2018-11-29 14:11:27

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 00/20] Implement use of HW assistance on TLB table walk on 8xx

The purpose of this serie is to implement hardware assistance for TLB table walk
on the 8xx.

First part prepares for using HW assistance in TLB routines:
- Trivial fixes:
- Remove CONFIG_BOOKE stuff from book3S headers.
- Removal of unneeded atomic PTE update requirement for 8xx.
- move book3s64 page fragment code in a common part for reusing it by the
8xx as 16k page size mode still uses 4k page tables.
- Fixing a bug in memcache handling when standard pages and hugepages share
caches of the same size (see original discussion in https://patchwork.ozlabs.org/patch/957565/)
- Optimise access to 8xx perf counters (hence reducing number of registers used)

Second part implements HW assistance in TLB routines in the following steps:
- Disable 16k page size mode and 512k hugepages
- Switch 4k to HW assistance
- Bring back 512k hugepages
- Bring back 16k page size mode.

Last part cleans up:
- Take benefit of Miss handler size reduction to regroup related parts
- Reduce number of registers used in miss handlers, freeing them for future use.

Tested successfully on 8xx and 83xx (book3s/32)

Changes in v9:
- Fixed PTE_INDEX_SIZE and PTE_SHIFT so that we always have PTE_SHIFT == PTE_INDEX_SIZE
- Using PTE_INDEX_SIZE instead of PTE_SHIFT to avoid build failure on PPC64
- Moved PTE_FRAG_NR from pgtable.h to mmu-8xx.h to reduce ifdefs

Changes in v8:
- Moved definitions in pgalloc.h to avoid conflicting with memcache patches.
- Included the memcache bugfix serie in this serie to avoid conflicts between the two series when coming to the 512k pages patch.
- In the 512k HW assistance patch, reduced the #ifdef mess by using IS_ENABLED(CONFIG_PPC_8xx) instead.

Changes in v7:
- Reordered to get trivial and already reviewed patches in front.
- Reordered to regroup all HW assistance related patches together.
- Rebased on today merge branch (28 Nov)
- Added a helper for access to mm_context_t.frag
- Reduced the amount of changes in PPC32 to support pte_fragment
- Applied pte_fragment to both nohash/32 and book3s/32

Changes in v6:
- Droped the part related to handling GUARD attribute at PGD/PMD level.
- Moved the commonalisation of page_fragment in the begining (this part has been reviewed by Aneesh)
- Rebased on today merge branch (19 Oct)

Changes in v5:
- Also avoid useless lock in get_pmd_from_cache()
- A new patch to relocate mmu headers in platform specific directories
- A new patch to distribute pgtable_t typedefs in platform specific
mmu headers instead of the uggly #ifdef
- Moved early_pte_alloc_kernel() in platform specific pgalloc
- Restricted definition of PTE_FRAG_SIZE and PTE_FRAG_NR to platforms
using the pte fragmentation.
- arch_exit_mmap() and destroy_pagetable_cache() are now platform specific.

Changes in v4:
- Reordered the serie to put at the end the modifications which makes
L1 and L2 entries independant.
- No modifications to ppc64 ioremap (we still have an opportunity to
merge them, for a future patch serie)
- 8xx code modified to use patch_site instead of patch_instruction
to get a clearer code and avoid object pollution with global symbols
- Moved perf counters in first 32kb of memory to optimise access
- Split the big bang to HW assistance in several steps:
1. Temporarily removes support of 16k pages and 512k hugepages
2. Change TLB routines to use HW assistance for 4k pages and 8M hugepages
3. Add back support for 512k hugepages
4. Add back support for 16k pages (using pte_fragment as page tables are still 4k)

Changes in v3:
- Fixed an issue in the 09/14 when CONFIG_PIN_TLB_TEXT was not enabled
- Added performance measurement in the 09/14 commit log
- Rebased on latest 'powerpc/merge' tree, which conflicted with 13/14

Changes in v2:
- Removed the 3 first patchs which have been applied already
- Fixed compilation errors reported by Michael
- Squashed the commonalisation of ioremap functions into a single patch
- Fixed the use of pte_fragment
- Added a patch optimising perf counting of TLB misses and instructions

Christophe Leroy (20):
powerpc/book3s32: Remove CONFIG_BOOKE dependent code
powerpc/8xx: Remove PTE_ATOMIC_UPDATES
powerpc/mm: Move pte_fragment_alloc() to a common location
powerpc/mm: Avoid useless lock with single page fragments
powerpc/mm: move platform specific mmu-xxx.h in platform directories
powerpc/mm: Move pgtable_t into platform headers
powerpc/mm: add helpers to get/set mm.context->pte_frag
powerpc/mm: Extend pte_fragment functionality to PPC32
powerpc/mm: enable the use of page table cache of order 0
powerpc/mm: replace hugetlb_cache by PGT_CACHE(PTE_T_ORDER)
powerpc/mm: fix a warning when a cache is common to PGD and hugepages
powerpc/mm: remove unnecessary test in pgtable_cache_init()
powerpc/8xx: Move SW perf counters in first 32kb of memory
powerpc/8xx: Temporarily disable 16k pages and hugepages
powerpc/8xx: Use hardware assistance in TLB handlers
powerpc/8xx: Enable 8M hugepage support with HW assistance
powerpc/8xx: Enable 512k hugepage support with HW assistance
powerpc/8xx: reintroduce 16K pages with HW assistance
powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers
powerpc/8xx: regroup TLB handler routines

arch/powerpc/include/asm/book3s/32/mmu-hash.h | 5 +
arch/powerpc/include/asm/book3s/32/pgalloc.h | 40 +--
arch/powerpc/include/asm/book3s/32/pgtable.h | 19 +-
arch/powerpc/include/asm/book3s/64/mmu.h | 9 +
arch/powerpc/include/asm/book3s/64/pgalloc.h | 6 +-
arch/powerpc/include/asm/hugetlb.h | 6 +-
arch/powerpc/include/asm/mmu.h | 14 +-
arch/powerpc/include/asm/mmu_context.h | 2 +-
arch/powerpc/include/asm/{ => nohash/32}/mmu-40x.h | 0
arch/powerpc/include/asm/{ => nohash/32}/mmu-44x.h | 0
arch/powerpc/include/asm/{ => nohash/32}/mmu-8xx.h | 4 +
arch/powerpc/include/asm/nohash/32/mmu.h | 25 ++
arch/powerpc/include/asm/nohash/32/pgalloc.h | 27 +-
arch/powerpc/include/asm/nohash/32/pgtable.h | 15 +-
arch/powerpc/include/asm/nohash/32/pte-8xx.h | 3 -
arch/powerpc/include/asm/nohash/64/mmu.h | 12 +
arch/powerpc/include/asm/nohash/64/pgalloc.h | 5 +-
arch/powerpc/include/asm/{ => nohash}/mmu-book3e.h | 0
arch/powerpc/include/asm/nohash/mmu.h | 11 +
arch/powerpc/include/asm/nohash/pgtable.h | 4 +
arch/powerpc/include/asm/page.h | 14 -
arch/powerpc/include/asm/page_32.h | 3 +-
arch/powerpc/include/asm/pgtable-types.h | 4 +
arch/powerpc/include/asm/pgtable.h | 31 +-
arch/powerpc/kernel/cpu_setup_fsl_booke.S | 2 +-
arch/powerpc/kernel/head_8xx.S | 366 ++++++++-------------
arch/powerpc/kvm/e500.h | 2 +-
arch/powerpc/mm/8xx_mmu.c | 4 +-
arch/powerpc/mm/Makefile | 5 +-
arch/powerpc/mm/hugetlbpage.c | 40 +--
arch/powerpc/mm/init-common.c | 56 ++--
arch/powerpc/mm/mmu_context.c | 10 +
arch/powerpc/mm/mmu_context_book3s64.c | 15 -
arch/powerpc/mm/mmu_context_nohash.c | 2 +-
arch/powerpc/mm/pgtable-book3s64.c | 88 +----
arch/powerpc/mm/pgtable-frag.c | 119 +++++++
arch/powerpc/mm/pgtable_32.c | 25 +-
37 files changed, 488 insertions(+), 505 deletions(-)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-40x.h (100%)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-44x.h (100%)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-8xx.h (98%)
create mode 100644 arch/powerpc/include/asm/nohash/32/mmu.h
create mode 100644 arch/powerpc/include/asm/nohash/64/mmu.h
rename arch/powerpc/include/asm/{ => nohash}/mmu-book3e.h (100%)
create mode 100644 arch/powerpc/include/asm/nohash/mmu.h
create mode 100644 arch/powerpc/mm/pgtable-frag.c

--
2.13.3



2018-11-29 14:08:11

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 01/20] powerpc/book3s32: Remove CONFIG_BOOKE dependent code

BOOK3S/32 cannot be BOOKE, so remove useless code

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/book3s/32/pgalloc.h | 18 ------------------
arch/powerpc/include/asm/book3s/32/pgtable.h | 14 --------------
2 files changed, 32 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 82e44b1a00ae..eb8882c6dbb0 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -50,8 +50,6 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
#define __pmd_free_tlb(tlb,x,a) do { } while (0)
/* #define pgd_populate(mm, pmd, pte) BUG() */

-#ifndef CONFIG_BOOKE
-
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
pte_t *pte)
{
@@ -65,22 +63,6 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmdp,
}

#define pmd_pgtable(pmd) pmd_page(pmd)
-#else
-
-static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp,
- pte_t *pte)
-{
- *pmdp = __pmd((unsigned long)pte | _PMD_PRESENT);
-}
-
-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);
-}
-
-#define pmd_pgtable(pmd) pmd_page(pmd)
-#endif

extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index c21d33704633..32c33eccc0e2 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -328,24 +328,10 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)

-/*
- * Note that on Book E processors, the pmd contains the kernel virtual
- * (lowmem) address of the pte page. The physical address is less useful
- * because everything runs with translation enabled (even the TLB miss
- * handler). On everything else the pmd contains the physical address
- * of the pte page. -- paulus
- */
-#ifndef CONFIG_BOOKE
#define pmd_page_vaddr(pmd) \
((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
#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))
-#define pmd_page(pmd) \
- pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
-#endif

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)
--
2.13.3


2018-11-29 14:08:21

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 04/20] powerpc/mm: Avoid useless lock with single page fragments

There is no point in taking the page table lock as pte_frag or
pmd_frag are always NULL when we have only one fragment.

