powerpc: port 64 bits pgtable_cache to 32 bits
Today powerpc64 uses a set of pgtable_caches while powerpc32 uses
standard pages when using 4k pages and a single pgtable_cache
if using other size pages.
In preparation of implementing huge pages on the 8xx, this patch
replaces the specific powerpc32 handling by the 64 bits approach.
This is done by:
* moving 64 bits pgtable_cache_add() and pgtable_cache_init()
in a new file called init-common.c
* modifying pgtable_cache_init() to also handle the case
without PMD
* removing the 32 bits version of pgtable_cache_add() and
pgtable_cache_init()
* copying related header contents from 64 bits into both the
book3s/32 and nohash/32 header files
On the 8xx, the following cache sizes will be used:
* 4k pages mode:
- PGT_CACHE(10) for PGD
- PGT_CACHE(3) for 512k hugepage tables
* 16k pages mode:
- PGT_CACHE(6) for PGD
- PGT_CACHE(7) for 512k hugepage tables
- PGT_CACHE(3) for 8M hugepage tables
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Scott Wood <oss@buserror.net>
diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 8e21bb4..d310546 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -2,14 +2,42 @@
#define _ASM_POWERPC_BOOK3S_32_PGALLOC_H
#include <linux/threads.h>
+#include <linux/slab.h>
-/* For 32-bit, all levels of page tables are just drawn from get_free_page() */
-#define MAX_PGTABLE_INDEX_SIZE 0
+/*
+ * Functions that deal with pagetables that could be at any level of
+ * the table need to be passed an "index_size" so they know how to
+ * handle allocation. For PTE pages (which are linked to a struct
+ * page for now, and drawn from the main get_free_pages() pool), the
+ * allocation size will be (2^index_size * sizeof(pointer)) and
+ * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
+ *
+ * The maximum index size needs to be big enough to allow any
+ * pagetable sizes we need, but small enough to fit in the low bits of
+ * any page table pointer. In other words all pagetables, even tiny
+ * ones, must be aligned to allow at least enough low 0 bits to
+ * contain this value. This value is also used as a mask, so it must
+ * be one less than a power of two.
+ */
+#define MAX_PGTABLE_INDEX_SIZE 0xf
extern void __bad_pte(pmd_t *pmd);
-extern pgd_t *pgd_alloc(struct mm_struct *mm);
-extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
+extern struct kmem_cache *pgtable_cache[];
+#define PGT_CACHE(shift) ({ \
+ BUG_ON(!(shift)); \
+ pgtable_cache[(shift) - 1]; \
+ })
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL);
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
+}
/*
* We don't have any real pmd's, and this code never triggers because
@@ -68,8 +96,12 @@
static inline void pgtable_free(void *table, unsigned index_size)
{
- BUG_ON(index_size); /* 32-bit doesn't use this */
- free_page((unsigned long)table);
+ if (!index_size) {
+ free_page((unsigned long)table);
+ } else {
+ BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
+ kmem_cache_free(PGT_CACHE(index_size), table);
+ }
}
#define check_pgt_cache() do { } while (0)
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 6b8b2d5..388b052 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -8,6 +8,23 @@
/* And here we include common definitions */
#include <asm/pte-common.h>
+#define PTE_INDEX_SIZE PTE_SHIFT
+#define PMD_INDEX_SIZE 0
+#define PUD_INDEX_SIZE 0
+#define PGD_INDEX_SIZE (32 - PGDIR_SHIFT)
+
+#define PMD_CACHE_INDEX PMD_INDEX_SIZE
+
+#ifndef __ASSEMBLY__
+#define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_INDEX_SIZE)
+#define PMD_TABLE_SIZE 0
+#define PUD_TABLE_SIZE 0
+#define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE)
+#endif /* __ASSEMBLY__ */
+
+#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
+#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
+
/*
* The normal case is that PTEs are 32-bits and we have a 1-page
* 1024-entry pgdir pointing to 1-page 1024-entry PTE pages. -- paulus
@@ -19,14 +36,10 @@
* -Matt
*/
/* PGDIR_SHIFT determines what a top-level page table entry can map */
-#define PGDIR_SHIFT (PAGE_SHIFT + PTE_SHIFT)
+#define PGDIR_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
-#define PTRS_PER_PTE (1 << PTE_SHIFT)
-#define PTRS_PER_PMD 1
-#define PTRS_PER_PGD (1 << (32 - PGDIR_SHIFT))
-
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
/*
* This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
@@ -82,12 +95,8 @@
extern unsigned long ioremap_bot;
-/*
- * entries per page directory level: our page-table tree is two-level, so
- * we don't really have any PMD directory.
