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

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

[Mike Rapoport]

From: Mike Rapoport <rppt@linux.ibm.com>

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/20200331154749.5457-1-pbonzini@redhat.com
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 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

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

[Huacai Chen]

Tested-by: Huacai Chen <chenhc@lemote.com>

On Thu, Apr 2, 2020 at 4:17 PM Mike Rapoport <rppt@kernel.org> wrote:
>
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> 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/20200331154749.5457-1-pbonzini@redhat.com
> Reported-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  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
>

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

[Philippe Mathieu-Daudé]

On 4/2/20 10:16 AM, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> 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/20200331154749.5457-1-pbonzini@redhat.com
> Reported-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  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);
> 

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

[Thomas Bogendoerfer]

On Thu, Apr 02, 2020 at 11:16:14AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> 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/20200331154749.5457-1-pbonzini@redhat.com
> Reported-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  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 ]