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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
45e576b1 | 2 | /* |
45e576b1 MS |
3 | * Copyright IBM Corp. 2008 |
4 | * | |
5 | * Guest page hinting for unused pages. | |
6 | * | |
7 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/mm.h> | |
c9b5ad54 | 14 | #include <linux/memblock.h> |
5a0e3ad6 | 15 | #include <linux/gfp.h> |
45e576b1 | 16 | #include <linux/init.h> |
c9b5ad54 | 17 | #include <asm/facility.h> |
2d42f947 | 18 | #include <asm/page-states.h> |
45e576b1 | 19 | |
2ddddf3e | 20 | static int cmma_flag = 1; |
45e576b1 MS |
21 | |
22 | static int __init cmma(char *str) | |
23 | { | |
24 | char *parm; | |
2ddddf3e | 25 | |
45e576b1 MS |
26 | parm = strstrip(str); |
27 | if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) { | |
28 | cmma_flag = 1; | |
29 | return 1; | |
30 | } | |
31 | cmma_flag = 0; | |
32 | if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0) | |
33 | return 1; | |
34 | return 0; | |
35 | } | |
45e576b1 MS |
36 | __setup("cmma=", cmma); |
37 | ||
931641c6 | 38 | static inline int cmma_test_essa(void) |
45e576b1 MS |
39 | { |
40 | register unsigned long tmp asm("0") = 0; | |
c9b5ad54 | 41 | register int rc asm("1"); |
45e576b1 | 42 | |
c9b5ad54 | 43 | /* test ESSA_GET_STATE */ |
45e576b1 | 44 | asm volatile( |
c9b5ad54 | 45 | " .insn rrf,0xb9ab0000,%1,%1,%2,0\n" |
45e576b1 MS |
46 | "0: la %0,0\n" |
47 | "1:\n" | |
48 | EX_TABLE(0b,1b) | |
c9b5ad54 MS |
49 | : "=&d" (rc), "+&d" (tmp) |
50 | : "i" (ESSA_GET_STATE), "0" (-EOPNOTSUPP)); | |
931641c6 HC |
51 | return rc; |
52 | } | |
53 | ||
54 | void __init cmma_init(void) | |
55 | { | |
56 | if (!cmma_flag) | |
57 | return; | |
c9b5ad54 | 58 | if (cmma_test_essa()) { |
45e576b1 | 59 | cmma_flag = 0; |
c9b5ad54 MS |
60 | return; |
61 | } | |
62 | if (test_facility(147)) | |
63 | cmma_flag = 2; | |
45e576b1 MS |
64 | } |
65 | ||
c9b5ad54 MS |
66 | static inline unsigned char get_page_state(struct page *page) |
67 | { | |
68 | unsigned char state; | |
69 | ||
70 | asm volatile(" .insn rrf,0xb9ab0000,%0,%1,%2,0" | |
71 | : "=&d" (state) | |
72 | : "a" (page_to_phys(page)), | |
73 | "i" (ESSA_GET_STATE)); | |
74 | return state & 0x3f; | |
75 | } | |
76 | ||
77 | static inline void set_page_unused(struct page *page, int order) | |
45e576b1 MS |
78 | { |
79 | int i, rc; | |
80 | ||
45e576b1 MS |
81 | for (i = 0; i < (1 << order); i++) |
82 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
83 | : "=&d" (rc) | |
846955c8 | 84 | : "a" (page_to_phys(page + i)), |
45e576b1 MS |
85 | "i" (ESSA_SET_UNUSED)); |
86 | } | |
87 | ||
c9b5ad54 | 88 | static inline void set_page_stable_dat(struct page *page, int order) |
45e576b1 | 89 | { |
c9b5ad54 MS |
90 | int i, rc; |
91 | ||
92 | for (i = 0; i < (1 << order); i++) | |
93 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
94 | : "=&d" (rc) | |
95 | : "a" (page_to_phys(page + i)), | |
96 | "i" (ESSA_SET_STABLE)); | |
846955c8 HC |
97 | } |
98 | ||
c9b5ad54 | 99 | static inline void set_page_stable_nodat(struct page *page, int order) |
846955c8 HC |
100 | { |
101 | int i, rc; | |
102 | ||
45e576b1 MS |
103 | for (i = 0; i < (1 << order); i++) |
104 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
105 | : "=&d" (rc) | |
846955c8 | 106 | : "a" (page_to_phys(page + i)), |
c9b5ad54 MS |
107 | "i" (ESSA_SET_STABLE_NODAT)); |
108 | } | |
109 | ||
110 | static void mark_kernel_pmd(pud_t *pud, unsigned long addr, unsigned long end) | |
111 | { | |
112 | unsigned long next; | |
113 | struct page *page; | |
114 | pmd_t *pmd; | |
115 | ||
116 | pmd = pmd_offset(pud, addr); | |
117 | do { | |
118 | next = pmd_addr_end(addr, end); | |
119 | if (pmd_none(*pmd) || pmd_large(*pmd)) | |
120 | continue; | |
121 | page = virt_to_page(pmd_val(*pmd)); | |
122 | set_bit(PG_arch_1, &page->flags); | |
123 | } while (pmd++, addr = next, addr != end); | |
124 | } | |
125 | ||
126 | static void mark_kernel_pud(p4d_t *p4d, unsigned long addr, unsigned long end) | |
127 | { | |
128 | unsigned long next; | |
129 | struct page *page; | |
130 | pud_t *pud; | |
131 | int i; | |
132 | ||
133 | pud = pud_offset(p4d, addr); | |
134 | do { | |
135 | next = pud_addr_end(addr, end); | |
136 | if (pud_none(*pud) || pud_large(*pud)) | |
137 | continue; | |
138 | if (!pud_folded(*pud)) { | |
139 | page = virt_to_page(pud_val(*pud)); | |
