hugetlb: modular state for hugetlb page size

The goal of this patchset is to support multiple hugetlb page sizes.  This
is achieved by introducing a new struct hstate structure, which
encapsulates the important hugetlb state and constants (eg.  huge page
size, number of huge pages currently allocated, etc).

The hstate structure is then passed around the code which requires these
fields, they will do the right thing regardless of the exact hstate they
are operating on.

This patch adds the hstate structure, with a single global instance of it
(default_hstate), and does the basic work of converting hugetlb to use the
hstate.

Future patches will add more hstate structures to allow for different
hugetlbfs mounts to have different page sizes.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 57d3b6097deb..5e0cc99e9cd5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1812,7 +1812,8 @@ int split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
         struct mempolicy *pol;
         struct vm_area_struct *new;
 
-        if (is_vm_hugetlb_page(vma) && (addr & ~HPAGE_MASK))
+        if (is_vm_hugetlb_page(vma) && (addr &
+                                        ~(huge_page_mask(hstate_vma(vma)))))
                 return -EINVAL;
 
         if (mm->map_count >= sysctl_max_map_count)