1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
|
// SPDX-License-Identifier: GPL-2.0
/*
* IBM System z Huge TLB Page Support for Kernel.
*
* Copyright IBM Corp. 2007,2020
* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
#define KMSG_COMPONENT "hugetlb"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mman.h>
#include <linux/sched/mm.h>
#include <linux/security.h>
/*
* If the bit selected by single-bit bitmask "a" is set within "x", move
* it to the position indicated by single-bit bitmask "b".
*/
#define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
static inline unsigned long __pte_to_rste(pte_t pte)
{
unsigned long rste;
/*
* Convert encoding pte bits pmd / pud bits
* lIR.uswrdy.p dy..R...I...wr
* empty 010.000000.0 -> 00..0...1...00
* prot-none, clean, old 111.000000.1 -> 00..1...1...00
* prot-none, clean, young 111.000001.1 -> 01..1...1...00
* prot-none, dirty, old 111.000010.1 -> 10..1...1...00
* prot-none, dirty, young 111.000011.1 -> 11..1...1...00
* read-only, clean, old 111.000100.1 -> 00..1...1...01
* read-only, clean, young 101.000101.1 -> 01..1...0...01
* read-only, dirty, old 111.000110.1 -> 10..1...1...01
* read-only, dirty, young 101.000111.1 -> 11..1...0...01
* read-write, clean, old 111.001100.1 -> 00..1...1...11
* read-write, clean, young 101.001101.1 -> 01..1...0...11
* read-write, dirty, old 110.001110.1 -> 10..0...1...11
* read-write, dirty, young 100.001111.1 -> 11..0...0...11
* HW-bits: R read-only, I invalid
* SW-bits: p present, y young, d dirty, r read, w write, s special,
* u unused, l large
*/
if (pte_present(pte)) {
rste = pte_val(pte) & PAGE_MASK;
rste |= move_set_bit(pte_val(pte), _PAGE_READ,
_SEGMENT_ENTRY_READ);
rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
_SEGMENT_ENTRY_WRITE);
rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
_SEGMENT_ENTRY_INVALID);
rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
_SEGMENT_ENTRY_PROTECT);
rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
_SEGMENT_ENTRY_DIRTY);
rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
_SEGMENT_ENTRY_YOUNG);
#ifdef CONFIG_MEM_SOFT_DIRTY
rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
_SEGMENT_ENTRY_SOFT_DIRTY);
#endif
rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC,
_SEGMENT_ENTRY_NOEXEC);
} else
rste = _SEGMENT_ENTRY_EMPTY;
return rste;
}
static inline pte_t __rste_to_pte(unsigned long rste)
{
int present;
pte_t pte;
if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
present = pud_present(__pud(rste));
else
present = pmd_present(__pmd(rste));
/*
* Convert encoding pmd / pud bits pte bits
* dy..R...I...wr lIR.uswrdy.p
* empty 00..0...1...00 -> 010.000000.0
* prot-none, clean, old 00..1...1...00 -> 111.000000.1
* prot-none, clean, young 01..1...1...00 -> 111.000001.1
* prot-none, dirty, old 10..1...1...00 -> 111.000010.1
* prot-none, dirty, young 11..1...1...00 -> 111.000011.1
* read-only, clean, old 00..1...1...01 -> 111.000100.1
* read-only, clean, young 01..1...0...01 -> 101.000101.1
* read-only, dirty, old 10..1...1...01 -> 111.000110.1
* read-only, dirty, young 11..1...0...01 -> 101.000111.1
* read-write, clean, old 00..1...1...11 -> 111.001100.1
* read-write, clean, young 01..1...0...11 -> 101.001101.1
* read-write, dirty, old 10..0...1...11 -> 110.001110.1
* read-write, dirty, young 11..0...0...11 -> 100.001111.1
* HW-bits: R read-only, I invalid
* SW-bits: p present, y young, d dirty, r read, w write, s special,
* u unused, l large
*/
if (present) {
pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
_PAGE_READ);
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
_PAGE_WRITE);
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
_PAGE_INVALID);
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
_PAGE_PROTECT);
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
_PAGE_DIRTY);
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
_PAGE_YOUNG);
#ifdef CONFIG_MEM_SOFT_DIRTY
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
_PAGE_DIRTY);
#endif
pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
_PAGE_NOEXEC);
} else
pte_val(pte) = _PAGE_INVALID;
return pte;
}
static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