140 | for (i = 0; i < 3; i++) | |
141 | set_bit(PG_arch_1, &page[i].flags); | |
142 | } | |
143 | mark_kernel_pmd(pud, addr, next); | |
144 | } while (pud++, addr = next, addr != end); | |
145 | } | |
146 | ||
147 | static void mark_kernel_p4d(pgd_t *pgd, unsigned long addr, unsigned long end) | |
148 | { | |
149 | unsigned long next; | |
150 | struct page *page; | |
151 | p4d_t *p4d; | |
152 | int i; | |
153 | ||
154 | p4d = p4d_offset(pgd, addr); | |
155 | do { | |
156 | next = p4d_addr_end(addr, end); | |
157 | if (p4d_none(*p4d)) | |
158 | continue; | |
159 | if (!p4d_folded(*p4d)) { | |
160 | page = virt_to_page(p4d_val(*p4d)); | |
161 | for (i = 0; i < 3; i++) | |
162 | set_bit(PG_arch_1, &page[i].flags); | |
163 | } | |
164 | mark_kernel_pud(p4d, addr, next); | |
165 | } while (p4d++, addr = next, addr != end); | |
166 | } | |
167 | ||
168 | static void mark_kernel_pgd(void) | |
169 | { | |
170 | unsigned long addr, next; | |
171 | struct page *page; | |
172 | pgd_t *pgd; | |
173 | int i; | |
174 | ||
175 | addr = 0; | |
176 | pgd = pgd_offset_k(addr); | |
177 | do { | |
178 | next = pgd_addr_end(addr, MODULES_END); | |
179 | if (pgd_none(*pgd)) | |
180 | continue; | |
181 | if (!pgd_folded(*pgd)) { | |
182 | page = virt_to_page(pgd_val(*pgd)); | |
183 | for (i = 0; i < 3; i++) | |
184 | set_bit(PG_arch_1, &page[i].flags); | |
185 | } | |
186 | mark_kernel_p4d(pgd, addr, next); | |
187 | } while (pgd++, addr = next, addr != MODULES_END); | |
188 | } | |
189 | ||
190 | void __init cmma_init_nodat(void) | |
191 | { | |
192 | struct memblock_region *reg; | |
193 | struct page *page; | |
194 | unsigned long start, end, ix; | |
195 | ||
196 | if (cmma_flag < 2) | |
197 | return; | |
198 | /* Mark pages used in kernel page tables */ | |
199 | mark_kernel_pgd(); | |
200 | ||
201 | /* Set all kernel pages not used for page tables to stable/no-dat */ | |
202 | for_each_memblock(memory, reg) { | |
203 | start = memblock_region_memory_base_pfn(reg); | |
204 | end = memblock_region_memory_end_pfn(reg); | |
205 | page = pfn_to_page(start); | |
206 | for (ix = start; ix < end; ix++, page++) { | |
207 | if (__test_and_clear_bit(PG_arch_1, &page->flags)) | |
208 | continue; /* skip page table pages */ | |
209 | if (!list_empty(&page->lru)) | |
210 | continue; /* skip free pages */ | |
211 | set_page_stable_nodat(page, 0); | |
212 | } | |
213 | } | |
214 | } | |
215 | ||
216 | void arch_free_page(struct page *page, int order) | |
217 | { | |
218 | if (!cmma_flag) | |
219 | return; | |
220 | set_page_unused(page, order); | |
45e576b1 | 221 | } |
846955c8 HC |
222 | |
223 | void arch_alloc_page(struct page *page, int order) | |
224 | { | |
225 | if (!cmma_flag) | |
226 | return; | |
c9b5ad54 MS |
227 | if (cmma_flag < 2) |
228 | set_page_stable_dat(page, order); | |
229 | else | |
230 | set_page_stable_nodat(page, order); | |
231 | } | |
232 | ||
233 | void arch_set_page_dat(struct page *page, int order) | |
234 | { | |
235 | if (!cmma_flag) | |
236 | return; | |
237 | set_page_stable_dat(page, order); | |
238 | } | |
239 | ||
240 | void arch_set_page_nodat(struct page *page, int order) | |
241 | { | |
242 | if (cmma_flag < 2) | |
243 | return; | |
244 | set_page_stable_nodat(page, order); | |
245 | } | |
246 | ||
247 | int arch_test_page_nodat(struct page *page) | |
248 | { | |
249 | unsigned char state; | |
250 | ||
251 | if (cmma_flag < 2) | |
252 | return 0; | |
253 | state = get_page_state(page); | |
254 | return !!(state & 0x20); | |
846955c8 HC |
255 | } |
256 | ||
257 | void arch_set_page_states(int make_stable) | |
258 | { | |
259 | unsigned long flags, order, t; | |
260 | struct list_head *l; | |
261 | struct page *page; | |
262 | struct zone *zone; | |
263 | ||
264 | if (!cmma_flag) | |
265 | return; | |
266 | if (make_stable) | |
267 | drain_local_pages(NULL); | |
268 | for_each_populated_zone(zone) { | |
269 | spin_lock_irqsave(&zone->lock, flags); | |
270 | for_each_migratetype_order(order, t) { | |
271 | list_for_each(l, &zone->free_area[order].free_list[t]) { | |
272 | page = list_entry(l, struct page, lru); | |
273 | if (make_stable) | |
c9b5ad54 | 274 | set_page_stable_dat(page, 0); |
846955c8 | 275 | else |
c9b5ad54 | 276 | set_page_unused(page, order); |
846955c8 HC |
277 | } |
278 | } | |
279 | spin_unlock_irqrestore(&zone->lock, flags); | |
280 | } | |
281 | } |