[RFC PATCH 3/6] powerpc/mm: Implement helpers for pagetable fragment support at PMD level
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Thu Feb 15 00:50:06 AEDT 2018
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hash-4k.h | 4 ++
arch/powerpc/include/asm/book3s/64/hash-64k.h | 4 ++
arch/powerpc/include/asm/book3s/64/mmu.h | 1 +
arch/powerpc/include/asm/book3s/64/pgalloc.h | 2 +
arch/powerpc/include/asm/book3s/64/pgtable.h | 6 ++
arch/powerpc/include/asm/book3s/64/radix-4k.h | 2 +
arch/powerpc/include/asm/book3s/64/radix-64k.h | 4 ++
arch/powerpc/mm/hash_utils_64.c | 2 +
arch/powerpc/mm/mmu_context_book3s64.c | 37 +++++++++--
arch/powerpc/mm/pgtable-radix.c | 2 +
arch/powerpc/mm/pgtable_64.c | 85 ++++++++++++++++++++++++++
11 files changed, 143 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 62098daa3af8..fc3dc6a93939 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -36,6 +36,10 @@
/* 8 bytes per each pte entry */
#define H_PTE_FRAG_SIZE_SHIFT (H_PTE_INDEX_SIZE + 3)
#define H_PTE_FRAG_NR (PAGE_SIZE >> H_PTE_FRAG_SIZE_SHIFT)
+
+#define H_PMD_FRAG_SIZE_SHIFT (H_PMD_INDEX_SIZE + 3)
+#define H_PMD_FRAG_NR (PAGE_SIZE >> H_PMD_FRAG_SIZE_SHIFT)
+
/*
* On all 4K setups, remap_4k_pfn() equates to remap_pfn_range()
*/
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 0aa4f755b3f6..b8ca64fd2bea 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -33,6 +33,10 @@
#define H_PTE_FRAG_SIZE_SHIFT (H_PTE_INDEX_SIZE + 3 + 1)
#define H_PTE_FRAG_NR (PAGE_SIZE >> H_PTE_FRAG_SIZE_SHIFT)
+/* +1 for THP and hugetlb */
+#define H_PMD_FRAG_SIZE_SHIFT (H_PMD_INDEX_SIZE + 3 + 1)
+#define H_PMD_FRAG_NR (PAGE_SIZE >> H_PMD_FRAG_SIZE_SHIFT)
+
#ifndef __ASSEMBLY__
#include <asm/errno.h>
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index 00a961bc76a9..ad19651ea10e 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -105,6 +105,7 @@ typedef struct {
* pagetable fragment support
*/
void *pte_frag;
+ void *pmd_frag;
#ifdef CONFIG_SPAPR_TCE_IOMMU
struct list_head iommu_group_mem_list;
#endif
diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index 8de75c2ae7c9..f3838ad0dc6c 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -42,7 +42,9 @@ extern struct kmem_cache *pgtable_cache[];
})
extern pte_t *pte_fragment_alloc(struct mm_struct *, unsigned long, int);
+extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long);
extern void pte_fragment_free(unsigned long *, int);
+extern void pmd_fragment_free(unsigned long *);
extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
#ifdef CONFIG_SMP
extern void __tlb_remove_table(void *_table);
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index a6b9f1d74600..88d10319adfe 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -265,6 +265,12 @@ extern unsigned long __pte_frag_size_shift;
#define PTE_FRAG_SIZE_SHIFT __pte_frag_size_shift
#define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)
+extern unsigned long __pmd_frag_nr;
+#define PMD_FRAG_NR __pmd_frag_nr
+extern unsigned long __pmd_frag_size_shift;
+#define PMD_FRAG_SIZE_SHIFT __pmd_frag_size_shift
+#define PMD_FRAG_SIZE (1UL << PMD_FRAG_SIZE_SHIFT)
+