Reviewed-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/mm/pgtable-book3s64.c | 3 +++
arch/powerpc/mm/pgtable-frag.c | 3 +++
2 files changed, 6 insertions(+)

diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index 0c0fd173208a..f3c31f5e1026 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -244,6 +244,9 @@ static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
{
void *pmd_frag, *ret;

+ if (PMD_FRAG_NR == 1)
+ return NULL;
+
spin_lock(&mm->page_table_lock);
ret = mm->context.pmd_frag;
if (ret) {
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index d61e7c2a9a79..7544d0d7177d 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -34,6 +34,9 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm)
{
void *pte_frag, *ret;

+ if (PTE_FRAG_NR == 1)
+ return NULL;
+
spin_lock(&mm->page_table_lock);
ret = mm->context.pte_frag;
if (ret) {
--
2.13.3


2018-11-29 14:08:23

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 07/20] powerpc/mm: add helpers to get/set mm.context->pte_frag

In order to handle pte_fragment functions with single fragment
without adding pte_frag in all mm_context_t, this patch creates
two helpers which do nothing on platforms using a single fragment.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/pgtable.h | 25 +++++++++++++++++++++++++
arch/powerpc/mm/pgtable-frag.c | 8 ++++----
2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 9679b7519a35..314a2890a972 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -110,6 +110,31 @@ void mark_initmem_nx(void);
static inline void mark_initmem_nx(void) { }
#endif

+/*
+ * When used, PTE_FRAG_NR is defined in subarch pgtable.h
+ * so we are sure it is included when arriving here.
+ */
+#ifdef PTE_FRAG_NR
+static inline void *pte_frag_get(mm_context_t *ctx)
+{
+ return ctx->pte_frag;
+}
+
+static inline void pte_frag_set(mm_context_t *ctx, void *p)
+{
+ ctx->pte_frag = p;
+}
+#else
+static inline void *pte_frag_get(mm_context_t *ctx)
+{
+ return NULL;
+}
+
+static inline void pte_frag_set(mm_context_t *ctx, void *p)
+{
+}
+#endif
+
#endif /* __ASSEMBLY__ */

#endif /* _ASM_POWERPC_PGTABLE_H */
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index 7544d0d7177d..af23a587f019 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -38,7 +38,7 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm)
return NULL;

spin_lock(&mm->page_table_lock);
- ret = mm->context.pte_frag;
+ ret = pte_frag_get(&mm->context);
if (ret) {
pte_frag = ret + PTE_FRAG_SIZE;
/*
@@ -46,7 +46,7 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm)
*/
if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
pte_frag = NULL;
- mm->context.pte_frag = pte_frag;
+ pte_frag_set(&mm->context, pte_frag);
}
spin_unlock(&mm->page_table_lock);
return (pte_t *)ret;
@@ -86,9 +86,9 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
* the allocated page with single fragement
* count.
*/
- if (likely(!mm->context.pte_frag)) {
+ if (likely(!pte_frag_get(&mm->context))) {
atomic_set(&page->pt_frag_refcount, PTE_FRAG_NR);
- mm->context.pte_frag = ret + PTE_FRAG_SIZE;
+ pte_frag_set(&mm->context, ret + PTE_FRAG_SIZE);
}
spin_unlock(&mm->page_table_lock);

--
2.13.3


2018-11-29 14:08:25

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 06/20] powerpc/mm: Move pgtable_t into platform headers

This patch move pgtable_t into platform headers.

It gets rid of the CONFIG_PPC_64K_PAGES case for PPC64
as nohash/64 doesn't support CONFIG_PPC_64K_PAGES.

Reviewed-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 2 ++
arch/powerpc/include/asm/book3s/64/mmu.h | 9 +++++++++
arch/powerpc/include/asm/nohash/32/mmu.h | 4 ++++
arch/powerpc/include/asm/nohash/64/mmu.h | 4 ++++
arch/powerpc/include/asm/page.h | 14 --------------
5 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e38c91388c40..5bd26c218b94 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -42,6 +42,8 @@ struct ppc_bat {
u32 batu;
u32 batl;
};
+
+typedef struct page *pgtable_t;
#endif /* !__ASSEMBLY__ */

/*
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index 6328857f259f..1ceee000c18d 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -2,6 +2,8 @@
#ifndef _ASM_POWERPC_BOOK3S_64_MMU_H_
#define _ASM_POWERPC_BOOK3S_64_MMU_H_

+#include <asm/page.h>
+
#ifndef __ASSEMBLY__
/*
* Page size definition
@@ -24,6 +26,13 @@ struct mmu_psize_def {
};
extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];

+/*
+ * For BOOK3s 64 with 4k and 64K linux page size
+ * we want to use pointers, because the page table
+ * actually store pfn
+ */
+typedef pte_t *pgtable_t;
+
#endif /* __ASSEMBLY__ */

/* 64-bit classic hash table MMU */
diff --git a/arch/powerpc/include/asm/nohash/32/mmu.h b/arch/powerpc/include/asm/nohash/32/mmu.h
index af0e8b54876a..f61f933a4cd8 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu.h
@@ -16,4 +16,8 @@
#include <asm/nohash/32/mmu-8xx.h>
#endif

+#ifndef __ASSEMBLY__
+typedef struct page *pgtable_t;
+#endif
+
#endif /* _ASM_POWERPC_NOHASH_32_MMU_H_ */
diff --git a/arch/powerpc/include/asm/nohash/64/mmu.h b/arch/powerpc/include/asm/nohash/64/mmu.h
index 87871d027b75..e6585480dfc4 100644
--- a/arch/powerpc/include/asm/nohash/64/mmu.h
+++ b/arch/powerpc/include/asm/nohash/64/mmu.h
@@ -5,4 +5,8 @@
/* Freescale Book-E software loaded TLB or Book-3e (ISA 2.06+) MMU */
#include <asm/nohash/mmu-book3e.h>

+#ifndef __ASSEMBLY__
+typedef struct page *pgtable_t;
+#endif
+
#endif /* _ASM_POWERPC_NOHASH_64_MMU_H_ */
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 9ea903221a9f..a7624a3b1435 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -335,20 +335,6 @@ void arch_free_page(struct page *page, int order);
#endif

struct vm_area_struct;
-#ifdef CONFIG_PPC_BOOK3S_64
-/*
- * For BOOK3s 64 with 4k and 64K linux page size
- * we want to use pointers, because the page table
- * actually store pfn
- */
-typedef pte_t *pgtable_t;
-#else
-#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64)
-typedef pte_t *pgtable_t;
-#else
-typedef struct page *pgtable_t;
-#endif
-#endif

#include <asm-generic/memory_model.h>
#endif /* __ASSEMBLY__ */
--
2.13.3


2018-11-29 14:08:29

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 09/20] powerpc/mm: enable the use of page table cache of order 0

hugepages uses a cache of order 0. Lets allow page tables
of order 0 in the common part in order to avoid open coding
in hugetlb

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/book3s/32/pgalloc.h | 5 +----
arch/powerpc/include/asm/book3s/64/pgalloc.h | 5 +----
arch/powerpc/include/asm/nohash/32/pgalloc.h | 5 +----
arch/powerpc/include/asm/nohash/64/pgalloc.h | 5 +----
arch/powerpc/mm/init-common.c | 6 +++---
5 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 0f58e5b9dbe7..b5b955eb2fb7 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -25,10 +25,7 @@
extern void __bad_pte(pmd_t *pmd);

extern struct kmem_cache *pgtable_cache[];
-#define PGT_CACHE(shift) ({ \
- BUG_ON(!(shift)); \
- pgtable_cache[(shift) - 1]; \
- })
+#define PGT_CACHE(shift) pgtable_cache[shift]

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index f949dd90af9b..4aba625389c4 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -37,10 +37,7 @@ extern struct vmemmap_backing *vmemmap_list;
#define MAX_PGTABLE_INDEX_SIZE 0xf

extern struct kmem_cache *pgtable_cache[];
-#define PGT_CACHE(shift) ({ \
- BUG_ON(!(shift)); \
- pgtable_cache[(shift) - 1]; \
- })
+#define PGT_CACHE(shift) pgtable_cache[shift]

extern pte_t *pte_fragment_alloc(struct mm_struct *, unsigned long, int);
extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long);
diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 7e234582dce5..17963951bdb0 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h
@@ -25,10 +25,7 @@
extern void __bad_pte(pmd_t *pmd);

extern struct kmem_cache *pgtable_cache[];
-#define PGT_CACHE(shift) ({ \
- BUG_ON(!(shift)); \
- pgtable_cache[(shift) - 1]; \
- })
+#define PGT_CACHE(shift) pgtable_cache[shift]

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h b/arch/powerpc/include/asm/nohash/64/pgalloc.h
index e2d62d033708..e95eb499a174 100644
--- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h
@@ -36,10 +36,7 @@ extern struct vmemmap_backing *vmemmap_list;
#define MAX_PGTABLE_INDEX_SIZE 0xf

extern struct kmem_cache *pgtable_cache[];
-#define PGT_CACHE(shift) ({ \
- BUG_ON(!(shift)); \
- pgtable_cache[(shift) - 1]; \
- })
+#define PGT_CACHE(shift) pgtable_cache[shift]

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 2b656e67f2ea..41190f2b60c2 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -40,7 +40,7 @@ static void pmd_ctor(void *addr)
memset(addr, 0, PMD_TABLE_SIZE);
}

-struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
+struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */

/*
@@ -71,7 +71,7 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
* moment, gcc doesn't seem to recognize is_power_of_2 as a
* constant expression, so so much for that. */
BUG_ON(!is_power_of_2(minalign));
- BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
+ BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);

if (PGT_CACHE(shift))
return; /* Already have a cache of this size */
@@ -83,7 +83,7 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
panic("Could not allocate pgtable cache for order %d", shift);

kfree(name);
- pgtable_cache[shift - 1] = new;
+ pgtable_cache[shift] = new;

pr_debug("Allocated pgtable cache for order %d\n", shift);
}
--
2.13.3


2018-11-29 14:08:30

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 03/20] powerpc/mm: Move pte_fragment_alloc() to a common location

In preparation of next patch which generalises the use of
pte_fragment_alloc() for all, this patch moves the related functions
in a place that is common to all subarches.

The 8xx will need that for supporting 16k pages, as in that mode
page tables still have a size of 4k.

Since pte_fragment with only once fragment is not different
from what is done in the general case, we can easily migrate all
subarchs to pte fragments.

Reviewed-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/book3s/64/pgalloc.h | 1 +
arch/powerpc/mm/Makefile | 4 +-
arch/powerpc/mm/mmu_context_book3s64.c | 15 ----
arch/powerpc/mm/pgtable-book3s64.c | 85 --------------------
arch/powerpc/mm/pgtable-frag.c | 116 +++++++++++++++++++++++++++
5 files changed, 120 insertions(+), 101 deletions(-)
create mode 100644 arch/powerpc/mm/pgtable-frag.c

diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index 391ed2c3b697..f949dd90af9b 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -50,6 +50,7 @@ extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
#ifdef CONFIG_SMP
extern void __tlb_remove_table(void *_table);
#endif
+void pte_frag_destroy(void *pte_frag);

static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm)
{
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index ca96e7be4d0e..3cbb1acf0745 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -15,7 +15,9 @@ obj-$(CONFIG_PPC_MMU_NOHASH) += mmu_context_nohash.o tlb_nohash.o \
obj-$(CONFIG_PPC_BOOK3E) += tlb_low_$(BITS)e.o
hash64-$(CONFIG_PPC_NATIVE) := hash_native_64.o
obj-$(CONFIG_PPC_BOOK3E_64) += pgtable-book3e.o
-obj-$(CONFIG_PPC_BOOK3S_64) += pgtable-hash64.o hash_utils_64.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o
+obj-$(CONFIG_PPC_BOOK3S_64) += pgtable-hash64.o hash_utils_64.o slb.o \
+ $(hash64-y) mmu_context_book3s64.o \
+ pgtable-book3s64.o pgtable-frag.o
obj-$(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_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c
index 510f103d7813..f720c5cc0b5e 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -164,21 +164,6 @@ static void destroy_contexts(mm_context_t *ctx)
}
}

-static void pte_frag_destroy(void *pte_frag)
-{
- int count;
- struct page *page;
-
- page = virt_to_page(pte_frag);
- /* drop all the pending references */
- count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
- /* We allow PTE_FRAG_NR fragments from a PTE page */
- if (atomic_sub_and_test(PTE_FRAG_NR - count, &page->pt_frag_refcount)) {
- pgtable_page_dtor(page);
- __free_page(page);
- }
-}
-
static void pmd_frag_destroy(void *pmd_frag)
{
int count;
diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index 9f93c9f985c5..0c0fd173208a 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -322,91 +322,6 @@ void pmd_fragment_free(unsigned long *pmd)
}
}

