powerpc/mm: Move THP headers around

We support THP only with book3s_64 and 64K page size. Move
THP details to hash64-64k.h to clarify the same.

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 175 insertions, 174 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 1857d19de18e..7570677c11c3 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -170,6 +170,132 @@ static inline int hugepd_ok(hugepd_t hpd)
 
 #endif /* CONFIG_HUGETLB_PAGE */
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern unsigned long pmd_hugepage_update(struct mm_struct *mm,
+					 unsigned long addr,
+					 pmd_t *pmdp,
+					 unsigned long clr,
+					 unsigned long set);
+static inline char *get_hpte_slot_array(pmd_t *pmdp)
+{
+	/*
+	 * The hpte hindex is stored in the pgtable whose address is in the
+	 * second half of the PMD
+	 *
+	 * Order this load with the test for pmd_trans_huge in the caller
+	 */
+	smp_rmb();
+	return *(char **)(pmdp + PTRS_PER_PMD);
+
+
+}
+/*
+ * The linux hugepage PMD now include the pmd entries followed by the address
+ * to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits.
+ * [ 1 bit secondary | 3 bit hidx | 1 bit valid | 000]. We use one byte per
+ * each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and
+ * with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t.
+ *
+ * The last three bits are intentionally left to zero. This memory location
+ * are also used as normal page PTE pointers. So if we have any pointers
+ * left around while we collapse a hugepage, we need to make sure
+ * _PAGE_PRESENT bit of that is zero when we look at them
+ */
+static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
+{
+	return (hpte_slot_array[index] >> 3) & 0x1;
+}
+
+static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
+					   int index)
+{
+	return hpte_slot_array[index] >> 4;
+}
+
+static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
+					unsigned int index, unsigned int hidx)
+{
+	hpte_slot_array[index] = hidx << 4 | 0x1 << 3;
+}
+
+/*
+ *
+ * For core kernel code by design pmd_trans_huge is never run on any hugetlbfs
+ * page. The hugetlbfs page table walking and mangling paths are totally
+ * separated form the core VM paths and they're differentiated by
+ *  VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run.
+ *
+ * pmd_trans_huge() is defined as false at build time if
+ * CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build
+ * time in such case.
+ *
+ * For ppc64 we need to differntiate from explicit hugepages from THP, because
+ * for THP we also track the subpage details at the pmd level. We don't do
+ * that for explicit huge pages.
+ *
+ */
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	/*
+	 * leaf pte for huge page, bottom two bits != 00
+	 */
+	return (pmd_val(pmd) & 0x3) && (pmd_val(pmd) & _PAGE_THP_HUGE);
+}
+
+static inline int pmd_trans_splitting(pmd_t pmd)
+{
+	if (pmd_trans_huge(pmd))
+		return pmd_val(pmd) & _PAGE_SPLITTING;
+	return 0;
+}
+
+static inline int pmd_large(pmd_t pmd)
+{
+	/*
+	 * leaf pte for huge page, bottom two bits != 00
+	 */
+	return ((pmd_val(pmd) & 0x3) != 0x0);
+}
+
+static inline pmd_t pmd_mknotpresent(pmd_t pmd)
+{
+	return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
+}
+
+static inline pmd_t pmd_mksplitting(pmd_t pmd)
+{
+	return __pmd(pmd_val(pmd) | _PAGE_SPLITTING);
+}
+
+#define __HAVE_ARCH_PMD_SAME
+static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
+{
+	return (((pmd_val(pmd_a) ^ pmd_val(pmd_b)) & ~_PAGE_HPTEFLAGS) == 0);
+}
+
+static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
+					      unsigned long addr, pmd_t *pmdp)
+{
+	unsigned long old;
+
+	if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
+		return 0;
+	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0);
+	return ((old & _PAGE_ACCESSED) != 0);
+}
+
+#define __HAVE_ARCH_PMDP_SET_WRPROTECT
+static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
+				      pmd_t *pmdp)
+{
+
+	if ((pmd_val(*pmdp) & _PAGE_RW) == 0)
+		return;
+
+	pmd_hugepage_update(mm, addr, pmdp, _PAGE_RW, 0);
+}
+
+#endif /*  CONFIG_TRANSPARENT_HUGEPAGE */
 #endif	/* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 9c212449b2e8..42e1273adad1 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -2,6 +2,55 @@
 #define _ASM_POWERPC_BOOK3S_64_HASH_H
 #ifdef __KERNEL__
 
