRY_LARGE;
168
169 clear_huge_pte_skeys(mm, rste);
170 pte_val(*ptep) = rste;
171}
172
173pte_t huge_ptep_get(pte_t *ptep)
174{
175 return __rste_to_pte(pte_val(*ptep));
176}
177
178pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
179 unsigned long addr, pte_t *ptep)
180{
181 pte_t pte = huge_ptep_get(ptep);
182 pmd_t *pmdp = (pmd_t *) ptep;
183 pud_t *pudp = (pud_t *) ptep;
184
185 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
186 pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
187 else
188 pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
189 return pte;
190}
191
192pte_t *huge_pte_alloc(struct mm_struct *mm,
193 unsigned long addr, unsigned long sz)
194{
195 pgd_t *pgdp;
196 p4d_t *p4dp;
197 pud_t *pudp;
198 pmd_t *pmdp = NULL;
199
200 pgdp = pgd_offset(mm, addr);
201 p4dp = p4d_alloc(mm, pgdp, addr);
202 if (p4dp) {
203 pudp = pud_alloc(mm, p4dp, addr);
204 if (pudp) {
205 if (sz == PUD_SIZE)
206 return (pte_t *) pudp;
207 else if (sz == PMD_SIZE)
208 pmdp = pmd_alloc(mm, pudp, addr);
209 }
210 }
211 return (pte_t *) pmdp;
212}
213
214pte_t *huge_pte_offset(struct mm_struct *mm,
215 unsigned long addr, unsigned long sz)
216{
217 pgd_t *pgdp;
218 p4d_t *p4dp;
219 pud_t *pudp;
220 pmd_t *pmdp = NULL;
221
222 pgdp = pgd_offset(mm, addr);
223 if (pgd_present(*pgdp)) {
224 p4dp = p4d_offset(pgdp, addr);
225 if (p4d_present(*p4dp)) {
226 pudp = pud_offset(p4dp, addr);
227 if (pud_present(*pudp)) {
228 if (pud_large(*pudp))
229 return (pte_t *) pudp;
230 pmdp = pmd_offset(pudp, addr);
231 }
232 }
233 }
234 return (pte_t *) pmdp;
235}
236
237int pmd_huge(pmd_t pmd)
238{
239 return pmd_large(pmd);
240}
241
242int pud_huge(pud_t pud)
243{
244 return pud_large(pud);
245}
246
247struct page *
248follow_huge_pud(struct mm_struct *mm, unsigned long address,
249 pud_t *pud, int flags)
250{
251 if (flags & FOLL_GET)
252 return NULL;
253
254 return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
255}
256
257bool __init arch_hugetlb_valid_size(unsigned long size)
258{
259 if (MACHINE_HAS_EDAT1 && size == PMD_SIZE)
260 return true;
261 else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE)
262 return true;
263 else
264 return false;
265}
266
267static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
268 unsigned long addr, unsigned long len,
269 unsigned long pgoff, unsigned long flags)
270{
271 struct hstate *h = hstate_file(file);
272 struct vm_unmapped_area_info info;
273
274 info.flags = 0;
275 info.length = len;
276 info.low_limit = current->mm->mmap_base;
277 info.high_limit = TASK_SIZE;
278 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
279 info.align_offset = 0;
280 return vm_unmapped_area(&info);
281}
282
283static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
284 unsigned long addr0, unsigned long len,
285 unsigned long pgoff, unsigned long flags)
286{
287 struct hstate *h = hstate_file(file);
288 struct vm_unmapped_area_info info;
289 unsigned long addr;
290
291 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
292 info.length = len;
293 info.low_limit = max(PAGE_SIZE, mmap_min_addr);
294 info.high_limit = current->mm->mmap_base;
295 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
296 info.align_offset = 0;
297 addr = vm_unmapped_area(&info);
298
299 /*
300 * A failed mmap() very likely causes application failure,
301 * so fall back to the bottom-up function here. This scenario
302 * can happen with large stack limits and large mmap()
303 * allocations.
304 */
305 if (addr & ~PAGE_MASK) {
306 VM_BUG_ON(addr != -ENOMEM);
307 info.flags = 0;
308 info.low_limit = TASK_UNMAPPED_BASE;
309 info.high_limit = TASK_SIZE;
310 addr = vm_unmapped_area(&info);
311 }
312
313 return addr;
314}
315
316unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
317 unsigned long len, unsigned long pgoff, unsigned long flags)
318{
319 struct hstate *h = hstate_file(file);
320 struct mm_struct *mm = current->mm;
321 struct vm_area_struct *vma;
322
323 if (len & ~huge_page_mask(h))
324 return -EINVAL;
325 if (len > TASK_SIZE - mmap_min_addr)
326 return -ENOMEM;
327
328 if (flags & MAP_FIXED) {
329 if (prepare_hugepage_range(file, addr, len))
330 return -EINVAL;
331 goto check_asce_limit;
332 }
333
334 if (addr) {
335 addr = ALIGN(addr, huge_page_size(h));
336 vma = find_vma(mm, addr);
337 if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
338 (!vma || addr + len <= vm_start_gap(vma)))
339 goto check_asce_limit;
340 }
341
342 if (mm->get_unmapped_area == arch_get_unmapped_area)
343 addr = hugetlb_get_unmapped_area_bottomup(file, addr, len,
344 pgoff, flags);
345 else
346 addr = hugetlb_get_unmapped_area_topdown(file, addr, len,
347 pgoff, flags);
348 if (offset_in_page(addr))
349 return addr;
350
351check_asce_limit:
352 return check_asce_limit(mm, addr, len);
353}
1/*
2 * IBM System z Huge TLB Page Support for Kernel.
