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
  25 extern void __bad_pte(pmd_t *pmd);
  26
  27 extern struct kmem_cache *pgtable_cache[];
  28 #define PGT_CACHE(shift) ({                             \
  29                         BUG_ON(!(shift));               \
  30                         pgtable_cache[(shift) - 1];     \
  31                 })
  32
  33 static 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
  39 static 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
  55 static 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
  61 static 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
  70 static 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
  76 static 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
  85 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
  86 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
  87
  88 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  89 {
  90         free_page((unsigned long)pte);
  91 }
  92
  93 static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
  94 {
  95         pgtable_page_dtor(ptepage);
  96         __free_page(ptepage);
  97 }
  98
  99 static inline void pgtable_free(void *table, unsigned index_size)
 100 {
 101         if (!index_size) {
 102                 free_page((unsigned long)table);
 103         } else {
 104                 BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
 105                 kmem_cache_free(PGT_CACHE(index_size), table);
 106         }
 107 }
 108
 109 #define check_pgt_cache()       do { } while (0)
 110
 111 #ifdef CONFIG_SMP
 112 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
 113                                     void *table, int shift)
 114 {
 115         unsigned long pgf = (unsigned long)table;
 116         BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 117         pgf |= shift;
 118         tlb_remove_table(tlb, (void *)pgf);
 119 }
 120
 121 static inline void __tlb_remove_table(void *_table)
 122 {
 123         void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
 124         unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
 125
 126         pgtable_free(table, shift);
 127 }
 128 #else
 129 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
 130                                     void *table, int shift)
 131 {
 132         pgtable_free(table, shift);
 133 }
 134 #endif
 135
 136 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
 137                                   unsigned long address)
 138 {
 139         pgtable_page_dtor(table);
 140         pgtable_free_tlb(tlb, page_address(table), 0);
 141 }
 142 #endif /* _ASM_POWERPC_BOOK3S_32_PGALLOC_H */