+/*
+ * Common bits between 4K and 64K pages in a linux-style PTE.
+ * These match the bits in the (hardware-defined) PowerPC PTE as closely
+ * as possible. Additional bits may be defined in pgtable-hash64-*.h
+ *
+ * Note: We only support user read/write permissions. Supervisor always
+ * have full read/write to pages above PAGE_OFFSET (pages below that
+ * always use the user access permissions).
+ *
+ * We could create separate kernel read-only if we used the 3 PP bits
+ * combinations that newer processors provide but we currently don't.
+ */
+#define _PAGE_PRESENT		0x00001 /* software: pte contains a translation */
+#define _PAGE_USER		0x00002 /* matches one of the PP bits */
+#define _PAGE_BIT_SWAP_TYPE	2
+#define _PAGE_EXEC		0x00004 /* No execute on POWER4 and newer (we invert) */
+#define _PAGE_GUARDED		0x00008
+/* We can derive Memory coherence from _PAGE_NO_CACHE */
+#define _PAGE_COHERENT		0x0
+#define _PAGE_NO_CACHE		0x00020 /* I: cache inhibit */
+#define _PAGE_WRITETHRU		0x00040 /* W: cache write-through */
+#define _PAGE_DIRTY		0x00080 /* C: page changed */
+#define _PAGE_ACCESSED		0x00100 /* R: page referenced */
+#define _PAGE_RW		0x00200 /* software: user write access allowed */
+#define _PAGE_HASHPTE		0x00400 /* software: pte has an associated HPTE */
+#define _PAGE_BUSY		0x00800 /* software: PTE & hash are busy */
+#define _PAGE_F_GIX		0x07000 /* full page: hidx bits */
+#define _PAGE_F_GIX_SHIFT	12
+#define _PAGE_F_SECOND		0x08000 /* Whether to use secondary hash or not */
+#define _PAGE_SPECIAL		0x10000 /* software: special page */
+
+/*
+ * THP pages can't be special. So use the _PAGE_SPECIAL
+ */
+#define _PAGE_SPLITTING _PAGE_SPECIAL
+
+/*
+ * We need to differentiate between explicit huge page and THP huge
+ * page, since THP huge page also need to track real subpage details
+ */
+#define _PAGE_THP_HUGE  _PAGE_4K_PFN
+
+/*
+ * set of bits not changed in pmd_modify.
+ */
+#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS |		\
+			 _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \
+			 _PAGE_THP_HUGE)
+
 #ifdef CONFIG_PPC_64K_PAGES
 #include <asm/book3s/64/hash-64k.h>
 #else
@@ -57,36 +106,6 @@
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 #endif /* CONFIG_PPC_MM_SLICES */
-/*
- * Common bits between 4K and 64K pages in a linux-style PTE.
- * These match the bits in the (hardware-defined) PowerPC PTE as closely
- * as possible. Additional bits may be defined in pgtable-hash64-*.h
- *
- * Note: We only support user read/write permissions. Supervisor always
- * have full read/write to pages above PAGE_OFFSET (pages below that
- * always use the user access permissions).
- *
- * We could create separate kernel read-only if we used the 3 PP bits
- * combinations that newer processors provide but we currently don't.
- */
-#define _PAGE_PRESENT		0x00001 /* software: pte contains a translation */
-#define _PAGE_USER		0x00002 /* matches one of the PP bits */
-#define _PAGE_BIT_SWAP_TYPE	2
-#define _PAGE_EXEC		0x00004 /* No execute on POWER4 and newer (we invert) */
-#define _PAGE_GUARDED		0x00008
-/* We can derive Memory coherence from _PAGE_NO_CACHE */
-#define _PAGE_COHERENT		0x0
-#define _PAGE_NO_CACHE		0x00020 /* I: cache inhibit */
-#define _PAGE_WRITETHRU		0x00040 /* W: cache write-through */
-#define _PAGE_DIRTY		0x00080 /* C: page changed */
-#define _PAGE_ACCESSED		0x00100 /* R: page referenced */
-#define _PAGE_RW		0x00200 /* software: user write access allowed */
-#define _PAGE_HASHPTE		0x00400 /* software: pte has an associated HPTE */
-#define _PAGE_BUSY		0x00800 /* software: PTE & hash are busy */
-#define _PAGE_F_GIX		0x07000 /* full page: hidx bits */
-#define _PAGE_F_GIX_SHIFT	12
-#define _PAGE_F_SECOND		0x08000 /* Whether to use secondary hash or not */
-#define _PAGE_SPECIAL		0x10000 /* software: special page */
 
 /* No separate kernel read-only */
 #define _PAGE_KERNEL_RW		(_PAGE_RW | _PAGE_DIRTY) /* user access blocked by key */
@@ -105,24 +124,6 @@
 
