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-rw-r--r--arch/x86/mm/hugetlbpage.c21
-rw-r--r--arch/x86/mm/init.c69
2 files changed, 55 insertions, 35 deletions
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index f581a18..df7d12c 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -56,9 +56,16 @@ static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
}
/*
- * search for a shareable pmd page for hugetlb.
+ * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
+ * and returns the corresponding pte. While this is not necessary for the
+ * !shared pmd case because we can allocate the pmd later as well, it makes the
+ * code much cleaner. pmd allocation is essential for the shared case because
+ * pud has to be populated inside the same i_mmap_mutex section - otherwise
+ * racing tasks could either miss the sharing (see huge_pte_offset) or select a
+ * bad pmd for sharing.
*/
-static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+static pte_t *
+huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
struct vm_area_struct *vma = find_vma(mm, addr);
struct address_space *mapping = vma->vm_file->f_mapping;
@@ -68,9 +75,10 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
struct vm_area_struct *svma;
unsigned long saddr;
pte_t *spte = NULL;
+ pte_t *pte;
if (!vma_shareable(vma, addr))
- return;
+ return (pte_t *)pmd_alloc(mm, pud, addr);
mutex_lock(&mapping->i_mmap_mutex);
vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
@@ -97,7 +105,9 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
put_page(virt_to_page(spte));
spin_unlock(&mm->page_table_lock);
out:
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
mutex_unlock(&mapping->i_mmap_mutex);
+ return pte;
}
/*
@@ -142,8 +152,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
} else {
BUG_ON(sz != PMD_SIZE);
if (pud_none(*pud))
- huge_pmd_share(mm, addr, pud);
- pte = (pte_t *) pmd_alloc(mm, pud, addr);
+ pte = huge_pmd_share(mm, addr, pud);
+ else
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
}
}
BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 87488b9..c22c423 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -28,36 +28,50 @@ int direct_gbpages
#endif
;
-static void __init find_early_table_space(unsigned long end, int use_pse,
- int use_gbpages)
+struct map_range {
+ unsigned long start;
+ unsigned long end;
+ unsigned page_size_mask;
+};
+
+/*
+ * First calculate space needed for kernel direct mapping page tables to cover
+ * mr[0].start to mr[nr_range - 1].end, while accounting for possible 2M and 1GB
+ * pages. Then find enough contiguous space for those page tables.
+ */
+static void __init find_early_table_space(struct map_range *mr, int nr_range)
{
- unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
+ int i;
+ unsigned long puds = 0, pmds = 0, ptes = 0, tables;
+ unsigned long start = 0, good_end;
phys_addr_t base;
- puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
- tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
+ for (i = 0; i < nr_range; i++) {
+ unsigned long range, extra;
- if (use_gbpages) {
- unsigned long extra;
+ range = mr[i].end - mr[i].start;
+ puds += (range + PUD_SIZE - 1) >> PUD_SHIFT;
- extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
- pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
- } else
- pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
-
- tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
+ if (mr[i].page_size_mask & (1 << PG_LEVEL_1G)) {
+ extra = range - ((range >> PUD_SHIFT) << PUD_SHIFT);
+ pmds += (extra + PMD_SIZE - 1) >> PMD_SHIFT;
+ } else {
+ pmds += (range + PMD_SIZE - 1) >> PMD_SHIFT;
+ }
- if (use_pse) {
- unsigned long extra;
-
- extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
+ if (mr[i].page_size_mask & (1 << PG_LEVEL_2M)) {
+ extra = range - ((range >> PMD_SHIFT) << PMD_SHIFT);
#ifdef CONFIG_X86_32
- extra += PMD_SIZE;
+ extra += PMD_SIZE;
#endif
- ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
- } else
- ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ ptes += (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ } else {
+ ptes += (range + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ }
+ }
+ tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
+ tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
#ifdef CONFIG_X86_32
@@ -74,8 +88,9 @@ static void __init find_early_table_space(unsigned long end, int use_pse,
pgt_buf_end = pgt_buf_start;
pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
- printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
- end, pgt_buf_start << PAGE_SHIFT, pgt_buf_top << PAGE_SHIFT);
+ printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx]\n",
+ mr[nr_range - 1].end - 1, pgt_buf_start << PAGE_SHIFT,
+ (pgt_buf_top << PAGE_SHIFT) - 1);
}
void __init native_pagetable_reserve(u64 start, u64 end)
@@ -83,12 +98,6 @@ void __init native_pagetable_reserve(u64 start, u64 end)
memblock_x86_reserve_range(start, end, "PGTABLE");
}
-struct map_range {
- unsigned long start;
- unsigned long end;
- unsigned page_size_mask;
-};
-
#ifdef CONFIG_X86_32
#define NR_RANGE_MR 3
#else /* CONFIG_X86_64 */
@@ -260,7 +269,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
* nodes are discovered.
*/
if (!after_bootmem)
- find_early_table_space(end, use_pse, use_gbpages);
+ find_early_table_space(mr, nr_range);
for (i = 0; i < nr_range; i++)
ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,