LXR linux/arch/powerpc/include/asm/book3s/32/pgalloc.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_POWERPC_BOOK3S_32_PGALLOC_H
   3#define _ASM_POWERPC_BOOK3S_32_PGALLOC_H
   4
   5#include <linux/threads.h>
   6#include <linux/slab.h>
   7
   8/*
   9 * Functions that deal with pagetables that could be at any level of
  10 * the table need to be passed an "index_size" so they know how to
  11 * handle allocation.  For PTE pages (which are linked to a struct
  12 * page for now, and drawn from the main get_free_pages() pool), the
  13 * allocation size will be (2^index_size * sizeof(pointer)) and
  14 * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
  15 *
  16 * The maximum index size needs to be big enough to allow any
  17 * pagetable sizes we need, but small enough to fit in the low bits of
  18 * any page table pointer.  In other words all pagetables, even tiny
  19 * ones, must be aligned to allow at least enough low 0 bits to
  20 * contain this value.  This value is also used as a mask, so it must
  21 * be one less than a power of two.
  22 */
  23#define MAX_PGTABLE_INDEX_SIZE  0xf
  24
  25extern void __bad_pte(pmd_t *pmd);
  26
  27extern struct kmem_cache *pgtable_cache[];
  28#define PGT_CACHE(shift) ({                             \
  29                        BUG_ON(!(shift));               \
  30                        pgtable_cache[(shift) - 1];     \
  31                })
  32
  33static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  34{
  35        return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
  36                        pgtable_gfp_flags(mm, GFP_KERNEL));
  37}
  38
  39static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  40{
  41        kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
  42}
  43
  44/*
  45 * We don't have any real pmd's, and this code never triggers because
  46 * the pgd will always be present..
  47 */
  48/* #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); }) */
  49#define pmd_free(mm, x)                 do { } while (0)
  50#define __pmd_free_tlb(tlb,x,a)         do { } while (0)
  51/* #define pgd_populate(mm, pmd, pte)      BUG() */
  52
  53#ifndef CONFIG_BOOKE
  54
  55static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
  56                                       pte_t *pte)
  57{
  58        *pmdp = __pmd(__pa(pte) | _PMD_PRESENT);
  59}
  60
  61static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
  62                                pgtable_t pte_page)
  63{
  64        *pmdp = __pmd((page_to_pfn(pte_page) << PAGE_SHIFT) | _PMD_PRESENT);
  65}
  66
  67#define pmd_pgtable(pmd) pmd_page(pmd)
  68#else
  69
  70static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
  71                                       pte_t *pte)
  72{
  73        *pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
  74}
  75
  76static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
  77                                pgtable_t pte_page)
  78{
  79        *pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
  80}
  81
  82#define pmd_pgtable(pmd) pmd_page(pmd)
  83#endif
  84
  85extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
  86extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
  87
  88static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  89{
  90        free_page((unsigned long)pte);
  91}
  92
  93static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
  94{
  95        pgtable_page_dtor(ptepage);
  96        __free_page(ptepage);
  97}
  98
  99static inline void pgtable_free(void *table, unsigned index_size)
 100{
 101        if (!index_size) {
 102                pgtable_page_dtor(virt_to_page(table));
 103                free_page((unsigned long)table);
 104        } else {
 105                BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
 106                kmem_cache_free(PGT_CACHE(index_size), table);
 107        }
 108}
 109
 110#define check_pgt_cache()       do { } while (0)
 111#define get_hugepd_cache_index(x)  (x)
 112
 113static inline void pgtable_free_tlb(struct mmu_gather *tlb,
 114                                    void *table, int shift)
 115{
 116        unsigned long pgf = (unsigned long)table;
 117        BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 118        pgf |= shift;
 119        tlb_remove_table(tlb, (void *)pgf);
 120}
 121
 122static inline void __tlb_remove_table(void *_table)
 123{
 124        void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
 125        unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
 126
 127        pgtable_free(table, shift);
 128}
 129
 130static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 131                                  unsigned long address)
 132{
 133        pgtable_free_tlb(tlb, page_address(table), 0);
 134}
 135#endif /* _ASM_POWERPC_BOOK3S_32_PGALLOC_H */
 136