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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1515ab93 RG |
2 | /* |
3 | * Copyright 2016, Rashmica Gupta, IBM Corp. | |
4 | * | |
5 | * This traverses the kernel virtual memory and dumps the pages that are in | |
6 | * the hash pagetable, along with their flags to | |
7 | * /sys/kernel/debug/kernel_hash_pagetable. | |
8 | * | |
9 | * If radix is enabled then there is no hash page table and so no debugfs file | |
10 | * is generated. | |
1515ab93 RG |
11 | */ |
12 | #include <linux/debugfs.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/seq_file.h> | |
1515ab93 RG |
18 | #include <linux/const.h> |
19 | #include <asm/page.h> | |
1515ab93 RG |
20 | #include <asm/plpar_wrappers.h> |
21 | #include <linux/memblock.h> | |
22 | #include <asm/firmware.h> | |
ca15ca40 | 23 | #include <asm/pgalloc.h> |
1515ab93 RG |
24 | |
25 | struct pg_state { | |
26 | struct seq_file *seq; | |
27 | const struct addr_marker *marker; | |
28 | unsigned long start_address; | |
29 | unsigned int level; | |
30 | u64 current_flags; | |
31 | }; | |
32 | ||
33 | struct addr_marker { | |
34 | unsigned long start_address; | |
35 | const char *name; | |
36 | }; | |
37 | ||
38 | static struct addr_marker address_markers[] = { | |
39 | { 0, "Start of kernel VM" }, | |
40 | { 0, "vmalloc() Area" }, | |
41 | { 0, "vmalloc() End" }, | |
42 | { 0, "isa I/O start" }, | |
43 | { 0, "isa I/O end" }, | |
44 | { 0, "phb I/O start" }, | |
45 | { 0, "phb I/O end" }, | |
46 | { 0, "I/O remap start" }, | |
47 | { 0, "I/O remap end" }, | |
48 | { 0, "vmemmap start" }, | |
49 | { -1, NULL }, | |
50 | }; | |
51 | ||
52 | struct flag_info { | |
53 | u64 mask; | |
54 | u64 val; | |
55 | const char *set; | |
56 | const char *clear; | |
57 | bool is_val; | |
58 | int shift; | |
59 | }; | |
60 | ||
61 | static const struct flag_info v_flag_array[] = { | |
62 | { | |
63 | .mask = SLB_VSID_B, | |
64 | .val = SLB_VSID_B_256M, | |
65 | .set = "ssize: 256M", | |
66 | .clear = "ssize: 1T ", | |
67 | }, { | |
68 | .mask = HPTE_V_SECONDARY, | |
69 | .val = HPTE_V_SECONDARY, | |
70 | .set = "secondary", | |
71 | .clear = "primary ", | |
72 | }, { | |
73 | .mask = HPTE_V_VALID, | |
74 | .val = HPTE_V_VALID, | |
75 | .set = "valid ", | |
76 | .clear = "invalid", | |
77 | }, { | |
78 | .mask = HPTE_V_BOLTED, | |
79 | .val = HPTE_V_BOLTED, | |
80 | .set = "bolted", | |
81 | .clear = "", | |
82 | } | |
83 | }; | |
84 | ||
85 | static const struct flag_info r_flag_array[] = { | |
86 | { | |
87 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
88 | .val = PP_RWXX, | |
89 | .set = "prot:RW--", | |
90 | }, { | |
91 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
92 | .val = PP_RWRX, | |
93 | .set = "prot:RWR-", | |
94 | }, { | |
95 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
96 | .val = PP_RWRW, | |
97 | .set = "prot:RWRW", | |
98 | }, { | |
99 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
100 | .val = PP_RXRX, | |
101 | .set = "prot:R-R-", | |
102 | }, { | |
103 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
104 | .val = PP_RXXX, | |
105 | .set = "prot:R---", | |
106 | }, { | |
107 | .mask = HPTE_R_KEY_HI | HPTE_R_KEY_LO, | |
108 | .val = HPTE_R_KEY_HI | HPTE_R_KEY_LO, | |
109 | .set = "key", | |
110 | .clear = "", | |
111 | .is_val = true, | |
112 | }, { | |
113 | .mask = HPTE_R_R, | |
114 | .val = HPTE_R_R, | |
115 | .set = "ref", | |
116 | .clear = " ", | |
117 | }, { | |
118 | .mask = HPTE_R_C, | |
119 | .val = HPTE_R_C, | |
120 | .set = "changed", | |
121 | .clear = " ", | |
122 | }, { | |
123 | .mask = HPTE_R_N, | |
124 | .val = HPTE_R_N, | |
125 | .set = "no execute", | |
