hugetlb: remove dummy definitions of HPAGE_MASK and HPAGE_SIZE

Dummy, non-zero definitions for HPAGE_MASK and HPAGE_SIZE were added in
51c6f666fceb ("mm: ZAP_BLOCK causes redundant work") to avoid a divide
by zero in generic kernel code.

That code has since been removed, but probably should never have been
added in the first place: we don't want HPAGE_SIZE to act like PAGE_SIZE
for code that is working with hugepages, for example, when the
dependency on CONFIG_HUGETLB_PAGE has not been fulfilled.

Because hugepage size can differ from architecture to architecture, each
is required to have their own definitions for both HPAGE_MASK and
HPAGE_SIZE.  This is always done in arch/*/include/asm/page.h.

So, just remove the dummy and dangerous definitions since they are no
longer needed and reveals the correct dependencies.  Tested on
architectures using the definitions with allyesconfig: x86 (even with
thp), hppa, mips, powerpc, s390, sh3, sh4, sparc, and sparc64, and with
defconfig on ia64.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 19644e0..d9d6c86 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -110,11 +110,6 @@ static inline void copy_huge_page(struct page *dst, struct page *src)
 
 #define hugetlb_change_protection(vma, address, end, newprot)
 
-#ifndef HPAGE_MASK
-#define HPAGE_MASK     PAGE_MASK               /* Keep the compiler happy */
-#define HPAGE_SIZE     PAGE_SIZE
-#endif
-
 #endif /* !CONFIG_HUGETLB_PAGE */
 
 #define HUGETLB_ANON_FILE "anon_hugepage"