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/slab.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 26 pte_t * 27 huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz) 28 { 29 unsigned long taddr = htlbpage_to_page(addr); 30 pgd_t *pgd; 31 pud_t *pud; 32 pmd_t *pmd; 33 pte_t *pte = NULL; 34 35 pgd = pgd_offset(mm, taddr); 36 pud = pud_alloc(mm, pgd, taddr); 37 if (pud) { 38 pmd = pmd_alloc(mm, pud, taddr); 39 if (pmd) 40 pte = pte_alloc_map(mm, pmd, taddr); 41 } 42 return pte; 43 } 44 45 pte_t * 46 huge_pte_offset (struct mm_struct *mm, unsigned long addr) 47 { 48 unsigned long taddr = htlbpage_to_page(addr); 49 pgd_t *pgd; 50 pud_t *pud; 51 pmd_t *pmd; 52 pte_t *pte = NULL; 53 54 pgd = pgd_offset(mm, taddr); 55 if (pgd_present(*pgd)) { 56 pud = pud_offset(pgd, taddr); 57 if (pud_present(*pud)) { 58 pmd = pmd_offset(pud, taddr); 59 if (pmd_present(*pmd)) 60 pte = pte_offset_map(pmd, taddr); 61 } 62 } 63 64 return pte; 65 } 66 67 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 68 { 69 return 0; 70 } 71 72 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; } 73 74 /* 75 * Don't actually need to do any preparation, but need to make sure 76 * the address is in the right region. 77 */ 78 int prepare_hugepage_range(struct file *file, 79 unsigned long addr, unsigned long len) 80 { 81 if (len & ~HPAGE_MASK) 82 return -EINVAL; 83 if (addr & ~HPAGE_MASK) 84 return -EINVAL; 85 if (REGION_NUMBER(addr) != RGN_HPAGE) 86 return -EINVAL; 87 88 return 0; 89 } 90 91 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write) 92 { 93 struct page *page; 94 pte_t *ptep; 95 96 if (REGION_NUMBER(addr) != RGN_HPAGE) 97 return ERR_PTR(-EINVAL); 98 99 ptep = huge_pte_offset(mm, addr); 100 if (!ptep || pte_none(*ptep)) 101 return NULL; 102 page = pte_page(*ptep); 103 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); 104 return page; 105 } 106 int pmd_huge(pmd_t pmd) 107 { 108 return 0; 109 } 110 111 int pud_huge(pud_t pud) 112 { 113 return 0; 114 } 115 116 struct page * 117 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) 118 { 119 return NULL; 120 } 121 122 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 123 unsigned long addr, unsigned long end, 124 unsigned long floor, unsigned long ceiling) 125 { 126 /* 127 * This is called to free hugetlb page tables. 128 * 129 * The offset of these addresses from the base of the hugetlb 130 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that 131 * the standard free_pgd_range will free the right page tables. 132 * 133 * If floor and ceiling are also in the hugetlb region, they 134 * must likewise be scaled down; but if outside, left unchanged. 135 */ 136 137 addr = htlbpage_to_page(addr); 138 end = htlbpage_to_page(end); 139 if (REGION_NUMBER(floor) == RGN_HPAGE) 140 floor = htlbpage_to_page(floor); 141 if (REGION_NUMBER(ceiling) == RGN_HPAGE) 142 ceiling = htlbpage_to_page(ceiling); 143 144 free_pgd_range(tlb, addr, end, floor, ceiling); 145 } 146 147 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, 148 unsigned long pgoff, unsigned long flags) 149 { 150 struct vm_area_struct *vmm; 151 152 if (len > RGN_MAP_LIMIT) 153 return -ENOMEM; 154 if (len & ~HPAGE_MASK) 155 return -EINVAL; 156 157 /* Handle MAP_FIXED */ 158 if (flags & MAP_FIXED) { 159 if (prepare_hugepage_range(file, addr, len)) 160 return -EINVAL; 161 return addr; 162 } 163 164 /* This code assumes that RGN_HPAGE != 0. */ 165 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1))) 166 addr = HPAGE_REGION_BASE; 167 else 168 addr = ALIGN(addr, HPAGE_SIZE); 169 for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) { 170 /* At this point: (!vmm || addr < vmm->vm_end). */ 171 if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT) 172 return -ENOMEM; 173 if (!vmm || (addr + len) <= vmm->vm_start) 174 return addr; 175 addr = ALIGN(vmm->vm_end, HPAGE_SIZE); 176 } 177 } 178 179 static int __init hugetlb_setup_sz(char *str) 180 { 181 u64 tr_pages; 182 unsigned long long size; 183 184 if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0) 185 /* 186 * shouldn't happen, but just in case. 187 */ 188 tr_pages = 0x15557000UL; 189 190 size = memparse(str, &str); 191 if (*str || !is_power_of_2(size) || !(tr_pages & size) || 192 size <= PAGE_SIZE || 193 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) { 194 printk(KERN_WARNING "Invalid huge page size specified\n"); 195 return 1; 196 } 197 198 hpage_shift = __ffs(size); 199 /* 200 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT 201 * override here with new page shift. 202 */ 203 ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2); 204 return 0; 205 } 206 early_param("hugepagesz", hugetlb_setup_sz); 207