2 * IA-32 Huge TLB Page Support for Kernel.
4 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
7 #include <linux/config.h>
8 #include <linux/init.h>
11 #include <linux/hugetlb.h>
12 #include <linux/pagemap.h>
13 #include <linux/smp_lock.h>
14 #include <linux/slab.h>
15 #include <linux/err.h>
16 #include <linux/sysctl.h>
19 #include <asm/tlbflush.h>
21 pte_t
*huge_pte_alloc(struct mm_struct
*mm
, unsigned long addr
)
27 pgd
= pgd_offset(mm
, addr
);
28 pud
= pud_alloc(mm
, pgd
, addr
);
29 pmd
= pmd_alloc(mm
, pud
, addr
);
33 pte_t
*huge_pte_offset(struct mm_struct
*mm
, unsigned long addr
)
39 pgd
= pgd_offset(mm
, addr
);
40 pud
= pud_offset(pgd
, addr
);
41 pmd
= pmd_offset(pud
, addr
);
46 * This function checks for proper alignment of input addr and len parameters.
48 int is_aligned_hugepage_range(unsigned long addr
, unsigned long len
)
50 if (len
& ~HPAGE_MASK
)
52 if (addr
& ~HPAGE_MASK
)
57 #if 0 /* This is just for testing */
59 follow_huge_addr(struct mm_struct
*mm
, unsigned long address
, int write
)
61 unsigned long start
= address
;
65 struct vm_area_struct
*vma
;
67 vma
= find_vma(mm
, addr
);
68 if (!vma
|| !is_vm_hugetlb_page(vma
))
69 return ERR_PTR(-EINVAL
);
71 pte
= huge_pte_offset(mm
, address
);
73 /* hugetlb should be locked, and hence, prefaulted */
74 WARN_ON(!pte
|| pte_none(*pte
));
76 page
= &pte_page(*pte
)[vpfn
% (HPAGE_SIZE
/PAGE_SIZE
)];
78 WARN_ON(!PageCompound(page
));
83 int pmd_huge(pmd_t pmd
)
89 follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
90 pmd_t
*pmd
, int write
)
98 follow_huge_addr(struct mm_struct
*mm
, unsigned long address
, int write
)
100 return ERR_PTR(-EINVAL
);
103 int pmd_huge(pmd_t pmd
)
105 return !!(pmd_val(pmd
) & _PAGE_PSE
);
109 follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
110 pmd_t
*pmd
, int write
)
114 page
= pte_page(*(pte_t
*)pmd
);
116 page
+= ((address
& ~HPAGE_MASK
) >> PAGE_SHIFT
);
121 void hugetlb_clean_stale_pgtable(pte_t
*pte
)
123 pmd_t
*pmd
= (pmd_t
*) pte
;
126 page
= pmd_page(*pmd
);
128 dec_page_state(nr_page_table_pages
);
129 page_cache_release(page
);
132 /* x86_64 also uses this file */
134 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
135 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file
*file
,
136 unsigned long addr
, unsigned long len
,
137 unsigned long pgoff
, unsigned long flags
)
139 struct mm_struct
*mm
= current
->mm
;
140 struct vm_area_struct
*vma
;
141 unsigned long start_addr
;
143 if (len
> mm
->cached_hole_size
) {
144 start_addr
= mm
->free_area_cache
;
146 start_addr
= TASK_UNMAPPED_BASE
;
147 mm
->cached_hole_size
= 0;
151 addr
= ALIGN(start_addr
, HPAGE_SIZE
);
153 for (vma
= find_vma(mm
, addr
); ; vma
= vma
->vm_next
) {
154 /* At this point: (!vma || addr < vma->vm_end). */
155 if (TASK_SIZE
- len
< addr
) {
157 * Start a new search - just in case we missed
160 if (start_addr
!= TASK_UNMAPPED_BASE
) {
161 start_addr
= TASK_UNMAPPED_BASE
;
162 mm
->cached_hole_size
= 0;
167 if (!vma
|| addr
+ len
<= vma
->vm_start
) {
168 mm
->free_area_cache
= addr
+ len
;
171 if (addr
+ mm
