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91f1da99 AK |
1 | /* |
2 | * Copyright IBM Corporation, 2015 | |
3 | * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of version 2 of the GNU Lesser General Public License | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it would be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <linux/mm.h> | |
16 | #include <asm/machdep.h> | |
17 | #include <asm/mmu.h> | |
bf680d51 AK |
18 | /* |
19 | * index from 0 - 15 | |
20 | */ | |
21 | bool __rpte_sub_valid(real_pte_t rpte, unsigned long index) | |
22 | { | |
23 | unsigned long g_idx; | |
24 | unsigned long ptev = pte_val(rpte.pte); | |
25 | ||
26 | g_idx = (ptev & _PAGE_COMBO_VALID) >> _PAGE_F_GIX_SHIFT; | |
27 | index = index >> 2; | |
28 | if (g_idx & (0x1 << index)) | |
29 | return true; | |
30 | else | |
31 | return false; | |
32 | } | |
33 | /* | |
34 | * index from 0 - 15 | |
35 | */ | |
36 | static unsigned long mark_subptegroup_valid(unsigned long ptev, unsigned long index) | |
37 | { | |
38 | unsigned long g_idx; | |
39 | ||
40 | if (!(ptev & _PAGE_COMBO)) | |
41 | return ptev; | |
42 | index = index >> 2; | |
43 | g_idx = 0x1 << index; | |
44 | ||
45 | return ptev | (g_idx << _PAGE_F_GIX_SHIFT); | |
46 | } | |
91f1da99 AK |
47 | |
48 | int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid, | |
49 | pte_t *ptep, unsigned long trap, unsigned long flags, | |
50 | int ssize, int subpg_prot) | |
51 | { | |
52 | real_pte_t rpte; | |
53 | unsigned long *hidxp; | |
54 | unsigned long hpte_group; | |
55 | unsigned int subpg_index; | |
56 | unsigned long rflags, pa, hidx; | |
57 | unsigned long old_pte, new_pte, subpg_pte; | |
58 | unsigned long vpn, hash, slot; | |
59 | unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift; | |
60 | ||
61 | /* | |
62 | * atomically mark the linux large page PTE busy and dirty | |
63 | */ | |
64 | do { | |
65 | pte_t pte = READ_ONCE(*ptep); | |
66 | ||
67 | old_pte = pte_val(pte); | |
68 | /* If PTE busy, retry the access */ | |
69 | if (unlikely(old_pte & _PAGE_BUSY)) | |
70 | return 0; | |
71 | /* If PTE permissions don't match, take page fault */ | |
72 | if (unlikely(access & ~old_pte)) | |
73 | return 1; | |
74 | /* | |
75 | * Try to lock the PTE, add ACCESSED and DIRTY if it was | |
76 | * a write access. Since this is 4K insert of 64K page size | |
77 | * also add _PAGE_COMBO | |
78 | */ | |
79 | new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO; | |
80 | if (access & _PAGE_RW) | |
81 | new_pte |= _PAGE_DIRTY; | |
82 | } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, | |
83 | old_pte, new_pte)); | |
84 | /* | |
85 | * Handle the subpage protection bits | |
86 | */ | |
87 | subpg_pte = new_pte & ~subpg_prot; | |
c6a3c495 | 88 | rflags = htab_convert_pte_flags(subpg_pte); |
91f1da99 AK |
89 | |
90 | if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && | |
91 | !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) { | |
92 | ||
93 | /* | |
94 | * No CPU has hugepages but lacks no execute, so we | |
95 | * don't need to worry about that case | |
96 | */ | |
97 | rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); | |
98 | } | |
99 | ||
100 | subpg_index = (ea & (PAGE_SIZE - 1)) >> shift; | |
101 | vpn = hpt_vpn(ea, vsid, ssize); | |
102 | rpte = __real_pte(__pte(old_pte), ptep); | |
103 | /* | |
104 | *None of the sub 4k page is hashed | |
105 | */ | |
106 | if (!(old_pte & _PAGE_HASHPTE)) | |
107 | goto htab_insert_hpte; | |
108 | /* | |
109 | * Check if the pte was already inserted into the hash table | |
110 | * as a 64k HW page, and invalidate the 64k HPTE if so. | |
111 | */ | |
112 | if (!(old_pte & _PAGE_COMBO)) { | |
113 | flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags); | |
9ab3ac23 AK |
114 | /* |
115 | * clear the old slot details from the old and new pte. | |
116 | * On hash insert failure we use old pte value and we don't | |
