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 p4d_t *p4d; 34 pud_t *pud; 35 pmd_t *pmd; 36 pte_t *pte = NULL; 37 38 pgd = pgd_offset(mm, taddr); 39 p4d = p4d_offset(pgd, taddr); 40 pud = pud_alloc(mm, p4d, taddr); 41 if (pud) { 42 pmd = pmd_alloc(mm, pud, taddr); 43 if (pmd) 44 pte = pte_alloc_map(mm, pmd, taddr); 45 } 46 return pte; 47 } 48 49 pte_t * 50 huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz) 51 { 52 unsigned long taddr = htlbpage_to_page(addr); 53 pgd_t *pgd; 54 p4d_t *p4d; 55 pud_t *pud; 56 pmd_t *pmd; 57 pte_t *pte = NULL; 58 59 pgd = pgd_offset(mm, taddr); 60 if (pgd_present(*pgd)) { 61 p4d = p4d_offset(pgd, addr); 62 if (p4d_present(*p4d)) { 63 pud = pud_offset(p4d, taddr); 64 if (pud_present(*pud)) { 65 pmd = pmd_offset(pud, taddr); 66 if (pmd_present(*pmd)) 67 pte = pte_offset_map(pmd, taddr); 68 } 69 } 70 } 71 72 return pte; 73 } 74 75 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; } 76 77 /* 78 * Don't actually need to do any preparation, but need to make sure 79 * the address is in the right region. 80 */ 81 int prepare_hugepage_range(struct file *file, 82 unsigned long addr, unsigned long len) 83 { 84 if (len & ~HPAGE_MASK) 85 return -EINVAL; 86 if (addr & ~HPAGE_MASK) 87 return -EINVAL; 88 if (REGION_NUMBER(addr) != RGN_HPAGE) 89 return -EINVAL; 90 91 return 0; 92 } 93 94 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write) 95 { 96 struct page *page; 97 pte_t *ptep; 98 99 if (REGION_NUMBER(addr) != RGN_HPAGE) 100 return ERR_PTR(-EINVAL); 101 102 ptep = huge_pte_offset(mm, addr, HPAGE_SIZE); 103 if (!ptep || pte_none(*ptep)) 104 return NULL; 105 page = pte_page(*ptep); 106 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); 107 return page; 108 } 109 int pmd_huge(pmd_t pmd) 110 { 111 return 0; 112 } 113 114 int pud_huge(pud_t pud) 115 { 116 return 0; 117 } 118 119 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 120 unsigned long addr, unsigned long end, 121 unsigned long floor, unsigned long ceiling) 122 { 123 /* 124 * This is called to free hugetlb page tables. 125 * 126 * The offset of these addresses from the base of the hugetlb 127 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that 128 * the standard free_pgd_range will free the right page tables. 129 * 130 * If floor and ceiling are also in the hugetlb region, they 131 * must likewise be scaled down; but if outside, left unchanged. 132 */ 133 134 addr = htlbpage_to_page(addr); 135 end = htlbpage_to_page(end); 136 if (REGION_NUMBER(floor) == RGN_HPAGE) 137 floor = htlbpage_to_page(floor); 138 if (REGION_NUMBER(ceiling) == RGN_HPAGE) 139 ceiling = htlbpage_to_page(ceiling); 140 141 free_pgd_range(tlb, addr, end, floor, ceiling); 142 } 143 144 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, 145 unsigned long pgoff, unsigned long flags) 146 { 147 struct vm_unmapped_area_info info; 148 149 if (len > RGN_MAP_LIMIT) 150 return -ENOMEM; 151 if (len & ~HPAGE_MASK) 152 return -EINVAL; 153 154 /* Handle MAP_FIXED */ 155 if (flags & MAP_FIXED) { 156 if (prepare_hugepage_range(file, addr, len)) 157 return -EINVAL; 158 return addr; 159 } 160 161 /* This code assumes that RGN_HPAGE != 0. */ 162 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1))) 163 addr = HPAGE_REGION_BASE; 164 165 info.flags = 0; 166 info.length = len; 167 info.low_limit = addr; 168 info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT; 169 info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1); 170 info.align_offset = 0; 171 return vm_unmapped_area(&info); 172 } 173 174 static int __init hugetlb_setup_sz(char *str) 175 { 176 u64 tr_pages; 177 unsigned long long size; 178 179 if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0) 180 /* 181 * shouldn't happen, but just in case. 182 */ 183 tr_pages = 0x15557000UL; 184 185 size = memparse(str, &str); 186 if (*str || !is_power_of_2(size) || !(tr_pages & size) || 187 size <= PAGE_SIZE || 188 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) { 189 printk(KERN_WARNING "Invalid huge page size specified\n"); 190 return 1; 191 } 192 193 hpage_shift = __ffs(size); 194 /* 195 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT 196 * override here with new page shift. 197 */ 198 ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2); 199 return 0; 200 } 201 early_param("hugepagesz", hugetlb_setup_sz); 202