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/slab.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) 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 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 70 { 71 return 0; 72 } 73 74 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; } 75 76 /* 77 * Don't actually need to do any preparation, but need to make sure 78 * the address is in the right region. 79 */ 80 int prepare_hugepage_range(struct file *file, 81 unsigned long addr, unsigned long len) 82 { 83 if (len & ~HPAGE_MASK) 84 return -EINVAL; 85 if (addr & ~HPAGE_MASK) 86 return -EINVAL; 87 if (REGION_NUMBER(addr) != RGN_HPAGE) 88 return -EINVAL; 89 90 return 0; 91 } 92 93 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write) 94 { 95 struct page *page; 96 pte_t *ptep; 97 98 if (REGION_NUMBER(addr) != RGN_HPAGE) 99 return ERR_PTR(-EINVAL); 100 101 ptep = huge_pte_offset(mm, addr); 102 if (!ptep || pte_none(*ptep)) 103 return NULL; 104 page = pte_page(*ptep); 105 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); 106 return page; 107 } 108 int pmd_huge(pmd_t pmd) 109 { 110 return 0; 111 } 112 113 int pud_huge(pud_t pud) 114 { 115 return 0; 116 } 117 118 struct page * 119 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) 120 { 121 return NULL; 122 } 123 124 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 125 unsigned long addr, unsigned long end, 126 unsigned long floor, unsigned long ceiling) 127 { 128 /* 129 * This is called to free hugetlb page tables. 130 * 131 * The offset of these addresses from the base of the hugetlb 132 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that 133 * the standard free_pgd_range will free the right page tables. 134 * 135 * If floor and ceiling are also in the hugetlb region, they 136 * must likewise be scaled down; but if outside, left unchanged. 137 */ 138 139 addr = htlbpage_to_page(addr); 140 end = htlbpage_to_page(end); 141 if (REGION_NUMBER(floor) == RGN_HPAGE) 142 floor = htlbpage_to_page(floor); 143 if (REGION_NUMBER(ceiling) == RGN_HPAGE) 144 ceiling = htlbpage_to_page(ceiling); 145 146 free_pgd_range(tlb, addr, end, floor, ceiling); 147 } 148 149 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, 150 unsigned long pgoff, unsigned long flags) 151 { 152 struct vm_area_struct *vmm; 153 154 if (len > RGN_MAP_LIMIT) 155 return -ENOMEM; 156 if (len & ~HPAGE_MASK) 157 return -EINVAL; 158 159 /* Handle MAP_FIXED */ 160 if (flags & MAP_FIXED) { 161 if (prepare_hugepage_range(file, addr, len)) 162 return -EINVAL; 163 return addr; 164 } 165 166 /* This code assumes that RGN_HPAGE != 0. */ 167 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1))) 168 addr = HPAGE_REGION_BASE; 169 else 170 addr = ALIGN(addr, HPAGE_SIZE); 171 for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) { 172 /* At this point: (!vmm || addr < vmm->vm_end). */ 173 if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT) 174 return -ENOMEM; 175 if (!vmm || (addr + len) <= vmm->vm_start) 176 return addr; 177 addr = ALIGN(vmm->vm_end, HPAGE_SIZE); 178 } 179 } 180 181 static int __init hugetlb_setup_sz(char *str) 182 { 183 u64 tr_pages; 184 unsigned long long size; 185 186 if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0) 187 /* 188 * shouldn't happen, but just in case. 189 */ 190 tr_pages = 0x15557000UL; 191 192 size = memparse(str, &str); 193 if (*str || !is_power_of_2(size) || !(tr_pages & size) || 194 size <= PAGE_SIZE || 195 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) { 196 printk(KERN_WARNING "Invalid huge page size specified\n"); 197 return 1; 198 } 199 200 hpage_shift = __ffs(size); 201 /* 202 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT 203 * override here with new page shift. 204 */ 205 ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2); 206 return 0; 207 } 208 early_param("hugepagesz", hugetlb_setup_sz); 209