2 * arch/metag/mm/hugetlbpage.c
4 * METAG HugeTLB page support.
8 * Cloned from sparc64 by Paul Mundt.
10 * Copyright (C) 2002, 2003 David S. Miller (davem@redhat.com)
13 #include <linux/init.h>
16 #include <linux/hugetlb.h>
17 #include <linux/pagemap.h>
18 #include <linux/sysctl.h>
21 #include <asm/pgalloc.h>
23 #include <asm/tlbflush.h>
24 #include <asm/cacheflush.h>
27 * If the arch doesn't supply something else, assume that hugepage
28 * size aligned regions are ok without further preparation.
30 int prepare_hugepage_range(struct file
*file
, unsigned long addr
,
33 struct mm_struct
*mm
= current
->mm
;
34 struct hstate
*h
= hstate_file(file
);
35 struct vm_area_struct
*vma
;
37 if (len
& ~huge_page_mask(h
))
39 if (addr
& ~huge_page_mask(h
))
41 if (TASK_SIZE
- len
< addr
)
44 vma
= find_vma(mm
, ALIGN_HUGEPT(addr
));
45 if (vma
&& !(vma
->vm_flags
& MAP_HUGETLB
))
48 vma
= find_vma(mm
, addr
);
50 if (addr
+ len
> vma
->vm_start
)
52 if (!(vma
->vm_flags
& MAP_HUGETLB
) &&
53 (ALIGN_HUGEPT(addr
+ len
) > vma
->vm_start
))
59 pte_t
*huge_pte_alloc(struct mm_struct
*mm
,
60 unsigned long addr
, unsigned long sz
)
67 pgd
= pgd_offset(mm
, addr
);
68 pud
= pud_offset(pgd
, addr
);
69 pmd
= pmd_offset(pud
, addr
);
70 pte
= pte_alloc_map(mm
, pmd
, addr
);
71 pgd
->pgd
&= ~_PAGE_SZ_MASK
;
72 pgd
->pgd
|= _PAGE_SZHUGE
;
77 pte_t
*huge_pte_offset(struct mm_struct
*mm
,
78 unsigned long addr
, unsigned long sz
)
85 pgd
= pgd_offset(mm
, addr
);
86 pud
= pud_offset(pgd
, addr
);
87 pmd
= pmd_offset(pud
, addr
);
88 pte
= pte_offset_kernel(pmd
, addr
);
93 int pmd_huge(pmd_t pmd
)
95 return pmd_page_shift(pmd
) > PAGE_SHIFT
;
98 int pud_huge(pud_t pud
)
103 struct page
*follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
104 pmd_t
*pmd
, int write
)
109 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
112 * Look for an unmapped area starting after another hugetlb vma.
113 * There are guaranteed to be no huge pte's spare if all the huge pages are
114 * full size (4MB), so in that case compile out this search.
116 #if HPAGE_SHIFT == HUGEPT_SHIFT
117 static inline unsigned long
118 hugetlb_get_unmapped_area_existing(unsigned long len
)
124 hugetlb_get_unmapped_area_existing(unsigned long len
)
126 struct mm_struct
*mm
= current
->mm
;
127 struct vm_area_struct
*vma
;
128 unsigned long start_addr
, addr
;
131 if (mm
->context
.part_huge
) {
132 start_addr
= mm
->context
.part_huge
;
135 start_addr
= TASK_UNMAPPED_BASE
;
141 for (vma
= find_vma(mm
, addr
); ; vma
= vma
->vm_next
) {
142 if ((!vma
&& !after_huge
) || TASK_SIZE
- len
< addr
) {
144 * Start a new search - just in case we missed
147 if (start_addr
!= TASK_UNMAPPED_BASE
) {
148 start_addr
= TASK_UNMAPPED_BASE
;
153 /* skip ahead if we've aligned right over some vmas */
154 if (vma
&& vma
->vm_end
<= addr
)
156 /* space before the next vma? */
157 if (after_huge
&& (!vma
|| ALIGN_HUGEPT(addr
+ len
)
159 unsigned long end
= addr
+ len
;
160 if (end
& HUGEPT_MASK
)
161 mm
->context
.part_huge
= end
;
162 else if (addr
== mm
->context
.part_huge
)
163 mm
->context
.part_huge
= 0;
166 if (vma
->vm_flags
& MAP_HUGETLB
) {
167 /* space after a huge vma in 2nd level page table? */
168 if (vma
->vm_end
& HUGEPT_MASK
) {
170 /* no need to align to the next PT block */
176 addr
= ALIGN_HUGEPT(vma
->vm_end
);
181 /* Do a full search to find an area without any nearby normal pages. */
183 hugetlb_get_unmapped_area_new_pmd(unsigned long len
)
185 struct vm_unmapped_area_info info
;
189 info
.low_limit
= TASK_UNMAPPED_BASE
;
190 info
.high_limit
= TASK_SIZE
;
191 info
.align_mask
= PAGE_MASK
& HUGEPT_MASK
;
192 info
.align_offset
= 0;
193 return vm_unmapped_area(&info
);
197 hugetlb_get_unmapped_area(struct file
*file
, unsigned long addr
,
198 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
200 struct hstate
*h
= hstate_file(file
);
202 if (len
& ~huge_page_mask(h
))
207 if (flags
& MAP_FIXED
) {
208 if (prepare_hugepage_range(file
, addr
, len
))
214 addr
= ALIGN(addr
, huge_page_size(h
));
215 if (!prepare_hugepage_range(file
, addr
, len
))
220 * Look for an existing hugetlb vma with space after it (this is to to
221 * minimise fragmentation caused by huge pages.
223 addr
= hugetlb_get_unmapped_area_existing(len
);
228 * Find an unmapped naturally aligned set of 4MB blocks that we can use
231 return hugetlb_get_unmapped_area_new_pmd(len
);
234 #endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
236 /* necessary for boot time 4MB huge page allocation */
237 static __init
int setup_hugepagesz(char *opt
)
239 unsigned long ps
= memparse(opt
, &opt
);
240 if (ps
== (1 << HPAGE_SHIFT
)) {
241 hugetlb_add_hstate(HPAGE_SHIFT
- PAGE_SHIFT
);
244 pr_err("hugepagesz: Unsupported page size %lu M\n",
250 __setup("hugepagesz=", setup_hugepagesz
);