#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
#define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
#define PTRS_PER_PUD (1 << PUD_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/book3s/64/radix-4k.h b/arch/powerpc/include/asm/book3s/64/radix-4k.h
index 14717cfe15e2..863c3e8286fb 100644
--- a/arch/powerpc/include/asm/book3s/64/radix-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/radix-4k.h
@@ -15,5 +15,7 @@
#define RADIX_PTE_FRAG_SIZE_SHIFT (RADIX_PTE_INDEX_SIZE + 3)
#define RADIX_PTE_FRAG_NR (PAGE_SIZE >> RADIX_PTE_FRAG_SIZE_SHIFT)
+#define RADIX_PMD_FRAG_SIZE_SHIFT (RADIX_PMD_INDEX_SIZE + 3)
+#define RADIX_PMD_FRAG_NR (PAGE_SIZE >> RADIX_PMD_FRAG_SIZE_SHIFT)
#endif /* _ASM_POWERPC_PGTABLE_RADIX_4K_H */
diff --git a/arch/powerpc/include/asm/book3s/64/radix-64k.h b/arch/powerpc/include/asm/book3s/64/radix-64k.h
index 830082496876..ccb78ca9d0c5 100644
--- a/arch/powerpc/include/asm/book3s/64/radix-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/radix-64k.h
@@ -16,4 +16,8 @@
*/
#define RADIX_PTE_FRAG_SIZE_SHIFT (RADIX_PTE_INDEX_SIZE + 3)
#define RADIX_PTE_FRAG_NR (PAGE_SIZE >> RADIX_PTE_FRAG_SIZE_SHIFT)
+
+#define RADIX_PMD_FRAG_SIZE_SHIFT (RADIX_PMD_INDEX_SIZE + 3)
+#define RADIX_PMD_FRAG_NR (PAGE_SIZE >> RADIX_PMD_FRAG_SIZE_SHIFT)
+
#endif /* _ASM_POWERPC_PGTABLE_RADIX_64K_H */
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index cf290d415dcd..efdb49124b2a 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1003,6 +1003,8 @@ void __init hash__early_init_mmu(void)
*/
__pte_frag_nr = H_PTE_FRAG_NR;
__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
+ __pmd_frag_nr = H_PMD_FRAG_NR;
+ __pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT;
__pte_index_size = H_PTE_INDEX_SIZE;
__pmd_index_size = H_PMD_INDEX_SIZE;
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c
index b4d795b5162a..ee2b1fa0cbe3 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -167,6 +167,7 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
mm->context.id = index;
mm->context.pte_frag = NULL;
+ mm->context.pmd_frag = NULL;
#ifdef CONFIG_SPAPR_TCE_IOMMU
mm_iommu_init(mm);
#endif
@@ -183,16 +184,11 @@ void __destroy_context(int context_id)
}
EXPORT_SYMBOL_GPL(__destroy_context);
-static void destroy_pagetable_page(struct mm_struct *mm)
+static void pte_frag_destory(void *pte_frag)
{
int count;
- void *pte_frag;
struct page *page;
- pte_frag = mm->context.pte_frag;
- if (!pte_frag)
- return;
-
page = virt_to_page(pte_frag);
/* drop all the pending references */
count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
@@ -203,6 +199,35 @@ static void destroy_pagetable_page(struct mm_struct *mm)
}
}
+static void pmd_frag_destory(void *pmd_frag)
+{
+ int count;
+ struct page *page;
+
+ page = virt_to_page(pmd_frag);
+ /* drop all the pending references */
+ count = ((unsigned long)pmd_frag & ~PAGE_MASK) >> PMD_FRAG_SIZE_SHIFT;
+ /* We allow PTE_FRAG_NR fragments from a PTE page */
+ if (page_ref_sub_and_test(page, PMD_FRAG_NR - count)) {
+ pgtable_pmd_page_dtor(page);
+ free_unref_page(page);
+ }
+}
+
+static void destroy_pagetable_page(struct mm_struct *mm)
+{
+ void *frag;
+
