arch/tile/include/asm/pgalloc.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_PGALLOC_H
  16 #define _ASM_TILE_PGALLOC_H
  17
  18 #include <linux/threads.h>
  19 #include <linux/mm.h>
  20 #include <linux/mmzone.h>
  21 #include <asm/fixmap.h>
  22 #include <asm/page.h>
  23 #include <hv/hypervisor.h>
  24
  25 /* Bits for the size of the second-level page table. */
  26 #define L2_KERNEL_PGTABLE_SHIFT _HV_LOG2_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
  27
  28 /* How big is a kernel L2 page table? */
  29 #define L2_KERNEL_PGTABLE_SIZE (1UL << L2_KERNEL_PGTABLE_SHIFT)
  30
  31 /* We currently allocate user L2 page tables by page (unlike kernel L2s). */
  32 #if L2_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
  33 #define L2_USER_PGTABLE_SHIFT PAGE_SHIFT
  34 #else
  35 #define L2_USER_PGTABLE_SHIFT L2_KERNEL_PGTABLE_SHIFT
  36 #endif
  37
  38 /* How many pages do we need, as an "order", for a user L2 page table? */
  39 #define L2_USER_PGTABLE_ORDER (L2_USER_PGTABLE_SHIFT - PAGE_SHIFT)
  40
  41 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
  42 {
  43 #ifdef CONFIG_64BIT
  44         set_pte(pmdp, pmd);
  45 #else
  46         set_pte(&pmdp->pud.pgd, pmd.pud.pgd);
  47 #endif
  48 }
  49
  50 static inline void pmd_populate_kernel(struct mm_struct *mm,
  51                                        pmd_t *pmd, pte_t *ptep)
  52 {
  53         set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(__pa(ptep)),
  54                               __pgprot(_PAGE_PRESENT)));
  55 }
  56
  57 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  58                                 pgtable_t page)
  59 {
  60         set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(PFN_PHYS(page_to_pfn(page))),
  61                               __pgprot(_PAGE_PRESENT)));
  62 }
  63
  64 /*
  65  * Allocate and free page tables.
  66  */
  67
  68 extern pgd_t *pgd_alloc(struct mm_struct *mm);
  69 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  70
  71 extern pgtable_t pgtable_alloc_one(struct mm_struct *mm, unsigned long address,
  72                                    int order);
  73 extern void pgtable_free(struct mm_struct *mm, struct page *pte, int order);
  74
  75 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
  76                                       unsigned long address)
  77 {
  78         return pgtable_alloc_one(mm, address, L2_USER_PGTABLE_ORDER);
  79 }
  80
  81 static inline void pte_free(struct mm_struct *mm, struct page *pte)
  82 {
  83         pgtable_free(mm, pte, L2_USER_PGTABLE_ORDER);
  84 }
  85
  86 #define pmd_pgtable(pmd) pmd_page(pmd)
  87
  88 static inline pte_t *
  89 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
  90 {
  91         return pfn_to_kaddr(page_to_pfn(pte_alloc_one(mm, address)));
  92 }
  93
  94 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  95 {
  96         BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
  97         pte_free(mm, virt_to_page(pte));
  98 }
  99
 100 extern void __pgtable_free_tlb(struct mmu_gather *tlb, struct page *pte,
 101                                unsigned long address, int order);
 102 static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
 103                                   unsigned long address)
 104 {
 105         __pgtable_free_tlb(tlb, pte, address, L2_USER_PGTABLE_ORDER);
 106 }
 107
 108 #define check_pgt_cache()       do { } while (0)
 109
 110 /*
 111  * Get the small-page pte_t lowmem entry for a given pfn.
 112  * This may or may not be in use, depending on whether the initial
 113  * huge-page entry for the page has already been shattered.
 114  */
 115 pte_t *get_prealloc_pte(unsigned long pfn);
 116
 117 /* During init, we can shatter kernel huge pages if needed. */
 118 void shatter_pmd(pmd_t *pmd);
 119
 120 /* After init, a more complex technique is required. */
 121 void shatter_huge_page(unsigned long addr);
 122
 123 #ifdef __tilegx__
 124
 125 #define pud_populate(mm, pud, pmd) \
 126   pmd_populate_kernel((mm), (pmd_t *)(pud), (pte_t *)(pmd))
 127
 128 /* Bits for the size of the L1 (intermediate) page table. */
 129 #define L1_KERNEL_PGTABLE_SHIFT _HV_LOG2_L1_SIZE(HPAGE_SHIFT)
 130
 131 /* How big is a kernel L2 page table? */
 132 #define L1_KERNEL_PGTABLE_SIZE (1UL << L1_KERNEL_PGTABLE_SHIFT)
 133
 134 /* We currently allocate L1 page tables by page. */
 135 #if L1_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
 136 #define L1_USER_PGTABLE_SHIFT PAGE_SHIFT
 137 #else
 138 #define L1_USER_PGTABLE_SHIFT L1_KERNEL_PGTABLE_SHIFT
 139 #endif
 140
 141 /* How many pages do we need, as an "order", for an L1 page table? */
 142 #define L1_USER_PGTABLE_ORDER (L1_USER_PGTABLE_SHIFT - PAGE_SHIFT)
 143
 144 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 145 {
 146         struct page *p = pgtable_alloc_one(mm, address, L1_USER_PGTABLE_ORDER);
 147         return (pmd_t *)page_to_virt(p);
 148 }
 149
 150 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
 151 {
 152         pgtable_free(mm, virt_to_page(pmdp), L1_USER_PGTABLE_ORDER);
 153 }
 154
 155 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 156                                   unsigned long address)
 157 {
 158         __pgtable_free_tlb(tlb, virt_to_page(pmdp), address,
 159                            L1_USER_PGTABLE_ORDER);
 160 }
 161
 162 #endif /* __tilegx__ */
 163
 164 #endif /* _ASM_TILE_PGALLOC_H */