linux/arch/s390/mm/dump_pagetables.c
Martin Schwidefsky e509861105 s390/mm: cleanup page table definitions
Improve the encoding of the different pte types and the naming of the
page, segment table and region table bits. Due to the different pte
encoding the hugetlbfs primitives need to be adapted as well. To improve
compatability with common code make the huge ptes use the encoding of
normal ptes. The conversion between the pte and pmd encoding for a huge
pte is done with set_huge_pte_at and huge_ptep_get.
Overall the code is now easier to understand.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-08-22 12:20:06 +02:00

247 lines
6.1 KiB
C

#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
static unsigned long max_addr;
struct addr_marker {
unsigned long start_address;
const char *name;
};
enum address_markers_idx {
IDENTITY_NR = 0,
KERNEL_START_NR,
KERNEL_END_NR,
VMEMMAP_NR,
VMALLOC_NR,
#ifdef CONFIG_64BIT
MODULES_NR,
#endif
};
static struct addr_marker address_markers[] = {
[IDENTITY_NR] = {0, "Identity Mapping"},
[KERNEL_START_NR] = {(unsigned long)&_stext, "Kernel Image Start"},
[KERNEL_END_NR] = {(unsigned long)&_end, "Kernel Image End"},
[VMEMMAP_NR] = {0, "vmemmap Area"},
[VMALLOC_NR] = {0, "vmalloc Area"},
#ifdef CONFIG_64BIT
[MODULES_NR] = {0, "Modules Area"},
#endif
{ -1, NULL }
};
struct pg_state {
int level;
unsigned int current_prot;
unsigned long start_address;
unsigned long current_address;
const struct addr_marker *marker;
};
static void print_prot(struct seq_file *m, unsigned int pr, int level)
{
static const char * const level_name[] =
{ "ASCE", "PGD", "PUD", "PMD", "PTE" };
seq_printf(m, "%s ", level_name[level]);
if (pr & _PAGE_INVALID) {
seq_printf(m, "I\n");
return;
}
seq_printf(m, "%s", pr & _PAGE_PROTECT ? "RO " : "RW ");
seq_printf(m, "%s", pr & _PAGE_CO ? "CO " : " ");
seq_putc(m, '\n');
}
static void note_page(struct seq_file *m, struct pg_state *st,
unsigned int new_prot, int level)
{
static const char units[] = "KMGTPE";
int width = sizeof(unsigned long) * 2;
const char *unit = units;
unsigned int prot, cur;
unsigned long delta;
/*
* If we have a "break" in the series, we need to flush the state
* that we have now. "break" is either changing perms, levels or
* address space marker.
*/
prot = new_prot;
cur = st->current_prot;
if (!st->level) {
/* First entry */
st->current_prot = new_prot;
st->level = level;
st->marker = address_markers;
seq_printf(m, "---[ %s ]---\n", st->marker->name);
} else if (prot != cur || level != st->level ||
st->current_address >= st->marker[1].start_address) {
/* Print the actual finished series */
seq_printf(m, "0x%0*lx-0x%0*lx",
width, st->start_address,
width, st->current_address);
delta = (st->current_address - st->start_address) >> 10;
while (!(delta & 0x3ff) && unit[1]) {
delta >>= 10;
unit++;
}
seq_printf(m, "%9lu%c ", delta, *unit);
print_prot(m, st->current_prot, st->level);
if (st->current_address >= st->marker[1].start_address) {
st->marker++;
seq_printf(m, "---[ %s ]---\n", st->marker->name);
}
st->start_address = st->current_address;
st->current_prot = new_prot;
st->level = level;
}
}
/*
* The actual page table walker functions. In order to keep the
* implementation of print_prot() short, we only check and pass
* _PAGE_INVALID and _PAGE_PROTECT flags to note_page() if a region,
* segment or page table entry is invalid or read-only.
* After all it's just a hint that the current level being walked
* contains an invalid or read-only entry.
*/
static void walk_pte_level(struct seq_file *m, struct pg_state *st,
pmd_t *pmd, unsigned long addr)
{
unsigned int prot;
pte_t *pte;
int i;
for (i = 0; i < PTRS_PER_PTE && addr < max_addr; i++) {
st->current_address = addr;
pte = pte_offset_kernel(pmd, addr);
prot = pte_val(*pte) & (_PAGE_PROTECT | _PAGE_INVALID);
note_page(m, st, prot, 4);
addr += PAGE_SIZE;
}
}
#ifdef CONFIG_64BIT
#define _PMD_PROT_MASK (_SEGMENT_ENTRY_PROTECT | _SEGMENT_ENTRY_CO)
#else
#define _PMD_PROT_MASK 0
#endif
static void walk_pmd_level(struct seq_file *m, struct pg_state *st,
pud_t *pud, unsigned long addr)
{
unsigned int prot;
pmd_t *pmd;
int i;
for (i = 0; i < PTRS_PER_PMD && addr < max_addr; i++) {
st->current_address = addr;
pmd = pmd_offset(pud, addr);
if (!pmd_none(*pmd)) {
if (pmd_large(*pmd)) {
prot = pmd_val(*pmd) & _PMD_PROT_MASK;
note_page(m, st, prot, 3);
} else
walk_pte_level(m, st, pmd, addr);
} else
note_page(m, st, _PAGE_INVALID, 3);
addr += PMD_SIZE;
}
}
#ifdef CONFIG_64BIT
#define _PUD_PROT_MASK (_REGION3_ENTRY_RO | _REGION3_ENTRY_CO)
#else
#define _PUD_PROT_MASK 0
#endif
static void walk_pud_level(struct seq_file *m, struct pg_state *st,
pgd_t *pgd, unsigned long addr)
{
unsigned int prot;
pud_t *pud;
int i;
for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++) {
st->current_address = addr;
pud = pud_offset(pgd, addr);
if (!pud_none(*pud))
if (pud_large(*pud)) {
prot = pud_val(*pud) & _PUD_PROT_MASK;
note_page(m, st, prot, 2);
} else
walk_pmd_level(m, st, pud, addr);
else
note_page(m, st, _PAGE_INVALID, 2);
addr += PUD_SIZE;
}
}
static void walk_pgd_level(struct seq_file *m)
{
unsigned long addr = 0;
struct pg_state st;
pgd_t *pgd;
int i;
memset(&st, 0, sizeof(st));
for (i = 0; i < PTRS_PER_PGD && addr < max_addr; i++) {
st.current_address = addr;
pgd = pgd_offset_k(addr);
if (!pgd_none(*pgd))
walk_pud_level(m, &st, pgd, addr);
else
note_page(m, &st, _PAGE_INVALID, 1);
addr += PGDIR_SIZE;
}
/* Flush out the last page */
st.current_address = max_addr;
note_page(m, &st, 0, 0);
}
static int ptdump_show(struct seq_file *m, void *v)
{
walk_pgd_level(m);
return 0;
}
static int ptdump_open(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show, NULL);
}
static const struct file_operations ptdump_fops = {
.open = ptdump_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int pt_dump_init(void)
{
/*
* Figure out the maximum virtual address being accessible with the
* kernel ASCE. We need this to keep the page table walker functions
* from accessing non-existent entries.
*/
#ifdef CONFIG_32BIT
max_addr = 1UL << 31;
#else
max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2;
max_addr = 1UL << (max_addr * 11 + 31);
address_markers[MODULES_NR].start_address = MODULES_VADDR;
#endif
address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap;
address_markers[VMALLOC_NR].start_address = VMALLOC_START;
debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops);
return 0;
}
device_initcall(pt_dump_init);