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1515ab93 RG |
1 | /* |
2 | * Copyright 2016, Rashmica Gupta, IBM Corp. | |
3 | * | |
4 | * This traverses the kernel virtual memory and dumps the pages that are in | |
5 | * the hash pagetable, along with their flags to | |
6 | * /sys/kernel/debug/kernel_hash_pagetable. | |
7 | * | |
8 | * If radix is enabled then there is no hash page table and so no debugfs file | |
9 | * is generated. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; version 2 | |
14 | * of the License. | |
15 | */ | |
16 | #include <linux/debugfs.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/mm.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <asm/fixmap.h> | |
23 | #include <asm/pgtable.h> | |
24 | #include <linux/const.h> | |
25 | #include <asm/page.h> | |
26 | #include <asm/pgalloc.h> | |
27 | #include <asm/plpar_wrappers.h> | |
28 | #include <linux/memblock.h> | |
29 | #include <asm/firmware.h> | |
30 | ||
31 | struct pg_state { | |
32 | struct seq_file *seq; | |
33 | const struct addr_marker *marker; | |
34 | unsigned long start_address; | |
35 | unsigned int level; | |
36 | u64 current_flags; | |
37 | }; | |
38 | ||
39 | struct addr_marker { | |
40 | unsigned long start_address; | |
41 | const char *name; | |
42 | }; | |
43 | ||
44 | static struct addr_marker address_markers[] = { | |
45 | { 0, "Start of kernel VM" }, | |
46 | { 0, "vmalloc() Area" }, | |
47 | { 0, "vmalloc() End" }, | |
48 | { 0, "isa I/O start" }, | |
49 | { 0, "isa I/O end" }, | |
50 | { 0, "phb I/O start" }, | |
51 | { 0, "phb I/O end" }, | |
52 | { 0, "I/O remap start" }, | |
53 | { 0, "I/O remap end" }, | |
54 | { 0, "vmemmap start" }, | |
55 | { -1, NULL }, | |
56 | }; | |
57 | ||
58 | struct flag_info { | |
59 | u64 mask; | |
60 | u64 val; | |
61 | const char *set; | |
62 | const char *clear; | |
63 | bool is_val; | |
64 | int shift; | |
65 | }; | |
66 | ||
67 | static const struct flag_info v_flag_array[] = { | |
68 | { | |
69 | .mask = SLB_VSID_B, | |
70 | .val = SLB_VSID_B_256M, | |
71 | .set = "ssize: 256M", | |
72 | .clear = "ssize: 1T ", | |
73 | }, { | |
74 | .mask = HPTE_V_SECONDARY, | |
75 | .val = HPTE_V_SECONDARY, | |
76 | .set = "secondary", | |
77 | .clear = "primary ", | |
78 | }, { | |
79 | .mask = HPTE_V_VALID, | |
80 | .val = HPTE_V_VALID, | |
81 | .set = "valid ", | |
82 | .clear = "invalid", | |
83 | }, { | |
84 | .mask = HPTE_V_BOLTED, | |
85 | .val = HPTE_V_BOLTED, | |
86 | .set = "bolted", | |
87 | .clear = "", | |
88 | } | |
89 | }; | |
90 | ||
91 | static const struct flag_info r_flag_array[] = { | |
92 | { | |
93 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
94 | .val = PP_RWXX, | |
95 | .set = "prot:RW--", | |
96 | }, { | |
97 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
98 | .val = PP_RWRX, | |
99 | .set = "prot:RWR-", | |
100 | }, { | |
101 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
102 | .val = PP_RWRW, | |
103 | .set = "prot:RWRW", | |
104 | }, { | |
105 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
106 | .val = PP_RXRX, | |
107 | .set = "prot:R-R-", | |
108 | }, { | |
109 | .mask = HPTE_R_PP0 | HPTE_R_PP, | |
110 | .val = PP_RXXX, | |
111 | .set = "prot:R---", | |
112 | }, { | |
113 | .mask = HPTE_R_KEY_HI | HPTE_R_KEY_LO, | |
114 | .val = HPTE_R_KEY_HI | HPTE_R_KEY_LO, | |
115 | .set = "key", | |
116 | .clear = "", | |
117 | .is_val = true, | |
118 | }, { | |
119 | .mask = HPTE_R_R, | |
120 | .val = HPTE_R_R, | |
121 | .set = "ref", | |
122 | .clear = " ", | |
123 | }, { | |
124 | .mask = HPTE_R_C, | |
125 | .val = HPTE_R_C, | |