{
struct page *page;
unsigned long size, paddr;
if (!mm_uses_skeys(mm) ||
rste & _SEGMENT_ENTRY_INVALID)
return;
if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
page = pud_page(__pud(rste));
size = PUD_SIZE;
paddr = rste & PUD_MASK;
} else {
page = pmd_page(__pmd(rste));
size = PMD_SIZE;
paddr = rste & PMD_MASK;
}
if (!test_and_set_bit(PG_arch_1, &page->flags))
__storage_key_init_range(paddr, paddr + size - 1);
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
unsigned long rste;
rste = __pte_to_rste(pte);
if (!MACHINE_HAS_NX)
rste &= ~_SEGMENT_ENTRY_NOEXEC;
/* Set correct table type for 2G hugepages */
if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
if (likely(pte_present(pte)))
rste |= _REGION3_ENTRY_LARGE;
rste |= _REGION_ENTRY_TYPE_R3;
} else if (likely(pte_present(pte)))
rste |= _SEGMENT_ENTRY_LARGE;
clear_huge_pte_skeys(mm, rste);
pte_val(*ptep) = rste;
}
pte_t huge_ptep_get(pte_t *ptep)
{
return __rste_to_pte(pte_val(*ptep));
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t pte = huge_ptep_get(ptep);
pmd_t *pmdp = (pmd_t *) ptep;
pud_t *pudp = (pud_t *) ptep;
if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
else
pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp = NULL;
pgdp = pgd_offset(mm, addr);
p4dp = p4d_alloc(mm, pgdp, addr);
if (p4dp) {
pudp = pud_alloc(mm, p4dp, addr);
if (pudp) {
if (sz == PUD_SIZE)
return (pte_t *) pudp;
else if (sz == PMD_SIZE)
pmdp = pmd_alloc(mm, pudp, addr);
}
}
return (pte_t *) pmdp;
}
pte_t *huge_pte_offset(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp = NULL;
pgdp = pgd_offset(mm, addr);
if (pgd_present(*pgdp)) {
p4dp = p4d_offset(pgdp, addr);
if (p4d_present(*p4dp)) {
pudp = pud_offset(p4dp, addr);
if (pud_present(*pudp)) {
if (pud_large(*pudp))
return (pte_t *) pudp;
pmdp = pmd_offset(pudp, addr);
}
}
}
return (pte_t *) pmdp;
}
int pmd_huge(pmd_t pmd)
{
return pmd_large(pmd);
}
int pud_huge(pud_t pud)
{
return pud_large(pud);
}
struct page *
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int flags)
{
if (flags & FOLL_GET)
return NULL;
return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
}
static __init int setup_hugepagesz(char *opt)
{
unsigned long size;
char *string = opt;
size = memparse(opt, &opt);
if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
} else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
} else {
hugetlb_bad_size();
pr_err("hugepagesz= specifies an unsupported page size %s\n",
string);
return 0;
}
return 1;
}
__setup("hugepagesz=", setup_hugepagesz);
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
struct vm_unmapped_area_info info;
info.flags = 0;
info.length = len;
info.low_limit = current->mm->mmap_base;
info.high_limit = TASK_SIZE;
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
return vm_unmapped_area(&info);
}
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
unsigned long addr0, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
struct vm_unmapped_area_info info;
unsigned long addr;
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = max(PAGE_SIZE, mmap_min_addr);
info.high_limit = current->mm->mmap_base;
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
addr = vm_unmapped_area(&info);
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
if (addr & ~PAGE_MASK) {
VM_BUG_ON(addr != -ENOMEM);
info.flags = 0;
info.low_limit = TASK_UNMAPPED_BASE;
info.high_limit = TASK_SIZE;
addr = vm_unmapped_area(&info);
}
return addr;
}
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
if (len & ~huge_page_mask(h))
return -EINVAL;
if (len > TASK_SIZE - mmap_min_addr)
return -ENOMEM;
if (flags & MAP_FIXED) {
if (prepare_hugepage_range(file, addr, len))
return -EINVAL;
goto check_asce_limit;
}
if (addr) {
addr = ALIGN(addr, huge_page_size(h));
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
(!vma || addr + len <= vm_start_gap(vma)))
goto check_asce_limit;
}
if (mm->get_unmapped_area == arch_get_unmapped_area)
addr = hugetlb_get_unmapped_area_bottomup(file, addr, len,
pgoff, flags);
else
addr = hugetlb_get_unmapped_area_topdown(file, addr, len,
pgoff, flags);
if (offset_in_page(addr))
return addr;
check_asce_limit:
return check_asce_limit(mm, addr, len);
}
|