-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;
- }
-
- atomic_set(&page->pt_frag_refcount, 1);
-
- ret = page_address(page);
- /*
- * if we support only one fragment just return the
- * allocated page.
- */
- if (PTE_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.pte_frag)) {
- atomic_set(&page->pt_frag_refcount, 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);
-}
-
-void pte_fragment_free(unsigned long *table, int kernel)
-{
- struct page *page = virt_to_page(table);
-
- BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
- if (atomic_dec_and_test(&page->pt_frag_refcount)) {
- if (!kernel)
- pgtable_page_dtor(page);
- __free_page(page);
- }
-}
-
static inline void pgtable_free(void *table, int index)
{
switch (index) {
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
new file mode 100644
index 000000000000..d61e7c2a9a79
--- /dev/null
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Handling Page Tables through page fragments
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/hugetlb.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+
+void pte_frag_destroy(void *pte_frag)
+{
+ int count;
+ struct page *page;
+
+ page = virt_to_page(pte_frag);
+ /* drop all the pending references */
+ count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
+ /* We allow PTE_FRAG_NR fragments from a PTE page */
+ if (atomic_sub_and_test(PTE_FRAG_NR - count, &page->pt_frag_refcount)) {
+ pgtable_page_dtor(page);
+ __free_page(page);
+ }
+}
+
+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;
+ }
+
+ atomic_set(&page->pt_frag_refcount, 1);
+
+ ret = page_address(page);
+ /*
+ * if we support only one fragment just return the
+ * allocated page.
+ */
+ if (PTE_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.pte_frag)) {
+ atomic_set(&page->pt_frag_refcount, 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);
+}
+
+void pte_fragment_free(unsigned long *table, int kernel)
+{
+ struct page *page = virt_to_page(table);
+
+ BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
+ if (atomic_dec_and_test(&page->pt_frag_refcount)) {
+ if (!kernel)
+ pgtable_page_dtor(page);
+ __free_page(page);
+ }
+}
--
2.13.3


2018-11-29 14:08:31

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 08/20] powerpc/mm: Extend pte_fragment functionality to PPC32

In order to allow the 8xx to handle pte_fragments, this patch
extends the use of pte_fragments to PPC32 platforms.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 5 ++++-
arch/powerpc/include/asm/book3s/32/pgalloc.h | 17 +++++++++--------
arch/powerpc/include/asm/book3s/32/pgtable.h | 5 +++--
arch/powerpc/include/asm/mmu_context.h | 2 +-
arch/powerpc/include/asm/nohash/32/mmu.h | 4 +++-
arch/powerpc/include/asm/nohash/32/pgalloc.h | 22 +++++++++++-----------
arch/powerpc/include/asm/nohash/32/pgtable.h | 7 ++++---
arch/powerpc/include/asm/pgtable.h | 4 ++++
arch/powerpc/mm/Makefile | 1 +
arch/powerpc/mm/mmu_context.c | 10 ++++++++++
arch/powerpc/mm/mmu_context_nohash.c | 2 +-
arch/powerpc/mm/pgtable_32.c | 25 ++++---------------------
12 files changed, 55 insertions(+), 49 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index 5bd26c218b94..2bb500d25de6 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_BOOK3S_32_MMU_HASH_H_
#define _ASM_POWERPC_BOOK3S_32_MMU_HASH_H_
+
/*
* 32-bit hash table MMU support
*/
@@ -9,6 +10,8 @@
* BATs
*/

+#include <asm/page.h>
+
/* Block size masks */
#define BL_128K 0x000
#define BL_256K 0x001
@@ -43,7 +46,7 @@ struct ppc_bat {
u32 batl;
};

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

/*
diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index eb8882c6dbb0..0f58e5b9dbe7 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -59,30 +59,31 @@ 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_PRESENT);
+ *pmdp = __pmd(__pa(pte_page) | _PMD_PRESENT);
}

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

extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
+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 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);
@@ -120,6 +121,6 @@ static inline void pgtable_free_tlb(struct mmu_gather *tlb,
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
unsigned long address)
{
- pgtable_free_tlb(tlb, page_address(table), 0);
+ pgtable_free_tlb(tlb, table, 0);
}
#endif /* _ASM_POWERPC_BOOK3S_32_PGALLOC_H */
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 32c33eccc0e2..47156b93f9af 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -329,7 +329,7 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)

#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)

@@ -346,7 +346,8 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
#define pte_offset_kernel(dir, addr) \
((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/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 0381394a425b..c05efd2e8736 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
+#ifdef CONFIG_PPC_BOOK3E_64
static inline void arch_exit_mmap(struct mm_struct *mm)
{
}
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 8825953c225b..7e234582dce5 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h
@@ -61,11 +61,10 @@ 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,
@@ -77,31 +76,32 @@ 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

extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long addr);
+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 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);
@@ -140,6 +140,6 @@ 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);
}
#endif /* _ASM_POWERPC_PGALLOC_32_H */
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index 3ffb0ff5a038..e9c8604cc8c5 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -333,12 +333,12 @@ 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
@@ -357,7 +357,8 @@ 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/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 314a2890a972..56ef5437eb2f 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -125,6 +125,10 @@ static inline void pte_frag_set(mm_context_t *ctx, void *p)
ctx->pte_frag = p;
}
#else
+#define PTE_FRAG_NR 1
+#define PTE_FRAG_SIZE_SHIFT PAGE_SHIFT
+#define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)
+
static inline void *pte_frag_get(mm_context_t *ctx)
{
return NULL;
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 3cbb1acf0745..c8778a640d68 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_PPC_BOOK3E_64) += pgtable-book3e.o
obj-$(CONFIG_PPC_BOOK3S_64) += pgtable-hash64.o hash_utils_64.o slb.o \
$(hash64-y) mmu_context_book3s64.o \
pgtable-book3s64.o pgtable-frag.o
+obj-$(CONFIG_PPC32) += pgtable-frag.o
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.c b/arch/powerpc/mm/mmu_context.c
index f84e14f23e50..bb52320b7369 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -15,6 +15,7 @@
#include <linux/sched/mm.h>

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

#if defined(CONFIG_PPC32)
static inline void switch_mm_pgdir(struct task_struct *tsk,
@@ -97,3 +98,12 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
switch_mmu_context(prev, next, tsk);
}

+#ifdef CONFIG_PPC32
+void arch_exit_mmap(struct mm_struct *mm)
+{
+ void *frag = pte_frag_get(&mm->context);
+
+ if (frag)
+ pte_frag_destroy(frag);
+}
+#endif
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 2faca46ad720..431ecf37f17c 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -385,6 +385,7 @@ int init_new_context(struct task_struct *t, struct mm_struct *mm)
#endif
mm->context.id = MMU_NO_CONTEXT;
mm->context.active = 0;
+ pte_frag_set(&mm->context, NULL);
return 0;
}

@@ -487,4 +488,3 @@ void __init mmu_context_init(void)
next_context = FIRST_CONTEXT;
nr_free_contexts = LAST_CONTEXT - FIRST_CONTEXT + 1;
}
-
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index bda3c6f1bd32..deb49a6e9cad 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -45,32 +45,15 @@ extern char etext[], _stext[], _sinittext[], _einittext[];

__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
- pte_t *pte;
+ if (!slab_is_available())
+ return memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);

- if (slab_is_available()) {
- pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
- } else {
- pte = __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
- if (pte)
- clear_page(pte);
- }
- return pte;
+ return (pte_t *)pte_fragment_alloc(mm, address, 1);
}

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);
}

void __iomem *
--
2.13.3


2018-11-29 14:08:34

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 13/20] powerpc/8xx: Move SW perf counters in first 32kb of memory

In order to simplify time critical exceptions handling 8xx
specific SW perf counters, this patch moves the counters into
the beginning of memory. This is possible because .text is readable
and the counters are never modified outside of the handlers.

By doing this, we avoid having to set a second register with
the upper part of the address of the counters.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 58 ++++++++++++++++++++----------------------
1 file changed, 28 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 3b67b9533c82..c203defe49a4 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -106,6 +106,23 @@ turn_on_mmu:
mtspr SPRN_SRR0,r0
rfi /* enables MMU */

+
+#ifdef CONFIG_PERF_EVENTS
+ .align 4
+
+ .globl itlb_miss_counter
+itlb_miss_counter:
+ .space 4
+
+ .globl dtlb_miss_counter
+dtlb_miss_counter:
+ .space 4
+
+ .globl instruction_counter
+instruction_counter:
+ .space 4
+#endif
+
/*
* Exception entry code. This code runs with address translation
* turned off, i.e. using physical addresses.
@@ -384,17 +401,16 @@ InstructionTLBMiss:

#ifdef CONFIG_PERF_EVENTS
patch_site 0f, patch__itlbmiss_perf
-0: lis r10, (itlb_miss_counter - PAGE_OFFSET)@ha
- lwz r11, (itlb_miss_counter - PAGE_OFFSET)@l(r10)
- addi r11, r11, 1
- stw r11, (itlb_miss_counter - PAGE_OFFSET)@l(r10)
-#endif
+0: lwz r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
+ addi r10, r10, 1
+ stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
mfspr r12, SPRN_SPRG_SCRATCH2
#endif
rfi
+#endif

#ifdef CONFIG_HUGETLB_PAGE
10: /* 8M pages */
@@ -509,15 +525,14 @@ DataStoreTLBMiss:

#ifdef CONFIG_PERF_EVENTS
patch_site 0f, patch__dtlbmiss_perf
-0: lis r10, (dtlb_miss_counter - PAGE_OFFSET)@ha
- lwz r11, (dtlb_miss_counter - PAGE_OFFSET)@l(r10)
- addi r11, r11, 1
- stw r11, (dtlb_miss_counter - PAGE_OFFSET)@l(r10)
-#endif
+0: lwz r10, (dtlb_miss_counter - PAGE_OFFSET)@l(0)
+ addi r10, r10, 1
+ stw r10, (dtlb_miss_counter - PAGE_OFFSET)@l(0)
mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
mfspr r12, SPRN_SPRG_SCRATCH2
rfi
+#endif

#ifdef CONFIG_HUGETLB_PAGE
10: /* 8M pages */
@@ -625,16 +640,13 @@ DataBreakpoint:
. = 0x1d00
InstructionBreakpoint:
mtspr SPRN_SPRG_SCRATCH0, r10
- mtspr SPRN_SPRG_SCRATCH1, r11
- lis r10, (instruction_counter - PAGE_OFFSET)@ha
- lwz r11, (instruction_counter - PAGE_OFFSET)@l(r10)
- addi r11, r11, -1
- stw r11, (instruction_counter - PAGE_OFFSET)@l(r10)
+ lwz r10, (instruction_counter - PAGE_OFFSET)@l(0)
+ addi r10, r10, -1
+ stw r10, (instruction_counter - PAGE_OFFSET)@l(0)
lis r10, 0xffff
ori r10, r10, 0x01
mtspr SPRN_COUNTA, r10
mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
rfi
#else
EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
@@ -1065,17 +1077,3 @@ swapper_pg_dir:
*/
abatron_pteptrs:
.space 8
-
-#ifdef CONFIG_PERF_EVENTS
- .globl itlb_miss_counter
-itlb_miss_counter:
- .space 4
-
- .globl dtlb_miss_counter
-dtlb_miss_counter:
- .space 4
-
- .globl instruction_counter
-instruction_counter:
- .space 4
-#endif
--
2.13.3


2018-11-29 14:08:48

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 17/20] powerpc/8xx: Enable 512k hugepage support with HW assistance