126 | .set = "changed", | |
127 | .clear = " ", | |
128 | }, { | |
129 | .mask = HPTE_R_N, | |
130 | .val = HPTE_R_N, | |
131 | .set = "no execute", | |
132 | }, { | |
133 | .mask = HPTE_R_WIMG, | |
134 | .val = HPTE_R_W, | |
135 | .set = "writethru", | |
136 | }, { | |
137 | .mask = HPTE_R_WIMG, | |
138 | .val = HPTE_R_I, | |
139 | .set = "no cache", | |
140 | }, { | |
141 | .mask = HPTE_R_WIMG, | |
142 | .val = HPTE_R_G, | |
143 | .set = "guarded", | |
144 | } | |
145 | }; | |
146 | ||
147 | static int calculate_pagesize(struct pg_state *st, int ps, char s[]) | |
148 | { | |
149 | static const char units[] = "BKMGTPE"; | |
150 | const char *unit = units; | |
151 | ||
152 | while (ps > 9 && unit[1]) { | |
153 | ps -= 10; | |
154 | unit++; | |
155 | } | |
156 | seq_printf(st->seq, " %s_ps: %i%c\t", s, 1<<ps, *unit); | |
157 | return ps; | |
158 | } | |
159 | ||
160 | static void dump_flag_info(struct pg_state *st, const struct flag_info | |
161 | *flag, u64 pte, int num) | |
162 | { | |
163 | unsigned int i; | |
164 | ||
165 | for (i = 0; i < num; i++, flag++) { | |
166 | const char *s = NULL; | |
167 | u64 val; | |
168 | ||
169 | /* flag not defined so don't check it */ | |
170 | if (flag->mask == 0) | |
171 | continue; | |
172 | /* Some 'flags' are actually values */ | |
173 | if (flag->is_val) { | |
174 | val = pte & flag->val; | |
175 | if (flag->shift) | |
176 | val = val >> flag->shift; | |
177 | seq_printf(st->seq, " %s:%llx", flag->set, val); | |
178 | } else { | |
179 | if ((pte & flag->mask) == flag->val) | |
180 | s = flag->set; | |
181 | else | |
182 | s = flag->clear; | |
183 | if (s) | |
184 | seq_printf(st->seq, " %s", s); | |
185 | } | |
186 | } | |
187 | } | |
188 | ||
189 | static void dump_hpte_info(struct pg_state *st, unsigned long ea, u64 v, u64 r, | |
190 | unsigned long rpn, int bps, int aps, unsigned long lp) | |
191 | { | |
192 | int aps_index; | |
193 | ||
194 | while (ea >= st->marker[1].start_address) { | |
195 | st->marker++; | |
196 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
197 | } | |
198 | seq_printf(st->seq, "0x%lx:\t", ea); | |
199 | seq_printf(st->seq, "AVPN:%llx\t", HPTE_V_AVPN_VAL(v)); | |
200 | dump_flag_info(st, v_flag_array, v, ARRAY_SIZE(v_flag_array)); | |
201 | seq_printf(st->seq, " rpn: %lx\t", rpn); | |
202 | dump_flag_info(st, r_flag_array, r, ARRAY_SIZE(r_flag_array)); | |
203 | ||
204 | calculate_pagesize(st, bps, "base"); | |
205 | aps_index = calculate_pagesize(st, aps, "actual"); | |
206 | if (aps_index != 2) | |
207 | seq_printf(st->seq, "LP enc: %lx", lp); | |
aae85e3c | 208 | seq_putc(st->seq, '\n'); |
1515ab93 RG |
209 | } |
210 | ||
211 | ||
212 | static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64 | |
213 | *r) | |
214 | { | |
215 | struct hash_pte *hptep; | |
216 | unsigned long hash, vsid, vpn, hpte_group, want_v, hpte_v; | |
217 | int i, ssize = mmu_kernel_ssize; | |
218 | unsigned long shift = mmu_psize_defs[psize].shift; | |
219 | ||
220 | /* calculate hash */ | |
221 | vsid = get_kernel_vsid(ea, ssize); | |
222 | vpn = hpt_vpn(ea, vsid, ssize); | |
223 | hash = hpt_hash(vpn, shift, ssize); | |
224 | want_v = hpte_encode_avpn(vpn, psize, ssize); | |
225 | ||
226 | /* to check in the secondary hash table, we invert the hash */ | |
227 | if (!primary) | |
228 | hash = ~hash; | |
229 | hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP; | |
230 | for (i = 0; i < HPTES_PER_GROUP; i++) { | |
231 | hptep = htab_address + hpte_group; | |
232 | hpte_v = be64_to_cpu(hptep->v); | |
233 | ||
