Subject: [PATCH V1 06/11] powerpc/mm/nohash: Remove pte fragment dependency from nohash

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 16 Apr 2018 16:57:19 +0530

From: "Aneesh Kumar K.V" <[email-masked]>

Now that we have removed 64K page size support, the RCU page table free can
be much simpler for nohash. Make a copy of the the rcu callback to pgalloc.h
header similar to nohash 32. We could possibly merge 32 and 64 bit there. But
that is for a later patch

We also move the book3s specific handler to pgtable_book3s64.c. This will be
updated in a later patch to handle split pmd ptlock.

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/include/asm/nohash/64/pgalloc.h |  57 +++++++++++---
 arch/powerpc/mm/pgtable-book3s64.c           | 114 +++++++++++++++++++++++++++
 arch/powerpc/mm/pgtable_64.c                 | 114 ---------------------------
 3 files changed, 159 insertions(+), 126 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h b/arch/powerpc/include/asm/nohash/64/pgalloc.h
index a6baf3c13bb5..21624ff1f065 100644
--- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h
@@ -84,6 +84,18 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
+			pgtable_gfp_flags(mm, GFP_KERNEL));
+}
+
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+	kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
+}
+
+
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 					  unsigned long address)
 {
@@ -118,26 +130,47 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 	__free_page(ptepage);
 }
 
-extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
+static inline void pgtable_free(void *table, int shift)
+{
+	if (!shift) {
+		pgtable_page_dtor(table);
+		free_page((unsigned long)table);
+	} else {
+		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
+		kmem_cache_free(PGT_CACHE(shift), table);
+	}
+}
+
 #ifdef CONFIG_SMP
-extern void __tlb_remove_table(void *_table);
-#endif
-static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
-				  unsigned long address)
+static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 {
-	tlb_flush_pgtable(tlb, address);
-	pgtable_free_tlb(tlb, page_address(table), 0);
+	unsigned long pgf = (unsigned long)table;
+
+	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
+	pgf |= shift;
+	tlb_remove_table(tlb, (void *)pgf);
 }
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+static inline void __tlb_remove_table(void *_table)
 {
-	return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
-			pgtable_gfp_flags(mm, GFP_KERNEL));
+	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
+	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
+
+	pgtable_free(table, shift);
 }
 
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+#else
+static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 {
-	kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
+	pgtable_free(table, shift);
+}
+#endif
+
+static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
+				  unsigned long address)
+{
+	tlb_flush_pgtable(tlb, address);
+	pgtable_free_tlb(tlb, page_address(table), 0);
 }
 
 #define __pmd_free_tlb(tlb, pmd, addr)		      \
diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index e1c304183172..e4e1b2d4ca27 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -225,3 +225,117 @@ void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
 	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
 }
 EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
+#ifdef CONFIG_PPC_64K_PAGES
+static pte_t *get_pte_from_cache(struct mm_struct *mm)
+{
+	void *pte_frag, *ret;
+
+	spin_lock(&mm->page_table_lock);
+	ret = mm->context.pte_frag;
+	if (ret) {
+		pte_frag = ret + PTE_FRAG_SIZE;
+		/*
+		 * If we have taken up all the fragments mark PTE page NULL
+		 */
+		if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
+			pte_frag = NULL;
+		mm->context.pte_frag = pte_frag;
+	}
+	spin_unlock(&mm->page_table_lock);
+	return (pte_t *)ret;
+}
+
+static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
+{
+	void *ret = NULL;
+	struct page *page;
+
+	if (!kernel) {
+		page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
+		if (!page)
+			return NULL;
+		if (!pgtable_page_ctor(page)) {
+			__free_page(page);
+			return NULL;
+		}
+	} else {
+		page = alloc_page(PGALLOC_GFP);
+		if (!page)
+			return NULL;
+	}
+
+	ret = page_address(page);
+	spin_lock(&mm->page_table_lock);
+	/*
+	 * If we find pgtable_page set, we return
+	 * the allocated page with single fragement
+	 * count.
+	 */
+	if (likely(!mm->context.pte_frag)) {
+		set_page_count(page, PTE_FRAG_NR);
+		mm->context.pte_frag = ret + PTE_FRAG_SIZE;
+	}
+	spin_unlock(&mm->page_table_lock);
+
+	return (pte_t *)ret;
+}
+
+pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
+{
+	pte_t *pte;
+
+	pte = get_pte_from_cache(mm);
+	if (pte)
+		return pte;
+
+	return __alloc_for_ptecache(mm, kernel);
+}
+
+#endif /* CONFIG_PPC_64K_PAGES */
+
+void pte_fragment_free(unsigned long *table, int kernel)
+{
+	struct page *page = virt_to_page(table);
+
+	if (put_page_testzero(page)) {
+		if (!kernel)
+			pgtable_page_dtor(page);
+		free_unref_page(page);
+	}
+}
+
+#ifdef CONFIG_SMP
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
+{
+	unsigned long pgf = (unsigned long)table;
+
+	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
+	pgf |= shift;
+	tlb_remove_table(tlb, (void *)pgf);
+}
+
+void __tlb_remove_table(void *_table)
+{
+	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
+	unsigned int shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
+
+	if (!shift)
+		/* PTE page needs special handling */
+		pte_fragment_free(table, 0);
+	else {
+		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
+		kmem_cache_free(PGT_CACHE(shift), table);
+	}
+}
+#else
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
+{
+	if (!shift) {
+		/* PTE page needs special handling */
+		pte_fragment_free(table, 0);
+	} else {
+		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
+		kmem_cache_free(PGT_CACHE(shift), table);
+	}
+}
+#endif
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 3873f94a3ae9..f0208f8f9dbb 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -313,120 +313,6 @@ struct page *pmd_page(pmd_t pmd)
 	return virt_to_page(pmd_page_vaddr(pmd));
 }
 