- */
-#define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_SHIFT)
-#define PGD_TABLE_SIZE (sizeof(pgd_t) << (32 - PGDIR_SHIFT))
+/* Bits to mask out from a PGD to get to the PUD page */
+#define PGD_MASKED_BITS 0
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
@@ -283,15 +292,6 @@
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 3 })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val << 3 })
-#ifndef CONFIG_PPC_4K_PAGES
-void pgtable_cache_init(void);
-#else
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init() do { } while (0)
-#endif
-
extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,
pmd_t **pmdp);
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 9fd77f8..0a46a5f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -789,9 +789,6 @@
#define pgd_ERROR(e) \
pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
-void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
-void pgtable_cache_init(void);
-
static inline int map_kernel_page(unsigned long ea, unsigned long pa,
unsigned long flags)
{
diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 76d6b9e..6331392 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h
@@ -2,14 +2,42 @@
#define _ASM_POWERPC_PGALLOC_32_H
#include <linux/threads.h>
+#include <linux/slab.h>
-/* For 32-bit, all levels of page tables are just drawn from get_free_page() */
-#define MAX_PGTABLE_INDEX_SIZE 0
+/*
+ * Functions that deal with pagetables that could be at any level of
+ * the table need to be passed an "index_size" so they know how to
+ * handle allocation. For PTE pages (which are linked to a struct
+ * page for now, and drawn from the main get_free_pages() pool), the
+ * allocation size will be (2^index_size * sizeof(pointer)) and
+ * allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
+ *
+ * The maximum index size needs to be big enough to allow any
+ * pagetable sizes we need, but small enough to fit in the low bits of
+ * any page table pointer. In other words all pagetables, even tiny
+ * ones, must be aligned to allow at least enough low 0 bits to
+ * contain this value. This value is also used as a mask, so it must
+ * be one less than a power of two.
+ */
+#define MAX_PGTABLE_INDEX_SIZE 0xf
extern void __bad_pte(pmd_t *pmd);
-extern pgd_t *pgd_alloc(struct mm_struct *mm);
-extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
+extern struct kmem_cache *pgtable_cache[];
+#define PGT_CACHE(shift) ({ \
+ BUG_ON(!(shift)); \
+ pgtable_cache[(shift) - 1]; \
+ })
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL);
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
+}
/*
* We don't have any real pmd's, and this code never triggers because
@@ -68,8 +96,12 @@
static inline void pgtable_free(void *table, unsigned index_size)
{
- BUG_ON(index_size); /* 32-bit doesn't use this */
- free_page((unsigned long)table);
+ if (!index_size) {
+ free_page((unsigned long)table);
+ } else {
+ BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
+ kmem_cache_free(PGT_CACHE(index_size), table);
+ }
}
#define check_pgt_cache() do { } while (0)
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index c219ef7..7bd916e 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -16,6 +16,23 @@
#endif /* __ASSEMBLY__ */
+#define PTE_INDEX_SIZE PTE_SHIFT
+#define PMD_INDEX_SIZE 0
+#define PUD_INDEX_SIZE 0
+#define PGD_INDEX_SIZE (32 - PGDIR_SHIFT)
+
+#define PMD_CACHE_INDEX PMD_INDEX_SIZE
+
+#ifndef __ASSEMBLY__
+#define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_INDEX_SIZE)
+#define PMD_TABLE_SIZE 0
+#define PUD_TABLE_SIZE 0
+#define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE)
+#endif /* __ASSEMBLY__ */
+
+#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
+#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
+
/*
* The normal case is that PTEs are 32-bits and we have a 1-page
* 1024-entry pgdir pointing to 1-page 1024-entry PTE pages. -- paulus
@@ -27,22 +44,12 @@
* -Matt
*/
/* PGDIR_SHIFT determines what a top-level page table entry can map */
-#define PGDIR_SHIFT (PAGE_SHIFT + PTE_SHIFT)
+#define PGDIR_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
-/*
- * entries per page directory level: our page-table tree is two-level, so
- * we don't really have any PMD directory.
- */
-#ifndef __ASSEMBLY__
-#define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_SHIFT)
-#define PGD_TABLE_SIZE (sizeof(pgd_t) << (32 - PGDIR_SHIFT))
-#endif /* __ASSEMBLY__ */
-
-#define PTRS_PER_PTE (1 << PTE_SHIFT)
-#define PTRS_PER_PMD 1
-#define PTRS_PER_PGD (1 << (32 - PGDIR_SHIFT))
+/* Bits to mask out from a PGD to get to the PUD page */
+#define PGD_MASKED_BITS 0
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
#define FIRST_USER_ADDRESS 0UL
@@ -328,15 +335,6 @@
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 3 })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val << 3 })
-#ifndef CONFIG_PPC_4K_PAGES
-void pgtable_cache_init(void);
-#else
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init() do { } while (0)
-#endif
-
extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,
pmd_t **pmdp);
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index e9e540a..6c4a142 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -346,8 +346,6 @@
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) })
#define __swp_entry_to_pte(x) __pte((x).val)
-void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
-void pgtable_cache_init(void);
extern int map_kernel_page(unsigned long ea, unsigned long pa,
unsigned long flags);
extern int __meminit vmemmap_create_mapping(unsigned long start,
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 9bd87f2..dd01212 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -78,6 +78,8 @@
unsigned long vmalloc_to_phys(void *vmalloc_addr);
+void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
+void pgtable_cache_init(void);
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_PGTABLE_H */