->cached_hole_size
< vma
->vm_start
)
172 mm
->cached_hole_size
= vma
->vm_start
- addr
;
173 addr
= ALIGN(vma
->vm_end
, HPAGE_SIZE
);
177 static unsigned long hugetlb_get_unmapped_area_topdown(struct file
*file
,
178 unsigned long addr0
, unsigned long len
,
179 unsigned long pgoff
, unsigned long flags
)
181 struct mm_struct
*mm
= current
->mm
;
182 struct vm_area_struct
*vma
, *prev_vma
;
183 unsigned long base
= mm
->mmap_base
, addr
= addr0
;
184 unsigned long largest_hole
= mm
->cached_hole_size
;
187 /* don't allow allocations above current base */
188 if (mm
->free_area_cache
> base
)
189 mm
->free_area_cache
= base
;
191 if (len
<= largest_hole
) {
193 mm
->free_area_cache
= base
;
196 /* make sure it can fit in the remaining address space */
197 if (mm
->free_area_cache
< len
)
200 /* either no address requested or cant fit in requested address hole */
201 addr
= (mm
->free_area_cache
- len
) & HPAGE_MASK
;
204 * Lookup failure means no vma is above this address,
205 * i.e. return with success:
207 if (!(vma
= find_vma_prev(mm
, addr
, &prev_vma
)))
211 * new region fits between prev_vma->vm_end and
212 * vma->vm_start, use it:
214 if (addr
+ len
<= vma
->vm_start
&&
215 (!prev_vma
|| (addr
>= prev_vma
->vm_end
))) {
216 /* remember the address as a hint for next time */
217 mm
->cached_hole_size
= largest_hole
;
218 return (mm
->free_area_cache
= addr
);
220 /* pull free_area_cache down to the first hole */
221 if (mm
->free_area_cache
== vma
->vm_end
) {
222 mm
->free_area_cache
= vma
->vm_start
;
223 mm
->cached_hole_size
= largest_hole
;
227 /* remember the largest hole we saw so far */
228 if (addr
+ largest_hole
< vma
->vm_start
)
229 largest_hole
= vma
->vm_start
- addr
;
231 /* try just below the current vma->vm_start */
232 addr
= (vma
->vm_start
- len
) & HPAGE_MASK
;
233 } while (len
<= vma
->vm_start
);
237 * if hint left us with no space for the requested
238 * mapping then try again:
241 mm
->free_area_cache
= base
;
247 * A failed mmap() very likely causes application failure,
248 * so fall back to the bottom-up function here. This scenario
249 * can happen with large stack limits and large mmap()
252 mm
->free_area_cache
= TASK_UNMAPPED_BASE
;
253 mm
->cached_hole_size
= ~0UL;
254 addr
= hugetlb_get_unmapped_area_bottomup(file
, addr0
,
258 * Restore the topdown base:
260 mm
->free_area_cache
= base
;
261 mm
->cached_hole_size
= ~0UL;
267 hugetlb_get_unmapped_area(struct file
*file
, unsigned long addr
,
268 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
270 struct mm_struct
*mm
= current
->mm
;
271 struct vm_area_struct
*vma
;
273 if (len
& ~HPAGE_MASK
)
279 addr
= ALIGN(addr
, HPAGE_SIZE
);
280 vma
= find_vma(mm
, addr
);
281 if (TASK_SIZE
- len
>= addr
&&
282 (!vma
|| addr
+ len
<= vma
->vm_start
))
285 if (mm
->get_unmapped_area
== arch_get_unmapped_area
)
286 return hugetlb_get_unmapped_area_bottomup(file
, addr
, len
,
289 return hugetlb_get_unmapped_area_topdown(file
, addr
, len
,
293 #endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
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