2020-04-02 08:17:56

by Mike Rapoport

[permalink] [raw]
Subject: [PATCH] mips: define pud_index() regardless of page table folding

From: Mike Rapoport <[email protected]>

Commit 31168f033e37 ("mips: drop __pXd_offset() macros that duplicate
pXd_index() ones") is correct that pud_index() & __pud_offset() are the
same when pud_index() is actually provided, however it does not take into
account the __PAGETABLE_PUD_FOLDED case. This has broken MIPS KVM
compilation because it relied on availability of pud_index().

Define pud_index() regardless of page table folded. It will evaluate to
actual index for 4-level pagetables and to 0 for folded PUD level.

Link: https://lore.kernel.org/lkml/[email protected]
Reported-by: Paolo Bonzini <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/mips/include/asm/pgtable-64.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index f92716cfa4f4..ee5dc0c145b9 100644
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -172,6 +172,8 @@

extern pte_t invalid_pte_table[PTRS_PER_PTE];

+#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
+
#ifndef __PAGETABLE_PUD_FOLDED
/*
* For 4-level pagetables we defines these ourselves, for 3-level the
@@ -210,8 +212,6 @@ static inline void p4d_clear(p4d_t *p4dp)
p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
}

-#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
-
static inline unsigned long p4d_page_vaddr(p4d_t p4d)
{
return p4d_val(p4d);
--
2.25.1


2020-04-13 09:00:01

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] mips: define pud_index() regardless of page table folding

Tested-by: Huacai Chen <[email protected]>

On Thu, Apr 2, 2020 at 4:17 PM Mike Rapoport <[email protected]> wrote:
>
> From: Mike Rapoport <[email protected]>
>
> Commit 31168f033e37 ("mips: drop __pXd_offset() macros that duplicate
> pXd_index() ones") is correct that pud_index() & __pud_offset() are the
> same when pud_index() is actually provided, however it does not take into
> account the __PAGETABLE_PUD_FOLDED case. This has broken MIPS KVM
> compilation because it relied on availability of pud_index().
>
> Define pud_index() regardless of page table folded. It will evaluate to
> actual index for 4-level pagetables and to 0 for folded PUD level.
>
> Link: https://lore.kernel.org/lkml/[email protected]
> Reported-by: Paolo Bonzini <[email protected]>
> Signed-off-by: Mike Rapoport <[email protected]>
> ---
> arch/mips/include/asm/pgtable-64.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
> index f92716cfa4f4..ee5dc0c145b9 100644
> --- a/arch/mips/include/asm/pgtable-64.h
> +++ b/arch/mips/include/asm/pgtable-64.h
> @@ -172,6 +172,8 @@
>
> extern pte_t invalid_pte_table[PTRS_PER_PTE];
>
> +#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
> +
> #ifndef __PAGETABLE_PUD_FOLDED
> /*
> * For 4-level pagetables we defines these ourselves, for 3-level the
> @@ -210,8 +212,6 @@ static inline void p4d_clear(p4d_t *p4dp)
> p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
> }
>
> -#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
> -
> static inline unsigned long p4d_page_vaddr(p4d_t p4d)
> {
> return p4d_val(p4d);
> --
> 2.25.1
>

2020-04-15 22:11:15

by Philippe Mathieu-Daudé

[permalink] [raw]
Subject: Re: [PATCH] mips: define pud_index() regardless of page table folding

On 4/2/20 10:16 AM, Mike Rapoport wrote:
> From: Mike Rapoport <[email protected]>
>
> Commit 31168f033e37 ("mips: drop __pXd_offset() macros that duplicate
> pXd_index() ones") is correct that pud_index() & __pud_offset() are the
> same when pud_index() is actually provided, however it does not take into
> account the __PAGETABLE_PUD_FOLDED case. This has broken MIPS KVM
> compilation because it relied on availability of pud_index().
>
> Define pud_index() regardless of page table folded. It will evaluate to
> actual index for 4-level pagetables and to 0 for folded PUD level.
>
> Link: https://lore.kernel.org/lkml/[email protected]
> Reported-by: Paolo Bonzini <[email protected]>
> Signed-off-by: Mike Rapoport <[email protected]>

Reviewed-by: Philippe Mathieu-Daudé <[email protected]>

> ---
> arch/mips/include/asm/pgtable-64.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
> index f92716cfa4f4..ee5dc0c145b9 100644
> --- a/arch/mips/include/asm/pgtable-64.h
> +++ b/arch/mips/include/asm/pgtable-64.h
> @@ -172,6 +172,8 @@
>
> extern pte_t invalid_pte_table[PTRS_PER_PTE];
>
> +#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
> +
> #ifndef __PAGETABLE_PUD_FOLDED
> /*
> * For 4-level pagetables we defines these ourselves, for 3-level the
> @@ -210,8 +212,6 @@ static inline void p4d_clear(p4d_t *p4dp)
> p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
> }
>
> -#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
> -
> static inline unsigned long p4d_page_vaddr(p4d_t p4d)
> {
> return p4d_val(p4d);
>

2020-04-16 16:45:53

by Thomas Bogendoerfer

[permalink] [raw]
Subject: Re: [PATCH] mips: define pud_index() regardless of page table folding

On Thu, Apr 02, 2020 at 11:16:14AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <[email protected]>
>
> Commit 31168f033e37 ("mips: drop __pXd_offset() macros that duplicate
> pXd_index() ones") is correct that pud_index() & __pud_offset() are the
> same when pud_index() is actually provided, however it does not take into
> account the __PAGETABLE_PUD_FOLDED case. This has broken MIPS KVM
> compilation because it relied on availability of pud_index().
>
> Define pud_index() regardless of page table folded. It will evaluate to
> actual index for 4-level pagetables and to 0 for folded PUD level.
>
> Link: https://lore.kernel.org/lkml/[email protected]
> Reported-by: Paolo Bonzini <[email protected]>
> Signed-off-by: Mike Rapoport <[email protected]>
> ---
> arch/mips/include/asm/pgtable-64.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]