+ frag = mm->context.pte_frag;
+ if (frag)
+ pte_frag_destory(frag);
+
+ frag = mm->context.pmd_frag;
+ if (frag)
+ pmd_frag_destory(frag);
+ return;
+}
+
void destroy_context(struct mm_struct *mm)
{
#ifdef CONFIG_SPAPR_TCE_IOMMU
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index f8b3f4a99659..b2f89851d8eb 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -559,6 +559,8 @@ void __init radix__early_init_mmu(void)
#endif
__pte_frag_nr = RADIX_PTE_FRAG_NR;
__pte_frag_size_shift = RADIX_PTE_FRAG_SIZE_SHIFT;
+ __pmd_frag_nr = RADIX_PMD_FRAG_NR;
+ __pmd_frag_size_shift = RADIX_PMD_FRAG_SIZE_SHIFT;
if (!firmware_has_feature(FW_FEATURE_LPAR)) {
radix_init_native();
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index ff4973565abb..0a6859e6ef76 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -114,6 +114,11 @@ unsigned long __pte_frag_nr;
EXPORT_SYMBOL(__pte_frag_nr);
unsigned long __pte_frag_size_shift;
EXPORT_SYMBOL(__pte_frag_size_shift);
+unsigned long __pmd_frag_nr;
+EXPORT_SYMBOL(__pmd_frag_nr);
+unsigned long __pmd_frag_size_shift;
+EXPORT_SYMBOL(__pmd_frag_size_shift);
+
unsigned long ioremap_bot;
#else /* !CONFIG_PPC_BOOK3S_64 */
unsigned long ioremap_bot = IOREMAP_BASE;
@@ -393,6 +398,75 @@ pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel
return __alloc_for_ptecache(mm, kernel);
}
+static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
+{
+ void *pmd_frag, *ret;
+
+ spin_lock(&mm->page_table_lock);
+ ret = mm->context.pmd_frag;
+ if (ret) {
+ pmd_frag = ret + PMD_FRAG_SIZE;
+ /*
+ * If we have taken up all the fragments mark PTE page NULL
+ */
+ if (((unsigned long)pmd_frag & ~PAGE_MASK) == 0)
+ pmd_frag = NULL;
+ mm->context.pmd_frag = pmd_frag;
+ }
+ spin_unlock(&mm->page_table_lock);
+ return (pmd_t *)ret;
+}
+
+static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
+{
+ void *ret = NULL;
+ struct page *page;
+ gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
+
+ if (mm == &init_mm)
+ gfp &= ~__GFP_ACCOUNT;
+ page = alloc_page(gfp);
+ if (!page)
+ return NULL;
+ if (!pgtable_pmd_page_ctor(page)) {
+ __free_pages(page, 0);
+ return NULL;
+ }
+
+ ret = page_address(page);
+ /*
+ * if we support only one fragment just return the
+ * allocated page.
+ */
+ if (PMD_FRAG_NR == 1)
+ return ret;
+
+ 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.pmd_frag)) {
+ set_page_count(page, PMD_FRAG_NR);
+ mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ return (pmd_t *)ret;
+}
+
+pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
+{
+ pmd_t *pmd;
+
+ pmd = get_pmd_from_cache(mm);
+ if (pmd)
+ return pmd;
+
+ return __alloc_for_pmdcache(mm);
+}
+
void pte_fragment_free(unsigned long *table, int kernel)
{
struct page *page = virt_to_page(table);
@@ -403,6 +477,17 @@ void pte_fragment_free(unsigned long *table, int kernel)
}
}
+void pmd_fragment_free(unsigned long *pmd)
+{
+ struct page *page = virt_to_page(pmd);
+
+ if (put_page_testzero(page)) {
+ pgtable_pmd_page_dtor(page);
+ free_unref_page(page);
+ }
+}
+
+
#ifdef CONFIG_SMP
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
{
--
2.14.3
More information about the Linuxppc-dev
mailing list