Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/hugetlb.h>
3#include <linux/pgalloc.h>
4
5#include <asm-generic/tlb.h>
6
7#include "internal.h"
8
9bool reclaim_pt_is_enabled(unsigned long start, unsigned long end,
10 struct zap_details *details)
11{
12 return details && details->reclaim_pt && (end - start >= PMD_SIZE);
13}
14
15bool try_get_and_clear_pmd(struct mm_struct *mm, pmd_t *pmd, pmd_t *pmdval)
16{
17 spinlock_t *pml = pmd_lockptr(mm, pmd);
18
19 if (!spin_trylock(pml))
20 return false;
21
22 *pmdval = pmdp_get_lockless(pmd);
23 pmd_clear(pmd);
24 spin_unlock(pml);
25
26 return true;
27}
28
29void free_pte(struct mm_struct *mm, unsigned long addr, struct mmu_gather *tlb,
30 pmd_t pmdval)
31{
32 pte_free_tlb(tlb, pmd_pgtable(pmdval), addr);
33 mm_dec_nr_ptes(mm);
34}
35
36void try_to_free_pte(struct mm_struct *mm, pmd_t *pmd, unsigned long addr,
37 struct mmu_gather *tlb)
38{
39 pmd_t pmdval;
40 spinlock_t *pml, *ptl = NULL;
41 pte_t *start_pte, *pte;
42 int i;
43
44 pml = pmd_lock(mm, pmd);
45 start_pte = pte_offset_map_rw_nolock(mm, pmd, addr, &pmdval, &ptl);
46 if (!start_pte)
47 goto out_ptl;
48 if (ptl != pml)
49 spin_lock_nested(ptl, SINGLE_DEPTH_NESTING);
50
51 /* Check if it is empty PTE page */
52 for (i = 0, pte = start_pte; i < PTRS_PER_PTE; i++, pte++) {
53 if (!pte_none(ptep_get(pte)))
54 goto out_ptl;
55 }
56 pte_unmap(start_pte);
57
58 pmd_clear(pmd);
59
60 if (ptl != pml)
61 spin_unlock(ptl);
62 spin_unlock(pml);
63
64 free_pte(mm, addr, tlb, pmdval);
65
66 return;
67out_ptl:
68 if (start_pte)
69 pte_unmap_unlock(start_pte, ptl);
70 if (ptl != pml)
71 spin_unlock(pml);
72}