 /* Hash table based platforms need atomic updates of the linux PTE */
 #define PTE_ATOMIC_UPDATES	1
-
-/*
- * THP pages can't be special. So use the _PAGE_SPECIAL
- */
-#define _PAGE_SPLITTING _PAGE_SPECIAL
-
-/*
- * We need to differentiate between explicit huge page and THP huge
- * page, since THP huge page also need to track real subpage details
- */
-#define _PAGE_THP_HUGE  _PAGE_4K_PFN
-
-/*
- * set of bits not changed in pmd_modify.
- */
-#define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS |		\
-			 _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \
-			 _PAGE_THP_HUGE)
 #define _PTE_NONE_MASK	_PAGE_HPTEFLAGS
 /*
  * The mask convered by the RPN must be a ULL on 32-bit platforms with
@@ -231,11 +232,6 @@
 
 extern void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
 			    pte_t *ptep, unsigned long pte, int huge);
-extern unsigned long pmd_hugepage_update(struct mm_struct *mm,
-					 unsigned long addr,
-					 pmd_t *pmdp,
-					 unsigned long clr,
-					 unsigned long set);
 extern unsigned long htab_convert_pte_flags(unsigned long pteflags);
 /* Atomic PTE updates */
 static inline unsigned long pte_update(struct mm_struct *mm,
@@ -361,127 +357,6 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
 #define __HAVE_ARCH_PTE_SAME
 #define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
 
-static inline char *get_hpte_slot_array(pmd_t *pmdp)
-{
-	/*
-	 * The hpte hindex is stored in the pgtable whose address is in the
-	 * second half of the PMD
-	 *
-	 * Order this load with the test for pmd_trans_huge in the caller
-	 */
-	smp_rmb();
-	return *(char **)(pmdp + PTRS_PER_PMD);
-
-
-}
-/*
- * The linux hugepage PMD now include the pmd entries followed by the address
- * to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits.
- * [ 1 bit secondary | 3 bit hidx | 1 bit valid | 000]. We use one byte per
- * each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and
- * with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t.
- *
- * The last three bits are intentionally left to zero. This memory location
- * are also used as normal page PTE pointers. So if we have any pointers
- * left around while we collapse a hugepage, we need to make sure
- * _PAGE_PRESENT bit of that is zero when we look at them
- */
-static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
-{
-	return (hpte_slot_array[index] >> 3) & 0x1;
-}
-
-static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
-					   int index)
-{
-	return hpte_slot_array[index] >> 4;
-}
-
-static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
-					unsigned int index, unsigned int hidx)
-{
-	hpte_slot_array[index] = hidx << 4 | 0x1 << 3;
-}
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/*
- *
- * For core kernel code by design pmd_trans_huge is never run on any hugetlbfs
- * page. The hugetlbfs page table walking and mangling paths are totally
- * separated form the core VM paths and they're differentiated by
- *  VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run.
- *
- * pmd_trans_huge() is defined as false at build time if
- * CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build
- * time in such case.
- *
- * For ppc64 we need to differntiate from explicit hugepages from THP, because
- * for THP we also track the subpage details at the pmd level. We don't do
- * that for explicit huge pages.
- *
- */
-static inline int pmd_trans_huge(pmd_t pmd)
-{
-	/*
-	 * leaf pte for huge page, bottom two bits != 00
-	 */
-	return (pmd_val(pmd) & 0x3) && (pmd_val(pmd) & _PAGE_THP_HUGE);
-}
-
-static inline int pmd_trans_splitting(pmd_t pmd)
-{
-	if (pmd_trans_huge(pmd))
-		return pmd_val(pmd) & _PAGE_SPLITTING;
-	return 0;
-}
-
-#endif
-static inline int pmd_large(pmd_t pmd)
-{
-	/*
-	 * leaf pte for huge page, bottom two bits != 00
-	 */
-	return ((pmd_val(pmd) & 0x3) != 0x0);
-}
-
-static inline pmd_t pmd_mknotpresent(pmd_t pmd)
-{
-	return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
-}
-
-static inline pmd_t pmd_mksplitting(pmd_t pmd)
-{
-	return __pmd(pmd_val(pmd) | _PAGE_SPLITTING);
-}
-
-#define __HAVE_ARCH_PMD_SAME
-static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
-{
-	return (((pmd_val(pmd_a) ^ pmd_val(pmd_b)) & ~_PAGE_HPTEFLAGS) == 0);
-}
-
-static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
-					      unsigned long addr, pmd_t *pmdp)
-{
-	unsigned long old;
-
-	if ((pmd_val(*pmdp) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
-		return 0;
-	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0);
-	return ((old & _PAGE_ACCESSED) != 0);
-}
-
-#define __HAVE_ARCH_PMDP_SET_WRPROTECT
-static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
-				      pmd_t *pmdp)
-{
-
-	if ((pmd_val(*pmdp) & _PAGE_RW) == 0)
-		return;
-
-	pmd_hugepage_update(mm, addr, pmdp, _PAGE_RW, 0);
-}
-
 /* Generic accessors to PTE bits */
 static inline int pte_write(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_RW);}
 static inline int pte_dirty(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_DIRTY); }