![Martin Schwidefsky](/assets/img/avatar_default.png)
Add support for different number of page table levels dependent on the highest address used for a process. This will cause a 31 bit process to use a two level page table instead of the four level page table that is the default after the pud has been introduced. Likewise a normal 64 bit process will use three levels instead of four. Only if a process runs out of the 4 tera bytes which can be addressed with a three level page table the fourth level is dynamically added. Then the process can use up to 8 peta byte. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
175 lines
4.7 KiB
C
175 lines
4.7 KiB
C
/*
|
|
* include/asm-s390/pgalloc.h
|
|
*
|
|
* S390 version
|
|
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
|
|
* Author(s): Hartmut Penner (hp@de.ibm.com)
|
|
* Martin Schwidefsky (schwidefsky@de.ibm.com)
|
|
*
|
|
* Derived from "include/asm-i386/pgalloc.h"
|
|
* Copyright (C) 1994 Linus Torvalds
|
|
*/
|
|
|
|
#ifndef _S390_PGALLOC_H
|
|
#define _S390_PGALLOC_H
|
|
|
|
#include <linux/threads.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/mm.h>
|
|
|
|
#define check_pgt_cache() do {} while (0)
|
|
|
|
unsigned long *crst_table_alloc(struct mm_struct *, int);
|
|
void crst_table_free(struct mm_struct *, unsigned long *);
|
|
|
|
unsigned long *page_table_alloc(struct mm_struct *);
|
|
void page_table_free(struct mm_struct *, unsigned long *);
|
|
void disable_noexec(struct mm_struct *, struct task_struct *);
|
|
|
|
static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
|
|
{
|
|
*s = val;
|
|
n = (n / 256) - 1;
|
|
asm volatile(
|
|
#ifdef CONFIG_64BIT
|
|
" mvc 8(248,%0),0(%0)\n"
|
|
#else
|
|
" mvc 4(252,%0),0(%0)\n"
|
|
#endif
|
|
"0: mvc 256(256,%0),0(%0)\n"
|
|
" la %0,256(%0)\n"
|
|
" brct %1,0b\n"
|
|
: "+a" (s), "+d" (n));
|
|
}
|
|
|
|
static inline void crst_table_init(unsigned long *crst, unsigned long entry)
|
|
{
|
|
clear_table(crst, entry, sizeof(unsigned long)*2048);
|
|
crst = get_shadow_table(crst);
|
|
if (crst)
|
|
clear_table(crst, entry, sizeof(unsigned long)*2048);
|
|
}
|
|
|
|
#ifndef __s390x__
|
|
|
|
static inline unsigned long pgd_entry_type(struct mm_struct *mm)
|
|
{
|
|
return _SEGMENT_ENTRY_EMPTY;
|
|
}
|
|
|
|
#define pud_alloc_one(mm,address) ({ BUG(); ((pud_t *)2); })
|
|
#define pud_free(mm, x) do { } while (0)
|
|
|
|
#define pmd_alloc_one(mm,address) ({ BUG(); ((pmd_t *)2); })
|
|
#define pmd_free(mm, x) do { } while (0)
|
|
|
|
#define pgd_populate(mm, pgd, pud) BUG()
|
|
#define pgd_populate_kernel(mm, pgd, pud) BUG()
|
|
|
|
#define pud_populate(mm, pud, pmd) BUG()
|
|
#define pud_populate_kernel(mm, pud, pmd) BUG()
|
|
|
|
#else /* __s390x__ */
|
|
|
|
static inline unsigned long pgd_entry_type(struct mm_struct *mm)
|
|
{
|
|
if (mm->context.asce_limit <= (1UL << 31))
|
|
return _SEGMENT_ENTRY_EMPTY;
|
|
if (mm->context.asce_limit <= (1UL << 42))
|
|
return _REGION3_ENTRY_EMPTY;
|
|
return _REGION2_ENTRY_EMPTY;
|
|
}
|
|
|
|
int crst_table_upgrade(struct mm_struct *, unsigned long limit);
|
|
void crst_table_downgrade(struct mm_struct *, unsigned long limit);
|
|
|
|
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
|
|
{
|
|
unsigned long *table = crst_table_alloc(mm, mm->context.noexec);
|
|
if (table)
|
|
crst_table_init(table, _REGION3_ENTRY_EMPTY);
|
|
return (pud_t *) table;
|
|
}
|
|
#define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
|
|
|
|
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
|
|
{
|
|
unsigned long *table = crst_table_alloc(mm, mm->context.noexec);
|
|
if (table)
|
|
crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
|
|
return (pmd_t *) table;
|
|
}
|
|
#define pmd_free(mm, pmd) crst_table_free(mm, (unsigned long *) pmd)
|
|
|
|
static inline void pgd_populate_kernel(struct mm_struct *mm,
|
|
pgd_t *pgd, pud_t *pud)
|
|
{
|
|
pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
|
|
}
|
|
|
|
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
|
|
{
|
|
pgd_populate_kernel(mm, pgd, pud);
|
|
if (mm->context.noexec) {
|
|
pgd = get_shadow_table(pgd);
|
|
pud = get_shadow_table(pud);
|
|
pgd_populate_kernel(mm, pgd, pud);
|
|
}
|
|
}
|
|
|
|
static inline void pud_populate_kernel(struct mm_struct *mm,
|
|
pud_t *pud, pmd_t *pmd)
|
|
{
|
|
pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
|
|
}
|
|
|
|
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
|
|
{
|
|
pud_populate_kernel(mm, pud, pmd);
|
|
if (mm->context.noexec) {
|
|
pud = get_shadow_table(pud);
|
|
pmd = get_shadow_table(pmd);
|
|
pud_populate_kernel(mm, pud, pmd);
|
|
}
|
|
}
|
|
|
|
#endif /* __s390x__ */
|
|
|
|
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
|
|
{
|
|
INIT_LIST_HEAD(&mm->context.crst_list);
|
|
INIT_LIST_HEAD(&mm->context.pgtable_list);
|
|
return (pgd_t *) crst_table_alloc(mm, s390_noexec);
|
|
}
|
|
#define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
|
|
|
|
static inline void pmd_populate_kernel(struct mm_struct *mm,
|
|
pmd_t *pmd, pte_t *pte)
|
|
{
|
|
pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
|
|
}
|
|
|
|
static inline void pmd_populate(struct mm_struct *mm,
|
|
pmd_t *pmd, pgtable_t pte)
|
|
{
|
|
pmd_populate_kernel(mm, pmd, pte);
|
|
if (mm->context.noexec) {
|
|
pmd = get_shadow_table(pmd);
|
|
pmd_populate_kernel(mm, pmd, pte + PTRS_PER_PTE);
|
|
}
|
|
}
|
|
|
|
#define pmd_pgtable(pmd) \
|
|
(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
|
|
|
|
/*
|
|
* page table entry allocation/free routines.
|
|
*/
|
|
#define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
|
|
#define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
|
|
|
|
#define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
|
|
#define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
|
|
|
|
#endif /* _S390_PGALLOC_H */
|