[PATCH v6 18/20] powerpc/mm: Extend pte_fragment functionality to nohash/32

From: Christophe Leroy
Date: Fri Oct 19 2018 - 02:55:34 EST

In order to allow the 8xx to handle pte_fragments, this patch
extends the use of pte_fragments to nohash/32 platforms.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/mmu_context.h | 2 +-
arch/powerpc/include/asm/nohash/32/mmu-40x.h | 1 +
arch/powerpc/include/asm/nohash/32/mmu-44x.h | 1 +
arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 1 +
arch/powerpc/include/asm/nohash/32/mmu.h | 4 ++-
arch/powerpc/include/asm/nohash/32/pgalloc.h | 52 +++++++++++++---------------
arch/powerpc/include/asm/nohash/32/pgtable.h | 11 ++++--
arch/powerpc/include/asm/nohash/mmu-book3e.h | 1 +
arch/powerpc/mm/Makefile | 3 ++
arch/powerpc/mm/mmu_context_nohash.c | 14 ++++++++
10 files changed, 57 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 0381394a425b..8eec1680b699 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -223,7 +223,7 @@ static inline int arch_dup_mmap(struct mm_struct *oldmm,
return 0;
}

-#ifndef CONFIG_PPC_BOOK3S_64
+#if defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_BOOK3S_32)
static inline void arch_exit_mmap(struct mm_struct *mm)
{
}
diff --git a/arch/powerpc/include/asm/nohash/32/mmu-40x.h b/arch/powerpc/include/asm/nohash/32/mmu-40x.h
index 74f4edb5916e..7c77ceed71d6 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-40x.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-40x.h
@@ -58,6 +58,7 @@ typedef struct {
unsigned int id;
unsigned int active;
unsigned long vdso_base;
+ void *pte_frag;
} mm_context_t;

#endif /* !__ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/nohash/32/mmu-44x.h b/arch/powerpc/include/asm/nohash/32/mmu-44x.h
index 295b3dbb2698..3d72e889ae7b 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-44x.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-44x.h
@@ -109,6 +109,7 @@ typedef struct {
unsigned int id;
unsigned int active;
unsigned long vdso_base;
+ void *pte_frag;
} mm_context_t;

#endif /* !__ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
index fa05aa566ece..750cef6f65e3 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
@@ -179,6 +179,7 @@ typedef struct {
unsigned int id;
unsigned int active;
unsigned long vdso_base;
+ void *pte_frag;
#ifdef CONFIG_PPC_MM_SLICES
u16 user_psize; /* page size index */
unsigned char low_slices_psize[SLICE_ARRAY_SIZE];
diff --git a/arch/powerpc/include/asm/nohash/32/mmu.h b/arch/powerpc/include/asm/nohash/32/mmu.h
index f61f933a4cd8..7d94a36d57d2 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu.h
@@ -2,6 +2,8 @@
#ifndef _ASM_POWERPC_NOHASH_32_MMU_H_
#define _ASM_POWERPC_NOHASH_32_MMU_H_

+#include <asm/page.h>
+
#if defined(CONFIG_40x)
/* 40x-style software loaded TLB */
#include <asm/nohash/32/mmu-40x.h>
@@ -17,7 +19,7 @@
#endif

#ifndef __ASSEMBLY__
-typedef struct page *pgtable_t;
+typedef pte_t *pgtable_t;
#endif

#endif /* _ASM_POWERPC_NOHASH_32_MMU_H_ */
diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 78367855a4f3..77c09bef3122 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h
@@ -28,6 +28,10 @@ extern void __bad_pte(pmd_t *pmd);
extern struct kmem_cache *pgtable_cache[];
#define PGT_CACHE(shift) pgtable_cache[shift]

+void pte_frag_destroy(void *pte_frag);
+pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel);
+void pte_fragment_free(unsigned long *table, int kernel);
+
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
@@ -59,11 +63,10 @@ static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pte_page)
{
- *pmdp = __pmd((page_to_pfn(pte_page) << PAGE_SHIFT) | _PMD_USER |
- _PMD_PRESENT);
+ *pmdp = __pmd(__pa(pte_page) | _PMD_USER | _PMD_PRESENT);
}

-#define pmd_pgtable(pmd) pmd_page(pmd)
+#define pmd_pgtable(pmd) ((pgtable_t)pmd_page_vaddr(pmd))
#else

static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
@@ -75,49 +78,38 @@ static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pte_page)
{
- *pmdp = __pmd((unsigned long)lowmem_page_address(pte_page) | _PMD_PRESENT);
+ *pmdp = __pmd((unsigned long)pte_page | _PMD_PRESENT);
}

-#define pmd_pgtable(pmd) pmd_page(pmd)
+#define pmd_pgtable(pmd) ((pgtable_t)pmd_page_vaddr(pmd))
#endif

-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
+ unsigned long address)
{
- return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+ return (pte_t *)pte_fragment_alloc(mm, address, 1);
}

