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