2 * Debug helper to dump the current kernel pagetables of the system
3 * so that we can see what the various memory ranges are set to.
5 * Derived from x86 implementation:
6 * (C) Copyright 2008 Intel Corporation
8 * Author: Arjan van de Ven <arjan@linux.intel.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; version 2
15 #include <linux/debugfs.h>
18 #include <linux/seq_file.h>
20 #include <asm/domain.h>
21 #include <asm/fixmap.h>
22 #include <asm/memory.h>
23 #include <asm/pgtable.h>
26 unsigned long start_address
;
30 static struct addr_marker address_markers
[] = {
31 { MODULES_VADDR
, "Modules" },
32 { PAGE_OFFSET
, "Kernel Mapping" },
33 { 0, "vmalloc() Area" },
34 { VMALLOC_END
, "vmalloc() End" },
35 { FIXADDR_START
, "Fixmap Area" },
36 { VECTORS_BASE
, "Vectors" },
37 { VECTORS_BASE
+ PAGE_SIZE
* 2, "Vectors End" },
43 const struct addr_marker
*marker
;
44 unsigned long start_address
;
47 const char *current_domain
;
57 static const struct prot_bits pte_bits
[] = {
79 .mask
= L_PTE_MT_MASK
,
80 .val
= L_PTE_MT_UNCACHED
,
83 .mask
= L_PTE_MT_MASK
,
84 .val
= L_PTE_MT_BUFFERABLE
,
85 .set
= "MEM/BUFFERABLE/WC",
87 .mask
= L_PTE_MT_MASK
,
88 .val
= L_PTE_MT_WRITETHROUGH
,
89 .set
= "MEM/CACHED/WT",
91 .mask
= L_PTE_MT_MASK
,
92 .val
= L_PTE_MT_WRITEBACK
,
93 .set
= "MEM/CACHED/WBRA",
94 #ifndef CONFIG_ARM_LPAE
96 .mask
= L_PTE_MT_MASK
,
97 .val
= L_PTE_MT_MINICACHE
,
98 .set
= "MEM/MINICACHE",
101 .mask
= L_PTE_MT_MASK
,
102 .val
= L_PTE_MT_WRITEALLOC
,
103 .set
= "MEM/CACHED/WBWA",
105 .mask
= L_PTE_MT_MASK
,
106 .val
= L_PTE_MT_DEV_SHARED
,
108 #ifndef CONFIG_ARM_LPAE
110 .mask
= L_PTE_MT_MASK
,
111 .val
= L_PTE_MT_DEV_NONSHARED
,
112 .set
= "DEV/NONSHARED",
115 .mask
= L_PTE_MT_MASK
,
116 .val
= L_PTE_MT_DEV_WC
,
119 .mask
= L_PTE_MT_MASK
,
120 .val
= L_PTE_MT_DEV_CACHED
,
125 static const struct prot_bits section_bits
[] = {
126 #ifdef CONFIG_ARM_LPAE
128 .mask
= PMD_SECT_USER
,
129 .val
= PMD_SECT_USER
,
132 .mask
= L_PMD_SECT_RDONLY
,
133 .val
= L_PMD_SECT_RDONLY
,
136 #elif __LINUX_ARM_ARCH__ >= 6
138 .mask
= PMD_SECT_APX
| PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
139 .val
= PMD_SECT_APX
| PMD_SECT_AP_WRITE
,
142 .mask
= PMD_SECT_APX
| PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
143 .val
= PMD_SECT_AP_WRITE
,
146 .mask
= PMD_SECT_APX
| PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
147 .val
= PMD_SECT_AP_READ
,
150 .mask
= PMD_SECT_APX
| PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
151 .val
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
153 #else /* ARMv4/ARMv5 */
154 /* These are approximate */
156 .mask
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
160 .mask
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
161 .val
= PMD_SECT_AP_WRITE
,
164 .mask
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
165 .val
= PMD_SECT_AP_READ
,
168 .mask
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
169 .val
= PMD_SECT_AP_READ
| PMD_SECT_AP_WRITE
,
186 const struct prot_bits
*bits
;
191 static struct pg_level pg_level
[] = {
196 .bits
= section_bits
,
197 .num
= ARRAY_SIZE(section_bits
),
200 .num
= ARRAY_SIZE(pte_bits
),
204 static void dump_prot(struct pg_state
*st
, const struct prot_bits
*bits
, size_t num
)
208 for (i
= 0; i
< num
; i
++, bits
++) {
211 if ((st
->current_prot
& bits
->mask
) == bits
->val
)
217 seq_printf(st
->seq
, " %s", s
);
221 static void note_page(struct pg_state
*st
, unsigned long addr
,
222 unsigned int level
, u64 val
, const char *domain
)
224 static const char units
[] = "KMGTPE";