-#ifdef CONFIG_PPC_64K_PAGES
-static pte_t *get_pte_from_cache(struct mm_struct *mm)
-{
-	void *pte_frag, *ret;
-
-	spin_lock(&mm->page_table_lock);
-	ret = mm->context.pte_frag;
-	if (ret) {
-		pte_frag = ret + PTE_FRAG_SIZE;
-		/*
-		 * If we have taken up all the fragments mark PTE page NULL
-		 */
-		if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
-			pte_frag = NULL;
-		mm->context.pte_frag = pte_frag;
-	}
-	spin_unlock(&mm->page_table_lock);
-	return (pte_t *)ret;
-}
-
-static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
-{
-	void *ret = NULL;
-	struct page *page;
-
-	if (!kernel) {
-		page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
-		if (!page)
-			return NULL;
-		if (!pgtable_page_ctor(page)) {
-			__free_page(page);
-			return NULL;
-		}
-	} else {
-		page = alloc_page(PGALLOC_GFP);
-		if (!page)
-			return NULL;
-	}
-
-	ret = page_address(page);
-	spin_lock(&mm->page_table_lock);
-	/*
-	 * If we find pgtable_page set, we return
-	 * the allocated page with single fragement
-	 * count.
-	 */
-	if (likely(!mm->context.pte_frag)) {
-		set_page_count(page, PTE_FRAG_NR);
-		mm->context.pte_frag = ret + PTE_FRAG_SIZE;
-	}
-	spin_unlock(&mm->page_table_lock);
-
-	return (pte_t *)ret;
-}
-
-pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
-{
-	pte_t *pte;
-
-	pte = get_pte_from_cache(mm);
-	if (pte)
-		return pte;
-
-	return __alloc_for_ptecache(mm, kernel);
-}
-
-#endif /* CONFIG_PPC_64K_PAGES */
-
-void pte_fragment_free(unsigned long *table, int kernel)
-{
-	struct page *page = virt_to_page(table);
-	if (put_page_testzero(page)) {
-		if (!kernel)
-			pgtable_page_dtor(page);
-		free_unref_page(page);
-	}
-}
-
-#ifdef CONFIG_SMP
-void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
-{
-	unsigned long pgf = (unsigned long)table;
-
-	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-	pgf |= shift;
-	tlb_remove_table(tlb, (void *)pgf);
-}
-
-void __tlb_remove_table(void *_table)
-{
-	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
-	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
-
-	if (!shift)
-		/* PTE page needs special handling */
-		pte_fragment_free(table, 0);
-	else {
-		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-		kmem_cache_free(PGT_CACHE(shift), table);
-	}
-}
-#else
-void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
-{
-	if (!shift) {
-		/* PTE page needs special handling */
-		pte_fragment_free(table, 0);
-	} else {
-		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
-		kmem_cache_free(PGT_CACHE(shift), table);
-	}
-}
-#endif
-
 #ifdef CONFIG_STRICT_KERNEL_RWX
 void mark_rodata_ro(void)
 {
-- 
2.14.3