For using 512k pages with hardware assistance, the PTEs have to be spread
every 128 bytes in the L2 table.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/hugetlb.h | 4 +++-
arch/powerpc/mm/hugetlbpage.c | 10 +++++++++-
arch/powerpc/mm/tlb_nohash.c | 3 +++
3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index dfb8bf236586..62a0ca02ca7d 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -74,7 +74,9 @@ static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
unsigned long idx = 0;

pte_t *dir = hugepd_page(hpd);
-#ifndef CONFIG_PPC_FSL_BOOK3E
+#ifdef CONFIG_PPC_8xx
+ idx = (addr & ((1UL << pdshift) - 1)) >> PAGE_SHIFT;
+#elif !defined(CONFIG_PPC_FSL_BOOK3E)
idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(hpd);
#endif

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index bc97874d7c74..5b236621d302 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -65,6 +65,9 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
if (pshift >= pdshift) {
cachep = PGT_CACHE(PTE_T_ORDER);
num_hugepd = 1 << (pshift - pdshift);
+ } else if (IS_ENABLED(CONFIG_PPC_8xx)) {
+ cachep = PGT_CACHE(PTE_INDEX_SIZE);
+ num_hugepd = 1;
} else {
cachep = PGT_CACHE(pdshift - pshift);
num_hugepd = 1;
@@ -331,6 +334,9 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif

if (shift >= pdshift)
hugepd_free(tlb, hugepte);
+ else if (IS_ENABLED(CONFIG_PPC_8xx))
+ pgtable_free_tlb(tlb, hugepte,
+ get_hugepd_cache_index(PTE_INDEX_SIZE));
else
pgtable_free_tlb(tlb, hugepte,
get_hugepd_cache_index(pdshift - shift));
@@ -700,7 +706,9 @@ static int __init hugetlbpage_init(void)
* if we have pdshift and shift value same, we don't
* use pgt cache for hugepd.
*/
- if (pdshift > shift)
+ if (pdshift > shift && IS_ENABLED(CONFIG_PPC_8xx))
+ pgtable_cache_add(PTE_INDEX_SIZE);
+ else if (pdshift > shift)
pgtable_cache_add(pdshift - shift);
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
else
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 8ad7aab150b7..ae5d568e267f 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,6 +97,9 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
.shift = 14,
},
#endif
+ [MMU_PAGE_512K] = {
+ .shift = 19,
+ },
[MMU_PAGE_8M] = {
.shift = 23,
},
--
2.13.3


2018-11-29 14:08:53

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 19/20] powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers

This patch reworks the TLB Miss handler in order to not use r12
register, hence avoiding having to save it into SPRN_SPRG_SCRATCH2.

In the DAR Fixup code we can now use SPRN_M_TW, freeing
SPRN_SPRG_SCRATCH2.

Then SPRN_SPRG_SCRATCH2 may be used for something else in the future.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 110 ++++++++++++++++++-----------------------
1 file changed, 49 insertions(+), 61 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 85fb4b8bf6c7..0a4f8a9c85ff 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -302,90 +302,87 @@ SystemCall:
*/

#ifdef CONFIG_8xx_CPU15
-#define INVALIDATE_ADJACENT_PAGES_CPU15(tmp, addr) \
- addi tmp, addr, PAGE_SIZE; \
- tlbie tmp; \
- addi tmp, addr, -PAGE_SIZE; \
- tlbie tmp
+#define INVALIDATE_ADJACENT_PAGES_CPU15(addr) \
+ addi addr, addr, PAGE_SIZE; \
+ tlbie addr; \
+ addi addr, addr, -(PAGE_SIZE << 1); \
+ tlbie addr; \
+ addi addr, addr, PAGE_SIZE
#else
-#define INVALIDATE_ADJACENT_PAGES_CPU15(tmp, addr)
+#define INVALIDATE_ADJACENT_PAGES_CPU15(addr)
#endif

InstructionTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
+#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP)
mtspr SPRN_SPRG_SCRATCH1, r11
-#ifdef ITLB_MISS_KERNEL
- mtspr SPRN_SPRG_SCRATCH2, r12
#endif

/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
- INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)
+ INVALIDATE_ADJACENT_PAGES_CPU15(r10)
mtspr SPRN_MD_EPN, r10
/* Only modules will cause ITLB Misses as we always
* pin the first 8MB of kernel memory */
#ifdef ITLB_MISS_KERNEL
- mfcr r12
+ mfcr r11
#if defined(SIMPLE_KERNEL_ADDRESS) && defined(CONFIG_PIN_TLB_TEXT)
- andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+ cmpi cr0, r10, 0 /* Address >= 0x80000000 */
#else
- rlwinm r11, r10, 16, 0xfff8
- cmpli cr0, r11, PAGE_OFFSET@h
+ rlwinm r10, r10, 16, 0xfff8
+ cmpli cr0, r10, PAGE_OFFSET@h
#ifndef CONFIG_PIN_TLB_TEXT
/* It is assumed that kernel code fits into the first 8M page */
-0: cmpli cr7, r11, (PAGE_OFFSET + 0x0800000)@h
+0: cmpli cr7, r10, (PAGE_OFFSET + 0x0800000)@h
patch_site 0b, patch__itlbmiss_linmem_top
#endif
#endif
#endif
- mfspr r11, SPRN_M_TWB /* Get level 1 table */
+ mfspr r10, SPRN_M_TWB /* Get level 1 table */
#ifdef ITLB_MISS_KERNEL
#if defined(SIMPLE_KERNEL_ADDRESS) && defined(CONFIG_PIN_TLB_TEXT)
- beq+ 3f
+ bge+ 3f
#else
blt+ 3f
#endif
#ifndef CONFIG_PIN_TLB_TEXT
blt cr7, ITLBMissLinear
#endif
- rlwinm r11, r11, 0, 20, 31
- oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
+ rlwinm r10, r10, 0, 20, 31
+ oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha
3:
#endif
- lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */
+ lwz r10, (swapper_pg_dir-PAGE_OFFSET)@l(r10) /* Get level 1 entry */
+ mtspr SPRN_MI_TWC, r10 /* Set segment attributes */

- mtspr SPRN_MD_TWC, r11
+ mtspr SPRN_MD_TWC, r10
mfspr r10, SPRN_MD_TWC
lwz r10, 0(r10) /* Get the pte */
#ifdef ITLB_MISS_KERNEL
- mtcr r12
+ mtcr r11
#endif
- /* Load the MI_TWC with the attributes for this "segment." */
- mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
-
#ifdef CONFIG_SWAP
rlwinm r11, r10, 32-5, _PAGE_PRESENT
and r11, r11, r10
rlwimi r10, r11, 0, _PAGE_PRESENT
#endif
- li r11, RPN_PATTERN | 0x200
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 20 and 23 must be clear.
* Software indicator bits 22, 24, 25, 26, and 27 must be
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
- rlwimi r11, r10, 4, 0x0400 /* Copy _PAGE_EXEC into bit 21 */
- rlwimi r10, r11, 0, 0x0ff0 /* Set 22, 24-27, clear 20,23 */
+ rlwimi r10, r10, 0, 0x0f00 /* Clear bits 20-23 */
+ rlwimi r10, r10, 4, 0x0400 /* Copy _PAGE_EXEC into bit 21 */
+ ori r10, r10, RPN_PATTERN | 0x200 /* Set 22 and 24-27 */
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */

/* Restore registers */
0: mfspr r10, SPRN_SPRG_SCRATCH0
+#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP)
mfspr r11, SPRN_SPRG_SCRATCH1
-#ifdef ITLB_MISS_KERNEL
- mfspr r12, SPRN_SPRG_SCRATCH2
#endif
rfi
patch_site 0b, patch__itlbmiss_exit_1
@@ -396,9 +393,8 @@ InstructionTLBMiss:
addi r10, r10, 1
stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
mfspr r10, SPRN_SPRG_SCRATCH0
+#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP)
mfspr r11, SPRN_SPRG_SCRATCH1
-#ifdef ITLB_MISS_KERNEL
- mfspr r12, SPRN_SPRG_SCRATCH2
#endif
rfi
#endif
@@ -407,40 +403,37 @@ InstructionTLBMiss:
DataStoreTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
mtspr SPRN_SPRG_SCRATCH1, r11
- mtspr SPRN_SPRG_SCRATCH2, r12
- mfcr r12
+ mfcr r11

/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
mfspr r10, SPRN_MD_EPN
- rlwinm r11, r10, 16, 0xfff8
- cmpli cr0, r11, PAGE_OFFSET@h
- mfspr r11, SPRN_M_TWB /* Get level 1 table */
- blt+ 3f
- rlwinm r11, r10, 16, 0xfff8
+ rlwinm r10, r10, 16, 0xfff8
+ cmpli cr0, r10, PAGE_OFFSET@h
#ifndef CONFIG_PIN_TLB_IMMR
- cmpli cr0, r11, VIRT_IMMR_BASE@h
+ cmpli cr6, r10, VIRT_IMMR_BASE@h
#endif
-0: cmpli cr7, r11, (PAGE_OFFSET + 0x1800000)@h
+0: cmpli cr7, r10, (PAGE_OFFSET + 0x1800000)@h
patch_site 0b, patch__dtlbmiss_linmem_top
+
+ mfspr r10, SPRN_M_TWB /* Get level 1 table */
+ blt+ 3f
#ifndef CONFIG_PIN_TLB_IMMR
-0: beq- DTLBMissIMMR
+0: beq- cr6, DTLBMissIMMR
patch_site 0b, patch__dtlbmiss_immr_jmp
#endif
blt cr7, DTLBMissLinear
- mfspr r11, SPRN_M_TWB /* Get level 1 table */
- rlwinm r11, r11, 0, 20, 31
- oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
+ rlwinm r10, r10, 0, 20, 31
+ oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha
3:
- lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */
+ mtcr r11
+ lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r10) /* Get level 1 entry */

mtspr SPRN_MD_TWC, r11
mfspr r10, SPRN_MD_TWC
lwz r10, 0(r10) /* Get the pte */

- mtcr r12
-
/* Insert the Guarded flag into the TWC from the Linux PTE.
* It is bit 27 of both the Linux PTE and the TWC (at least
* I got that right :-). It will be better when we can put
@@ -478,7 +471,6 @@ DataStoreTLBMiss:

0: mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r12, SPRN_SPRG_SCRATCH2
rfi
patch_site 0b, patch__dtlbmiss_exit_1

@@ -489,7 +481,6 @@ DataStoreTLBMiss:
stw r10, (dtlb_miss_counter - PAGE_OFFSET)@l(0)
mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r12, SPRN_SPRG_SCRATCH2
rfi
#endif

@@ -597,7 +588,7 @@ InstructionBreakpoint:
* not enough space in the DataStoreTLBMiss area.
*/
DTLBMissIMMR:
- mtcr r12
+ mtcr r11
/* Set 512k byte guarded page and mark it valid */
li r10, MD_PS512K | MD_GUARDED | MD_SVALID
mtspr SPRN_MD_TWC, r10
@@ -612,16 +603,15 @@ DTLBMissIMMR:

0: mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r12, SPRN_SPRG_SCRATCH2
rfi
patch_site 0b, patch__dtlbmiss_exit_2

DTLBMissLinear:
- mtcr r12
+ mtcr r11
/* Set 8M byte page and mark it valid */
li r11, MD_PS8MEG | MD_SVALID
mtspr SPRN_MD_TWC, r11
- rlwinm r10, r10, 0, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
_PAGE_PRESENT
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
@@ -631,24 +621,22 @@ DTLBMissLinear:

