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 24 unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT; 25 EXPORT_SYMBOL(hpage_shift); 26 27 pte_t * 28 huge_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 46 pte_t * 47 huge_pte_offset (struct mm_struct *mm, unsigned long addr) 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 */ 74 int 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 87 struct 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); 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 } 102 int pmd_huge(pmd_t pmd) 103 { 104 return 0; 105 } 106 107 int pud_huge(pud_t pud) 108 { 109 return 0; 110 } 111 112 void 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 } 136 137 unsigned 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 } 166 167 static 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 } 194 early_param("hugepagesz", hugetlb_setup_sz); 195