117 | * want slot information there if we have a insert failure. | |
118 | */ | |
119 | old_pte &= ~(_PAGE_HASHPTE | _PAGE_F_GIX | _PAGE_F_SECOND); | |
120 | new_pte &= ~(_PAGE_HASHPTE | _PAGE_F_GIX | _PAGE_F_SECOND); | |
91f1da99 AK |
121 | goto htab_insert_hpte; |
122 | } | |
123 | /* | |
124 | * Check for sub page valid and update | |
125 | */ | |
126 | if (__rpte_sub_valid(rpte, subpg_index)) { | |
127 | int ret; | |
128 | ||
129 | hash = hpt_hash(vpn, shift, ssize); | |
130 | hidx = __rpte_to_hidx(rpte, subpg_index); | |
131 | if (hidx & _PTEIDX_SECONDARY) | |
132 | hash = ~hash; | |
133 | slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; | |
134 | slot += hidx & _PTEIDX_GROUP_IX; | |
135 | ||
136 | ret = ppc_md.hpte_updatepp(slot, rflags, vpn, | |
137 | MMU_PAGE_4K, MMU_PAGE_4K, | |
138 | ssize, flags); | |
139 | /* | |
140 | *if we failed because typically the HPTE wasn't really here | |
141 | * we try an insertion. | |
142 | */ | |
143 | if (ret == -1) | |
144 | goto htab_insert_hpte; | |
145 | ||
146 | *ptep = __pte(new_pte & ~_PAGE_BUSY); | |
147 | return 0; | |
148 | } | |
149 | ||
150 | htab_insert_hpte: | |
151 | /* | |
152 | * handle _PAGE_4K_PFN case | |
153 | */ | |
154 | if (old_pte & _PAGE_4K_PFN) { | |
155 | /* | |
156 | * All the sub 4k page have the same | |
157 | * physical address. | |
158 | */ | |
159 | pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT; | |
160 | } else { | |
161 | pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; | |
162 | pa += (subpg_index << shift); | |
163 | } | |
164 | hash = hpt_hash(vpn, shift, ssize); | |
165 | repeat: | |
166 | hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; | |
167 | ||
168 | /* Insert into the hash table, primary slot */ | |
169 | slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0, | |
170 | MMU_PAGE_4K, MMU_PAGE_4K, ssize); | |
171 | /* | |
172 | * Primary is full, try the secondary | |
173 | */ | |
174 | if (unlikely(slot == -1)) { | |
175 | hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; | |
176 | slot = ppc_md.hpte_insert(hpte_group, vpn, pa, | |
177 | rflags, HPTE_V_SECONDARY, | |
178 | MMU_PAGE_4K, MMU_PAGE_4K, ssize); | |
179 | if (slot == -1) { | |
180 | if (mftb() & 0x1) | |
181 | hpte_group = ((hash & htab_hash_mask) * | |
182 | HPTES_PER_GROUP) & ~0x7UL; | |
183 | ppc_md.hpte_remove(hpte_group); | |
184 | /* | |
185 | * FIXME!! Should be try the group from which we removed ? | |
186 | */ | |
187 | goto repeat; | |
188 | } | |
189 | } | |
190 | /* | |
e9a68147 | 191 | * Hypervisor failure. Restore old pte and return -1 |
91f1da99 AK |
192 | * similar to __hash_page_* |
193 | */ | |
194 | if (unlikely(slot == -2)) { | |
195 | *ptep = __pte(old_pte); | |
196 | hash_failure_debug(ea, access, vsid, trap, ssize, | |
197 | MMU_PAGE_4K, MMU_PAGE_4K, old_pte); | |
198 | return -1; | |
199 | } | |
200 | /* | |
201 | * Insert slot number & secondary bit in PTE second half, | |
202 | * clear _PAGE_BUSY and set appropriate HPTE slot bit | |
203 | * Since we have _PAGE_BUSY set on ptep, we can be sure | |
204 | * nobody is undating hidx. | |
205 | */ | |
206 | hidxp = (unsigned long *)(ptep + PTRS_PER_PTE); | |
91f1da99 AK |
207 | rpte.hidx &= ~(0xfUL << (subpg_index << 2)); |
208 | *hidxp = rpte.hidx | (slot << (subpg_index << 2)); | |
bf680d51 AK |
209 | new_pte = mark_subptegroup_valid(new_pte, subpg_index); |
210 | new_pte |= _PAGE_HASHPTE; | |
91f1da99 AK |
211 | /* |
212 | * check __real_pte for details on matching smp_rmb() | |
213 | */ | |
214 | smp_wmb(); | |
215 | *ptep = __pte(new_pte & ~_PAGE_BUSY); | |
216 | return 0; | |
217 | } | |
89ff7250 AK |
218 | |
219 | int __hash_page_64K(unsigned long ea, unsigned long access, | |
220 | unsigned long vsid, pte_t *ptep, unsigned long trap, | |
221 | unsigned long flags, int ssize) | |
222 | { | |
223 | ||
224 | unsigned long hpte_group; | |
