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

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * IA-64 Huge TLB Page Support for Kernel.
   4 *
   5 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
   6 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
   7 *
   8 * Sep, 2003: add numa support
   9 * Feb, 2004: dynamic hugetlb page size via boot parameter
  10 */
  11
  12#include <linux/init.h>
  13#include <linux/fs.h>
  14#include <linux/mm.h>
  15#include <linux/hugetlb.h>
  16#include <linux/pagemap.h>
  17#include <linux/module.h>
  18#include <linux/sysctl.h>
  19#include <linux/log2.h>
  20#include <asm/mman.h>
  21#include <asm/pgalloc.h>
  22#include <asm/tlb.h>
  23#include <asm/tlbflush.h>
  24
  25unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
  26EXPORT_SYMBOL(hpage_shift);
  27
  28pte_t *
  29huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
  30{
  31        unsigned long taddr = htlbpage_to_page(addr);
  32        pgd_t *pgd;
  33        pud_t *pud;
  34        pmd_t *pmd;
  35        pte_t *pte = NULL;
  36
  37        pgd = pgd_offset(mm, taddr);
  38        pud = pud_alloc(mm, pgd, taddr);
  39        if (pud) {
  40                pmd = pmd_alloc(mm, pud, taddr);
  41                if (pmd)
  42                        pte = pte_alloc_map(mm, pmd, taddr);
  43        }
  44        return pte;
  45}
  46
  47pte_t *
  48huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz)
  49{
  50        unsigned long taddr = htlbpage_to_page(addr);
  51        pgd_t *pgd;
  52        pud_t *pud;
  53        pmd_t *pmd;
  54        pte_t *pte = NULL;
  55
  56        pgd = pgd_offset(mm, taddr);
  57        if (pgd_present(*pgd)) {
  58                pud = pud_offset(pgd, taddr);
  59                if (pud_present(*pud)) {
  60                        pmd = pmd_offset(pud, taddr);
  61                        if (pmd_present(*pmd))
  62                                pte = pte_offset_map(pmd, taddr);
  63                }
  64        }
  65
  66        return pte;
  67}
  68
  69#define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
  70
  71/*
  72 * Don't actually need to do any preparation, but need to make sure
  73 * the address is in the right region.
  74 */
  75int prepare_hugepage_range(struct file *file,
  76                        unsigned long addr, unsigned long len)
  77{
  78        if (len & ~HPAGE_MASK)
  79                return -EINVAL;
  80        if (addr & ~HPAGE_MASK)
  81                return -EINVAL;
  82        if (REGION_NUMBER(addr) != RGN_HPAGE)
  83                return -EINVAL;
  84
  85        return 0;
  86}
  87
  88struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
  89{
  90        struct page *page;
  91        pte_t *ptep;
  92
  93        if (REGION_NUMBER(addr) != RGN_HPAGE)
  94                return ERR_PTR(-EINVAL);
  95
  96        ptep = huge_pte_offset(mm, addr, HPAGE_SIZE);
  97        if (!ptep || pte_none(*ptep))
  98                return NULL;
  99        page = pte_page(*ptep);
 100        page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
 101        return page;
 102}
 103int pmd_huge(pmd_t pmd)
 104{
 105        return 0;
 106}
 107
 108int pud_huge(pud_t pud)
 109{
 110        return 0;
 111}
 112
 113void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 114                        unsigned long addr, unsigned long end,
 115                        unsigned long floor, unsigned long ceiling)
 116{
 117        /*
 118         * This is called to free hugetlb page tables.
 119         *
 120         * The offset of these addresses from the base of the hugetlb
 121         * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
 122         * the standard free_pgd_range will free the right page tables.
 123         *
 124         * If floor and ceiling are also in the hugetlb region, they
 125         * must likewise be scaled down; but if outside, left unchanged.
 126         */
 127
 128        addr = htlbpage_to_page(addr);
 129        end  = htlbpage_to_page(end);
 130        if (REGION_NUMBER(floor) == RGN_HPAGE)
 131                floor = htlbpage_to_page(floor);
 132        if (REGION_NUMBER(ceiling) == RGN_HPAGE)
 133                ceiling = htlbpage_to_page(ceiling);
 134
 135        free_pgd_range(tlb, addr, end, floor, ceiling);
 136}
 137
 138unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 139                unsigned long pgoff, unsigned long flags)
 140{
 141        struct vm_unmapped_area_info info;
 142
 143        if (len > RGN_MAP_LIMIT)
 144                return -ENOMEM;
 145        if (len & ~HPAGE_MASK)
 146                return -EINVAL;
 147
 148        /* Handle MAP_FIXED */
 149        if (flags & MAP_FIXED) {
 150                if (prepare_hugepage_range(file, addr, len))
 151                        return -EINVAL;
 152                return addr;
 153        }
 154
 155        /* This code assumes that RGN_HPAGE != 0. */
 156        if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
 157                addr = HPAGE_REGION_BASE;
 158
 159        info.flags = 0;
 160        info.length = len;
 161        info.low_limit = addr;
 162        info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT;
 163        info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1);
 164        info.align_offset = 0;
 165        return vm_unmapped_area(&info);
 166}
 167
 168static int __init hugetlb_setup_sz(char *str)
 169{
 170        u64 tr_pages;
 171        unsigned long long size;
 172
 173        if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
 174                /*
 175                 * shouldn't happen, but just in case.
 176                 */
 177                tr_pages = 0x15557000UL;
 178
 179        size = memparse(str, &str);
 180        if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
 181                size <= PAGE_SIZE ||
 182                size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
 183                printk(KERN_WARNING "Invalid huge page size specified\n");
 184                return 1;
 185        }
 186
 187        hpage_shift = __ffs(size);
 188        /*
 189         * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
 190         * override here with new page shift.
 191         */
 192        ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
 193        return 0;
 194}
 195early_param("hugepagesz", hugetlb_setup_sz);
 196