From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: benh@kernel.crashing.org, mpe@ellerman.id.au,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH V4 06/18] powerpc/mm: Switch book3s 64 with 64K page size to 4 level page table
Date: Fri, 26 Feb 2016 07:37:51 +0530 [thread overview]
Message-ID: <87bn74jkaw.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160225033932.GE18753@oak.ozlabs.ibm.com>
Paul Mackerras <paulus@ozlabs.org> writes:
> On Tue, Feb 23, 2016 at 10:18:08AM +0530, Aneesh Kumar K.V wrote:
>> This is needed so that we can support both hash and radix page table
>> using single kernel. Radix kernel uses a 4 level table.
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/Kconfig | 1 +
>> arch/powerpc/include/asm/book3s/64/hash-4k.h | 33 +--------------------------
>> arch/powerpc/include/asm/book3s/64/hash-64k.h | 20 +++++++++-------
>> arch/powerpc/include/asm/book3s/64/hash.h | 11 +++++++++
>> arch/powerpc/include/asm/book3s/64/pgtable.h | 25 +++++++++++++++++++-
>> arch/powerpc/include/asm/pgalloc-64.h | 28 ++++++++++++++++++++---
>> arch/powerpc/include/asm/pgtable-types.h | 13 +++++++----
>> arch/powerpc/mm/init_64.c | 21 ++++++++++++-----
>> 8 files changed, 97 insertions(+), 55 deletions(-)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 9faa18c4f3f7..599329332613 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -303,6 +303,7 @@ config ZONE_DMA32
>> config PGTABLE_LEVELS
>> int
>> default 2 if !PPC64
>> + default 4 if PPC_BOOK3S_64
>> default 3 if PPC_64K_PAGES
>> default 4
>
> Why not just "default 4"? Why do we still need the if PPC_BOOK3S_64
> line at all?
You are suggesting remove that PPC_64K_PAGES line right ? I was not sure
about other platforms that use 64K pages.
>
> [...]
>
>> diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
>> index ef9bd68f7e6d..d0ee6fcef823 100644
>> --- a/arch/powerpc/include/asm/book3s/64/hash.h
>> +++ b/arch/powerpc/include/asm/book3s/64/hash.h
>> @@ -235,6 +235,7 @@
>> #define __pgtable_ptr_val(ptr) __pa(ptr)
>>
>> #define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & (PTRS_PER_PGD - 1))
>> +#define pud_index(address) (((address) >> (PUD_SHIFT)) & (PTRS_PER_PUD - 1))
>> #define pmd_index(address) (((address) >> (PMD_SHIFT)) & (PTRS_PER_PMD - 1))
>> #define pte_index(address) (((address) >> (PAGE_SHIFT)) & (PTRS_PER_PTE - 1))
>>
>> @@ -363,8 +364,18 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
>> :"cc");
>> }
>>
>> +static inline int pgd_bad(pgd_t pgd)
>> +{
>> + return (pgd_val(pgd) == 0);
>> +}
>> +
>> #define __HAVE_ARCH_PTE_SAME
>> #define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
>> +static inline unsigned long pgd_page_vaddr(pgd_t pgd)
>> +{
>> + return (unsigned long)__va(pgd_val(pgd) & ~PGD_MASKED_BITS);
>> +}
>> +
>>
>> /* Generic accessors to PTE bits */
>> static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_RW);}
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> index 7482f69117b6..77d3ce05798e 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> @@ -106,6 +106,26 @@ static inline void pgd_set(pgd_t *pgdp, unsigned long val)
>> *pgdp = __pgd(val);
>> }
>>
>> +static inline void pgd_clear(pgd_t *pgdp)
>> +{
>> + *pgdp = __pgd(0);
>> +}
>> +
>> +#define pgd_none(pgd) (!pgd_val(pgd))
>> +#define pgd_present(pgd) (!pgd_none(pgd))
>> +
>> +static inline pte_t pgd_pte(pgd_t pgd)
>> +{
>> + return __pte(pgd_val(pgd));
>> +}
>> +
>> +static inline pgd_t pte_pgd(pte_t pte)
>> +{
>> + return __pgd(pte_val(pte));
>> +}
>> +
>> +extern struct page *pgd_page(pgd_t pgd);
>
> Why did you put pgd_bad() and pgd_page_vaddr() in hash.h, but
> pgd_clear(), pgd_none, pgd_present etc. in pgtable.h? Why split them
> between two headers rather than putting them all in the same header?