3 *
4 * Copyright IBM Corp. 2007
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#include <linux/mm.h>
9#include <linux/hugetlb.h>
10
11static inline pmd_t __pte_to_pmd(pte_t pte)
12{
13 pmd_t pmd;
14
15 /*
16 * Convert encoding pte bits pmd bits
17 * lIR.uswrdy.p dy..R...I...wr
18 * empty 010.000000.0 -> 00..0...1...00
19 * prot-none, clean, old 111.000000.1 -> 00..1...1...00
20 * prot-none, clean, young 111.000001.1 -> 01..1...1...00
21 * prot-none, dirty, old 111.000010.1 -> 10..1...1...00
22 * prot-none, dirty, young 111.000011.1 -> 11..1...1...00
23 * read-only, clean, old 111.000100.1 -> 00..1...1...01
24 * read-only, clean, young 101.000101.1 -> 01..1...0...01
25 * read-only, dirty, old 111.000110.1 -> 10..1...1...01
26 * read-only, dirty, young 101.000111.1 -> 11..1...0...01
27 * read-write, clean, old 111.001100.1 -> 00..1...1...11
28 * read-write, clean, young 101.001101.1 -> 01..1...0...11
29 * read-write, dirty, old 110.001110.1 -> 10..0...1...11
30 * read-write, dirty, young 100.001111.1 -> 11..0...0...11
31 * HW-bits: R read-only, I invalid
32 * SW-bits: p present, y young, d dirty, r read, w write, s special,
33 * u unused, l large
34 */
35 if (pte_present(pte)) {
36 pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
37 pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
38 pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
39 pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5;
40 pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
41 pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
42 pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
43 pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
44 } else
45 pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
46 return pmd;
47}
48
49static inline pte_t __pmd_to_pte(pmd_t pmd)
50{
51 pte_t pte;
52
53 /*
54 * Convert encoding pmd bits pte bits
55 * dy..R...I...wr lIR.uswrdy.p
56 * empty 00..0...1...00 -> 010.000000.0
57 * prot-none, clean, old 00..1...1...00 -> 111.000000.1
58 * prot-none, clean, young 01..1...1...00 -> 111.000001.1
59 * prot-none, dirty, old 10..1...1...00 -> 111.000010.1
60 * prot-none, dirty, young 11..1...1...00 -> 111.000011.1
61 * read-only, clean, old 00..1...1...01 -> 111.000100.1
62 * read-only, clean, young 01..1...0...01 -> 101.000101.1
63 * read-only, dirty, old 10..1...1...01 -> 111.000110.1
64 * read-only, dirty, young 11..1...0...01 -> 101.000111.1
65 * read-write, clean, old 00..1...1...11 -> 111.001100.1
66 * read-write, clean, young 01..1...0...11 -> 101.001101.1
67 * read-write, dirty, old 10..0...1...11 -> 110.001110.1
68 * read-write, dirty, young 11..0...0...11 -> 100.001111.1
69 * HW-bits: R read-only, I invalid
70 * SW-bits: p present, y young, d dirty, r read, w write, s special,
71 * u unused, l large
72 */
73 if (pmd_present(pmd)) {
74 pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
75 pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
76 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
77 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
78 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
79 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
80 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
81 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
82 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
83 } else
84 pte_val(pte) = _PAGE_INVALID;
85 return pte;
86}
87
88void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
89 pte_t *ptep, pte_t pte)
90{
91 pmd_t pmd = __pte_to_pmd(pte);
92
93 pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
94 *(pmd_t *) ptep = pmd;
95}
96
97pte_t huge_ptep_get(pte_t *ptep)
98{
99 pmd_t pmd = *(pmd_t *) ptep;
100
101 return __pmd_to_pte(pmd);
102}
103
104pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
105 unsigned long addr, pte_t *ptep)
106{
107 pmd_t *pmdp = (pmd_t *) ptep;
108 pmd_t old;
109
110 old = pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
111 return __pmd_to_pte(old);
112}
113
114pte_t *huge_pte_alloc(struct mm_struct *mm,
115 unsigned long addr, unsigned long sz)
116{
117 pgd_t *pgdp;
118 pud_t *pudp;
119 pmd_t *pmdp = NULL;
120
121 pgdp = pgd_offset(mm, addr);
122 pudp = pud_alloc(mm, pgdp, addr);
123 if (pudp)
124 pmdp = pmd_alloc(mm, pudp, addr);
125 return (pte_t *) pmdp;
126}
127
128pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
129{
130 pgd_t *pgdp;
131 pud_t *pudp;
132 pmd_t *pmdp = NULL;
133
134 pgdp = pgd_offset(mm, addr);
135 if (pgd_present(*pgdp)) {
136 pudp = pud_offset(pgdp, addr);
137 if (pud_present(*pudp))
138 pmdp = pmd_offset(pudp, addr);
139 }
140 return (pte_t *) pmdp;
141}
142
143int pmd_huge(pmd_t pmd)
144{
145 return pmd_large(pmd);
146}
147
148int pud_huge(pud_t pud)
149{
150 return 0;
151}