xen: introduce xen_remap, use it instead of ioremap

Commit Message

Stefano Stabellini Feb. 19, 2013, 1:59 p.m. UTC

ioremap can't be used to map ring pages on ARM because it uses device
memory caching attributes (MT_DEVICE*).

Introduce a Xen specific abstraction to map ring pages, called
xen_remap, that is defined as ioremap on x86 (no behavioral changes).
On ARM it explicitly calls __arm_ioremap with the right caching
attributes: MT_MEMORY.

Signed-off-by: Stefano Stabellini <[e-mail]>

Comments

Konrad Rzeszutek Wilk Feb. 19, 2013, 2:42 p.m. UTC | #1

On Tue, Feb 19, 2013 at 01:59:19PM +0000, Stefano Stabellini wrote:
> ioremap can't be used to map ring pages on ARM because it uses device
> memory caching attributes (MT_DEVICE*).
> 
> Introduce a Xen specific abstraction to map ring pages, called
> xen_remap, that is defined as ioremap on x86 (no behavioral changes).
> On ARM it explicitly calls __arm_ioremap with the right caching
> attributes: MT_MEMORY.

Do you want to push this to Linus yourself or should I just include it
in my 'for-39' tree?

Do you have other patches for 3.9?
> 
> Signed-off-by: Stefano Stabellini <[e-mail]>
> 
> diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
> index c6b9096..30cdacb 100644
> --- a/arch/arm/include/asm/xen/page.h
> +++ b/arch/arm/include/asm/xen/page.h
> @@ -1,6 +1,7 @@
>  #ifndef _ASM_ARM_XEN_PAGE_H
>  #define _ASM_ARM_XEN_PAGE_H
>  
> +#include <asm/mach/map.h>
>  #include <asm/page.h>
>  #include <asm/pgtable.h>
>  
> @@ -86,4 +87,7 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
>  {
>  	return __set_phys_to_machine(pfn, mfn);
>  }
> +
> +#define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
> +
>  #endif /* _ASM_ARM_XEN_PAGE_H */
> diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
> index 472b9b7..6aef9fb 100644
> --- a/arch/x86/include/asm/xen/page.h
> +++ b/arch/x86/include/asm/xen/page.h
> @@ -212,4 +212,6 @@ unsigned long arbitrary_virt_to_mfn(void *vaddr);
>  void make_lowmem_page_readonly(void *vaddr);
>  void make_lowmem_page_readwrite(void *vaddr);
>  
> +#define xen_remap(cookie, size) ioremap((cookie), (size));
> +
>  #endif /* _ASM_X86_XEN_PAGE_H */
> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> index 19843ec..682210d7 100644
> --- a/drivers/tty/hvc/hvc_xen.c
> +++ b/drivers/tty/hvc/hvc_xen.c
> @@ -230,7 +230,7 @@ static int xen_hvm_console_init(void)
>  	if (r < 0 || v == 0)
>  		goto err;
>  	mfn = v;
> -	info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
> +	info->intf = xen_remap(mfn << PAGE_SHIFT, PAGE_SIZE);
>  	if (info->intf == NULL)
>  		goto err;
>  	info->vtermno = HVC_COOKIE;
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 7038de5..1c2a1e5 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -1146,7 +1146,7 @@ int gnttab_resume(void)
>  		return gnttab_map(0, nr_grant_frames - 1);
>  
>  	if (gnttab_shared.addr == NULL) {
> -		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
> +		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
>  						PAGE_SIZE * max_nr_gframes);
>  		if (gnttab_shared.addr == NULL) {
>  			printk(KERN_WARNING
> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> index 038b71d..3325884 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -769,7 +769,7 @@ static int __init xenbus_init(void)
>  			goto out_error;
>  		xen_store_mfn = (unsigned long)v;
>  		xen_store_interface =
> -			ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> +			xen_remap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
>  		break;
>  	default:
>  		pr_warn("Xenstore state unknown\n");

