LXR linux/arch/ia64/mm/hugetlbpage.c

   1/*
   2 * IA-64 Huge TLB Page Support for Kernel.
   3 *
   4 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
   5 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
   6 *
   7 * Sep, 2003: add numa support
   8 * Feb, 2004: dynamic hugetlb page size via boot parameter
   9 */
  10
  11#include <linux/init.h>
  12#include <linux/fs.h>
  13#include <linux/mm.h>
  14#include <linux/hugetlb.h>
  15#include <linux/pagemap.h>
  16#include <linux/module.h>
  17#include <linux/sysctl.h>
  18#include <linux/log2.h>
  19#include <asm/mman.h>
  20#include <asm/pgalloc.h>
  21#include <asm/tlb.h>
  22#include <asm/tlbflush.h>
  23
  24unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
  25EXPORT_SYMBOL(hpage_shift);
  26
  27pte_t *
  28huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
  29{
  30        unsigned long taddr = htlbpage_to_page(addr);
  31        pgd_t *pgd;
  32        pud_t *pud;
  33        pmd_t *pmd;
  34        pte_t *pte = NULL;
  35
  36        pgd = pgd_offset(mm, taddr);
  37        pud = pud_alloc(mm, pgd, taddr);
  38        if (pud) {
  39                pmd = pmd_alloc(mm, pud, taddr);
  40                if (pmd)
  41                        pte = pte_alloc_map(mm, pmd, taddr);
  42        }
  43        return pte;
  44}
  45
  46pte_t *
  47huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz)
  48{
  49        unsigned long taddr = htlbpage_to_page(addr);
  50        pgd_t *pgd;
  51        pud_t *pud;
  52        pmd_t *pmd;
  53        pte_t *pte = NULL;
  54
  55        pgd = pgd_offset(mm, taddr);
  56        if (pgd_present(*pgd)) {
  57                pud = pud_offset(pgd, taddr);
  58                if (pud_present(*pud)) {
  59                        pmd = pmd_offset(pud, taddr);
  60                        if (pmd_present(*pmd))
  61                                pte = pte_offset_map(pmd, taddr);
  62                }
  63        }
  64
  65        return pte;
  66}
  67
  68#define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
  69
  70/*
  71 * Don't actually need to do any preparation, but need to make sure
  72 * the address is in the right region.
  73 */
  74int prepare_hugepage_range(struct file *file,
  75                        unsigned long addr, unsigned long len)
  76{
  77        if (len & ~HPAGE_MASK)
  78                return -EINVAL;
  79        if (addr & ~HPAGE_MASK)
  80                return -EINVAL;
  81        if (REGION_NUMBER(addr) != RGN_HPAGE)
  82                return -EINVAL;
  83
  84        return 0;
  85}
  86
  87struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
  88{
  89        struct page *page;
  90        pte_t *ptep;
  91
  92        if (REGION_NUMBER(addr) != RGN_HPAGE)
  93                return ERR_PTR(-EINVAL);
  94
  95        ptep = huge_pte_offset(mm, addr, HPAGE_SIZE);
  96        if (!ptep || pte_none(*ptep))
  97                return NULL;
  98        page = pte_page(*ptep);
  99        page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
 100        return page;
 101}
 102int pmd_huge(pmd_t pmd)
 103{
 104        return 0;
 105}
 106
 107int pud_huge(pud_t pud)
 108{
 109        return 0;
 110}
 111
 112void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 113                        unsigned long addr, unsigned long end,
 114                        unsigned long floor, unsigned long ceiling)
 115{
 116        /*
 117         * This is called to free hugetlb page tables.
 118         *
 119         * The offset of these addresses from the base of the hugetlb
 120         * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
 121         * the standard free_pgd_range will free the right page tables.
 122         *
 123         * If floor and ceiling are also in the hugetlb region, they
 124         * must likewise be scaled down; but if outside, left unchanged.
 125         */
 126
 127        addr = htlbpage_to_page(addr);
 128        end  = htlbpage_to_page(end);
 129        if (REGION_NUMBER(floor) == RGN_HPAGE)
 130                floor = htlbpage_to_page(floor);
 131        if (REGION_NUMBER(ceiling) == RGN_HPAGE)
 132                ceiling = htlbpage_to_page(ceiling);
 133
 134        free_pgd_range(tlb, addr, end, floor, ceiling);
 135}
 136
 137unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 138                unsigned long pgoff, unsigned long flags)
 139{
 140        struct vm_unmapped_area_info info;
 141
 142        if (len > RGN_MAP_LIMIT)
 143                return -ENOMEM;
 144        if (len & ~HPAGE_MASK)
 145                return -EINVAL;
 146
 147        /* Handle MAP_FIXED */
 148        if (flags & MAP_FIXED) {
 149                if (prepare_hugepage_range(file, addr, len))
 150                        return -EINVAL;
 151                return addr;
 152        }
 153
 154        /* This code assumes that RGN_HPAGE != 0. */
 155        if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
 156                addr = HPAGE_REGION_BASE;
 157
 158        info.flags = 0;
 159        info.length = len;
 160        info.low_limit = addr;
 161        info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT;
 162        info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1);
 163        info.align_offset = 0;
 164        return vm_unmapped_area(&info);
 165}
 166
 167static int __init hugetlb_setup_sz(char *str)
 168{
 169        u64 tr_pages;
 170        unsigned long long size;
 171
 172        if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
 173                /*
 174                 * shouldn't happen, but just in case.
 175                 */
 176                tr_pages = 0x15557000UL;
 177
 178        size = memparse(str, &str);
 179        if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
 180                size <= PAGE_SIZE ||
 181                size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
 182                printk(KERN_WARNING "Invalid huge page size specified\n");
 183                return 1;
 184        }
 185
 186        hpage_shift = __ffs(size);
 187        /*
 188         * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
 189         * override here with new page shift.
 190         */
 191        ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
 192        return 0;
 193}
 194early_param("hugepagesz", hugetlb_setup_sz);
 195