234 | if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) { | |
235 | /* HPTE matches */ | |
236 | *v = be64_to_cpu(hptep->v); | |
237 | *r = be64_to_cpu(hptep->r); | |
238 | return 0; | |
239 | } | |
240 | ++hpte_group; | |
241 | } | |
242 | return -1; | |
243 | } | |
244 | ||
245 | #ifdef CONFIG_PPC_PSERIES | |
246 | static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *r) | |
247 | { | |
248 | struct hash_pte ptes[4]; | |
249 | unsigned long vsid, vpn, hash, hpte_group, want_v; | |
250 | int i, j, ssize = mmu_kernel_ssize; | |
251 | long lpar_rc = 0; | |
252 | unsigned long shift = mmu_psize_defs[psize].shift; | |
253 | ||
254 | /* calculate hash */ | |
255 | vsid = get_kernel_vsid(ea, ssize); | |
256 | vpn = hpt_vpn(ea, vsid, ssize); | |
257 | hash = hpt_hash(vpn, shift, ssize); | |
258 | want_v = hpte_encode_avpn(vpn, psize, ssize); | |
259 | ||
260 | /* to check in the secondary hash table, we invert the hash */ | |
261 | if (!primary) | |
262 | hash = ~hash; | |
263 | hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; | |
264 | /* see if we can find an entry in the hpte with this hash */ | |
265 | for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) { | |
266 | lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes); | |
267 | ||
268 | if (lpar_rc != H_SUCCESS) | |
269 | continue; | |
270 | for (j = 0; j < 4; j++) { | |
271 | if (HPTE_V_COMPARE(ptes[j].v, want_v) && | |
272 | (ptes[j].v & HPTE_V_VALID)) { | |
273 | /* HPTE matches */ | |
274 | *v = ptes[j].v; | |
275 | *r = ptes[j].r; | |
276 | return 0; | |
277 | } | |
278 | } | |
279 | } | |
280 | return -1; | |
281 | } | |
282 | #endif | |
283 | ||
284 | static void decode_r(int bps, unsigned long r, unsigned long *rpn, int *aps, | |
285 | unsigned long *lp_bits) | |
286 | { | |
287 | struct mmu_psize_def entry; | |
288 | unsigned long arpn, mask, lp; | |
289 | int penc = -2, idx = 0, shift; | |
290 | ||
291 | /*. | |
292 | * The LP field has 8 bits. Depending on the actual page size, some of | |
293 | * these bits are concatenated with the APRN to get the RPN. The rest | |
294 | * of the bits in the LP field is the LP value and is an encoding for | |
295 | * the base page size and the actual page size. | |
296 | * | |
297 | * - find the mmu entry for our base page size | |
298 | * - go through all page encodings and use the associated mask to | |
299 | * find an encoding that matches our encoding in the LP field. | |
300 | */ | |
301 | arpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT; | |
302 | lp = arpn & 0xff; | |
303 | ||
304 | entry = mmu_psize_defs[bps]; | |
305 | while (idx < MMU_PAGE_COUNT) { | |
306 | penc = entry.penc[idx]; | |
307 | if ((penc != -1) && (mmu_psize_defs[idx].shift)) { | |
308 | shift = mmu_psize_defs[idx].shift - HPTE_R_RPN_SHIFT; | |
309 | mask = (0x1 << (shift)) - 1; | |
310 | if ((lp & mask) == penc) { | |
311 | *aps = mmu_psize_to_shift(idx); | |
312 | *lp_bits = lp & mask; | |
313 | *rpn = arpn >> shift; | |
314 | return; | |
315 | } | |
316 | } | |
317 | idx++; | |
318 | } | |
319 | } | |
320 | ||
321 | static int base_hpte_find(unsigned long ea, int psize, bool primary, u64 *v, | |
322 | u64 *r) | |
323 | { | |
324 | #ifdef CONFIG_PPC_PSERIES | |
325 | if (firmware_has_feature(FW_FEATURE_LPAR)) | |
326 | return pseries_find(ea, psize, primary, v, r); | |
327 | #endif | |
328 | return native_find(ea, psize, primary, v, r); | |
329 | } | |
330 | ||
331 | static unsigned long hpte_find(struct pg_state *st, unsigned long ea, int psize) | |
332 | { | |
333 | unsigned long slot; | |
334 | u64 v = 0, r = 0; | |