Stefano Stabellini Feb. 19, 2013, 2:48 p.m. UTC | #2

On Tue, 19 Feb 2013, Konrad Rzeszutek Wilk wrote:
> On Tue, Feb 19, 2013 at 01:59:19PM +0000, Stefano Stabellini wrote:
> > ioremap can't be used to map ring pages on ARM because it uses device
> > memory caching attributes (MT_DEVICE*).
> > 
> > Introduce a Xen specific abstraction to map ring pages, called
> > xen_remap, that is defined as ioremap on x86 (no behavioral changes).
> > On ARM it explicitly calls __arm_ioremap with the right caching
> > attributes: MT_MEMORY.
> 
> Do you want to push this to Linus yourself or should I just include it
> in my 'for-39' tree?
> 
> Do you have other patches for 3.9?

Ian has two patches ("linux: public interface changes for arm"), it
would be great if they could go in 3.9.
Given the small number of patches (three all together), it is probably
easier to go via your tree, if you are OK with that.



> > Signed-off-by: Stefano Stabellini <[e-mail]>
> > 
> > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
> > index c6b9096..30cdacb 100644
> > --- a/arch/arm/include/asm/xen/page.h
> > +++ b/arch/arm/include/asm/xen/page.h
> > @@ -1,6 +1,7 @@
> >  #ifndef _ASM_ARM_XEN_PAGE_H
> >  #define _ASM_ARM_XEN_PAGE_H
> >  
> > +#include <asm/mach/map.h>
> >  #include <asm/page.h>
> >  #include <asm/pgtable.h>
> >  
> > @@ -86,4 +87,7 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> >  {
> >  	return __set_phys_to_machine(pfn, mfn);
> >  }
> > +
> > +#define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
> > +
> >  #endif /* _ASM_ARM_XEN_PAGE_H */
> > diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
> > index 472b9b7..6aef9fb 100644
> > --- a/arch/x86/include/asm/xen/page.h
> > +++ b/arch/x86/include/asm/xen/page.h
> > @@ -212,4 +212,6 @@ unsigned long arbitrary_virt_to_mfn(void *vaddr);
> >  void make_lowmem_page_readonly(void *vaddr);
> >  void make_lowmem_page_readwrite(void *vaddr);
> >  
> > +#define xen_remap(cookie, size) ioremap((cookie), (size));
> > +
> >  #endif /* _ASM_X86_XEN_PAGE_H */
> > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> > index 19843ec..682210d7 100644
> > --- a/drivers/tty/hvc/hvc_xen.c
> > +++ b/drivers/tty/hvc/hvc_xen.c
> > @@ -230,7 +230,7 @@ static int xen_hvm_console_init(void)
> >  	if (r < 0 || v == 0)
> >  		goto err;
> >  	mfn = v;
> > -	info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
> > +	info->intf = xen_remap(mfn << PAGE_SHIFT, PAGE_SIZE);
> >  	if (info->intf == NULL)
> >  		goto err;
> >  	info->vtermno = HVC_COOKIE;
> > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> > index 7038de5..1c2a1e5 100644
> > --- a/drivers/xen/grant-table.c
> > +++ b/drivers/xen/grant-table.c
> > @@ -1146,7 +1146,7 @@ int gnttab_resume(void)
> >  		return gnttab_map(0, nr_grant_frames - 1);
> >  
> >  	if (gnttab_shared.addr == NULL) {
> > -		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
> > +		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
> >  						PAGE_SIZE * max_nr_gframes);
> >  		if (gnttab_shared.addr == NULL) {
> >  			printk(KERN_WARNING
> > diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> > index 038b71d..3325884 100644
> > --- a/drivers/xen/xenbus/xenbus_probe.c
> > +++ b/drivers/xen/xenbus/xenbus_probe.c
> > @@ -769,7 +769,7 @@ static int __init xenbus_init(void)
> >  			goto out_error;
> >  		xen_store_mfn = (unsigned long)v;
> >  		xen_store_interface =
> > -			ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> > +			xen_remap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> >  		break;
> >  	default:
> >  		pr_warn("Xenstore state unknown\n");
>