126 | }, { | |
127 | .mask = HPTE_R_WIMG, | |
128 | .val = HPTE_R_W, | |
129 | .set = "writethru", | |
130 | }, { | |
131 | .mask = HPTE_R_WIMG, | |
132 | .val = HPTE_R_I, | |
133 | .set = "no cache", | |
134 | }, { | |
135 | .mask = HPTE_R_WIMG, | |
136 | .val = HPTE_R_G, | |
137 | .set = "guarded", | |
138 | } | |
139 | }; | |
140 | ||
141 | static int calculate_pagesize(struct pg_state *st, int ps, char s[]) | |
142 | { | |
143 | static const char units[] = "BKMGTPE"; | |
144 | const char *unit = units; | |
145 | ||
146 | while (ps > 9 && unit[1]) { | |
147 | ps -= 10; | |
148 | unit++; | |
149 | } | |
150 | seq_printf(st->seq, " %s_ps: %i%c\t", s, 1<<ps, *unit); | |
151 | return ps; | |
152 | } | |
153 | ||
154 | static void dump_flag_info(struct pg_state *st, const struct flag_info | |
155 | *flag, u64 pte, int num) | |
156 | { | |
157 | unsigned int i; | |
158 | ||
159 | for (i = 0; i < num; i++, flag++) { | |
160 | const char *s = NULL; | |
161 | u64 val; | |
162 | ||
163 | /* flag not defined so don't check it */ | |
164 | if (flag->mask == 0) | |
165 | continue; | |
166 | /* Some 'flags' are actually values */ | |
167 | if (flag->is_val) { | |
168 | val = pte & flag->val; | |
169 | if (flag->shift) | |
170 | val = val >> flag->shift; | |
171 | seq_printf(st->seq, " %s:%llx", flag->set, val); | |
172 | } else { | |
173 | if ((pte & flag->mask) == flag->val) | |
174 | s = flag->set; | |
175 | else | |
176 | s = flag->clear; | |
177 | if (s) | |
178 | seq_printf(st->seq, " %s", s); | |
179 | } | |
180 | } | |
181 | } | |
182 | ||
183 | static void dump_hpte_info(struct pg_state *st, unsigned long ea, u64 v, u64 r, | |
184 | unsigned long rpn, int bps, int aps, unsigned long lp) | |
185 | { | |
186 | int aps_index; | |
187 | ||
188 | while (ea >= st->marker[1].start_address) { | |
189 | st->marker++; | |
190 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
191 | } | |
192 | seq_printf(st->seq, "0x%lx:\t", ea); | |
193 | seq_printf(st->seq, "AVPN:%llx\t", HPTE_V_AVPN_VAL(v)); | |
194 | dump_flag_info(st, v_flag_array, v, ARRAY_SIZE(v_flag_array)); | |
195 | seq_printf(st->seq, " rpn: %lx\t", rpn); | |
196 | dump_flag_info(st, r_flag_array, r, ARRAY_SIZE(r_flag_array)); | |
197 | ||
198 | calculate_pagesize(st, bps, "base"); | |
199 | aps_index = calculate_pagesize(st, aps, "actual"); | |
200 | if (aps_index != 2) | |
201 | seq_printf(st->seq, "LP enc: %lx", lp); | |
aae85e3c | 202 | seq_putc(st->seq, '\n'); |
1515ab93 RG |
203 | } |
204 | ||
205 | ||
206 | static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64 | |
207 | *r) | |
208 | { | |
209 | struct hash_pte *hptep; | |
210 | unsigned long hash, vsid, vpn, hpte_group, want_v, hpte_v; | |
211 | int i, ssize = mmu_kernel_ssize; | |
212 | unsigned long shift = mmu_psize_defs[psize].shift; | |
213 | ||
214 | /* calculate hash */ | |
215 | vsid = get_kernel_vsid(ea, ssize); | |
216 | vpn = hpt_vpn(ea, vsid, ssize); | |
217 | hash = hpt_hash(vpn, shift, ssize); | |
218 | want_v = hpte_encode_avpn(vpn, psize, ssize); | |
219 | ||
220 | /* to check in the secondary hash table, we invert the hash */ | |
221 | if (!primary) | |
222 | hash = ~hash; | |
223 | hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP; | |
224 | for (i = 0; i < HPTES_PER_GROUP; i++) { | |
225 | hptep = htab_address + hpte_group; | |
226 | hpte_v = be64_to_cpu(hptep->v); | |
227 | ||
228 | if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) { | |
229 | /* HPTE matches */ | |
230 | *v = be64_to_cpu(hptep->v); | |
231 | *r = be64_to_cpu(hptep->r); | |
232 | return 0; | |
233 | } | |
234 | ++hpte_group; | |
235 | } | |
236 | return -1; | |
