diff options
Diffstat (limited to 'mm/sparse-vmemmap.c')
| -rw-r--r-- | mm/sparse-vmemmap.c | 47 |
1 files changed, 31 insertions, 16 deletions
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index e881f5db7091..c64d1aa3c4b5 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -53,8 +53,7 @@ struct vmemmap_remap_walk { struct list_head *vmemmap_pages; }; -static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start, - struct vmemmap_remap_walk *walk) +static int __split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start) { pmd_t __pmd; int i; @@ -76,15 +75,34 @@ static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start, set_pte_at(&init_mm, addr, pte, entry); } - /* Make pte visible before pmd. See comment in pmd_install(). */ - smp_wmb(); - pmd_populate_kernel(&init_mm, pmd, pgtable); - - flush_tlb_kernel_range(start, start + PMD_SIZE); + spin_lock(&init_mm.page_table_lock); + if (likely(pmd_leaf(*pmd))) { + /* Make pte visible before pmd. See comment in pmd_install(). */ + smp_wmb(); + pmd_populate_kernel(&init_mm, pmd, pgtable); + flush_tlb_kernel_range(start, start + PMD_SIZE); + } else { + pte_free_kernel(&init_mm, pgtable); + } + spin_unlock(&init_mm.page_table_lock); return 0; } +static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start) +{ + int leaf; + + spin_lock(&init_mm.page_table_lock); + leaf = pmd_leaf(*pmd); + spin_unlock(&init_mm.page_table_lock); + + if (!leaf) + return 0; + + return __split_vmemmap_huge_pmd(pmd, start); +} + static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct vmemmap_remap_walk *walk) @@ -121,13 +139,12 @@ static int vmemmap_pmd_range(pud_t *pud, unsigned long addr, pmd = pmd_offset(pud, addr); do { - if (pmd_leaf(*pmd)) { - int ret; + int ret; + + ret = split_vmemmap_huge_pmd(pmd, addr & PMD_MASK); + if (ret) + return ret; - ret = split_vmemmap_huge_pmd(pmd, addr & PMD_MASK, walk); - if (ret) - return ret; - } next = pmd_addr_end(addr, end); vmemmap_pte_range(pmd, addr, next, walk); } while (pmd++, addr = next, addr != end); @@ -321,10 +338,8 @@ int vmemmap_remap_free(unsigned long start, unsigned long end, */ BUG_ON(start - reuse != PAGE_SIZE); - mmap_write_lock(&init_mm); + mmap_read_lock(&init_mm); ret = vmemmap_remap_range(reuse, end, &walk); - mmap_write_downgrade(&init_mm); - if (ret && walk.nr_walked) { end = reuse + walk.nr_walked * PAGE_SIZE; /* |