Konrad Rzeszutek Wilk Feb. 19, 2013, 2:50 p.m. UTC | #3

On Tue, Feb 19, 2013 at 02:48:30PM +0000, Stefano Stabellini wrote:
> On Tue, 19 Feb 2013, Konrad Rzeszutek Wilk wrote:
> > On Tue, Feb 19, 2013 at 01:59:19PM +0000, Stefano Stabellini wrote:
> > > ioremap can't be used to map ring pages on ARM because it uses device
> > > memory caching attributes (MT_DEVICE*).
> > > 
> > > Introduce a Xen specific abstraction to map ring pages, called
> > > xen_remap, that is defined as ioremap on x86 (no behavioral changes).
> > > On ARM it explicitly calls __arm_ioremap with the right caching
> > > attributes: MT_MEMORY.
> > 
> > Do you want to push this to Linus yourself or should I just include it
> > in my 'for-39' tree?
> > 
> > Do you have other patches for 3.9?
> 
> Ian has two patches ("linux: public interface changes for arm"), it
> would be great if they could go in 3.9.
> Given the small number of patches (three all together), it is probably
> easier to go via your tree, if you are OK with that.

Sure. Can you Ack them please?
> 
> 
> 
> > > Signed-off-by: Stefano Stabellini <[e-mail]>
> > > 
> > > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
> > > index c6b9096..30cdacb 100644
> > > --- a/arch/arm/include/asm/xen/page.h
> > > +++ b/arch/arm/include/asm/xen/page.h
> > > @@ -1,6 +1,7 @@
> > >  #ifndef _ASM_ARM_XEN_PAGE_H
> > >  #define _ASM_ARM_XEN_PAGE_H
> > >  
> > > +#include <asm/mach/map.h>
> > >  #include <asm/page.h>
> > >  #include <asm/pgtable.h>
> > >  
> > > @@ -86,4 +87,7 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> > >  {
> > >  	return __set_phys_to_machine(pfn, mfn);
> > >  }
> > > +
> > > +#define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
> > > +
> > >  #endif /* _ASM_ARM_XEN_PAGE_H */
> > > diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
> > > index 472b9b7..6aef9fb 100644
> > > --- a/arch/x86/include/asm/xen/page.h
> > > +++ b/arch/x86/include/asm/xen/page.h
> > > @@ -212,4 +212,6 @@ unsigned long arbitrary_virt_to_mfn(void *vaddr);
> > >  void make_lowmem_page_readonly(void *vaddr);
> > >  void make_lowmem_page_readwrite(void *vaddr);
> > >  
> > > +#define xen_remap(cookie, size) ioremap((cookie), (size));
> > > +
> > >  #endif /* _ASM_X86_XEN_PAGE_H */
> > > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> > > index 19843ec..682210d7 100644
> > > --- a/drivers/tty/hvc/hvc_xen.c
> > > +++ b/drivers/tty/hvc/hvc_xen.c
> > > @@ -230,7 +230,7 @@ static int xen_hvm_console_init(void)
> > >  	if (r < 0 || v == 0)
> > >  		goto err;
> > >  	mfn = v;
> > > -	info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
> > > +	info->intf = xen_remap(mfn << PAGE_SHIFT, PAGE_SIZE);
> > >  	if (info->intf == NULL)
> > >  		goto err;
> > >  	info->vtermno = HVC_COOKIE;
> > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> > > index 7038de5..1c2a1e5 100644
> > > --- a/drivers/xen/grant-table.c
> > > +++ b/drivers/xen/grant-table.c
> > > @@ -1146,7 +1146,7 @@ int gnttab_resume(void)
> > >  		return gnttab_map(0, nr_grant_frames - 1);
> > >  
> > >  	if (gnttab_shared.addr == NULL) {
> > > -		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
> > > +		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
> > >  						PAGE_SIZE * max_nr_gframes);
> > >  		if (gnttab_shared.addr == NULL) {
> > >  			printk(KERN_WARNING
> > > diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> > > index 038b71d..3325884 100644
> > > --- a/drivers/xen/xenbus/xenbus_probe.c
> > > +++ b/drivers/xen/xenbus/xenbus_probe.c
> > > @@ -769,7 +769,7 @@ static int __init xenbus_init(void)
> > >  			goto out_error;
> > >  		xen_store_mfn = (unsigned long)v;
> > >  		xen_store_interface =
> > > -			ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> > > +			xen_remap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> > >  		break;
> > >  	default:
> > >  		pr_warn("Xenstore state unknown\n");
> >

