1 // SPDX-License-Identifier: GPL-2.0
3 * IA-64 Huge TLB Page Support for Kernel.
5 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
6 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
8 * Sep, 2003: add numa support
9 * Feb, 2004: dynamic hugetlb page size via boot parameter
12 #include <linux/init.h>
15 #include <linux/hugetlb.h>
16 #include <linux/pagemap.h>
17 #include <linux/module.h>
18 #include <linux/sysctl.h>
19 #include <linux/log2.h>
22 #include <asm/tlbflush.h>
24 unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
25 EXPORT_SYMBOL(hpage_shift);
28 huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
30 unsigned long taddr = htlbpage_to_page(addr);
37 pgd = pgd_offset(mm, taddr);
38 p4d = p4d_offset(pgd, taddr);
39 pud = pud_alloc(mm, p4d, taddr);
41 pmd = pmd_alloc(mm, pud, taddr);
43 pte = pte_alloc_map(mm, pmd, taddr);
49 huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz)
51 unsigned long taddr = htlbpage_to_page(addr);
58 pgd = pgd_offset(mm, taddr);
59 if (pgd_present(*pgd)) {
60 p4d = p4d_offset(pgd, taddr);
61 if (p4d_present(*p4d)) {
62 pud = pud_offset(p4d, taddr);
63 if (pud_present(*pud)) {
64 pmd = pmd_offset(pud, taddr);
65 if (pmd_present(*pmd))
66 pte = pte_offset_map(pmd, taddr);
74 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
77 * Don't actually need to do any preparation, but need to make sure
78 * the address is in the right region.
80 int prepare_hugepage_range(struct file *file,
81 unsigned long addr, unsigned long len)
83 if (len & ~HPAGE_MASK)
85 if (addr & ~HPAGE_MASK)
87 if (REGION_NUMBER(addr) != RGN_HPAGE)
93 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
98 if (REGION_NUMBER(addr) != RGN_HPAGE)
99 return ERR_PTR(-EINVAL);
101 ptep = huge_pte_offset(mm, addr, HPAGE_SIZE);
102 if (!ptep || pte_none(*ptep))
104 page = pte_page(*ptep);
105 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
108 int pmd_huge(pmd_t pmd)
113 int pud_huge(pud_t pud)
118 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
119 unsigned long addr, unsigned long end,
120 unsigned long floor, unsigned long ceiling)
123 * This is called to free hugetlb page tables.
125 * The offset of these addresses from the base of the hugetlb
126 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
127 * the standard free_pgd_range will free the right page tables.
129 * If floor and ceiling are also in the hugetlb region, they
130 * must likewise be scaled down; but if outside, left unchanged.
133 addr = htlbpage_to_page(addr);
134 end = htlbpage_to_page(end);
135 if (REGION_NUMBER(floor) == RGN_HPAGE)
136 floor = htlbpage_to_page(floor);
137 if (REGION_NUMBER(ceiling) == RGN_HPAGE)
138 ceiling = htlbpage_to_page(ceiling);
140 free_pgd_range(tlb, addr, end, floor, ceiling);
143 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
144 unsigned long pgoff, unsigned long flags)
146 struct vm_unmapped_area_info info;
148 if (len > RGN_MAP_LIMIT)
150 if (len & ~HPAGE_MASK)
153 /* Handle MAP_FIXED */
154 if (flags & MAP_FIXED) {
155 if (prepare_hugepage_range(file, addr, len))
160 /* This code assumes that RGN_HPAGE != 0. */
161 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
162 addr = HPAGE_REGION_BASE;
166 info.low_limit = addr;
167 info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT;
168 info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1);
169 info.align_offset = 0;
170 return vm_unmapped_area(&info);
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 || !is_power_of_2(size) || !(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 early_param("hugepagesz", hugetlb_setup_sz);