335 | unsigned long rpn, lp_bits; | |
336 | int base_psize = 0, actual_psize = 0; | |
337 | ||
e63739b1 | 338 | if (ea < PAGE_OFFSET) |
1515ab93 RG |
339 | return -1; |
340 | ||
341 | /* Look in primary table */ | |
342 | slot = base_hpte_find(ea, psize, true, &v, &r); | |
343 | ||
344 | /* Look in secondary table */ | |
345 | if (slot == -1) | |
346 | slot = base_hpte_find(ea, psize, true, &v, &r); | |
347 | ||
348 | /* No entry found */ | |
349 | if (slot == -1) | |
350 | return -1; | |
351 | ||
352 | /* | |
353 | * We found an entry in the hash page table: | |
354 | * - check that this has the same base page | |
355 | * - find the actual page size | |
356 | * - find the RPN | |
357 | */ | |
358 | base_psize = mmu_psize_to_shift(psize); | |
359 | ||
360 | if ((v & HPTE_V_LARGE) == HPTE_V_LARGE) { | |
361 | decode_r(psize, r, &rpn, &actual_psize, &lp_bits); | |
362 | } else { | |
363 | /* 4K actual page size */ | |
364 | actual_psize = 12; | |
365 | rpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT; | |
366 | /* In this case there are no LP bits */ | |
367 | lp_bits = -1; | |
368 | } | |
369 | /* | |
370 | * We didn't find a matching encoding, so the PTE we found isn't for | |
371 | * this address. | |
372 | */ | |
373 | if (actual_psize == -1) | |
374 | return -1; | |
375 | ||
376 | dump_hpte_info(st, ea, v, r, rpn, base_psize, actual_psize, lp_bits); | |
377 | return 0; | |
378 | } | |
379 | ||
380 | static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) | |
381 | { | |
382 | pte_t *pte = pte_offset_kernel(pmd, 0); | |
383 | unsigned long addr, pteval, psize; | |
384 | int i, status; | |
385 | ||
386 | for (i = 0; i < PTRS_PER_PTE; i++, pte++) { | |
387 | addr = start + i * PAGE_SIZE; | |
388 | pteval = pte_val(*pte); | |
389 | ||
390 | if (addr < VMALLOC_END) | |
391 | psize = mmu_vmalloc_psize; | |
392 | else | |
393 | psize = mmu_io_psize; | |
394 | #ifdef CONFIG_PPC_64K_PAGES | |
395 | /* check for secret 4K mappings */ | |
396 | if (((pteval & H_PAGE_COMBO) == H_PAGE_COMBO) || | |
397 | ((pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN)) | |
398 | psize = mmu_io_psize; | |
399 | #endif | |
400 | /* check for hashpte */ | |
401 | status = hpte_find(st, addr, psize); | |
402 | ||
403 | if (((pteval & H_PAGE_HASHPTE) != H_PAGE_HASHPTE) | |
404 | && (status != -1)) { | |
405 | /* found a hpte that is not in the linux page tables */ | |
406 | seq_printf(st->seq, "page probably bolted before linux" | |
407 | " pagetables were set: addr:%lx, pteval:%lx\n", | |
408 | addr, pteval); | |
409 | } | |
410 | } | |
411 | } | |
412 | ||
413 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
414 | { | |
415 | pmd_t *pmd = pmd_offset(pud, 0); | |
416 | unsigned long addr; | |
417 | unsigned int i; | |
418 | ||
419 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
420 | addr = start + i * PMD_SIZE; | |
421 | if (!pmd_none(*pmd)) | |
422 | /* pmd exists */ | |
423 | walk_pte(st, pmd, addr); | |
424 | } | |
425 | } | |
426 | ||
427 | static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) | |
428 | { | |
429 | pud_t *pud = pud_offset(pgd, 0); | |
430 | unsigned long addr; | |
431 | unsigned int i; | |
432 | ||
433 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
434 | addr = start + i * PUD_SIZE; | |
435 | if (!pud_none(*pud)) | |
436 | /* pud exists */ | |
437 | walk_pmd(st, pud, addr); | |
438 | } | |
439 | } | |
440 | ||
441 | static void walk_pagetables(struct pg_state *st) | |
442 | { | |
443 | pgd_t *pgd = pgd_offset_k(0UL); | |
444 | unsigned int i; | |
445 | unsigned long addr; | |