Ian Campbell Feb. 19, 2013, 2:50 p.m. UTC | #4

On Tue, 2013-02-19 at 14:48 +0000, Stefano Stabellini wrote:
> On Tue, 19 Feb 2013, Konrad Rzeszutek Wilk wrote:
> > On Tue, Feb 19, 2013 at 01:59:19PM +0000, Stefano Stabellini wrote:
> > > ioremap can't be used to map ring pages on ARM because it uses device
> > > memory caching attributes (MT_DEVICE*).
> > > 
> > > Introduce a Xen specific abstraction to map ring pages, called
> > > xen_remap, that is defined as ioremap on x86 (no behavioral changes).
> > > On ARM it explicitly calls __arm_ioremap with the right caching
> > > attributes: MT_MEMORY.
> > 
> > Do you want to push this to Linus yourself or should I just include it
> > in my 'for-39' tree?
> > 
> > Do you have other patches for 3.9?
> 
> Ian has two patches ("linux: public interface changes for arm"), it
> would be great if they could go in 3.9.

My two are one for Xen and one for Linux, so just one as far as the
merge window is concerned, I just reposted them 10s ago..

> Given the small number of patches (three all together), it is probably
> easier to go via your tree, if you are OK with that.
> 
> 
> 
> > > Signed-off-by: Stefano Stabellini <[e-mail]>
> > > 
> > > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
> > > index c6b9096..30cdacb 100644
> > > --- a/arch/arm/include/asm/xen/page.h
> > > +++ b/arch/arm/include/asm/xen/page.h
> > > @@ -1,6 +1,7 @@
> > >  #ifndef _ASM_ARM_XEN_PAGE_H
> > >  #define _ASM_ARM_XEN_PAGE_H
> > >  
> > > +#include <asm/mach/map.h>
> > >  #include <asm/page.h>
> > >  #include <asm/pgtable.h>
> > >  
> > > @@ -86,4 +87,7 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> > >  {
> > >  	return __set_phys_to_machine(pfn, mfn);
> > >  }
> > > +
> > > +#define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
> > > +
> > >  #endif /* _ASM_ARM_XEN_PAGE_H */
> > > diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
> > > index 472b9b7..6aef9fb 100644
> > > --- a/arch/x86/include/asm/xen/page.h
> > > +++ b/arch/x86/include/asm/xen/page.h
> > > @@ -212,4 +212,6 @@ unsigned long arbitrary_virt_to_mfn(void *vaddr);
> > >  void make_lowmem_page_readonly(void *vaddr);
> > >  void make_lowmem_page_readwrite(void *vaddr);
> > >  
> > > +#define xen_remap(cookie, size) ioremap((cookie), (size));
> > > +
> > >  #endif /* _ASM_X86_XEN_PAGE_H */
> > > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> > > index 19843ec..682210d7 100644
> > > --- a/drivers/tty/hvc/hvc_xen.c
> > > +++ b/drivers/tty/hvc/hvc_xen.c
> > > @@ -230,7 +230,7 @@ static int xen_hvm_console_init(void)
> > >  	if (r < 0 || v == 0)
> > >  		goto err;
> > >  	mfn = v;
> > > -	info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
> > > +	info->intf = xen_remap(mfn << PAGE_SHIFT, PAGE_SIZE);
> > >  	if (info->intf == NULL)
> > >  		goto err;
> > >  	info->vtermno = HVC_COOKIE;
> > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> > > index 7038de5..1c2a1e5 100644
> > > --- a/drivers/xen/grant-table.c
> > > +++ b/drivers/xen/grant-table.c
> > > @@ -1146,7 +1146,7 @@ int gnttab_resume(void)
> > >  		return gnttab_map(0, nr_grant_frames - 1);
> > >  
> > >  	if (gnttab_shared.addr == NULL) {
> > > -		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
> > > +		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
> > >  						PAGE_SIZE * max_nr_gframes);
> > >  		if (gnttab_shared.addr == NULL) {
> > >  			printk(KERN_WARNING
> > > diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> > > index 038b71d..3325884 100644
> > > --- a/drivers/xen/xenbus/xenbus_probe.c
> > > +++ b/drivers/xen/xenbus/xenbus_probe.c
> > > @@ -769,7 +769,7 @@ static int __init xenbus_init(void)
> > >  			goto out_error;
> > >  		xen_store_mfn = (unsigned long)v;
> > >  		xen_store_interface =
> > > -			ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> > > +			xen_remap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> > >  		break;
> > >  	default:
> > >  		pr_warn("Xenstore state unknown\n");
> >

