mm, x86: add support for PUD-sized transparent hugepages

[karo-tx-linux.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 035a688e5472b01e925e3d8c7a1e440fb4294b5b..d8b75d7d6a9e41f0befe6152856580ad4605339a 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -424,6 +424,10 @@ static inline int pmd_devmap(pmd_t pmd)
 {
        return 0;
 }
+static inline int pud_devmap(pud_t pud)
+{
+       return 0;
+}
 #endif
 
 /*
@@ -1199,6 +1203,10 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
 
 /**
  * mm_walk - callbacks for walk_page_range
+ * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
+ *            this handler should only handle pud_trans_huge() puds.
+ *            the pmd_entry or pte_entry callbacks will be used for
+ *            regular PUDs.
  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
  *            this handler is required to be able to handle
  *            pmd_trans_huge() pmds.  They may simply choose to
@@ -1218,6 +1226,8 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
  * (see the comment on walk_page_range() for more details)
  */
 struct mm_walk {
+       int (*pud_entry)(pud_t *pud, unsigned long addr,
+                        unsigned long next, struct mm_walk *walk);
        int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
                         unsigned long next, struct mm_walk *walk);
        int (*pte_entry)(pte_t *pte, unsigned long addr,
@@ -1801,8 +1811,26 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
        return ptl;
 }
 
-extern void __init pagecache_init(void);
+/*
+ * No scalability reason to split PUD locks yet, but follow the same pattern
+ * as the PMD locks to make it easier if we decide to.  The VM should not be
+ * considered ready to switch to split PUD locks yet; there may be places
+ * which need to be converted from page_table_lock.
+ */
+static inline spinlock_t *pud_lockptr(struct mm_struct *mm, pud_t *pud)
+{
+       return &mm->page_table_lock;
+}
+
+static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
+{
+       spinlock_t *ptl = pud_lockptr(mm, pud);
+
+       spin_lock(ptl);
+       return ptl;
+}
 
+extern void __init pagecache_init(void);
 extern void free_area_init(unsigned long * zones_size);
 extern void free_area_init_node(int nid, unsigned long * zones_size,
                unsigned long zone_start_pfn, unsigned long *zholes_size);