237 | } | |
238 | ||
1515ab93 RG |
239 | static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *r) |
240 | { | |
241 | struct hash_pte ptes[4]; | |
242 | unsigned long vsid, vpn, hash, hpte_group, want_v; | |
243 | int i, j, ssize = mmu_kernel_ssize; | |
244 | long lpar_rc = 0; | |
245 | unsigned long shift = mmu_psize_defs[psize].shift; | |
246 | ||
247 | /* calculate hash */ | |
248 | vsid = get_kernel_vsid(ea, ssize); | |
249 | vpn = hpt_vpn(ea, vsid, ssize); | |
250 | hash = hpt_hash(vpn, shift, ssize); | |
251 | want_v = hpte_encode_avpn(vpn, psize, ssize); | |
252 | ||
253 | /* to check in the secondary hash table, we invert the hash */ | |
254 | if (!primary) | |
255 | hash = ~hash; | |
1531cff4 | 256 | hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP; |
1515ab93 RG |
257 | /* see if we can find an entry in the hpte with this hash */ |
258 | for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) { | |
259 | lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes); | |
260 | ||
7c466b08 | 261 | if (lpar_rc) |
1515ab93 RG |
262 | continue; |
263 | for (j = 0; j < 4; j++) { | |
264 | if (HPTE_V_COMPARE(ptes[j].v, want_v) && | |
265 | (ptes[j].v & HPTE_V_VALID)) { | |
266 | /* HPTE matches */ | |
267 | *v = ptes[j].v; | |
268 | *r = ptes[j].r; | |
269 | return 0; | |
270 | } | |
271 | } | |
272 | } | |
273 | return -1; | |
274 | } | |
1515ab93 RG |
275 | |
276 | static void decode_r(int bps, unsigned long r, unsigned long *rpn, int *aps, | |
277 | unsigned long *lp_bits) | |
278 | { | |
279 | struct mmu_psize_def entry; | |
280 | unsigned long arpn, mask, lp; | |
281 | int penc = -2, idx = 0, shift; | |
282 | ||
283 | /*. | |
284 | * The LP field has 8 bits. Depending on the actual page size, some of | |
285 | * these bits are concatenated with the APRN to get the RPN. The rest | |
286 | * of the bits in the LP field is the LP value and is an encoding for | |
287 | * the base page size and the actual page size. | |
288 | * | |
289 | * - find the mmu entry for our base page size | |
290 | * - go through all page encodings and use the associated mask to | |
291 | * find an encoding that matches our encoding in the LP field. | |
292 | */ | |
293 | arpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT; | |
294 | lp = arpn & 0xff; | |
295 | ||
296 | entry = mmu_psize_defs[bps]; | |
297 | while (idx < MMU_PAGE_COUNT) { | |
298 | penc = entry.penc[idx]; | |
299 | if ((penc != -1) && (mmu_psize_defs[idx].shift)) { | |
300 | shift = mmu_psize_defs[idx].shift - HPTE_R_RPN_SHIFT; | |
301 | mask = (0x1 << (shift)) - 1; | |
302 | if ((lp & mask) == penc) { | |
303 | *aps = mmu_psize_to_shift(idx); | |
304 | *lp_bits = lp & mask; | |
305 | *rpn = arpn >> shift; | |
306 | return; | |
307 | } | |
308 | } | |
309 | idx++; | |
310 | } | |
311 | } | |
312 | ||
313 | static int base_hpte_find(unsigned long ea, int psize, bool primary, u64 *v, | |
314 | u64 *r) | |
315 | { | |
65e701b2 | 316 | if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR)) |
1515ab93 | 317 | return pseries_find(ea, psize, primary, v, r); |
65e701b2 | 318 | |
1515ab93 RG |
319 | return native_find(ea, psize, primary, v, r); |
320 | } | |
321 | ||
322 | static unsigned long hpte_find(struct pg_state *st, unsigned long ea, int psize) | |
323 | { | |
324 | unsigned long slot; | |
325 | u64 v = 0, r = 0; | |
326 | unsigned long rpn, lp_bits; | |
327 | int base_psize = 0, actual_psize = 0; | |
328 | ||
e63739b1 | 329 | if (ea < PAGE_OFFSET) |
1515ab93 RG |
330 | return -1; |
331 | ||
332 | /* Look in primary table */ | |
333 | slot = base_hpte_find(ea, psize, true, &v, &r); | |
334 | ||
335 | /* Look in secondary table */ | |