Ian Campbell Feb. 20, 2013, 11:17 a.m. UTC | #5

On Tue, 2013-02-19 at 13:59 +0000, Stefano Stabellini wrote:
> ioremap can't be used to map ring pages on ARM because it uses device
> memory caching attributes (MT_DEVICE*).
> 
> Introduce a Xen specific abstraction to map ring pages, called
> xen_remap, that is defined as ioremap on x86 (no behavioral changes).
> On ARM it explicitly calls __arm_ioremap with the right caching
> attributes: MT_MEMORY.
> 
> Signed-off-by: Stefano Stabellini <[e-mail]>

Acked-by: Ian Campbell <[e-mail]>

If you were respinning for any reason I might suggest
s/xen_remap/xen_map_shared/ or something of that nature.

Ian.

Patch

diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
index c6b9096..30cdacb 100644
--- a/arch/arm/include/asm/xen/page.h
+++ b/arch/arm/include/asm/xen/page.h
@@ -1,6 +1,7 @@ 
 #ifndef _ASM_ARM_XEN_PAGE_H
 #define _ASM_ARM_XEN_PAGE_H
 
+#include <asm/mach/map.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 
@@ -86,4 +87,7 @@  static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
 	return __set_phys_to_machine(pfn, mfn);
 }
+
+#define xen_remap(cookie, size) __arm_ioremap((cookie), (size), MT_MEMORY);
+
 #endif /* _ASM_ARM_XEN_PAGE_H */
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 472b9b7..6aef9fb 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -212,4 +212,6 @@  unsigned long arbitrary_virt_to_mfn(void *vaddr);
 void make_lowmem_page_readonly(void *vaddr);
 void make_lowmem_page_readwrite(void *vaddr);
 
+#define xen_remap(cookie, size) ioremap((cookie), (size));
+
 #endif /* _ASM_X86_XEN_PAGE_H */
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 19843ec..682210d7 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -230,7 +230,7 @@  static int xen_hvm_console_init(void)
 	if (r < 0 || v == 0)
 		goto err;
 	mfn = v;
-	info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
+	info->intf = xen_remap(mfn << PAGE_SHIFT, PAGE_SIZE);
 	if (info->intf == NULL)
 		goto err;
 	info->vtermno = HVC_COOKIE;
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 7038de5..1c2a1e5 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1146,7 +1146,7 @@  int gnttab_resume(void)
 		return gnttab_map(0, nr_grant_frames - 1);
 
 	if (gnttab_shared.addr == NULL) {
-		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
+		gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
 						PAGE_SIZE * max_nr_gframes);
 		if (gnttab_shared.addr == NULL) {
 			printk(KERN_WARNING
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 038b71d..3325884 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -769,7 +769,7 @@  static int __init xenbus_init(void)
 			goto out_error;
 		xen_store_mfn = (unsigned long)v;
 		xen_store_interface =
-			ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
+			xen_remap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
 		break;
 	default:
 		pr_warn("Xenstore state unknown\n");