#ifndef _ASM_POWERPC_BOOK3S_64_PGALLOC_H
#define _ASM_POWERPC_BOOK3S_64_PGALLOC_H
/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/slab.h>
#include <linux/cpumask.h>
#include <linux/kmemleak.h>
#include <linux/percpu.h>

struct vmemmap_backing {
        struct vmemmap_backing *list;
        unsigned long phys;
        unsigned long virt_addr;
};
extern struct vmemmap_backing *vmemmap_list;

/*
 * Functions that deal with pagetables that could be at any level of
 * the table need to be passed an "index_size" so they know how to
 * handle allocation.  For PTE pages (which are linked to a struct
 * page for now, and drawn from the main get_free_pages() pool), the
 * allocation size will be (2^index_size * sizeof(pointer)) and
 * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
 *
 * The maximum index size needs to be big enough to allow any
 * pagetable sizes we need, but small enough to fit in the low bits of
 * any page table pointer.  In other words all pagetables, even tiny
 * ones, must be aligned to allow at least enough low 0 bits to
 * contain this value.  This value is also used as a mask, so it must
 * be one less than a power of two.
 */
#define MAX_PGTABLE_INDEX_SIZE  0xf

extern struct kmem_cache *pgtable_cache[];
#define PGT_CACHE(shift) ({                             \
                        BUG_ON(!(shift));               \
                        pgtable_cache[(shift) - 1];     \
                })

extern pte_t *pte_fragment_alloc(struct mm_struct *, int);
extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long);
extern void pte_fragment_free(unsigned long *, int);
extern void pmd_fragment_free(unsigned long *);
extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
extern void __tlb_remove_table(void *_table);

static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm)
{
#ifdef CONFIG_PPC_64K_PAGES
        return (pgd_t *)__get_free_page(pgtable_gfp_flags(mm, PGALLOC_GFP));
#else
        struct page *page;
        page = alloc_pages(pgtable_gfp_flags(mm, PGALLOC_GFP | __GFP_RETRY_MAYFAIL),
                                4);
        if (!page)
                return NULL;
        return (pgd_t *) page_address(page);
#endif
}

static inline void radix__pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
#ifdef CONFIG_PPC_64K_PAGES
        free_page((unsigned long)pgd);
#else
        free_pages((unsigned long)pgd, 4);
#endif
}

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
        pgd_t *pgd;

        if (radix_enabled())
                return radix__pgd_alloc(mm);

        pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
                               pgtable_gfp_flags(mm, GFP_KERNEL));
        if (unlikely(!pgd))
                return pgd;

        /*
         * Don't scan the PGD for pointers, it contains references to PUDs but
         * those references are not full pointers and so can't be recognised by
         * kmemleak.
         */
        kmemleak_no_scan(pgd);

        /*
         * With hugetlb, we don't clear the second half of the page table.
         * If we share the same slab cache with the pmd or pud level table,
         * we need to make sure we zero out the full table on alloc.
         * With 4K we don't store slot in the second half. Hence we don't
         * need to do this for 4k.
         */
#if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_PPC_64K_PAGES) && \
        (H_PGD_INDEX_SIZE == H_PUD_CACHE_INDEX)
        memset(pgd, 0, PGD_TABLE_SIZE);
#endif
        return pgd;
}

static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
        if (radix_enabled())
                return radix__pgd_free(mm, pgd);
        kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
}

static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
{
        pgd_set(pgd, __pgtable_ptr_val(pud) | PGD_VAL_BITS);
}

static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
        pud_t *pud;

        pud = kmem_cache_alloc(PGT_CACHE(PUD_CACHE_INDEX),
                               pgtable_gfp_flags(mm, GFP_KERNEL));
        /*
         * Tell kmemleak to ignore the PUD, that means don't scan it for
         * pointers and don't consider it a leak. PUDs are typically only
         * referred to by their PGD, but kmemleak is not able to recognise those
         * as pointers, leading to false leak reports.
         */
        kmemleak_ignore(pud);

        return pud;
}

static inline void __pud_free(pud_t *pud)
{
        struct page *page = virt_to_page(pud);

        /*
         * Early pud pages allocated via memblock allocator
         * can't be directly freed to slab
         */
        if (PageReserved(page))
                free_reserved_page(page);
        else
                kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), pud);
}

static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
        return __pud_free(pud);
}

static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
        pud_set(pud, __pgtable_ptr_val(pmd) | PUD_VAL_BITS);
}

static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
                                  unsigned long address)
{
        /*
         * By now all the pud entries should be none entries. So go
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
        pgtable_free_tlb(tlb, pud, PUD_INDEX);
}

static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
        return pmd_fragment_alloc(mm, addr);
}

static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
        pmd_fragment_free((unsigned long *)pmd);
}

static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
                                  unsigned long address)
{
        /*
         * By now all the pud entries should be none entries. So go
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
        return pgtable_free_tlb(tlb, pmd, PMD_INDEX);
}

static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
                                       pte_t *pte)
{
        pmd_set(pmd, __pgtable_ptr_val(pte) | PMD_VAL_BITS);
}

static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
                                pgtable_t pte_page)
{
        pmd_set(pmd, __pgtable_ptr_val(pte_page) | PMD_VAL_BITS);
}

static inline pgtable_t pmd_pgtable(pmd_t pmd)
{
        return (pgtable_t)pmd_page_vaddr(pmd);
}

static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
{
        return (pte_t *)pte_fragment_alloc(mm, 1);
}

static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
{
        return (pgtable_t)pte_fragment_alloc(mm, 0);
}

static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
        pte_fragment_free((unsigned long *)pte, 1);
}

static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
        pte_fragment_free((unsigned long *)ptepage, 0);
}

static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
                                  unsigned long address)
{
        /*
         * By now all the pud entries should be none entries. So go
         * ahead and flush the page walk cache
         */
        flush_tlb_pgtable(tlb, address);
        pgtable_free_tlb(tlb, table, PTE_INDEX);
}

#define check_pgt_cache()       do { } while (0)

#endif /* _ASM_POWERPC_BOOK3S_64_PGALLOC_H */