/*
 *  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)
{
        typedef struct { char _[n]; } addrtype;

        *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), "=m" (*(addrtype *) s)
                : "m" (*(addrtype *) s));
}

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)
{
        spin_lock_init(&mm->context.list_lock);
        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 */