336 | if (slot == -1) | |
790845e2 | 337 | slot = base_hpte_find(ea, psize, false, &v, &r); |
1515ab93 RG |
338 | |
339 | /* No entry found */ | |
340 | if (slot == -1) | |
341 | return -1; | |
342 | ||
343 | /* | |
344 | * We found an entry in the hash page table: | |
345 | * - check that this has the same base page | |
346 | * - find the actual page size | |
347 | * - find the RPN | |
348 | */ | |
349 | base_psize = mmu_psize_to_shift(psize); | |
350 | ||
351 | if ((v & HPTE_V_LARGE) == HPTE_V_LARGE) { | |
352 | decode_r(psize, r, &rpn, &actual_psize, &lp_bits); | |
353 | } else { | |
354 | /* 4K actual page size */ | |
355 | actual_psize = 12; | |
356 | rpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT; | |
357 | /* In this case there are no LP bits */ | |
358 | lp_bits = -1; | |
359 | } | |
360 | /* | |
361 | * We didn't find a matching encoding, so the PTE we found isn't for | |
362 | * this address. | |
363 | */ | |
364 | if (actual_psize == -1) | |
365 | return -1; | |
366 | ||
367 | dump_hpte_info(st, ea, v, r, rpn, base_psize, actual_psize, lp_bits); | |
368 | return 0; | |
369 | } | |
370 | ||
371 | static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) | |
372 | { | |
373 | pte_t *pte = pte_offset_kernel(pmd, 0); | |
374 | unsigned long addr, pteval, psize; | |
375 | int i, status; | |
376 | ||
377 | for (i = 0; i < PTRS_PER_PTE; i++, pte++) { | |
378 | addr = start + i * PAGE_SIZE; | |
379 | pteval = pte_val(*pte); | |
380 | ||
381 | if (addr < VMALLOC_END) | |
382 | psize = mmu_vmalloc_psize; | |
383 | else | |
384 | psize = mmu_io_psize; | |
65e701b2 | 385 | |
1515ab93 | 386 | /* check for secret 4K mappings */ |
65e701b2 CL |
387 | if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && |
388 | ((pteval & H_PAGE_COMBO) == H_PAGE_COMBO || | |
389 | (pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN)) | |
1515ab93 | 390 | psize = mmu_io_psize; |
65e701b2 | 391 | |
1515ab93 RG |
392 | /* check for hashpte */ |
393 | status = hpte_find(st, addr, psize); | |
394 | ||
395 | if (((pteval & H_PAGE_HASHPTE) != H_PAGE_HASHPTE) | |
396 | && (status != -1)) { | |
397 | /* found a hpte that is not in the linux page tables */ | |
398 | seq_printf(st->seq, "page probably bolted before linux" | |
399 | " pagetables were set: addr:%lx, pteval:%lx\n", | |
400 | addr, pteval); | |
401 | } | |
402 | } | |
403 | } | |
404 | ||
405 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
406 | { | |
407 | pmd_t *pmd = pmd_offset(pud, 0); | |
408 | unsigned long addr; | |
409 | unsigned int i; | |
410 | ||
411 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
412 | addr = start + i * PMD_SIZE; | |
413 | if (!pmd_none(*pmd)) | |
414 | /* pmd exists */ | |
415 | walk_pte(st, pmd, addr); | |
416 | } | |
417 | } | |
418 | ||
2fb47060 | 419 | static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start) |
1515ab93 | 420 | { |
2fb47060 | 421 | pud_t *pud = pud_offset(p4d, 0); |
1515ab93 RG |
422 | unsigned long addr; |
423 | unsigned int i; | |
424 | ||
425 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
426 | addr = start + i * PUD_SIZE; | |
427 | if (!pud_none(*pud)) | |
428 | /* pud exists */ | |
429 | walk_pmd(st, pud, addr); | |
430 | } | |
431 | } | |
432 | ||
2fb47060 MR |
433 | static void walk_p4d(struct pg_state *st, pgd_t *pgd, unsigned long start) |
434 | { | |
435 | p4d_t *p4d = p4d_offset(pgd, 0); | |
436 | unsigned long addr; | |
437 | unsigned int i; | |
438 | ||
439 | for (i = 0; i < PTRS_PER_P4D; i++, p4d++) { | |
440 | addr = start + i * P4D_SIZE; | |
441 | if (!p4d_none(*p4d)) | |
442 | /* p4d exists */ | |
443 | walk_pud(st, p4d, addr); | |
444 | } | |