-static inline pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
+static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
+ unsigned long address)
{
- struct page *ptepage;
-
- gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT;
-
- ptepage = alloc_pages(flags, 0);
- if (!ptepage)
- return NULL;
- if (!pgtable_page_ctor(ptepage)) {
- __free_page(ptepage);
- return NULL;
- }
- return ptepage;
+ return (pgtable_t)pte_fragment_alloc(mm, address, 0);
}

static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
- free_page((unsigned long)pte);
+ pte_fragment_free((unsigned long *)pte, 1);
}

static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
- pgtable_page_dtor(ptepage);
- __free_page(ptepage);
+ pte_fragment_free((unsigned long *)ptepage, 0);
}

static inline void pgtable_free(void *table, unsigned index_size)
{
if (!index_size) {
- pgtable_page_dtor(virt_to_page(table));
- free_page((unsigned long)table);
+ pte_fragment_free((unsigned long *)table, 0);
} else {
BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
kmem_cache_free(PGT_CACHE(index_size), table);
@@ -156,18 +148,22 @@ 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);
+ pgtable_free_tlb(tlb, table, 0);
}

static inline pte_t *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
{
if (!pmd_present(*pmdp)) {
- pte_t *ptep = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
+ pte_t *ptep = __va(memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE));

if (!ptep)
return NULL;

- clear_page(ptep);
+ if (PTE_FRAG_SIZE == PAGE_SIZE)
+ clear_page(ptep);
+ else
+ memset(ptep, 0, PTE_FRAG_SIZE);
+
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
return pte_offset_kernel(pmdp, va);
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index f7b129a83054..c33fbbb7ce82 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -20,6 +20,10 @@ extern int icache_44x_need_flush;
#endif /* __ASSEMBLY__ */

#define PTE_INDEX_SIZE PTE_SHIFT
+#define PTE_FRAG_NR 1
+#define PTE_FRAG_SIZE_SHIFT PAGE_SHIFT
+#define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)
+
#define PMD_INDEX_SIZE 0
#define PUD_INDEX_SIZE 0
#define PGD_INDEX_SIZE (32 - PGDIR_SHIFT)
@@ -339,12 +343,12 @@ static inline int pte_young(pte_t pte)
*/
#ifndef CONFIG_BOOKE
#define pmd_page_vaddr(pmd) \
- ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+ ((unsigned long)__va(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
#define pmd_page(pmd) \
pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
#else
#define pmd_page_vaddr(pmd) \
- ((unsigned long) (pmd_val(pmd) & PAGE_MASK))
+ ((unsigned long)(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
#define pmd_page(pmd) \
pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
#endif
@@ -363,7 +367,8 @@ static inline int pte_young(pte_t pte)
(pmd_bad(*(dir)) ? NULL : (pte_t *)pmd_page_vaddr(*(dir)) + \
pte_index(addr))
#define pte_offset_map(dir, addr) \
- ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
+ ((pte_t *)(kmap_atomic(pmd_page(*(dir))) + \
+ (pmd_page_vaddr(*(dir)) & ~PAGE_MASK)) + pte_index(addr))
#define pte_unmap(pte) kunmap_atomic(pte)

/*
diff --git a/arch/powerpc/include/asm/nohash/mmu-book3e.h b/arch/powerpc/include/asm/nohash/mmu-book3e.h
index e20072972e35..8e8aad5172ab 100644
--- a/arch/powerpc/include/asm/nohash/mmu-book3e.h
+++ b/arch/powerpc/include/asm/nohash/mmu-book3e.h
@@ -230,6 +230,7 @@ typedef struct {
unsigned int id;
unsigned int active;
unsigned long vdso_base;
+ void *pte_frag;
} mm_context_t;

/* Page size definitions, common between 32 and 64-bit
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 3cbb1acf0745..cf9e29472c2d 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -18,6 +18,9 @@ obj-$(CONFIG_PPC_BOOK3E_64) += pgtable-book3e.o
obj-$(CONFIG_PPC_BOOK3S_64) += pgtable-hash64.o hash_utils_64.o slb.o \
$(hash64-y) mmu_context_book3s64.o \
pgtable-book3s64.o pgtable-frag.o
+ifndef CONFIG_PPC_BOOK3S_32
+obj-$(CONFIG_PPC32) += pgtable-frag.o
+endif
obj-$(CONFIG_PPC_RADIX_MMU) += pgtable-radix.o tlb-radix.o
obj-$(CONFIG_PPC_STD_MMU_32) += ppc_mmu_32.o hash_low_32.o mmu_context_hash32.o
obj-$(CONFIG_PPC_STD_MMU) += tlb_hash$(BITS).o
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 4d80239ef83c..c434c254adce 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -51,6 +51,7 @@

#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>

#include "mmu_decl.h"

@@ -385,6 +386,7 @@ int init_new_context(struct task_struct *t, struct mm_struct *mm)
#endif
mm->context.id = MMU_NO_CONTEXT;
mm->context.active = 0;
+ mm->context.pte_frag = NULL;
return 0;
}

@@ -487,3 +489,15 @@ void __init mmu_context_init(void)
nr_free_contexts = LAST_CONTEXT - FIRST_CONTEXT + 1;
}

+#ifdef CONFIG_PPC32
+void arch_exit_mmap(struct mm_struct *mm)
+{
+ void *frag;
+
+ frag = mm->context.pte_frag;
+ if (frag)
+ pte_frag_destroy(frag);
+
+ return;
+}
+#endif
--
2.13.3