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