2 * IA-64 Huge TLB Page Support for Kernel.
4 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
5 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
7 * Sep, 2003: add numa support
8 * Feb, 2004: dynamic hugetlb page size via boot parameter
11 #include <linux/init.h>
14 #include <linux/hugetlb.h>
15 #include <linux/pagemap.h>
16 #include <linux/slab.h>
17 #include <linux/sysctl.h>
19 #include <asm/pgalloc.h>
21 #include <asm/tlbflush.h>
23 unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT;
26 huge_pte_alloc (struct mm_struct *mm, unsigned long addr)
28 unsigned long taddr = htlbpage_to_page(addr);
34 pgd = pgd_offset(mm, taddr);
35 pud = pud_alloc(mm, pgd, taddr);
37 pmd = pmd_alloc(mm, pud, taddr);
39 pte = pte_alloc_map(mm, pmd, taddr);
45 huge_pte_offset (struct mm_struct *mm, unsigned long addr)
47 unsigned long taddr = htlbpage_to_page(addr);
53 pgd = pgd_offset(mm, taddr);
54 if (pgd_present(*pgd)) {
55 pud = pud_offset(pgd, taddr);
56 if (pud_present(*pud)) {
57 pmd = pmd_offset(pud, taddr);
58 if (pmd_present(*pmd))
59 pte = pte_offset_map(pmd, taddr);
66 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
71 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
74 * Don't actually need to do any preparation, but need to make sure
75 * the address is in the right region.
77 int prepare_hugepage_range(unsigned long addr, unsigned long len, pgoff_t pgoff)
79 if (pgoff & (~HPAGE_MASK >> PAGE_SHIFT))
81 if (len & ~HPAGE_MASK)
83 if (addr & ~HPAGE_MASK)
85 if (REGION_NUMBER(addr) != RGN_HPAGE)
91 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
96 if (REGION_NUMBER(addr) != RGN_HPAGE)
97 return ERR_PTR(-EINVAL);
99 ptep = huge_pte_offset(mm, addr);
100 if (!ptep || pte_none(*ptep))
102 page = pte_page(*ptep);
103 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
106 int pmd_huge(pmd_t pmd)
111 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
116 void hugetlb_free_pgd_range(struct mmu_gather **tlb,
117 unsigned long addr, unsigned long end,
118 unsigned long floor, unsigned long ceiling)
121 * This is called to free hugetlb page tables.
123 * The offset of these addresses from the base of the hugetlb
124 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
125 * the standard free_pgd_range will free the right page tables.
127 * If floor and ceiling are also in the hugetlb region, they
128 * must likewise be scaled down; but if outside, left unchanged.
131 addr = htlbpage_to_page(addr);
132 end = htlbpage_to_page(end);
133 if (REGION_NUMBER(floor) == RGN_HPAGE)
134 floor = htlbpage_to_page(floor);
135 if (REGION_NUMBER(ceiling) == RGN_HPAGE)
136 ceiling = htlbpage_to_page(ceiling);
138 free_pgd_range(tlb, addr, end, floor, ceiling);
141 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
142 unsigned long pgoff, unsigned long flags)
144 struct vm_area_struct *vmm;
146 if (len > RGN_MAP_LIMIT)
148 if (len & ~HPAGE_MASK)
151 /* Handle MAP_FIXED */
152 if (flags & MAP_FIXED) {
153 if (prepare_hugepage_range(addr, len, pgoff))
158 /* This code assumes that RGN_HPAGE != 0. */
159 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
160 addr = HPAGE_REGION_BASE;
162 addr = ALIGN(addr, HPAGE_SIZE);
163 for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
164 /* At this point: (!vmm || addr < vmm->vm_end). */
165 if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
167 if (!vmm || (addr + len) <= vmm->vm_start)
169 addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
173 static int __init hugetlb_setup_sz(char *str)
176 unsigned long long size;
178 if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
180 * shouldn't happen, but just in case.
182 tr_pages = 0x15557000UL;
184 size = memparse(str, &str);
185 if (*str || (size & (size-1)) || !(tr_pages & size) ||
187 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
188 printk(KERN_WARNING "Invalid huge page size specified\n");
192 hpage_shift = __ffs(size);
194 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
195 * override here with new page shift.
197 ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
200 __setup("hugepagesz=", hugetlb_setup_sz);