0: mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r12, SPRN_SPRG_SCRATCH2
rfi
patch_site 0b, patch__dtlbmiss_exit_3

#ifndef CONFIG_PIN_TLB_TEXT
ITLBMissLinear:
- mtcr r12
+ mtcr r11
/* Set 8M byte page and mark it valid */
li r11, MI_PS8MEG | MI_SVALID
mtspr SPRN_MI_TWC, r11
- rlwinm r10, r10, 0, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
_PAGE_PRESENT
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */

0: mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r12, SPRN_SPRG_SCRATCH2
rfi
patch_site 0b, patch__itlbmiss_exit_2
#endif
@@ -660,7 +648,7 @@ ITLBMissLinear:
/* define if you don't want to use self modifying code */
#define NO_SELF_MODIFYING_CODE
FixupDAR:/* Entry point for dcbx workaround. */
- mtspr SPRN_SPRG_SCRATCH2, r10
+ mtspr SPRN_M_TW, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
mtspr SPRN_MD_EPN, r10
@@ -705,7 +693,7 @@ FixupDAR:/* Entry point for dcbx workaround. */
beq+ 142f
cmpwi cr0, r10, 1964 /* Is icbi? */
beq+ 142f
-141: mfspr r10,SPRN_SPRG_SCRATCH2
+141: mfspr r10,SPRN_M_TW
b DARFixed /* Nope, go back to normal TLB processing */

200:
@@ -740,7 +728,7 @@ modified_instr:
bne+ 143f
subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */
143: mtdar r10 /* store faulting EA in DAR */
- mfspr r10,SPRN_SPRG_SCRATCH2
+ mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */
#else
mfctr r10
@@ -794,7 +782,7 @@ modified_instr:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
mtdar r10 /* save fault EA to DAR */
- mfspr r10,SPRN_SPRG_SCRATCH2
+ mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */

/* special handling for r10,r11 since these are modified already */
--
2.13.3


2018-11-29 14:08:56

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 20/20] powerpc/8xx: regroup TLB handler routines

As this is running with MMU off, the CPU only does speculative
fetch for code in the same page.

Following the significant size reduction of TLB handler routines,
the side handlers can be brought back close to the main part,
ie in the same page.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 112 ++++++++++++++++++++---------------------
1 file changed, 54 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 0a4f8a9c85ff..b171b7c0a0e7 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -399,6 +399,23 @@ InstructionTLBMiss:
rfi
#endif

+#ifndef CONFIG_PIN_TLB_TEXT
+ITLBMissLinear:
+ mtcr r11
+ /* Set 8M byte page and mark it valid */
+ li r11, MI_PS8MEG | MI_SVALID
+ mtspr SPRN_MI_TWC, r11
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
+ _PAGE_PRESENT
+ mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
+
+0: mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+ patch_site 0b, patch__itlbmiss_exit_2
+#endif
+
. = 0x1200
DataStoreTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
@@ -484,6 +501,43 @@ DataStoreTLBMiss:
rfi
#endif

+DTLBMissIMMR:
+ mtcr r11
+ /* Set 512k byte guarded page and mark it valid */
+ li r10, MD_PS512K | MD_GUARDED | MD_SVALID
+ mtspr SPRN_MD_TWC, r10
+ mfspr r10, SPRN_IMMR /* Get current IMMR */
+ rlwinm r10, r10, 0, 0xfff80000 /* Get 512 kbytes boundary */
+ ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
+ _PAGE_PRESENT | _PAGE_NO_CACHE
+ mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+
+0: mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+ patch_site 0b, patch__dtlbmiss_exit_2
+
+DTLBMissLinear:
+ mtcr r11
+ /* Set 8M byte page and mark it valid */
+ li r11, MD_PS8MEG | MD_SVALID
+ mtspr SPRN_MD_TWC, r11
+ rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
+ ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
+ _PAGE_PRESENT
+ mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR */
+
+0: mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH1
+ rfi
+ patch_site 0b, patch__dtlbmiss_exit_3
+
/* This is an instruction TLB error on the MPC8xx. This could be due
* to many reasons, such as executing guarded memory or illegal instruction
* addresses. There is nothing to do but handle a big time error fault.
@@ -583,64 +637,6 @@ InstructionBreakpoint:

. = 0x2000

-/*
- * Bottom part of DataStoreTLBMiss handlers for IMMR area and linear RAM.
- * not enough space in the DataStoreTLBMiss area.
- */
-DTLBMissIMMR:
- mtcr r11
- /* Set 512k byte guarded page and mark it valid */
- li r10, MD_PS512K | MD_GUARDED | MD_SVALID
- mtspr SPRN_MD_TWC, r10
- mfspr r10, SPRN_IMMR /* Get current IMMR */
- rlwinm r10, r10, 0, 0xfff80000 /* Get 512 kbytes boundary */
- ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
- _PAGE_PRESENT | _PAGE_NO_CACHE
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
-
- li r11, RPN_PATTERN
- mtspr SPRN_DAR, r11 /* Tag DAR */
-
-0: mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
- patch_site 0b, patch__dtlbmiss_exit_2
-
-DTLBMissLinear:
- mtcr r11
- /* Set 8M byte page and mark it valid */
- li r11, MD_PS8MEG | MD_SVALID
- mtspr SPRN_MD_TWC, r11
- rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
- ori r10, r10, 0xf0 | MD_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
- _PAGE_PRESENT
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
-
- li r11, RPN_PATTERN
- mtspr SPRN_DAR, r11 /* Tag DAR */
-
-0: mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
- patch_site 0b, patch__dtlbmiss_exit_3
-
-#ifndef CONFIG_PIN_TLB_TEXT
-ITLBMissLinear:
- mtcr r11
- /* Set 8M byte page and mark it valid */
- li r11, MI_PS8MEG | MI_SVALID
- mtspr SPRN_MI_TWC, r11
- rlwinm r10, r10, 20, 0x0f800000 /* 8xx supports max 256Mb RAM */
- ori r10, r10, 0xf0 | MI_SPS16K | _PAGE_SH | _PAGE_DIRTY | \
- _PAGE_PRESENT
- mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
-
-0: mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
- rfi
- patch_site 0b, patch__itlbmiss_exit_2
-#endif
-
/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
* by decoding the registers used by the dcbx instruction and adding them.
* DAR is set to the calculated address.
--
2.13.3


2018-11-29 14:09:19

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 14/20] powerpc/8xx: Temporarily disable 16k pages and hugepages

In preparation of making use of hardware assistance in TLB handlers,
this patch temporarily disables 16K pages and hugepages. The reason
is that when using HW assistance in 4K pages mode, the linux model
fit with the HW model for 4K pages and 8M pages.

However for 16K pages and 512K mode some additional work is needed
to get linux model fit with HW model.
For the 8M pages, they will naturaly come back when we switch to
HW assistance, without any additional handling.
In order to keep the following patch smaller, the removal of the
current special handling for 8M pages gets removed here as well.

Therefore the 4K pages mode will be implemented first and without
support for 512k hugepages. Then the 512k hugepages will be brought
back. And the 16K pages will be implemented in the following step.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/Kconfig | 2 +-
arch/powerpc/kernel/head_8xx.S | 74 +++---------------------------------------
arch/powerpc/mm/tlb_nohash.c | 6 ----
3 files changed, 6 insertions(+), 76 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8be31261aec8..ddfccdf004fe 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -689,7 +689,7 @@ config PPC_4K_PAGES

config PPC_16K_PAGES
bool "16k page size"
- depends on 44x || PPC_8xx
+ depends on 44x

config PPC_64K_PAGES
bool "64k page size"
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index c203defe49a4..01f58b1d9ae7 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -314,7 +314,7 @@ SystemCall:
InstructionTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
mtspr SPRN_SPRG_SCRATCH1, r11
-#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
+#ifdef ITLB_MISS_KERNEL
mtspr SPRN_SPRG_SCRATCH2, r12
#endif

@@ -325,10 +325,8 @@ InstructionTLBMiss:
INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)
/* Only modules will cause ITLB Misses as we always
* pin the first 8MB of kernel memory */
-#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
- mfcr r12
-#endif
#ifdef ITLB_MISS_KERNEL
+ mfcr r12
#if defined(SIMPLE_KERNEL_ADDRESS) && defined(CONFIG_PIN_TLB_TEXT)
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
#else
@@ -360,15 +358,9 @@ InstructionTLBMiss:

/* Extract level 2 index */
rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
-#ifdef CONFIG_HUGETLB_PAGE
- mtcr r11
- bt- 28, 10f /* bit 28 = Large page (8M) */
- bt- 29, 20f /* bit 29 = Large page (8M or 512k) */
-#endif
rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
-4:
-#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
+#ifdef ITLB_MISS_KERNEL
mtcr r12
#endif
/* Load the MI_TWC with the attributes for this "segment." */
@@ -393,7 +385,7 @@ InstructionTLBMiss:
/* Restore registers */
0: mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
-#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
+#ifdef ITLB_MISS_KERNEL
mfspr r12, SPRN_SPRG_SCRATCH2
#endif
rfi
@@ -406,35 +398,12 @@ InstructionTLBMiss:
stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
-#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)
+#ifdef ITLB_MISS_KERNEL
mfspr r12, SPRN_SPRG_SCRATCH2
#endif
rfi
#endif

-#ifdef CONFIG_HUGETLB_PAGE
-10: /* 8M pages */
-#ifdef CONFIG_PPC_16K_PAGES
- /* Extract level 2 index */
- rlwinm r10, r10, 32 - (PAGE_SHIFT_8M - PAGE_SHIFT), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
- /* Add level 2 base */
- rlwimi r10, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
-#else
- /* Level 2 base */
- rlwinm r10, r11, 0, ~HUGEPD_SHIFT_MASK
-#endif
- lwz r10, 0(r10) /* Get the pte */
- b 4b
-
-20: /* 512k pages */
- /* Extract level 2 index */
- rlwinm r10, r10, 32 - (PAGE_SHIFT_512K - PAGE_SHIFT), 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1), 29
- /* Add level 2 base */
- rlwimi r10, r11, 0, 0, 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1) - 1
- lwz r10, 0(r10) /* Get the pte */
- b 4b
-#endif
-
. = 0x1200
DataStoreTLBMiss:
mtspr SPRN_SPRG_SCRATCH0, r10
@@ -472,11 +441,6 @@ DataStoreTLBMiss:
*/
/* Extract level 2 index */
rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
-#ifdef CONFIG_HUGETLB_PAGE
- mtcr r11
- bt- 28, 10f /* bit 28 = Large page (8M) */
- bt- 29, 20f /* bit 29 = Large page (8M or 512k) */
-#endif
rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
4:
@@ -534,29 +498,6 @@ DataStoreTLBMiss:
rfi
#endif

-#ifdef CONFIG_HUGETLB_PAGE
-10: /* 8M pages */
- /* Extract level 2 index */
-#ifdef CONFIG_PPC_16K_PAGES
- rlwinm r10, r10, 32 - (PAGE_SHIFT_8M - PAGE_SHIFT), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
- /* Add level 2 base */
- rlwimi r10, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
-#else
- /* Level 2 base */
- rlwinm r10, r11, 0, ~HUGEPD_SHIFT_MASK
-#endif
- lwz r10, 0(r10) /* Get the pte */
- b 4b
-
-20: /* 512k pages */
- /* Extract level 2 index */
- rlwinm r10, r10, 32 - (PAGE_SHIFT_512K - PAGE_SHIFT), 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1), 29
- /* Add level 2 base */
- rlwimi r10, r11, 0, 0, 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1) - 1
- lwz r10, 0(r10) /* Get the pte */
- b 4b
-#endif
-
/* This is an instruction TLB error on the MPC8xx. This could be due
* to many reasons, such as executing guarded memory or illegal instruction
* addresses. There is nothing to do but handle a big time error fault.
@@ -773,12 +714,7 @@ FixupDAR:/* Entry point for dcbx workaround. */

