diff mbox series

[v5,11/25] mm: Introduce arch_calc_vm_flag_bits()

Message ID 20200624175244.25837-12-catalin.marinas@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Memory Tagging Extension user-space support | expand

Commit Message

Catalin Marinas June 24, 2020, 5:52 p.m. UTC 
From: Kevin Brodsky <Kevin.Brodsky@arm.com>

Similarly to arch_calc_vm_prot_bits(), introduce a dummy
arch_calc_vm_flag_bits() invoked from calc_vm_flag_bits(). This macro
can be overridden by architectures to insert specific VM_* flags derived
from the mmap() MAP_* flags.

Signed-off-by: Kevin Brodsky <Kevin.Brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---

Notes:
    v2:
    - Updated the comment above arch_calc_vm_prot_bits().
    - Changed author since this patch had already been posted (internally).

 include/linux/mman.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Andrew Morton June 24, 2020, 6:36 p.m. UTC | #1 
On Wed, 24 Jun 2020 18:52:30 +0100 Catalin Marinas <catalin.marinas@arm.com> wrote:

> From: Kevin Brodsky <Kevin.Brodsky@arm.com>
> 
> Similarly to arch_calc_vm_prot_bits(), introduce a dummy
> arch_calc_vm_flag_bits() invoked from calc_vm_flag_bits(). This macro
> can be overridden by architectures to insert specific VM_* flags derived
> from the mmap() MAP_* flags.
> 
> ...
>
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -74,13 +74,17 @@ static inline void vm_unacct_memory(long pages)
>  }
>  
>  /*
> - * Allow architectures to handle additional protection bits
> + * Allow architectures to handle additional protection and flag bits
>   */
>  
>  #ifndef arch_calc_vm_prot_bits
>  #define arch_calc_vm_prot_bits(prot, pkey) 0
>  #endif
>  
> +#ifndef arch_calc_vm_flag_bits
> +#define arch_calc_vm_flag_bits(flags) 0
> +#endif

It would be helpful to add a comment specifying which arch header file
is responsible for defining arch_calc_vm_flag_bits.  Because in the
past we've messed this sort of thing up and had different architectures
define things in different header files, resulting in build issues as
code evolves.

>  #ifndef arch_vm_get_page_prot
>  #define arch_vm_get_page_prot(vm_flags) __pgprot(0)
>  #endif
> @@ -131,7 +135,8 @@ calc_vm_flag_bits(unsigned long flags)
>  	return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
>  	       _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
>  	       _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    ) |
> -	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      );
> +	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      ) |
> +	       arch_calc_vm_flag_bits(flags);
>  }
>  
>  unsigned long vm_commit_limit(void);
Catalin Marinas June 25, 2020, 5:34 p.m. UTC | #2 
On Wed, Jun 24, 2020 at 11:36:11AM -0700, Andrew Morton wrote:
> On Wed, 24 Jun 2020 18:52:30 +0100 Catalin Marinas <catalin.marinas@arm.com> wrote:
> > From: Kevin Brodsky <Kevin.Brodsky@arm.com>
> > Similarly to arch_calc_vm_prot_bits(), introduce a dummy
> > arch_calc_vm_flag_bits() invoked from calc_vm_flag_bits(). This macro
> > can be overridden by architectures to insert specific VM_* flags derived
> > from the mmap() MAP_* flags.
> > 
> > ...
> >
> > --- a/include/linux/mman.h
> > +++ b/include/linux/mman.h
> > @@ -74,13 +74,17 @@ static inline void vm_unacct_memory(long pages)
> >  }
> >  
> >  /*
> > - * Allow architectures to handle additional protection bits
> > + * Allow architectures to handle additional protection and flag bits
> >   */
> >  
> >  #ifndef arch_calc_vm_prot_bits
> >  #define arch_calc_vm_prot_bits(prot, pkey) 0
> >  #endif
> >  
> > +#ifndef arch_calc_vm_flag_bits
> > +#define arch_calc_vm_flag_bits(flags) 0
> > +#endif
> 
> It would be helpful to add a comment specifying which arch header file
> is responsible for defining arch_calc_vm_flag_bits.  Because in the
> past we've messed this sort of thing up and had different architectures
> define things in different header files, resulting in build issues as
> code evolves.

I'll add a comment that the overriding definitions need to go in the
arch asm/mman.h file.

Thanks.
diff mbox series

Patch

diff --git a/include/linux/mman.h b/include/linux/mman.h
index 4b08e9c9c538..15c1162b9d65 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -74,13 +74,17 @@  static inline void vm_unacct_memory(long pages)
 }
 
 /*
- * Allow architectures to handle additional protection bits
+ * Allow architectures to handle additional protection and flag bits
  */
 
 #ifndef arch_calc_vm_prot_bits
 #define arch_calc_vm_prot_bits(prot, pkey) 0
 #endif
 
+#ifndef arch_calc_vm_flag_bits
+#define arch_calc_vm_flag_bits(flags) 0
+#endif
+
 #ifndef arch_vm_get_page_prot
 #define arch_vm_get_page_prot(vm_flags) __pgprot(0)
 #endif
@@ -131,7 +135,8 @@  calc_vm_flag_bits(unsigned long flags)
 	return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
 	       _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
 	       _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    ) |
-	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      );
+	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      ) |
+	       arch_calc_vm_flag_bits(flags);
 }
 
 unsigned long vm_commit_limit(void);