225 | unsigned long rflags, pa; | |
226 | unsigned long old_pte, new_pte; | |
227 | unsigned long vpn, hash, slot; | |
228 | unsigned long shift = mmu_psize_defs[MMU_PAGE_64K].shift; | |
229 | ||
230 | /* | |
231 | * atomically mark the linux large page PTE busy and dirty | |
232 | */ | |
233 | do { | |
234 | pte_t pte = READ_ONCE(*ptep); | |
235 | ||
236 | old_pte = pte_val(pte); | |
237 | /* If PTE busy, retry the access */ | |
238 | if (unlikely(old_pte & _PAGE_BUSY)) | |
239 | return 0; | |
240 | /* If PTE permissions don't match, take page fault */ | |
241 | if (unlikely(access & ~old_pte)) | |
242 | return 1; | |
243 | /* | |
244 | * Check if PTE has the cache-inhibit bit set | |
245 | * If so, bail out and refault as a 4k page | |
246 | */ | |
247 | if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) && | |
248 | unlikely(old_pte & _PAGE_NO_CACHE)) | |
249 | return 0; | |
250 | /* | |
251 | * Try to lock the PTE, add ACCESSED and DIRTY if it was | |
1ec3f937 | 252 | * a write access. |
89ff7250 AK |
253 | */ |
254 | new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; | |
255 | if (access & _PAGE_RW) | |
256 | new_pte |= _PAGE_DIRTY; | |
257 | } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, | |
258 | old_pte, new_pte)); | |
c6a3c495 AK |
259 | |
260 | rflags = htab_convert_pte_flags(new_pte); | |
89ff7250 AK |
261 | |
262 | if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && | |
263 | !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) | |
264 | rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); | |
265 | ||
266 | vpn = hpt_vpn(ea, vsid, ssize); | |
267 | if (unlikely(old_pte & _PAGE_HASHPTE)) { | |
268 | /* | |
269 | * There MIGHT be an HPTE for this pte | |
270 | */ | |
271 | hash = hpt_hash(vpn, shift, ssize); | |
272 | if (old_pte & _PAGE_F_SECOND) | |
273 | hash = ~hash; | |
274 | slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; | |
275 | slot += (old_pte & _PAGE_F_GIX) >> _PAGE_F_GIX_SHIFT; | |
276 | ||
277 | if (ppc_md.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_64K, | |
278 | MMU_PAGE_64K, ssize, flags) == -1) | |
279 | old_pte &= ~_PAGE_HPTEFLAGS; | |
280 | } | |
281 | ||
282 | if (likely(!(old_pte & _PAGE_HASHPTE))) { | |
283 | ||
284 | pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; | |
285 | hash = hpt_hash(vpn, shift, ssize); | |
286 | ||
287 | repeat: | |
288 | hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; | |
289 | ||
290 | /* Insert into the hash table, primary slot */ | |
291 | slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0, | |
292 | MMU_PAGE_64K, MMU_PAGE_64K, ssize); | |
293 | /* | |
294 | * Primary is full, try the secondary | |
295 | */ | |
296 | if (unlikely(slot == -1)) { | |
297 | hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; | |
298 | slot = ppc_md.hpte_insert(hpte_group, vpn, pa, | |
299 | rflags, HPTE_V_SECONDARY, | |
300 | MMU_PAGE_64K, MMU_PAGE_64K, ssize); | |
301 | if (slot == -1) { | |
302 | if (mftb() & 0x1) | |
303 | hpte_group = ((hash & htab_hash_mask) * | |
304 | HPTES_PER_GROUP) & ~0x7UL; | |
305 | ppc_md.hpte_remove(hpte_group); | |
306 | /* | |
307 | * FIXME!! Should be try the group from which we removed ? | |
308 | */ | |
309 | goto repeat; | |
310 | } | |
311 | } | |
312 | /* | |
e9a68147 | 313 | * Hypervisor failure. Restore old pte and return -1 |
89ff7250 AK |
314 | * similar to __hash_page_* |
315 | */ | |
316 | if (unlikely(slot == -2)) { | |
317 | *ptep = __pte(old_pte); | |
318 | hash_failure_debug(ea, access, vsid, trap, ssize, | |
319 | MMU_PAGE_64K, MMU_PAGE_64K, old_pte); | |
320 | return -1; | |
321 | } | |
322 | new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE; | |
323 | new_pte |= (slot << _PAGE_F_GIX_SHIFT) & (_PAGE_F_SECOND | _PAGE_F_GIX); | |
324 | } | |
325 | *ptep = __pte(new_pte & ~_PAGE_BUSY); | |
326 | return 0; | |
327 | } |