445 | } | |
446 | ||
1515ab93 RG |
447 | static void walk_pagetables(struct pg_state *st) |
448 | { | |
449 | pgd_t *pgd = pgd_offset_k(0UL); | |
450 | unsigned int i; | |
451 | unsigned long addr; | |
452 | ||
453 | /* | |
454 | * Traverse the linux pagetable structure and dump pages that are in | |
455 | * the hash pagetable. | |
456 | */ | |
457 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
458 | addr = KERN_VIRT_START + i * PGDIR_SIZE; | |
459 | if (!pgd_none(*pgd)) | |
460 | /* pgd exists */ | |
2fb47060 | 461 | walk_p4d(st, pgd, addr); |
1515ab93 RG |
462 | } |
463 | } | |
464 | ||
465 | ||
466 | static void walk_linearmapping(struct pg_state *st) | |
467 | { | |
468 | unsigned long addr; | |
469 | ||
470 | /* | |
471 | * Traverse the linear mapping section of virtual memory and dump pages | |
472 | * that are in the hash pagetable. | |
473 | */ | |
474 | unsigned long psize = 1 << mmu_psize_defs[mmu_linear_psize].shift; | |
475 | ||
476 | for (addr = PAGE_OFFSET; addr < PAGE_OFFSET + | |
9e4114b3 | 477 | memblock_end_of_DRAM(); addr += psize) |
1515ab93 RG |
478 | hpte_find(st, addr, mmu_linear_psize); |
479 | } | |
480 | ||
481 | static void walk_vmemmap(struct pg_state *st) | |
482 | { | |
1515ab93 RG |
483 | struct vmemmap_backing *ptr = vmemmap_list; |
484 | ||
65e701b2 CL |
485 | if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) |
486 | return; | |
1515ab93 RG |
487 | /* |
488 | * Traverse the vmemmaped memory and dump pages that are in the hash | |
489 | * pagetable. | |
490 | */ | |
491 | while (ptr->list) { | |
492 | hpte_find(st, ptr->virt_addr, mmu_vmemmap_psize); | |
493 | ptr = ptr->list; | |
494 | } | |
495 | seq_puts(st->seq, "---[ vmemmap end ]---\n"); | |
1515ab93 RG |
496 | } |
497 | ||
498 | static void populate_markers(void) | |
499 | { | |
500 | address_markers[0].start_address = PAGE_OFFSET; | |
501 | address_markers[1].start_address = VMALLOC_START; | |
502 | address_markers[2].start_address = VMALLOC_END; | |
503 | address_markers[3].start_address = ISA_IO_BASE; | |
504 | address_markers[4].start_address = ISA_IO_END; | |
505 | address_markers[5].start_address = PHB_IO_BASE; | |
506 | address_markers[6].start_address = PHB_IO_END; | |
507 | address_markers[7].start_address = IOREMAP_BASE; | |
508 | address_markers[8].start_address = IOREMAP_END; | |
0034d395 | 509 | address_markers[9].start_address = H_VMEMMAP_START; |
1515ab93 RG |
510 | } |
511 | ||
512 | static int ptdump_show(struct seq_file *m, void *v) | |
513 | { | |
514 | struct pg_state st = { | |
515 | .seq = m, | |
516 | .start_address = PAGE_OFFSET, | |
517 | .marker = address_markers, | |
518 | }; | |
519 | /* | |
520 | * Traverse the 0xc, 0xd and 0xf areas of the kernel virtual memory and | |
521 | * dump pages that are in the hash pagetable. | |
522 | */ | |
523 | walk_linearmapping(&st); | |
524 | walk_pagetables(&st); | |
525 | walk_vmemmap(&st); | |
526 | return 0; | |
527 | } | |
528 | ||
529 | static int ptdump_open(struct inode *inode, struct file *file) | |
530 | { | |
531 | return single_open(file, ptdump_show, NULL); | |
532 | } | |
533 | ||
534 | static const struct file_operations ptdump_fops = { | |
535 | .open = ptdump_open, | |
536 | .read = seq_read, | |
537 | .llseek = seq_lseek, | |
538 | .release = single_release, | |
539 | }; | |
540 | ||
541 | static int ptdump_init(void) | |
542 | { | |
1515ab93 RG |
543 | if (!radix_enabled()) { |
544 | populate_markers(); | |
f3c05201 GKH |
545 | debugfs_create_file("kernel_hash_pagetable", 0400, NULL, NULL, |
546 | &ptdump_fops); | |
1515ab93 RG |
547 | } |
548 | return 0; | |
549 | } | |
550 | device_initcall(ptdump_init); |