Re: [tip:x86/urgent] x86/mm/pat: Adjust default caching mode translation tables

[Toshi Kani <toshi.kani@hp.com>]

Ingo,

Please drop this change as I explained below.
http://marc.info/?l=linux-kernel&m=143751782107284&w=2

Thanks,
-Toshi


On Tue, 2015-07-21 at 02:38 -0700, tip-bot for Jan Beulich wrote:
> Commit-ID:  ca1fec58bc6a90be96a59b4769e951156846c6ca
> Gitweb:     
> http://git.kernel.org/tip/ca1fec58bc6a90be96a59b4769e951156846c6ca
> Author:     Jan Beulich <JBeulich@suse.com>
> AuthorDate: Mon, 20 Jul 2015 08:46:14 +0100
> Committer:  Ingo Molnar <mingo@kernel.org>
> CommitDate: Tue, 21 Jul 2015 08:23:06 +0200
> 
> x86/mm/pat: Adjust default caching mode translation tables
> 
> Make WT really mean WT (rather than UC).
> 
> I can't see why commit 9cd25aac1f ("x86/mm/pat: Emulate PAT when
> it is disabled") didn't make this to match its changes to
> pat_init().
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Toshi Kani <toshi.kani@hp.com>
> Link: 
> http://lkml.kernel.org/r/55ACC3660200007800092E62@mail.emea.novell.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> ---
>  arch/x86/mm/init.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index 8533b46..7a45322 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -43,18 +43,18 @@ uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = 
> {
>  	[_PAGE_CACHE_MODE_WC      ]	= 0         | _PAGE_PCD,
>  	[_PAGE_CACHE_MODE_UC_MINUS]	= 0         | _PAGE_PCD,
>  	[_PAGE_CACHE_MODE_UC      ]	= _PAGE_PWT | _PAGE_PCD,
> -	[_PAGE_CACHE_MODE_WT      ]	= 0         | _PAGE_PCD,
> +	[_PAGE_CACHE_MODE_WT      ]	= _PAGE_PWT | 0,
>  	[_PAGE_CACHE_MODE_WP      ]	= 0         | _PAGE_PCD,
>  };
>  EXPORT_SYMBOL(__cachemode2pte_tbl);
>  
>  uint8_t __pte2cachemode_tbl[8] = {
>  	[__pte2cm_idx( 0        | 0         | 0        )] = 
> _PAGE_CACHE_MODE_WB,
> -	[__pte2cm_idx(_PAGE_PWT | 0         | 0        )] = 
> _PAGE_CACHE_MODE_UC_MINUS,
> +	[__pte2cm_idx(_PAGE_PWT | 0         | 0        )] = 
> _PAGE_CACHE_MODE_WT,
>  	[__pte2cm_idx( 0        | _PAGE_PCD | 0        )] = 
> _PAGE_CACHE_MODE_UC_MINUS,
>  	[__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | 0        )] = 
> _PAGE_CACHE_MODE_UC,
>  	[__pte2cm_idx( 0        | 0         | _PAGE_PAT)] = 
> _PAGE_CACHE_MODE_WB,
> -	[__pte2cm_idx(_PAGE_PWT | 0         | _PAGE_PAT)] = 
> _PAGE_CACHE_MODE_UC_MINUS,
> +	[__pte2cm_idx(_PAGE_PWT | 0         | _PAGE_PAT)] = 
> _PAGE_CACHE_MODE_WT,
>  	[__pte2cm_idx(0         | _PAGE_PCD | _PAGE_PAT)] = 
> _PAGE_CACHE_MODE_UC_MINUS,
>  	[__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = 
> _PAGE_CACHE_MODE_UC,
>  };