Re: [PATCH v3] mtrr: avoid ifdef'ery with phys_wc_to_mtrr_index()

["Luis R. Rodriguez" <mcgrof@suse.com>]

On Tue, Apr 21, 2015 at 01:42:51PM -0700, Luis R. Rodriguez wrote:
> From: "Luis R. Rodriguez" <mcgrof@suse.com>
> 
> There is only one user but since we're going to bury
> MTRR next out of access to drivers expose this last
> piece of API to drivers in a general fashion only
> needing io.h for access to helpers.
> 
> Cc: Toshi Kani <toshi.kani@hp.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Thierry Reding <treding@nvidia.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Abhilash Kesavan <a.kesavan@samsung.com>
> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> Cc: Cristian Stoica <cristian.stoica@freescale.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: Suresh Siddha <sbsiddha@gmail.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Antonino Daplas <adaplas@gmail.com>
> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: Ville Syrjälä <syrjala@sci.fi>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Davidlohr Bueso <dbueso@suse.de>
> Cc: x86@kernel.org
> Cc: linux-fbdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
> ---
>  arch/x86/include/asm/io.h       |  3 +++
>  arch/x86/include/asm/mtrr.h     |  5 -----
>  arch/x86/kernel/cpu/mtrr/main.c |  6 +++---
>  drivers/gpu/drm/drm_ioctl.c     | 14 +-------------
>  include/linux/io.h              |  6 ++++++
>  5 files changed, 13 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
> index 4afc05f..a2b9740 100644
> --- a/arch/x86/include/asm/io.h
> +++ b/arch/x86/include/asm/io.h
> @@ -339,6 +339,9 @@ extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
>  #define IO_SPACE_LIMIT 0xffff
>  
>  #ifdef CONFIG_MTRR
> +extern int __must_check arch_phys_wc_index(int handle);
> +#define arch_phys_wc_index arch_phys_wc_index
> +
>  extern int __must_check arch_phys_wc_add(unsigned long base,
>  					 unsigned long size);
>  extern void arch_phys_wc_del(int handle);
> diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
> index da8dff1..27e3dc0 100644
> --- a/arch/x86/include/asm/mtrr.h
> +++ b/arch/x86/include/asm/mtrr.h
> @@ -48,7 +48,6 @@ extern void mtrr_aps_init(void);
>  extern void mtrr_bp_restore(void);
>  extern int mtrr_trim_uncached_memory(unsigned long end_pfn);
>  extern int amd_special_default_mtrr(void);
> -extern int phys_wc_to_mtrr_index(int handle);
>  #  else
>  static inline u8 mtrr_type_lookup(u64 addr, u64 end, u8 *uniform)
>  {
> @@ -85,10 +84,6 @@ static inline int mtrr_trim_uncached_memory(unsigned long end_pfn)
>  static inline void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
>  {
>  }
> -static inline int phys_wc_to_mtrr_index(int handle)
> -{
> -	return -1;
> -}
>  
>  #define mtrr_ap_init() do {} while (0)
>  #define mtrr_bp_init() do {} while (0)
> diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
> index 12abdbe..d8c106c 100644
> --- a/arch/x86/kernel/cpu/mtrr/main.c
> +++ b/arch/x86/kernel/cpu/mtrr/main.c
> @@ -580,7 +580,7 @@ void arch_phys_wc_del(int handle)
>  EXPORT_SYMBOL(arch_phys_wc_del);
>  
>  /*
> - * phys_wc_to_mtrr_index - translates arch_phys_wc_add's return value
> + * arch_phys_wc_index - translates arch_phys_wc_add's return value
>   * @handle: Return value from arch_phys_wc_add
>   *
>   * This will turn the return value from arch_phys_wc_add into an mtrr
> @@ -590,14 +590,14 @@ EXPORT_SYMBOL(arch_phys_wc_del);
>   * in printk line.  Alas there is an illegitimate use in some ancient
>   * drm ioctls.
>   */
> -int phys_wc_to_mtrr_index(int handle)
> +int arch_phys_wc_index(int handle)
>  {
>  	if (handle < MTRR_TO_PHYS_WC_OFFSET)
>  		return -1;
>  	else
>  		return handle - MTRR_TO_PHYS_WC_OFFSET;
>  }
> -EXPORT_SYMBOL_GPL(phys_wc_to_mtrr_index);
> +EXPORT_SYMBOL_GPL(arch_phys_wc_index);
>  
>  /*
>   * HACK ALERT!
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index 266dcd6..0a95782 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -36,9 +36,6 @@
>  
>  #include <linux/pci.h>
>  #include <linux/export.h>
> -#ifdef CONFIG_X86
> -#include <asm/mtrr.h>
> -#endif
>  
>  static int drm_version(struct drm_device *dev, void *data,
>  		       struct drm_file *file_priv);
> @@ -197,16 +194,7 @@ static int drm_getmap(struct drm_device *dev, void *data,
>  	map->type = r_list->map->type;
>  	map->flags = r_list->map->flags;
>  	map->handle = (void *)(unsigned long) r_list->user_token;
> -
> -#ifdef CONFIG_X86
> -	/*
> -	 * There appears to be exactly one user of the mtrr index: dritest.
> -	 * It's easy enough to keep it working on non-PAT systems.
> -	 */
> -	map->mtrr = phys_wc_to_mtrr_index(r_list->map->mtrr);
> -#else
> -	map->mtrr = -1;
> -#endif
> +	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
>  
>  	mutex_unlock(&dev->struct_mutex);
>  
> diff --git a/include/linux/io.h b/include/linux/io.h
> index 986f2bf..6e29acf 100644
> --- a/include/linux/io.h
> +++ b/include/linux/io.h
> @@ -111,6 +111,12 @@ static inline void arch_phys_wc_del(int handle)
>  }
>  
>  #define arch_phys_wc_add arch_phys_wc_add
> +#ifndef arch_phys_wc_index
> +static inline int arch_phys_wc_index(int handle)
> +{
> +	return -1;
> +}
> +#define arch_phys_wc_index arch_phys_wc_index
>  #endif

Sorry this is missing an #endif here, will send a v4.

  Luis