~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/powerpc/mm/ptdump/hashpagetable.c

Version: ~ [ linux-5.13-rc1 ] ~ [ linux-5.12.2 ] ~ [ linux-5.11.19 ] ~ [ linux-5.10.35 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.117 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.190 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.232 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.268 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.268 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  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.
 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>
 18 #include <linux/const.h>
 19 #include <asm/page.h>
 20 #include <asm/plpar_wrappers.h>
 21 #include <linux/memblock.h>
 22 #include <asm/firmware.h>
 23 #include <asm/pgalloc.h>
 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);
202         seq_putc(st->seq, '\n');
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 
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;
256         hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
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 
261                 if (lpar_rc)
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 }
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 {
316         if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR))
317                 return pseries_find(ea, psize, primary, v, r);
318 
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 
329         if (ea < PAGE_OFFSET)
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)
337                 slot = base_hpte_find(ea, psize, false, &v, &r);
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;
385 
386                 /* check for secret 4K mappings */
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))
390                         psize = mmu_io_psize;
391 
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 
419 static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
420 {
421         pud_t *pud = pud_offset(p4d, 0);
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 
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 
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 */
461                         walk_p4d(st, pgd, addr);
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 +
477                         memblock_end_of_DRAM(); addr += psize)
478                 hpte_find(st, addr, mmu_linear_psize);
479 }
480 
481 static void walk_vmemmap(struct pg_state *st)
482 {
483         struct vmemmap_backing *ptr = vmemmap_list;
484 
485         if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
486                 return;
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");
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;
509         address_markers[9].start_address =  H_VMEMMAP_START;
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 {
543         if (!radix_enabled()) {
544                 populate_markers();
545                 debugfs_create_file("kernel_hash_pagetable", 0400, NULL, NULL,
546                                     &ptdump_fops);
547         }
548         return 0;
549 }
550 device_initcall(ptdump_init);
551 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp