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 25 unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT; 26 EXPORT_SYMBOL(hpage_shift); 27 28 pte_t * 29 huge_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 47 pte_t * 48 huge_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 */ 75 int 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 88 struct 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 } 103 int pmd_huge(pmd_t pmd) 104 { 105 return 0; 106 } 107 108 int pud_huge(pud_t pud) 109 { 110 return 0; 111 } 112 113 void 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 } 137 138 unsigned 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 } 167 168 static 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 } 195 early_param("hugepagesz", hugetlb_setup_sz); 196