>
Any page table operation that involved PTE bit position I am moving to
hash.h with the expectation that we will have to put a conditional call
in there. Functions like pgd_none and pgd_clear don't use bit
positions.
-aneesh
next prev parent reply other threads:[~2016-02-26 2:08 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 4:48 [PATCH V4 00/18] Book3s abstraction in preparation for new MMU model Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 01/18] powerp/mm: Update code comments Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 02/18] mm: Some arch may want to use HPAGE_PMD related values as variables Aneesh Kumar K.V
2016-02-25 5:06 ` Balbir Singh
2016-02-23 4:48 ` [PATCH V4 03/18] powerpc/mm: add _PAGE_HASHPTE similar to 4K hash Aneesh Kumar K.V
2016-02-23 5:38 ` Paul Mackerras
2016-02-23 9:22 ` Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 04/18] powerpc/mm: Split pgtable types to separate header Aneesh Kumar K.V
2016-02-25 3:12 ` Paul Mackerras
2016-02-25 5:35 ` Balbir Singh
2016-02-23 4:48 ` [PATCH V4 05/18] powerpc/mm: Don't have conditional defines for real_pte_t Aneesh Kumar K.V
2016-02-25 3:24 ` Paul Mackerras
2016-02-25 6:03 ` Balbir Singh
2016-02-23 4:48 ` [PATCH V4 06/18] powerpc/mm: Switch book3s 64 with 64K page size to 4 level page table Aneesh Kumar K.V
2016-02-25 3:39 ` Paul Mackerras
2016-02-26 2:07 ` Aneesh Kumar K.V [this message]
2016-02-23 4:48 ` [PATCH V4 07/18] powerpc/mm: Update masked bits for linux " Aneesh Kumar K.V
2016-02-25 3:41 ` Paul Mackerras
2016-02-26 2:08 ` Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 08/18] powerpc/mm: Copy pgalloc (part 1) Aneesh Kumar K.V
2016-02-25 4:27 ` Paul Mackerras
2016-02-26 2:11 ` Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 09/18] powerpc/mm: Copy pgalloc (part 2) Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 10/18] powerpc/mm: Copy pgalloc (part 3) Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 11/18] powerpc/mm: Hugetlbfs is book3s_64 and fsl_book3e (32 or 64) Aneesh Kumar K.V
2016-02-25 5:41 ` Paul Mackerras
2016-02-26 9:57 ` Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 12/18] powerpc/mm: Use flush_tlb_page in ptep_clear_flush_young Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 13/18] powerpc/mm: Move hash related mmu-*.h headers to book3s/ Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 14/18] powerpc/mm: Create a new headers for tlbflush for hash64 Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 15/18] powerpc/mm: Move hash page table related functions to pgtable-hash64.c Aneesh Kumar K.V
2016-02-25 4:32 ` Scott Wood
2016-02-26 10:00 ` Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 16/18] powerpc/mm: THP is only available on hash64 as of now Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 17/18] powerpc/mm: Use generic version of pmdp_clear_flush_young Aneesh Kumar K.V
2016-02-23 4:48 ` [PATCH V4 18/18] powerpc/mm: Move hash64 specific definitions to separate header Aneesh Kumar K.V
2016-02-23 9:26 ` [PATCH V4 00/18] Book3s abstraction in preparation for new MMU model Aneesh Kumar K.V
2016-02-25 4:34 ` Scott Wood
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