/* concat physical page address(r11) and page offset(r10) */
200:
-#ifdef CONFIG_PPC_16K_PAGES
- rlwinm r11, r11, 0, 0, 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1) - 1
- rlwimi r11, r10, 32 - (PAGE_SHIFT_8M - 2), 32 + PAGE_SHIFT_8M - (PAGE_SHIFT << 1), 29
-#else
rlwinm r11, r10, 0, ~HUGEPD_SHIFT_MASK
-#endif
lwz r11, 0(r11) /* Get the pte */
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 32 - PAGE_SHIFT_8M, 31
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index ae5d568e267f..4f79639e432f 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,12 +97,6 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
.shift = 14,
},
#endif
- [MMU_PAGE_512K] = {
- .shift = 19,
- },
- [MMU_PAGE_8M] = {
- .shift = 23,
- },
};
#else
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
--
2.13.3


2018-11-29 14:09:28

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 16/20] powerpc/8xx: Enable 8M hugepage support with HW assistance

HW assistance naturally supports 8M huge pages without
further modifications.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/mm/tlb_nohash.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 4f79639e432f..8ad7aab150b7 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -97,6 +97,9 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
.shift = 14,
},
#endif
+ [MMU_PAGE_8M] = {
+ .shift = 23,
+ },
};
#else
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
--
2.13.3


2018-11-29 14:09:35

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 15/20] powerpc/8xx: Use hardware assistance in TLB handlers

Today, on the 8xx the TLB handlers do SW tablewalk by doing all
the calculation in ASM, in order to match with the Linux page
table structure.

The 8xx offers hardware assistance which allows significant size
reduction of the TLB handlers, hence also reduces the time spent
in the handlers.

However, using this HW assistance implies some constraints on the
page table structure:
- Regardless of the main page size used (4k or 16k), the
level 1 table (PGD) contains 1024 entries and each PGD entry covers
a 4Mbytes area which is managed by a level 2 table (PTE) containing
also 1024 entries each describing a 4k page.
- 16k pages require 4 identifical entries in the L2 table
- 512k pages PTE have to be spread every 128 bytes in the L2 table
- 8M pages PTE are at the address pointed by the L1 entry and each
8M page require 2 identical entries in the PGD.

This patch modifies the TLB handlers to use HW assistance for 4K PAGES.

Before that patch, the mean time spent in TLB miss handlers is:
- ITLB miss: 80 ticks
- DTLB miss: 62 ticks
After that patch, the mean time spent in TLB miss handlers is:
- ITLB miss: 72 ticks
- DTLB miss: 54 ticks
So the improvement is 10% for ITLB and 13% for DTLB misses

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 58 +++++++++++++++++-------------------------
arch/powerpc/mm/8xx_mmu.c | 4 +--
2 files changed, 26 insertions(+), 36 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 01f58b1d9ae7..85fb4b8bf6c7 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -292,7 +292,7 @@ SystemCall:
. = 0x1100
/*
* For the MPC8xx, this is a software tablewalk to load the instruction
- * TLB. The task switch loads the M_TW register with the pointer to the first
+ * TLB. The task switch loads the M_TWB register with the pointer to the first
* level table.
* If we discover there is no second level table (value is zero) or if there
* is an invalid pte, we load that into the TLB, which causes another fault
@@ -323,6 +323,7 @@ InstructionTLBMiss:
*/
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)
+ mtspr SPRN_MD_EPN, r10
/* Only modules will cause ITLB Misses as we always
* pin the first 8MB of kernel memory */
#ifdef ITLB_MISS_KERNEL
@@ -339,7 +340,7 @@ InstructionTLBMiss:
#endif
#endif
#endif
- mfspr r11, SPRN_M_TW /* Get level 1 table */
+ mfspr r11, SPRN_M_TWB /* Get level 1 table */
#ifdef ITLB_MISS_KERNEL
#if defined(SIMPLE_KERNEL_ADDRESS) && defined(CONFIG_PIN_TLB_TEXT)
beq+ 3f
@@ -349,16 +350,14 @@ InstructionTLBMiss:
#ifndef CONFIG_PIN_TLB_TEXT
blt cr7, ITLBMissLinear
#endif
- lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
+ rlwinm r11, r11, 0, 20, 31
+ oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
3:
#endif
- /* Insert level 1 index */
- rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */

- /* Extract level 2 index */
- rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
- rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
+ mtspr SPRN_MD_TWC, r11
+ mfspr r10, SPRN_MD_TWC
lwz r10, 0(r10) /* Get the pte */
#ifdef ITLB_MISS_KERNEL
mtcr r12
@@ -417,7 +416,7 @@ DataStoreTLBMiss:
mfspr r10, SPRN_MD_EPN
rlwinm r11, r10, 16, 0xfff8
cmpli cr0, r11, PAGE_OFFSET@h
- mfspr r11, SPRN_M_TW /* Get level 1 table */
+ mfspr r11, SPRN_M_TWB /* Get level 1 table */
blt+ 3f
rlwinm r11, r10, 16, 0xfff8
#ifndef CONFIG_PIN_TLB_IMMR
@@ -430,20 +429,16 @@ DataStoreTLBMiss:
patch_site 0b, patch__dtlbmiss_immr_jmp
#endif
blt cr7, DTLBMissLinear
- lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
+ mfspr r11, SPRN_M_TWB /* Get level 1 table */
+ rlwinm r11, r11, 0, 20, 31
+ oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
3:
-
- /* Insert level 1 index */
- rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */

- /* We have a pte table, so load fetch the pte from the table.
- */
- /* Extract level 2 index */
- rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
- rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
+ mtspr SPRN_MD_TWC, r11
+ mfspr r10, SPRN_MD_TWC
lwz r10, 0(r10) /* Get the pte */
-4:
+
mtcr r12

/* Insert the Guarded flag into the TWC from the Linux PTE.
@@ -668,9 +663,10 @@ FixupDAR:/* Entry point for dcbx workaround. */
mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
+ mtspr SPRN_MD_EPN, r10
rlwinm r11, r10, 16, 0xfff8
cmpli cr0, r11, PAGE_OFFSET@h
- mfspr r11, SPRN_M_TW /* Get level 1 table */
+ mfspr r11, SPRN_M_TWB /* Get level 1 table */
blt+ 3f
rlwinm r11, r10, 16, 0xfff8

@@ -680,17 +676,17 @@ FixupDAR:/* Entry point for dcbx workaround. */
/* create physical page address from effective address */
tophys(r11, r10)
blt- cr7, 201f
- lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha
- /* Insert level 1 index */
-3: rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+ mfspr r11, SPRN_M_TWB /* Get level 1 table */
+ rlwinm r11, r11, 0, 20, 31
+ oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
+3:
lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */
+ mtspr SPRN_MD_TWC, r11
mtcr r11
+ mfspr r11, SPRN_MD_TWC
+ lwz r11, 0(r11) /* Get the pte */
bt 28,200f /* bit 28 = Large page (8M) */
bt 29,202f /* bit 29 = Large page (8M or 512K) */
- rlwinm r11, r11,0,0,19 /* Extract page descriptor page address */
- /* Insert level 2 index */
- rlwimi r11, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
- lwz r11, 0(r11) /* Get the pte */
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 32 - PAGE_SHIFT, 31
201: lwz r11,0(r11)
@@ -712,18 +708,12 @@ FixupDAR:/* Entry point for dcbx workaround. */
141: mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Nope, go back to normal TLB processing */

- /* concat physical page address(r11) and page offset(r10) */
200:
- rlwinm r11, r10, 0, ~HUGEPD_SHIFT_MASK
- lwz r11, 0(r11) /* Get the pte */
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 32 - PAGE_SHIFT_8M, 31
b 201b

202:
- rlwinm r11, r11, 0, 0, 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1) - 1
- rlwimi r11, r10, 32 - (PAGE_SHIFT_512K - 2), 32 + PAGE_SHIFT_512K - (PAGE_SHIFT << 1), 29
- lwz r11, 0(r11) /* Get the pte */
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 32 - PAGE_SHIFT_512K, 31
b 201b
@@ -839,7 +829,7 @@ start_here:

lis r6, swapper_pg_dir@ha
tophys(r6,r6)
- mtspr SPRN_M_TW, r6
+ mtspr SPRN_M_TWB, r6

bl early_init /* We have to do this with MMU on */

diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
index 01b7f5107c3a..e2b6687ebb50 100644
--- a/arch/powerpc/mm/8xx_mmu.c
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -175,12 +175,12 @@ void set_context(unsigned long id, pgd_t *pgd)
*(ptr + 1) = pgd;
#endif

- /* Register M_TW will contain base address of level 1 table minus the
+ /* Register M_TWB will contain base address of level 1 table minus the
* lower part of the kernel PGDIR base address, so that all accesses to
* level 1 table are done relative to lower part of kernel PGDIR base
* address.
*/
- mtspr(SPRN_M_TW, __pa(pgd) - offset);
+ mtspr(SPRN_M_TWB, __pa(pgd) - offset);

/* Update context */
mtspr(SPRN_M_CASID, id - 1);
--
2.13.3


2018-11-29 14:09:41

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 11/20] powerpc/mm: fix a warning when a cache is common to PGD and hugepages

While implementing TLB miss HW assistance on the 8xx, the following
warning was encountered:

[ 423.732965] WARNING: CPU: 0 PID: 345 at mm/slub.c:2412 ___slab_alloc.constprop.30+0x26c/0x46c
[ 423.733033] CPU: 0 PID: 345 Comm: mmap Not tainted 4.18.0-rc8-00664-g2dfff9121c55 #671
[ 423.733075] NIP: c0108f90 LR: c0109ad0 CTR: 00000004
[ 423.733121] REGS: c455bba0 TRAP: 0700 Not tainted (4.18.0-rc8-00664-g2dfff9121c55)
[ 423.733147] MSR: 00021032 <ME,IR,DR,RI> CR: 24224848 XER: 20000000
[ 423.733319]
[ 423.733319] GPR00: c0109ad0 c455bc50 c4521910 c60053c0 007080c0 c0011b34 c7fa41e0 c455be30
[ 423.733319] GPR08: 00000001 c00103a0 c7fa41e0 c49afcc4 24282842 10018840 c079b37c 00000040
[ 423.733319] GPR16: 73f00000 00210d00 00000000 00000001 c455a000 00000100 00000200 c455a000
[ 423.733319] GPR24: c60053c0 c0011b34 007080c0 c455a000 c455a000 c7fa41e0 00000000 00009032
[ 423.734190] NIP [c0108f90] ___slab_alloc.constprop.30+0x26c/0x46c
[ 423.734257] LR [c0109ad0] kmem_cache_alloc+0x210/0x23c
[ 423.734283] Call Trace:
[ 423.734326] [c455bc50] [00000100] 0x100 (unreliable)
[ 423.734430] [c455bcc0] [c0109ad0] kmem_cache_alloc+0x210/0x23c
[ 423.734543] [c455bcf0] [c0011b34] huge_pte_alloc+0xc0/0x1dc
[ 423.734633] [c455bd20] [c01044dc] hugetlb_fault+0x408/0x48c
[ 423.734720] [c455bdb0] [c0104b20] follow_hugetlb_page+0x14c/0x44c
[ 423.734826] [c455be10] [c00e8e54] __get_user_pages+0x1c4/0x3dc
[ 423.734919] [c455be80] [c00e9924] __mm_populate+0xac/0x140
[ 423.735020] [c455bec0] [c00db14c] vm_mmap_pgoff+0xb4/0xb8
[ 423.735127] [c455bf00] [c00f27c0] ksys_mmap_pgoff+0xcc/0x1fc
[ 423.735222] [c455bf40] [c000e0f8] ret_from_syscall+0x0/0x38
[ 423.735271] Instruction dump:
[ 423.735321] 7cbf482e 38fd0008 7fa6eb78 7fc4f378 4bfff5dd 7fe3fb78 4bfffe24 81370010
[ 423.735536] 71280004 41a2ff88 4840c571 4bffff80 <0fe00000> 4bfffeb8 81340010 712a0004
[ 423.735757] ---[ end trace e9b222919a470790 ]---

This warning occurs when calling kmem_cache_zalloc() on a
cache having a constructor.