446 | ||
447 | /* | |
448 | * Traverse the linux pagetable structure and dump pages that are in | |
449 | * the hash pagetable. | |
450 | */ | |
451 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
452 | addr = KERN_VIRT_START + i * PGDIR_SIZE; | |
453 | if (!pgd_none(*pgd)) | |
454 | /* pgd exists */ | |
455 | walk_pud(st, pgd, addr); | |
456 | } | |
457 | } | |
458 | ||
459 | ||
460 | static void walk_linearmapping(struct pg_state *st) | |
461 | { | |
462 | unsigned long addr; | |
463 | ||
464 | /* | |
465 | * Traverse the linear mapping section of virtual memory and dump pages | |
466 | * that are in the hash pagetable. | |
467 | */ | |
468 | unsigned long psize = 1 << mmu_psize_defs[mmu_linear_psize].shift; | |
469 | ||
470 | for (addr = PAGE_OFFSET; addr < PAGE_OFFSET + | |
9e4114b3 | 471 | memblock_end_of_DRAM(); addr += psize) |
1515ab93 RG |
472 | hpte_find(st, addr, mmu_linear_psize); |
473 | } | |
474 | ||
475 | static void walk_vmemmap(struct pg_state *st) | |
476 | { | |
477 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
478 | struct vmemmap_backing *ptr = vmemmap_list; | |
479 | ||
480 | /* | |
481 | * Traverse the vmemmaped memory and dump pages that are in the hash | |
482 | * pagetable. | |
483 | */ | |
484 | while (ptr->list) { | |
485 | hpte_find(st, ptr->virt_addr, mmu_vmemmap_psize); | |
486 | ptr = ptr->list; | |
487 | } | |
488 | seq_puts(st->seq, "---[ vmemmap end ]---\n"); | |
489 | #endif | |
490 | } | |
491 | ||
492 | static void populate_markers(void) | |
493 | { | |
494 | address_markers[0].start_address = PAGE_OFFSET; | |
495 | address_markers[1].start_address = VMALLOC_START; | |
496 | address_markers[2].start_address = VMALLOC_END; | |
497 | address_markers[3].start_address = ISA_IO_BASE; | |
498 | address_markers[4].start_address = ISA_IO_END; | |
499 | address_markers[5].start_address = PHB_IO_BASE; | |
500 | address_markers[6].start_address = PHB_IO_END; | |
501 | address_markers[7].start_address = IOREMAP_BASE; | |
502 | address_markers[8].start_address = IOREMAP_END; | |
4e003747 | 503 | #ifdef CONFIG_PPC_BOOK3S_64 |
1515ab93 RG |
504 | address_markers[9].start_address = H_VMEMMAP_BASE; |
505 | #else | |
506 | address_markers[9].start_address = VMEMMAP_BASE; | |
507 | #endif | |
508 | } | |
509 | ||
510 | static int ptdump_show(struct seq_file *m, void *v) | |
511 | { | |
512 | struct pg_state st = { | |
513 | .seq = m, | |
514 | .start_address = PAGE_OFFSET, | |
515 | .marker = address_markers, | |
516 | }; | |
517 | /* | |
518 | * Traverse the 0xc, 0xd and 0xf areas of the kernel virtual memory and | |
519 | * dump pages that are in the hash pagetable. | |
520 | */ | |
521 | walk_linearmapping(&st); | |
522 | walk_pagetables(&st); | |
523 | walk_vmemmap(&st); | |
524 | return 0; | |
525 | } | |
526 | ||
527 | static int ptdump_open(struct inode *inode, struct file *file) | |
528 | { | |
529 | return single_open(file, ptdump_show, NULL); | |
530 | } | |
531 | ||
532 | static const struct file_operations ptdump_fops = { | |
533 | .open = ptdump_open, | |
534 | .read = seq_read, | |
535 | .llseek = seq_lseek, | |
536 | .release = single_release, | |
537 | }; | |
538 | ||
539 | static int ptdump_init(void) | |
540 | { | |
541 | struct dentry *debugfs_file; | |
542 | ||
543 | if (!radix_enabled()) { | |
544 | populate_markers(); | |
545 | debugfs_file = debugfs_create_file("kernel_hash_pagetable", | |
546 | 0400, NULL, NULL, &ptdump_fops); | |
547 | return debugfs_file ? 0 : -ENOMEM; | |
548 | } | |
549 | return 0; | |
550 | } | |
551 | device_initcall(ptdump_init); |