1 // SPDX-License-Identifier: GPL-2.0
3 * IBM System z Huge TLB Page Support for Kernel.
5 * Copyright IBM Corp. 2007,2016
6 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
9 #define KMSG_COMPONENT "hugetlb"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 #include <linux/hugetlb.h>
16 * If the bit selected by single-bit bitmask "a" is set within "x", move
17 * it to the position indicated by single-bit bitmask "b".
19 #define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
21 static inline unsigned long __pte_to_rste(pte_t pte)
26 * Convert encoding pte bits pmd / pud bits
27 * lIR.uswrdy.p dy..R...I...wr
28 * empty 010.000000.0 -> 00..0...1...00
29 * prot-none, clean, old 111.000000.1 -> 00..1...1...00
30 * prot-none, clean, young 111.000001.1 -> 01..1...1...00
31 * prot-none, dirty, old 111.000010.1 -> 10..1...1...00
32 * prot-none, dirty, young 111.000011.1 -> 11..1...1...00
33 * read-only, clean, old 111.000100.1 -> 00..1...1...01
34 * read-only, clean, young 101.000101.1 -> 01..1...0...01
35 * read-only, dirty, old 111.000110.1 -> 10..1...1...01
36 * read-only, dirty, young 101.000111.1 -> 11..1...0...01
37 * read-write, clean, old 111.001100.1 -> 00..1...1...11
38 * read-write, clean, young 101.001101.1 -> 01..1...0...11
39 * read-write, dirty, old 110.001110.1 -> 10..0...1...11
40 * read-write, dirty, young 100.001111.1 -> 11..0...0...11
41 * HW-bits: R read-only, I invalid
42 * SW-bits: p present, y young, d dirty, r read, w write, s special,
45 if (pte_present(pte)) {
46 rste = pte_val(pte) & PAGE_MASK;
47 rste |= move_set_bit(pte_val(pte), _PAGE_READ,
49 rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
50 _SEGMENT_ENTRY_WRITE);
51 rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
52 _SEGMENT_ENTRY_INVALID);
53 rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
54 _SEGMENT_ENTRY_PROTECT);
55 rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
56 _SEGMENT_ENTRY_DIRTY);
57 rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
58 _SEGMENT_ENTRY_YOUNG);
59 #ifdef CONFIG_MEM_SOFT_DIRTY
60 rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
61 _SEGMENT_ENTRY_SOFT_DIRTY);
63 rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC,
64 _SEGMENT_ENTRY_NOEXEC);
66 rste = _SEGMENT_ENTRY_EMPTY;
70 static inline pte_t __rste_to_pte(unsigned long rste)
75 if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
76 present = pud_present(__pud(rste));
78 present = pmd_present(__pmd(rste));
81 * Convert encoding pmd / pud bits pte bits
82 * dy..R...I...wr lIR.uswrdy.p
83 * empty 00..0...1...00 -> 010.000000.0
84 * prot-none, clean, old 00..1...1...00 -> 111.000000.1
85 * prot-none, clean, young 01..1...1...00 -> 111.000001.1
86 * prot-none, dirty, old 10..1...1...00 -> 111.000010.1
87 * prot-none, dirty, young 11..1...1...00 -> 111.000011.1
88 * read-only, clean, old 00..1...1...01 -> 111.000100.1
89 * read-only, clean, young 01..1...0...01 -> 101.000101.1
90 * read-only, dirty, old 10..1...1...01 -> 111.000110.1
91 * read-only, dirty, young 11..1...0...01 -> 101.000111.1
92 * read-write, clean, old 00..1...1...11 -> 111.001100.1
93 * read-write, clean, young 01..1...0...11 -> 101.001101.1
94 * read-write, dirty, old 10..0...1...11 -> 110.001110.1
95 * read-write, dirty, young 11..0...0...11 -> 100.001111.1
96 * HW-bits: R read-only, I invalid
97 * SW-bits: p present, y young, d dirty, r read, w write, s special,
101 pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
102 pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
103 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
105 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
107 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
109 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
111 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
113 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
115 #ifdef CONFIG_MEM_SOFT_DIRTY
116 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
119 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
122 pte_val(pte) = _PAGE_INVALID;
126 static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
129 unsigned long size, paddr;
131 if (!mm_uses_skeys(mm) ||
132 rste & _SEGMENT_ENTRY_INVALID)
135 if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
136 page = pud_page(__pud(rste));
138 paddr = rste & PUD_MASK;
140 page = pmd_page(__pmd(rste));
142 paddr = rste & PMD_MASK;
145 if (!test_and_set_bit(PG_arch_1, &page->flags))
146 __storage_key_init_range(paddr, paddr + size - 1);
149 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
150 pte_t *ptep, pte_t pte)
154 rste = __pte_to_rste(pte);
156 rste &= ~_SEGMENT_ENTRY_NOEXEC;
158 /* Set correct table type for 2G hugepages */
159 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
160 rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
162 rste |= _SEGMENT_ENTRY_LARGE;
163 clear_huge_pte_skeys(mm, rste);
164 pte_val(*ptep) = rste;
167 pte_t huge_ptep_get(pte_t *ptep)
169 return __rste_to_pte(pte_val(*ptep));
172 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
173 unsigned long addr, pte_t *ptep)
175 pte_t pte = huge_ptep_get(ptep);
176 pmd_t *pmdp = (pmd_t *) ptep;
177 pud_t *pudp = (pud_t *) ptep;
179 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
180 pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
182 pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
186 pte_t *huge_pte_alloc(struct mm_struct *mm,
187 unsigned long addr, unsigned long sz)
194 pgdp = pgd_offset(mm, addr);
195 p4dp = p4d_alloc(mm, pgdp, addr);
197 pudp = pud_alloc(mm, p4dp, addr);
200 return (pte_t *) pudp;
201 else if (sz == PMD_SIZE)
202 pmdp = pmd_alloc(mm, pudp, addr);
205 return (pte_t *) pmdp;
208 pte_t *huge_pte_offset(struct mm_struct *mm,
209 unsigned long addr, unsigned long sz)
216 pgdp = pgd_offset(mm, addr);
217 if (pgd_present(*pgdp)) {
218 p4dp = p4d_offset(pgdp, addr);
219 if (p4d_present(*p4dp)) {
220 pudp = pud_offset(p4dp, addr);
221 if (pud_present(*pudp)) {
222 if (pud_large(*pudp))
223 return (pte_t *) pudp;
224 pmdp = pmd_offset(pudp, addr);
228 return (pte_t *) pmdp;
231 int pmd_huge(pmd_t pmd)
233 return pmd_large(pmd);
236 int pud_huge(pud_t pud)
238 return pud_large(pud);
242 follow_huge_pud(struct mm_struct *mm, unsigned long address,
243 pud_t *pud, int flags)
245 if (flags & FOLL_GET)
248 return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
251 static __init int setup_hugepagesz(char *opt)
256 size = memparse(opt, &opt);
257 if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
258 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
259 } else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
260 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
263 pr_err("hugepagesz= specifies an unsupported page size %s\n",
269 __setup("hugepagesz=", setup_hugepagesz);