In this case it happens because PGD cache and 512k hugepte cache are
the same size (4k). While a cache with constructor is created for
the PGD, hugepages create cache without constructor and uses
kmem_cache_zalloc(). As both expect a cache with the same size,
the hugepages reuse the cache created for PGD, hence the conflict.

In order to avoid this conflict, this patch:
- modifies pgtable_cache_add() so that a zeroising constructor is
added for any cache size.
- replaces calls to kmem_cache_zalloc() by kmem_cache_alloc()

Signed-off-by: Christophe Leroy <[email protected]>
---
see original discussion in https://patchwork.ozlabs.org/patch/957565/

arch/powerpc/include/asm/pgtable.h | 2 +-
arch/powerpc/mm/hugetlbpage.c | 6 ++---
arch/powerpc/mm/init-common.c | 46 ++++++++++++++++++++++++++------------
3 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 56ef5437eb2f..f2bfaf674674 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -101,7 +101,7 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
/* can we use this in kvm */
unsigned long vmalloc_to_phys(void *vmalloc_addr);

-void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
+void pgtable_cache_add(unsigned int shift);
void pgtable_cache_init(void);

#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_PPC32)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index c4f1263228b8..bc97874d7c74 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -70,7 +70,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
num_hugepd = 1;
}

- new = kmem_cache_zalloc(cachep, pgtable_gfp_flags(mm, GFP_KERNEL));
+ new = kmem_cache_alloc(cachep, pgtable_gfp_flags(mm, GFP_KERNEL));

BUG_ON(pshift > HUGEPD_SHIFT_MASK);
BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
@@ -701,10 +701,10 @@ static int __init hugetlbpage_init(void)
* use pgt cache for hugepd.
*/
if (pdshift > shift)
- pgtable_cache_add(pdshift - shift, NULL);
+ pgtable_cache_add(pdshift - shift);
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
else
- pgtable_cache_add(PTE_T_ORDER, NULL);
+ pgtable_cache_add(PTE_T_ORDER);
#endif
}

diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 41190f2b60c2..b7ca03643d0b 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -25,19 +25,37 @@
#include <asm/pgalloc.h>
#include <asm/pgtable.h>

-static void pgd_ctor(void *addr)
-{
- memset(addr, 0, PGD_TABLE_SIZE);
+#define CTOR(shift) static void ctor_##shift(void *addr) \
+{ \
+ memset(addr, 0, sizeof(void *) << (shift)); \
}

-static void pud_ctor(void *addr)
-{
- memset(addr, 0, PUD_TABLE_SIZE);
-}
+CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
+CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);

-static void pmd_ctor(void *addr)
+static inline void (*ctor(int shift))(void *)
{
- memset(addr, 0, PMD_TABLE_SIZE);
+ BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
+
+ switch (shift) {
+ case 0: return ctor_0;
+ case 1: return ctor_1;
+ case 2: return ctor_2;
+ case 3: return ctor_3;
+ case 4: return ctor_4;
+ case 5: return ctor_5;
+ case 6: return ctor_6;
+ case 7: return ctor_7;
+ case 8: return ctor_8;
+ case 9: return ctor_9;
+ case 10: return ctor_10;
+ case 11: return ctor_11;
+ case 12: return ctor_12;
+ case 13: return ctor_13;
+ case 14: return ctor_14;
+ case 15: return ctor_15;
+ }
+ return NULL;
}

struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
@@ -50,7 +68,7 @@ EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */
* everything else. Caches created by this function are used for all
* the higher level pagetables, and for hugepage pagetables.
*/
-void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
+void pgtable_cache_add(unsigned int shift)
{
char *name;
unsigned long table_size = sizeof(void *) << shift;
@@ -78,7 +96,7 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))

align = max_t(unsigned long, align, minalign);
name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
- new = kmem_cache_create(name, table_size, align, 0, ctor);
+ new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
if (!new)
panic("Could not allocate pgtable cache for order %d", shift);

@@ -91,15 +109,15 @@ EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */

void pgtable_cache_init(void)
{
- pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
+ pgtable_cache_add(PGD_INDEX_SIZE);

if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX))
- pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
+ pgtable_cache_add(PMD_CACHE_INDEX);
/*
* In all current configs, when the PUD index exists it's the
* same size as either the pgd or pmd index except with THP enabled
* on book3s 64
*/
if (PUD_CACHE_INDEX && !PGT_CACHE(PUD_CACHE_INDEX))
- pgtable_cache_add(PUD_CACHE_INDEX, pud_ctor);
+ pgtable_cache_add(PUD_CACHE_INDEX);
}
--
2.13.3


2018-11-29 14:10:15

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 18/20] powerpc/8xx: reintroduce 16K pages with HW assistance

Using this HW assistance implies some constraints on the
page table structure:
- Regardless of the main page size used (4k or 16k), the
level 1 table (PGD) contains 1024 entries and each PGD entry covers
a 4Mbytes area which is managed by a level 2 table (PTE) containing
also 1024 entries each describing a 4k page.
- 16k pages require 4 identifical entries in the L2 table
- 512k pages PTE have to be spread every 128 bytes in the L2 table
- 8M pages PTE are at the address pointed by the L1 entry and each
8M page require 2 identical entries in the PGD.

In order to use hardware assistance with 16K pages, this patch does
the following modifications:
- Make PGD size independent of the main page size
- In 16k pages mode, redefine pte_t as a struct with 4 elements,
and populate those 4 elements in __set_pte_at() and pte_update()
- Adapt the size of the hugepage tables.
- Define a PTE_FRAGMENT_NB so that a 16k page contains 4 page tables.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/Kconfig | 2 +-
arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 4 ++++
arch/powerpc/include/asm/nohash/32/pgtable.h | 8 +++++++-
arch/powerpc/include/asm/nohash/pgtable.h | 4 ++++
arch/powerpc/include/asm/page_32.h | 3 ++-
arch/powerpc/include/asm/pgtable-types.h | 4 ++++
6 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ddfccdf004fe..8be31261aec8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -689,7 +689,7 @@ config PPC_4K_PAGES

config PPC_16K_PAGES
bool "16k page size"
- depends on 44x
+ depends on 44x || PPC_8xx

config PPC_64K_PAGES
bool "64k page size"
diff --git a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
index fa05aa566ece..b0f764c827c0 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
@@ -190,6 +190,7 @@ typedef struct {
struct slice_mask mask_8m;
# endif
#endif
+ void *pte_frag;
} mm_context_t;

#define PHYS_IMMR_BASE (mfspr(SPRN_IMMR) & 0xfff80000)
@@ -244,6 +245,9 @@ extern s32 patch__itlbmiss_perf, patch__dtlbmiss_perf;
#define mmu_virtual_psize MMU_PAGE_4K
#elif defined(CONFIG_PPC_16K_PAGES)
#define mmu_virtual_psize MMU_PAGE_16K
+#define PTE_FRAG_NR 4
+#define PTE_FRAG_SIZE_SHIFT 12
+#define PTE_FRAG_SIZE (1UL << 12)
#else
#error "Unsupported PAGE_SIZE"
#endif
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index e9c8604cc8c5..bed433358260 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -232,7 +232,13 @@ static inline unsigned long pte_update(pte_t *p,
: "cc" );
#else /* PTE_ATOMIC_UPDATES */
unsigned long old = pte_val(*p);
- *p = __pte((old & ~clr) | set);
+ unsigned long new = (old & ~clr) | set;
+
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
+ p->pte = p->pte1 = p->pte2 = p->pte3 = new;
+#else
+ *p = __pte(new);
+#endif
#endif /* !PTE_ATOMIC_UPDATES */

#ifdef CONFIG_44x
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 70ff23974b59..1ca1c1864b32 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -209,7 +209,11 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
/* Anything else just stores the PTE normally. That covers all 64-bit
* cases, and 32-bit non-hash with 32-bit PTEs.
*/
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
+ ptep->pte = ptep->pte1 = ptep->pte2 = ptep->pte3 = pte_val(pte);
+#else
*ptep = pte;
+#endif

/*
* With hardware tablewalk, a sync is needed to ensure that
diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h
index 5c378e9b78c8..683dfbc67ca8 100644
--- a/arch/powerpc/include/asm/page_32.h
+++ b/arch/powerpc/include/asm/page_32.h
@@ -22,7 +22,8 @@
#define PTE_FLAGS_OFFSET 0
#endif

-#ifdef CONFIG_PPC_256K_PAGES
+#if defined(CONFIG_PPC_256K_PAGES) || \
+ (defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES))
#define PTE_SHIFT (PAGE_SHIFT - PTE_T_LOG2 - 2) /* 1/4 of a page */
#else
#define PTE_SHIFT (PAGE_SHIFT - PTE_T_LOG2) /* full page */
diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index eccb30b38b47..3b0edf041b2e 100644
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -3,7 +3,11 @@
#define _ASM_POWERPC_PGTABLE_TYPES_H

/* PTE level */
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
+typedef struct { pte_basic_t pte, pte1, pte2, pte3; } pte_t;
+#else
typedef struct { pte_basic_t pte; } pte_t;
+#endif
#define __pte(x) ((pte_t) { (x) })
static inline pte_basic_t pte_val(pte_t x)
{
--
2.13.3


2018-11-29 14:10:21

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 12/20] powerpc/mm: remove unnecessary test in pgtable_cache_init()

pgtable_cache_add() gracefully handles the case when a cache that
size already exists by returning early with the following test:

if (PGT_CACHE(shift))
return; /* Already have a cache of this size */

It is then not needed to test the existence of the cache before.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/mm/init-common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index b7ca03643d0b..1e6910eb70ed 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -111,13 +111,13 @@ void pgtable_cache_init(void)
{
pgtable_cache_add(PGD_INDEX_SIZE);

- if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX))
+ if (PMD_CACHE_INDEX)
pgtable_cache_add(PMD_CACHE_INDEX);
/*
* In all current configs, when the PUD index exists it's the
* same size as either the pgd or pmd index except with THP enabled
* on book3s 64
*/
- if (PUD_CACHE_INDEX && !PGT_CACHE(PUD_CACHE_INDEX))
+ if (PUD_CACHE_INDEX)
pgtable_cache_add(PUD_CACHE_INDEX);
}
--
2.13.3


2018-11-29 14:10:38

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 05/20] powerpc/mm: move platform specific mmu-xxx.h in platform directories

The purpose of this patch is to move platform specific
mmu-xxx.h files in platform directories like pte-xxx.h files.

In the meantime this patch creates common nohash and
nohash/32 + nohash/64 mmu.h files for future common parts.

