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 <hv/hypervisor.h>
  23
  24 /* Bits for the size of the second-level page table. */
  25 #define L2_KERNEL_PGTABLE_SHIFT \
  26   (HV_LOG2_PAGE_SIZE_LARGE - HV_LOG2_PAGE_SIZE_SMALL + HV_LOG2_PTE_SIZE)
  27
  28 /* We currently allocate user L2 page tables by page (unlike kernel L2s). */
  29 #if L2_KERNEL_PGTABLE_SHIFT < HV_LOG2_PAGE_SIZE_SMALL
  30 #define L2_USER_PGTABLE_SHIFT HV_LOG2_PAGE_SIZE_SMALL
  31 #else
  32 #define L2_USER_PGTABLE_SHIFT L2_KERNEL_PGTABLE_SHIFT
  33 #endif
  34
  35 /* How many pages do we need, as an "order", for a user L2 page table? */
  36 #define L2_USER_PGTABLE_ORDER (L2_USER_PGTABLE_SHIFT - HV_LOG2_PAGE_SIZE_SMALL)
  37
  38 /* How big is a kernel L2 page table? */
  39 #define L2_KERNEL_PGTABLE_SIZE (1 << L2_KERNEL_PGTABLE_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(__pa(ptep) >> HV_LOG2_PAGE_TABLE_ALIGN,
  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_PFN_TO_PTFN(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 pte_alloc_one(struct mm_struct *mm, unsigned long address);
  72 extern void pte_free(struct mm_struct *mm, struct page *pte);
  73
  74 #define pmd_pgtable(pmd) pmd_page(pmd)
  75
  76 static inline pte_t *
  77 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
  78 {
  79         return pfn_to_kaddr(page_to_pfn(pte_alloc_one(mm, address)));
  80 }
  81
  82 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  83 {
  84         BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
  85         pte_free(mm, virt_to_page(pte));
  86 }
  87
  88 extern void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
  89                            unsigned long address);
  90
  91 #define check_pgt_cache()       do { } while (0)
  92
  93 /*
  94  * Get the small-page pte_t lowmem entry for a given pfn.
  95  * This may or may not be in use, depending on whether the initial
  96  * huge-page entry for the page has already been shattered.
  97  */
  98 pte_t *get_prealloc_pte(unsigned long pfn);
  99
 100 /* During init, we can shatter kernel huge pages if needed. */
 101 void shatter_pmd(pmd_t *pmd);
 102
 103 /* After init, a more complex technique is required. */
 104 void shatter_huge_page(unsigned long addr);
 105
 106 #ifdef __tilegx__
 107 /* We share a single page allocator for both L1 and L2 page tables. */
 108 #if HV_L1_SIZE != HV_L2_SIZE
 109 # error Rework assumption that L1 and L2 page tables are same size.
 110 #endif
 111 #define L1_USER_PGTABLE_ORDER L2_USER_PGTABLE_ORDER
 112 #define pud_populate(mm, pud, pmd) \
 113   pmd_populate_kernel((mm), (pmd_t *)(pud), (pte_t *)(pmd))
 114 #define pmd_alloc_one(mm, addr) \
 115   ((pmd_t *)page_to_virt(pte_alloc_one((mm), (addr))))
 116 #define pmd_free(mm, pmdp) \
 117   pte_free((mm), virt_to_page(pmdp))
 118 #define __pmd_free_tlb(tlb, pmdp, address) \
 119   __pte_free_tlb((tlb), virt_to_page(pmdp), (address))
 120 #endif
 121
 122 #endif /* _ASM_TILE_PGALLOC_H */