225 u64 prot
= val
& pg_level
[level
].mask
;
229 st
->current_prot
= prot
;
230 st
->current_domain
= domain
;
231 seq_printf(st
->seq
, "---[ %s ]---\n", st
->marker
->name
);
232 } else if (prot
!= st
->current_prot
|| level
!= st
->level
||
233 domain
!= st
->current_domain
||
234 addr
>= st
->marker
[1].start_address
) {
235 const char *unit
= units
;
238 if (st
->current_prot
) {
239 seq_printf(st
->seq
, "0x%08lx-0x%08lx ",
240 st
->start_address
, addr
);
242 delta
= (addr
- st
->start_address
) >> 10;
243 while (!(delta
& 1023) && unit
[1]) {
247 seq_printf(st
->seq
, "%9lu%c", delta
, *unit
);
248 if (st
->current_domain
)
249 seq_printf(st
->seq
, " %s", st
->current_domain
);
250 if (pg_level
[st
->level
].bits
)
251 dump_prot(st
, pg_level
[st
->level
].bits
, pg_level
[st
->level
].num
);
252 seq_printf(st
->seq
, "\n");
255 if (addr
>= st
->marker
[1].start_address
) {
257 seq_printf(st
->seq
, "---[ %s ]---\n", st
->marker
->name
);
259 st
->start_address
= addr
;
260 st
->current_prot
= prot
;
261 st
->current_domain
= domain
;
266 static void walk_pte(struct pg_state
*st
, pmd_t
*pmd
, unsigned long start
,
269 pte_t
*pte
= pte_offset_kernel(pmd
, 0);
273 for (i
= 0; i
< PTRS_PER_PTE
; i
++, pte
++) {
274 addr
= start
+ i
* PAGE_SIZE
;
275 note_page(st
, addr
, 4, pte_val(*pte
), domain
);
279 static const char *get_domain_name(pmd_t
*pmd
)
281 #ifndef CONFIG_ARM_LPAE
282 switch (pmd_val(*pmd
) & PMD_DOMAIN_MASK
) {
283 case PMD_DOMAIN(DOMAIN_KERNEL
):
285 case PMD_DOMAIN(DOMAIN_USER
):
287 case PMD_DOMAIN(DOMAIN_IO
):
289 case PMD_DOMAIN(DOMAIN_VECTORS
):
298 static void walk_pmd(struct pg_state
*st
, pud_t
*pud
, unsigned long start
)
300 pmd_t
*pmd
= pmd_offset(pud
, 0);
305 for (i
= 0; i
< PTRS_PER_PMD
; i
++, pmd
++) {
306 addr
= start
+ i
* PMD_SIZE
;
307 domain
= get_domain_name(pmd
);
308 if (pmd_none(*pmd
) || pmd_large(*pmd
) || !pmd_present(*pmd
))
309 note_page(st
, addr
, 3, pmd_val(*pmd
), domain
);
311 walk_pte(st
, pmd
, addr
, domain
);
313 if (SECTION_SIZE
< PMD_SIZE
&& pmd_large(pmd
[1])) {
314 addr
+= SECTION_SIZE
;
316 domain
= get_domain_name(pmd
);
317 note_page(st
, addr
, 3, pmd_val(*pmd
), domain
);
322 static void walk_pud(struct pg_state
*st
, pgd_t
*pgd
, unsigned long start
)
324 pud_t
*pud
= pud_offset(pgd
, 0);
328 for (i
= 0; i
< PTRS_PER_PUD
; i
++, pud
++) {
329 addr
= start
+ i
* PUD_SIZE
;
330 if (!pud_none(*pud
)) {
331 walk_pmd(st
, pud
, addr
);
333 note_page(st
, addr
, 2, pud_val(*pud
), NULL
);
338 static void walk_pgd(struct seq_file
*m
)
340 pgd_t
*pgd
= swapper_pg_dir
;
345 memset(&st
, 0, sizeof(st
));
347 st
.marker
= address_markers
;
349 for (i
= 0; i
< PTRS_PER_PGD
; i
++, pgd
++) {
350 addr
= i
* PGDIR_SIZE
;
351 if (!pgd_none(*pgd
)) {
352 walk_pud(&st
, pgd
, addr
);
354 note_page(&st
, addr
, 1, pgd_val(*pgd
), NULL
);
358 note_page(&st
, 0, 0, 0, NULL
);
361 static int ptdump_show(struct seq_file
*m
, void *v
)
367 static int ptdump_open(struct inode
*inode
, struct file
*file
)
369 return single_open(file
, ptdump_show
, NULL
);
372 static const struct file_operations ptdump_fops
= {
376 .release
= single_release
,
379 static int ptdump_init(void)
384 for (i
= 0; i
< ARRAY_SIZE(pg_level
); i
++)
385 if (pg_level
[i
].bits
)
386 for (j
= 0; j
< pg_level
[i
].num
; j
++)
387 pg_level
[i
].mask
|= pg_level
[i
].bits
[j
].mask
;
389 address_markers
[2].start_address
= VMALLOC_START
;
391 pe
= debugfs_create_file("kernel_page_tables", 0400, NULL
, NULL
,
393 return pe
? 0 : -ENOMEM
;
395 __initcall(ptdump_init
);