Reviewed-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/mmu.h | 14 ++------------
arch/powerpc/include/asm/{ => nohash/32}/mmu-40x.h | 0
arch/powerpc/include/asm/{ => nohash/32}/mmu-44x.h | 0
arch/powerpc/include/asm/{ => nohash/32}/mmu-8xx.h | 0
arch/powerpc/include/asm/nohash/32/mmu.h | 19 +++++++++++++++++++
arch/powerpc/include/asm/nohash/64/mmu.h | 8 ++++++++
arch/powerpc/include/asm/{ => nohash}/mmu-book3e.h | 0
arch/powerpc/include/asm/nohash/mmu.h | 11 +++++++++++
arch/powerpc/kernel/cpu_setup_fsl_booke.S | 2 +-
arch/powerpc/kvm/e500.h | 2 +-
10 files changed, 42 insertions(+), 14 deletions(-)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-40x.h (100%)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-44x.h (100%)
rename arch/powerpc/include/asm/{ => nohash/32}/mmu-8xx.h (100%)
create mode 100644 arch/powerpc/include/asm/nohash/32/mmu.h
create mode 100644 arch/powerpc/include/asm/nohash/64/mmu.h
rename arch/powerpc/include/asm/{ => nohash}/mmu-book3e.h (100%)
create mode 100644 arch/powerpc/include/asm/nohash/mmu.h

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index eb20eb3b8fb0..2184021b0e1c 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -341,18 +341,8 @@ static inline void mmu_early_init_devtree(void) { }
#if defined(CONFIG_PPC_STD_MMU_32)
/* 32-bit classic hash table MMU */
#include <asm/book3s/32/mmu-hash.h>
-#elif defined(CONFIG_40x)
-/* 40x-style software loaded TLB */
-# include <asm/mmu-40x.h>
-#elif defined(CONFIG_44x)
-/* 44x-style software loaded TLB */
-# include <asm/mmu-44x.h>
-#elif defined(CONFIG_PPC_BOOK3E_MMU)
-/* Freescale Book-E software loaded TLB or Book-3e (ISA 2.06+) MMU */
-# include <asm/mmu-book3e.h>
-#elif defined (CONFIG_PPC_8xx)
-/* Motorola/Freescale 8xx software loaded TLB */
-# include <asm/mmu-8xx.h>
+#elif defined(CONFIG_PPC_MMU_NOHASH)
+#include <asm/nohash/mmu.h>
#endif

#endif /* __KERNEL__ */
diff --git a/arch/powerpc/include/asm/mmu-40x.h b/arch/powerpc/include/asm/nohash/32/mmu-40x.h
similarity index 100%
rename from arch/powerpc/include/asm/mmu-40x.h
rename to arch/powerpc/include/asm/nohash/32/mmu-40x.h
diff --git a/arch/powerpc/include/asm/mmu-44x.h b/arch/powerpc/include/asm/nohash/32/mmu-44x.h
similarity index 100%
rename from arch/powerpc/include/asm/mmu-44x.h
rename to arch/powerpc/include/asm/nohash/32/mmu-44x.h
diff --git a/arch/powerpc/include/asm/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
similarity index 100%
rename from arch/powerpc/include/asm/mmu-8xx.h
rename to arch/powerpc/include/asm/nohash/32/mmu-8xx.h
diff --git a/arch/powerpc/include/asm/nohash/32/mmu.h b/arch/powerpc/include/asm/nohash/32/mmu.h
new file mode 100644
index 000000000000..af0e8b54876a
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/32/mmu.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_NOHASH_32_MMU_H_
+#define _ASM_POWERPC_NOHASH_32_MMU_H_
+
+#if defined(CONFIG_40x)
+/* 40x-style software loaded TLB */
+#include <asm/nohash/32/mmu-40x.h>
+#elif defined(CONFIG_44x)
+/* 44x-style software loaded TLB */
+#include <asm/nohash/32/mmu-44x.h>
+#elif defined(CONFIG_PPC_BOOK3E_MMU)
+/* Freescale Book-E software loaded TLB or Book-3e (ISA 2.06+) MMU */
+#include <asm/nohash/mmu-book3e.h>
+#elif defined (CONFIG_PPC_8xx)
+/* Motorola/Freescale 8xx software loaded TLB */
+#include <asm/nohash/32/mmu-8xx.h>
+#endif
+
+#endif /* _ASM_POWERPC_NOHASH_32_MMU_H_ */
diff --git a/arch/powerpc/include/asm/nohash/64/mmu.h b/arch/powerpc/include/asm/nohash/64/mmu.h
new file mode 100644
index 000000000000..87871d027b75
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/64/mmu.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_NOHASH_64_MMU_H_
+#define _ASM_POWERPC_NOHASH_64_MMU_H_
+
+/* Freescale Book-E software loaded TLB or Book-3e (ISA 2.06+) MMU */
+#include <asm/nohash/mmu-book3e.h>
+
+#endif /* _ASM_POWERPC_NOHASH_64_MMU_H_ */
diff --git a/arch/powerpc/include/asm/mmu-book3e.h b/arch/powerpc/include/asm/nohash/mmu-book3e.h
similarity index 100%
rename from arch/powerpc/include/asm/mmu-book3e.h
rename to arch/powerpc/include/asm/nohash/mmu-book3e.h
diff --git a/arch/powerpc/include/asm/nohash/mmu.h b/arch/powerpc/include/asm/nohash/mmu.h
new file mode 100644
index 000000000000..a037cb1efb57
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/mmu.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_NOHASH_MMU_H_
+#define _ASM_POWERPC_NOHASH_MMU_H_
+
+#ifdef CONFIG_PPC64
+#include <asm/nohash/64/mmu.h>
+#else
+#include <asm/nohash/32/mmu.h>
+#endif
+
+#endif /* _ASM_POWERPC_NOHASH_MMU_H_ */
diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
index 8d142e5d84cd..5fbc890d1094 100644
--- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
+++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
@@ -17,7 +17,7 @@
#include <asm/processor.h>
#include <asm/cputable.h>
#include <asm/ppc_asm.h>
-#include <asm/mmu-book3e.h>
+#include <asm/nohash/mmu-book3e.h>
#include <asm/asm-offsets.h>
#include <asm/mpc85xx.h>

diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 94f04fcb373e..962ee90a0dfe 100644
--- a/arch/powerpc/kvm/e500.h
+++ b/arch/powerpc/kvm/e500.h
@@ -20,7 +20,7 @@
#define KVM_E500_H

#include <linux/kvm_host.h>
-#include <asm/mmu-book3e.h>
+#include <asm/nohash/mmu-book3e.h>
#include <asm/tlb.h>
#include <asm/cputhreads.h>

--
2.13.3


2018-11-29 18:24:38

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 10/20] powerpc/mm: replace hugetlb_cache by PGT_CACHE(PTE_T_ORDER)

Instead of opencoding cache handling for the special case
of hugepage tables having a single pte_t element, this
patch makes use of the common pgtable_cache helpers

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/hugetlb.h | 2 --
arch/powerpc/mm/hugetlbpage.c | 26 +++++++-------------------
2 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index 98004262bc87..dfb8bf236586 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -5,8 +5,6 @@
#ifdef CONFIG_HUGETLB_PAGE
#include <asm/page.h>

-extern struct kmem_cache *hugepte_cache;
-
#ifdef CONFIG_PPC_BOOK3S_64

#include <asm/book3s/64/hugetlb.h>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 8cf035e68378..c4f1263228b8 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -42,6 +42,8 @@ EXPORT_SYMBOL(HPAGE_SHIFT);

#define hugepd_none(hpd) (hpd_val(hpd) == 0)

+#define PTE_T_ORDER (__builtin_ffs(sizeof(pte_t)) - __builtin_ffs(sizeof(void *)))
+
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
/*
@@ -61,7 +63,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
int num_hugepd;

if (pshift >= pdshift) {
- cachep = hugepte_cache;
+ cachep = PGT_CACHE(PTE_T_ORDER);
num_hugepd = 1 << (pshift - pdshift);
} else {
cachep = PGT_CACHE(pdshift - pshift);
@@ -264,7 +266,7 @@ static void hugepd_free_rcu_callback(struct rcu_head *head)
unsigned int i;

for (i = 0; i < batch->index; i++)
- kmem_cache_free(hugepte_cache, batch->ptes[i]);
+ kmem_cache_free(PGT_CACHE(PTE_T_ORDER), batch->ptes[i]);

free_page((unsigned long)batch);
}
@@ -277,7 +279,7 @@ static void hugepd_free(struct mmu_gather *tlb, void *hugepte)

if (atomic_read(&tlb->mm->mm_users) < 2 ||
mm_is_thread_local(tlb->mm)) {
- kmem_cache_free(hugepte_cache, hugepte);
+ kmem_cache_free(PGT_CACHE(PTE_T_ORDER), hugepte);
put_cpu_var(hugepd_freelist_cur);
return;
}
@@ -652,7 +654,6 @@ static int __init hugepage_setup_sz(char *str)
}
__setup("hugepagesz=", hugepage_setup_sz);

-struct kmem_cache *hugepte_cache;
static int __init hugetlbpage_init(void)
{
int psize;
@@ -702,21 +703,8 @@ static int __init hugetlbpage_init(void)
if (pdshift > shift)
pgtable_cache_add(pdshift - shift, NULL);
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
- else if (!hugepte_cache) {
- /*
- * Create a kmem cache for hugeptes. The bottom bits in
- * the pte have size information encoded in them, so
- * align them to allow this
- */
- hugepte_cache = kmem_cache_create("hugepte-cache",
- sizeof(pte_t),
- HUGEPD_SHIFT_MASK + 1,
- 0, NULL);
- if (hugepte_cache == NULL)
- panic("%s: Unable to create kmem cache "
- "for hugeptes\n", __func__);
-
- }
+ else
+ pgtable_cache_add(PTE_T_ORDER, NULL);
#endif
}

--
2.13.3


2018-11-29 19:08:26

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v9 02/20] powerpc/8xx: Remove PTE_ATOMIC_UPDATES

commit 1bc54c03117b9 ("powerpc: rework 4xx PTE access and TLB miss")
introduced non atomic PTE updates and started the work of removing
PTE updates in TLB miss handlers, but kept PTE_ATOMIC_UPDATES for the
8xx with the following comment:
/* Until my rework is finished, 8xx still needs atomic PTE updates */

commit fe11dc3f9628e ("powerpc/8xx: Update TLB asm so it behaves as
linux mm expects") removed all PTE updates done in TLB miss handlers

Therefore, atomic PTE updates are not needed anymore for the 8xx

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/nohash/32/pte-8xx.h | 3 ---
1 file changed, 3 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
index 6bfe041ef59d..c9e4b2d90f65 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
@@ -65,9 +65,6 @@

#define _PTE_NONE_MASK 0

-/* Until my rework is finished, 8xx still needs atomic PTE updates */
-#define PTE_ATOMIC_UPDATES 1
-
#ifdef CONFIG_PPC_16K_PAGES
#define _PAGE_PSIZE _PAGE_SPS
#else
--
2.13.3


2018-12-07 13:08:08

by Michael Ellerman

[permalink] [raw]
Subject: Re: [v9,01/20] powerpc/book3s32: Remove CONFIG_BOOKE dependent code

On Thu, 2018-11-29 at 14:06:47 UTC, Christophe Leroy wrote:
> BOOK3S/32 cannot be BOOKE, so remove useless code
>
> Signed-off-by: Christophe Leroy <[email protected]>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/a43ccc4bc499cb592e2cb3b4ada8d3

cheers