[PATCH v6 3/7] powerpc/mm: Introduce _PAGE_GIGANTIC and _PAGE_LARGE software pte bits

[Aneesh Kumar K.V]

This patch adds two new software defined pte bits. We use the reserved
fields of ISA 3.0 pte definitions here, because we will only be using this
on DD1 code paths. We can possibly look at removing this code later.

These two software bits will be used to differentiate between 64K, 2M and 1G ptes.
We need to know the page size mapping pte so that we can do efficient tlb flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/hugetlb.h | 13 +++++++++++++
 arch/powerpc/include/asm/book3s/64/pgtable.h | 10 ++++++++++
 arch/powerpc/include/asm/book3s/64/radix.h   |  2 +-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index d9c283f95e05..f246dadaf1f9 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -30,4 +30,17 @@ static inline int hstate_get_psize(struct hstate *hstate)
 		return mmu_virtual_psize;
 	}
 }
+
+#define arch_make_huge_pte arch_make_huge_pte
+static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
+				       struct page *page, int writable)
+{
+	unsigned long page_shift = huge_page_shift(hstate_vma(vma));
+
+	if (page_shift == mmu_psize_defs[MMU_PAGE_2M].shift ||
+	    page_shift == mmu_psize_defs[MMU_PAGE_16M].shift)
+		return __pte(pte_val(entry) | _PAGE_LARGE);
+	else
+		return __pte(pte_val(entry) | _PAGE_GIGANTIC);
+}
 #endif
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 86870c11917b..e05028894a8e 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -26,6 +26,11 @@
 #define _RPAGE_SW1		0x00800
 #define _RPAGE_SW2		0x00400
 #define _RPAGE_SW3		0x00200
+#define _RPAGE_RSV1		0x1000000000000000UL
+#define _RPAGE_RSV2		0x0800000000000000UL
+#define _RPAGE_RSV3		0x0400000000000000UL
+#define _RPAGE_RSV4		0x0200000000000000UL
+
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY	_RPAGE_SW3 /* software: software dirty tracking */
 #else
@@ -34,6 +39,11 @@
 #define _PAGE_SPECIAL		_RPAGE_SW2 /* software: special page */
 #define _PAGE_DEVMAP		_RPAGE_SW1
 #define __HAVE_ARCH_PTE_DEVMAP
+/*
+ * For DD1 only, we need to track whether the pte huge or gigantic.
+ */
+#define _PAGE_GIGANTIC	_RPAGE_RSV1
+#define _PAGE_LARGE	_RPAGE_RSV2
 
 
 #define _PAGE_PTE		(1ul << 62)	/* distinguishes PTEs from pointers */
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 2a46dea8e1b1..de009387e258 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -243,7 +243,7 @@ static inline int radix__pmd_trans_huge(pmd_t pmd)
 
 static inline pmd_t radix__pmd_mkhuge(pmd_t pmd)
 {
-	return __pmd(pmd_val(pmd) | _PAGE_PTE);
+	return __pmd(pmd_val(pmd) | _PAGE_PTE | _PAGE_LARGE);
 }
 static inline void radix__pmdp_huge_split_prepare(struct vm_area_struct *vma,
 					    unsigned long address, pmd_t *pmdp)
-- 
2.10.2