powerpc/mm: Enable _PAGE_NUMA for book3s

We steal the _PAGE_COHERENCE bit and use that for indicating NUMA ptes.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 72 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7d6eacf249cf..b999ca318985 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -3,6 +3,7 @@
 #ifdef __KERNEL__
 
 #ifndef __ASSEMBLY__
+#include <linux/mmdebug.h>
 #include <asm/processor.h>              /* For TASK_SIZE */
 #include <asm/mmu.h>
 #include <asm/page.h>
@@ -33,10 +34,73 @@ static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
 static inline int pte_young(pte_t pte)          { return pte_val(pte) & _PAGE_ACCESSED; }
 static inline int pte_file(pte_t pte)           { return pte_val(pte) & _PAGE_FILE; }
 static inline int pte_special(pte_t pte)        { return pte_val(pte) & _PAGE_SPECIAL; }
-static inline int pte_present(pte_t pte)        { return pte_val(pte) & _PAGE_PRESENT; }
 static inline int pte_none(pte_t pte)           { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
 static inline pgprot_t pte_pgprot(pte_t pte)    { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
 
+#ifdef CONFIG_NUMA_BALANCING
+
+static inline int pte_present(pte_t pte)
+{
+        return pte_val(pte) & (_PAGE_PRESENT | _PAGE_NUMA);
+}
+
+#define pte_numa pte_numa
+static inline int pte_numa(pte_t pte)
+{
+        return (pte_val(pte) &
+                (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
+}
+
+#define pte_mknonnuma pte_mknonnuma
+static inline pte_t pte_mknonnuma(pte_t pte)
+{
+        pte_val(pte) &= ~_PAGE_NUMA;
+        pte_val(pte) |=  _PAGE_PRESENT | _PAGE_ACCESSED;
+        return pte;
+}
+
+#define pte_mknuma pte_mknuma
+static inline pte_t pte_mknuma(pte_t pte)
+{
+        /*
+         * We should not set _PAGE_NUMA on non present ptes. Also clear the
+         * present bit so that hash_page will return 1 and we collect this
+         * as numa fault.
+         */
+        if (pte_present(pte)) {
+                pte_val(pte) |= _PAGE_NUMA;
+                pte_val(pte) &= ~_PAGE_PRESENT;
+        } else
+                VM_BUG_ON(1);
+        return pte;
+}
+
+#define pmd_numa pmd_numa
+static inline int pmd_numa(pmd_t pmd)
+{
+        return pte_numa(pmd_pte(pmd));
+}
+
+#define pmd_mknonnuma pmd_mknonnuma
+static inline pmd_t pmd_mknonnuma(pmd_t pmd)
+{
+        return pte_pmd(pte_mknonnuma(pmd_pte(pmd)));
+}
+
+#define pmd_mknuma pmd_mknuma
+static inline pmd_t pmd_mknuma(pmd_t pmd)
+{
+        return pte_pmd(pte_mknuma(pmd_pte(pmd)));
+}
+
+# else
+
+static inline int pte_present(pte_t pte)
+{
+        return pte_val(pte) & _PAGE_PRESENT;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
 /* Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  *
diff --git a/arch/powerpc/include/asm/pte-hash64.h b/arch/powerpc/include/asm/pte-hash64.h
index 55aea0caf95e..2505d8eab15c 100644
--- a/arch/powerpc/include/asm/pte-hash64.h
+++ b/arch/powerpc/include/asm/pte-hash64.h
@@ -27,6 +27,12 @@
 #define _PAGE_RW                0x0200 /* software: user write access allowed */
 #define _PAGE_BUSY              0x0800 /* software: PTE & hash are busy */
 
+/*
+ * Used for tracking numa faults
+ */
+#define _PAGE_NUMA      0x00000010 /* Gather numa placement stats */
+
+
 /* No separate kernel read-only */
 #define _PAGE_KERNEL_RW         (_PAGE_RW | _PAGE_DIRTY) /* user access blocked by key */
 #define _PAGE_KERNEL_RO          _PAGE_KERNEL_RW
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index bca2465a9c34..434fda39bf8b 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -72,6 +72,7 @@ config PPC_BOOK3S_64
         select PPC_HAVE_PMU_SUPPORT
         select SYS_SUPPORTS_HUGETLBFS
         select HAVE_ARCH_TRANSPARENT_HUGEPAGE if PPC_64K_PAGES
+        select ARCH_SUPPORTS_NUMA_BALANCING
 
 config PPC_BOOK3E_64
         bool "Embedded processors"