mm: Some arch may want to use HPAGE_PMD related values as variables

With next generation power processor, we are having a new mmu model
[1] that require us to maintain a different linux page table format.

Inorder to support both current and future ppc64 systems with a single
kernel we need to make sure kernel can select between different page
table format at runtime. With the new MMU (radix MMU) added, we will
have two different pmd hugepage size 16MB for hash model and 2MB for
Radix model. Hence make HPAGE_PMD related values as a variable.

Actual conversion of HPAGE_PMD to a variable for ppc64 happens in a
followup patch.

[1] http://ibm.biz/power-isa3 (Needs registration).

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Kirill A. Shutemov
2016-03-01 09:45:14 +05:30
committed by Michael Ellerman
parent 368ced78e6
commit ff20c2e0ac
4 changed files with 30 additions and 6 deletions

View File

@@ -20,6 +20,7 @@ struct pt_regs;
#define BUILD_BUG_ON_MSG(cond, msg) (0)
#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
#define MAYBE_BUILD_BUG_ON(cond) (0)
#else /* __CHECKER__ */
/* Force a compilation error if a constant expression is not a power of 2 */
@@ -83,6 +84,14 @@ struct pt_regs;
*/
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
#define MAYBE_BUILD_BUG_ON(cond) \
do { \
if (__builtin_constant_p((cond))) \
BUILD_BUG_ON(cond); \
else \
BUG_ON(cond); \
} while (0)
#endif /* __CHECKER__ */
#ifdef CONFIG_GENERIC_BUG