Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-03-25 Thread Stefano Stabellini
On Mon, 17 Feb 2014, Stefano Stabellini wrote:
> On Tue, 21 Jan 2014, Will Deacon wrote:
> > On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
> > > Remove !GENERIC_ATOMIC64 build dependency:
> > > - introduce xen_atomic64_xchg
> > > - use it to implement xchg_xen_ulong
> > > 
> > > Remove !CPU_V6 build dependency:
> > > - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
> > >   CONFIG_CPU_V6
> > > - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> > > 
> > > Signed-off-by: Stefano Stabellini 
> > > CC: a...@arndb.de
> > > CC: li...@arm.linux.org.uk
> > > CC: will.dea...@arm.com
> > > CC: catalin.mari...@arm.com
> > > CC: linux-arm-ker...@lists.infradead.org
> > > CC: linux-kernel@vger.kernel.org
> > > CC: xen-de...@lists.xenproject.org
> > 
> >   Reviewed-by: Will Deacon 
> 
> Russell, are you OK with this patch for 3.15?

Ping?
Is there anything else that I need to do here?
Do you want me to submit to your patch tracking system?

> 
> > Changes in v4:
> > - avoid moving and renaming atomic64_xchg
> > - introduce xen_atomic64_xchg
> > - fix asm comment in __cmpxchg8 and __cmpxchg16.
> > 
> > ---
> >  arch/arm/Kconfig   |3 +-
> >  arch/arm/include/asm/cmpxchg.h |   60 
> > 
> >  arch/arm/include/asm/sync_bitops.h |   24 ++-
> >  arch/arm/include/asm/xen/events.h  |   32 ++-
> >  4 files changed, 95 insertions(+), 24 deletions(-)
> > 
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index c1f1a7e..ae54ae0 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -1881,8 +1881,7 @@ config XEN_DOM0
> >  config XEN
> > bool "Xen guest support on ARM (EXPERIMENTAL)"
> > depends on ARM && AEABI && OF
> > -   depends on CPU_V7 && !CPU_V6
> > -   depends on !GENERIC_ATOMIC64
> > +   depends on CPU_V7
> > select ARM_PSCI
> > select SWIOTLB_XEN
> > help
> > diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
> > index df2fbba..a17cff1 100644
> > --- a/arch/arm/include/asm/cmpxchg.h
> > +++ b/arch/arm/include/asm/cmpxchg.h
> > @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int 
> > size);
> >   * cmpxchg only support 32-bits operands on ARMv6.
> >   */
> >  
> > +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long 
> > old,
> > + unsigned long new)
> > +{
> > +   unsigned long oldval, res;
> > +
> > +   do {
> > +   asm volatile("@ __cmpxchg8\n"
> > +   "   ldrexb  %1, [%2]\n"
> > +   "   mov %0, #0\n"
> > +   "   teq %1, %3\n"
> > +   "   strexbeq %0, %4, [%2]\n"
> > +   : "=" (res), "=" (oldval)
> > +   : "r" (ptr), "Ir" (old), "r" (new)
> > +   : "memory", "cc");
> > +   } while (res);
> > +
> > +   return oldval;
> > +}
> > +
> > +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long 
> > old,
> > + unsigned long new)
> > +{
> > +   unsigned long oldval, res;
> > +
> > +   do {
> > +   asm volatile("@ __cmpxchg16\n"
> > +   "   ldrexh  %1, [%2]\n"
> > +   "   mov %0, #0\n"
> > +   "   teq %1, %3\n"
> > +   "   strexheq %0, %4, [%2]\n"
> > +   : "=" (res), "=" (oldval)
> > +   : "r" (ptr), "Ir" (old), "r" (new)
> > +   : "memory", "cc");
> > +   } while (res);
> > +
> > +   return oldval;
> > +}
> > +
> >  static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long 
> > old,
> >   unsigned long new, int size)
> >  {
> > @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void 
> > *ptr, unsigned long old,
> > switch (size) {
> >  #ifndef CONFIG_CPU_V6  /* min ARCH >= ARMv6K */
> > case 1:
> > -   do {
> > -   asm volatile("@ __cmpxchg1\n"
> > -   "   ldrexb  %1, [%2]\n"
> > -   "   mov %0, #0\n"
> > -   "   teq %1, %3\n"
> > -   "   strexbeq %0, %4, [%2]\n"
> > -   : "=" (res), "=" (oldval)
> > -   : "r" (ptr), "Ir" (old), "r" (new)
> > -   : "memory", "cc");
> > -   } while (res);
> > +   oldval = __cmpxchg8(ptr, old, new);
> > break;
> > case 2:
> > -   do {
> > -   asm volatile("@ __cmpxchg1\n"
> > -   "   ldrexh  %1, [%2]\n"
> > -   "   mov %0, #0\n"
> > -   "   teq %1, %3\n"
> > -   "   strexheq %0, %4, [%2]\n"
> > -   : "=" (res), "=" (oldval)
> > -   : "r" (ptr), "Ir" (old), "r" (new)
> > -   : "memory", "cc");
> > - 

Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-03-25 Thread Stefano Stabellini
On Mon, 17 Feb 2014, Stefano Stabellini wrote:
 On Tue, 21 Jan 2014, Will Deacon wrote:
  On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
   Remove !GENERIC_ATOMIC64 build dependency:
   - introduce xen_atomic64_xchg
   - use it to implement xchg_xen_ulong
   
   Remove !CPU_V6 build dependency:
   - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
 CONFIG_CPU_V6
   - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
   
   Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
   CC: a...@arndb.de
   CC: li...@arm.linux.org.uk
   CC: will.dea...@arm.com
   CC: catalin.mari...@arm.com
   CC: linux-arm-ker...@lists.infradead.org
   CC: linux-kernel@vger.kernel.org
   CC: xen-de...@lists.xenproject.org
  
Reviewed-by: Will Deacon will.dea...@arm.com
 
 Russell, are you OK with this patch for 3.15?

Ping?
Is there anything else that I need to do here?
Do you want me to submit to your patch tracking system?

 
  Changes in v4:
  - avoid moving and renaming atomic64_xchg
  - introduce xen_atomic64_xchg
  - fix asm comment in __cmpxchg8 and __cmpxchg16.
  
  ---
   arch/arm/Kconfig   |3 +-
   arch/arm/include/asm/cmpxchg.h |   60 
  
   arch/arm/include/asm/sync_bitops.h |   24 ++-
   arch/arm/include/asm/xen/events.h  |   32 ++-
   4 files changed, 95 insertions(+), 24 deletions(-)
  
  diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
  index c1f1a7e..ae54ae0 100644
  --- a/arch/arm/Kconfig
  +++ b/arch/arm/Kconfig
  @@ -1881,8 +1881,7 @@ config XEN_DOM0
   config XEN
  bool Xen guest support on ARM (EXPERIMENTAL)
  depends on ARM  AEABI  OF
  -   depends on CPU_V7  !CPU_V6
  -   depends on !GENERIC_ATOMIC64
  +   depends on CPU_V7
  select ARM_PSCI
  select SWIOTLB_XEN
  help
  diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
  index df2fbba..a17cff1 100644
  --- a/arch/arm/include/asm/cmpxchg.h
  +++ b/arch/arm/include/asm/cmpxchg.h
  @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int 
  size);
* cmpxchg only support 32-bits operands on ARMv6.
*/
   
  +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long 
  old,
  + unsigned long new)
  +{
  +   unsigned long oldval, res;
  +
  +   do {
  +   asm volatile(@ __cmpxchg8\n
  +  ldrexb  %1, [%2]\n
  +  mov %0, #0\n
  +  teq %1, %3\n
  +  strexbeq %0, %4, [%2]\n
  +   : =r (res), =r (oldval)
  +   : r (ptr), Ir (old), r (new)
  +   : memory, cc);
  +   } while (res);
  +
  +   return oldval;
  +}
  +
  +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long 
  old,
  + unsigned long new)
  +{
  +   unsigned long oldval, res;
  +
  +   do {
  +   asm volatile(@ __cmpxchg16\n
  +  ldrexh  %1, [%2]\n
  +  mov %0, #0\n
  +  teq %1, %3\n
  +  strexheq %0, %4, [%2]\n
  +   : =r (res), =r (oldval)
  +   : r (ptr), Ir (old), r (new)
  +   : memory, cc);
  +   } while (res);
  +
  +   return oldval;
  +}
  +
   static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long 
  old,
unsigned long new, int size)
   {
  @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void 
  *ptr, unsigned long old,
  switch (size) {
   #ifndef CONFIG_CPU_V6  /* min ARCH = ARMv6K */
  case 1:
  -   do {
  -   asm volatile(@ __cmpxchg1\n
  -  ldrexb  %1, [%2]\n
  -  mov %0, #0\n
  -  teq %1, %3\n
  -  strexbeq %0, %4, [%2]\n
  -   : =r (res), =r (oldval)
  -   : r (ptr), Ir (old), r (new)
  -   : memory, cc);
  -   } while (res);
  +   oldval = __cmpxchg8(ptr, old, new);
  break;
  case 2:
  -   do {
  -   asm volatile(@ __cmpxchg1\n
  -  ldrexh  %1, [%2]\n
  -  mov %0, #0\n
  -  teq %1, %3\n
  -  strexheq %0, %4, [%2]\n
  -   : =r (res), =r (oldval)
  -   : r (ptr), Ir (old), r (new)
  -   : memory, cc);
  -   } while (res);
  +   oldval = __cmpxchg16(ptr, old, new);
  break;
   #endif
  case 4:
  diff --git a/arch/arm/include/asm/sync_bitops.h 
  b/arch/arm/include/asm/sync_bitops.h
  index 63479ee..942659a 100644
  --- a/arch/arm/include/asm/sync_bitops.h
  +++ 

Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-02-17 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
> On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
> > Remove !GENERIC_ATOMIC64 build dependency:
> > - introduce xen_atomic64_xchg
> > - use it to implement xchg_xen_ulong
> > 
> > Remove !CPU_V6 build dependency:
> > - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
> >   CONFIG_CPU_V6
> > - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> > 
> > Signed-off-by: Stefano Stabellini 
> > CC: a...@arndb.de
> > CC: li...@arm.linux.org.uk
> > CC: will.dea...@arm.com
> > CC: catalin.mari...@arm.com
> > CC: linux-arm-ker...@lists.infradead.org
> > CC: linux-kernel@vger.kernel.org
> > CC: xen-de...@lists.xenproject.org
> 
>   Reviewed-by: Will Deacon 

Russell, are you OK with this patch for 3.15?


> Changes in v4:
> - avoid moving and renaming atomic64_xchg
> - introduce xen_atomic64_xchg
> - fix asm comment in __cmpxchg8 and __cmpxchg16.
> 
> ---
>  arch/arm/Kconfig   |3 +-
>  arch/arm/include/asm/cmpxchg.h |   60 
> 
>  arch/arm/include/asm/sync_bitops.h |   24 ++-
>  arch/arm/include/asm/xen/events.h  |   32 ++-
>  4 files changed, 95 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index c1f1a7e..ae54ae0 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1881,8 +1881,7 @@ config XEN_DOM0
>  config XEN
>   bool "Xen guest support on ARM (EXPERIMENTAL)"
>   depends on ARM && AEABI && OF
> - depends on CPU_V7 && !CPU_V6
> - depends on !GENERIC_ATOMIC64
> + depends on CPU_V7
>   select ARM_PSCI
>   select SWIOTLB_XEN
>   help
> diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
> index df2fbba..a17cff1 100644
> --- a/arch/arm/include/asm/cmpxchg.h
> +++ b/arch/arm/include/asm/cmpxchg.h
> @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size);
>   * cmpxchg only support 32-bits operands on ARMv6.
>   */
>  
> +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old,
> +   unsigned long new)
> +{
> + unsigned long oldval, res;
> +
> + do {
> + asm volatile("@ __cmpxchg8\n"
> + "   ldrexb  %1, [%2]\n"
> + "   mov %0, #0\n"
> + "   teq %1, %3\n"
> + "   strexbeq %0, %4, [%2]\n"
> + : "=" (res), "=" (oldval)
> + : "r" (ptr), "Ir" (old), "r" (new)
> + : "memory", "cc");
> + } while (res);
> +
> + return oldval;
> +}
> +
> +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long 
> old,
> +   unsigned long new)
> +{
> + unsigned long oldval, res;
> +
> + do {
> + asm volatile("@ __cmpxchg16\n"
> + "   ldrexh  %1, [%2]\n"
> + "   mov %0, #0\n"
> + "   teq %1, %3\n"
> + "   strexheq %0, %4, [%2]\n"
> + : "=" (res), "=" (oldval)
> + : "r" (ptr), "Ir" (old), "r" (new)
> + : "memory", "cc");
> + } while (res);
> +
> + return oldval;
> +}
> +
>  static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
> unsigned long new, int size)
>  {
> @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void 
> *ptr, unsigned long old,
>   switch (size) {
>  #ifndef CONFIG_CPU_V6/* min ARCH >= ARMv6K */
>   case 1:
> - do {
> - asm volatile("@ __cmpxchg1\n"
> - "   ldrexb  %1, [%2]\n"
> - "   mov %0, #0\n"
> - "   teq %1, %3\n"
> - "   strexbeq %0, %4, [%2]\n"
> - : "=" (res), "=" (oldval)
> - : "r" (ptr), "Ir" (old), "r" (new)
> - : "memory", "cc");
> - } while (res);
> + oldval = __cmpxchg8(ptr, old, new);
>   break;
>   case 2:
> - do {
> - asm volatile("@ __cmpxchg1\n"
> - "   ldrexh  %1, [%2]\n"
> - "   mov %0, #0\n"
> - "   teq %1, %3\n"
> - "   strexheq %0, %4, [%2]\n"
> - : "=" (res), "=" (oldval)
> - : "r" (ptr), "Ir" (old), "r" (new)
> - : "memory", "cc");
> - } while (res);
> + oldval = __cmpxchg16(ptr, old, new);
>   break;
>  #endif
>   case 4:
> diff --git a/arch/arm/include/asm/sync_bitops.h 
> b/arch/arm/include/asm/sync_bitops.h
> index 63479ee..942659a 100644
> --- a/arch/arm/include/asm/sync_bitops.h
> +++ 

Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-02-17 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
 On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
  Remove !GENERIC_ATOMIC64 build dependency:
  - introduce xen_atomic64_xchg
  - use it to implement xchg_xen_ulong
  
  Remove !CPU_V6 build dependency:
  - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
CONFIG_CPU_V6
  - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
  
  Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
  CC: a...@arndb.de
  CC: li...@arm.linux.org.uk
  CC: will.dea...@arm.com
  CC: catalin.mari...@arm.com
  CC: linux-arm-ker...@lists.infradead.org
  CC: linux-kernel@vger.kernel.org
  CC: xen-de...@lists.xenproject.org
 
   Reviewed-by: Will Deacon will.dea...@arm.com

Russell, are you OK with this patch for 3.15?


 Changes in v4:
 - avoid moving and renaming atomic64_xchg
 - introduce xen_atomic64_xchg
 - fix asm comment in __cmpxchg8 and __cmpxchg16.
 
 ---
  arch/arm/Kconfig   |3 +-
  arch/arm/include/asm/cmpxchg.h |   60 
 
  arch/arm/include/asm/sync_bitops.h |   24 ++-
  arch/arm/include/asm/xen/events.h  |   32 ++-
  4 files changed, 95 insertions(+), 24 deletions(-)
 
 diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
 index c1f1a7e..ae54ae0 100644
 --- a/arch/arm/Kconfig
 +++ b/arch/arm/Kconfig
 @@ -1881,8 +1881,7 @@ config XEN_DOM0
  config XEN
   bool Xen guest support on ARM (EXPERIMENTAL)
   depends on ARM  AEABI  OF
 - depends on CPU_V7  !CPU_V6
 - depends on !GENERIC_ATOMIC64
 + depends on CPU_V7
   select ARM_PSCI
   select SWIOTLB_XEN
   help
 diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
 index df2fbba..a17cff1 100644
 --- a/arch/arm/include/asm/cmpxchg.h
 +++ b/arch/arm/include/asm/cmpxchg.h
 @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size);
   * cmpxchg only support 32-bits operands on ARMv6.
   */
  
 +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old,
 +   unsigned long new)
 +{
 + unsigned long oldval, res;
 +
 + do {
 + asm volatile(@ __cmpxchg8\n
 +ldrexb  %1, [%2]\n
 +mov %0, #0\n
 +teq %1, %3\n
 +strexbeq %0, %4, [%2]\n
 + : =r (res), =r (oldval)
 + : r (ptr), Ir (old), r (new)
 + : memory, cc);
 + } while (res);
 +
 + return oldval;
 +}
 +
 +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long 
 old,
 +   unsigned long new)
 +{
 + unsigned long oldval, res;
 +
 + do {
 + asm volatile(@ __cmpxchg16\n
 +ldrexh  %1, [%2]\n
 +mov %0, #0\n
 +teq %1, %3\n
 +strexheq %0, %4, [%2]\n
 + : =r (res), =r (oldval)
 + : r (ptr), Ir (old), r (new)
 + : memory, cc);
 + } while (res);
 +
 + return oldval;
 +}
 +
  static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 unsigned long new, int size)
  {
 @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void 
 *ptr, unsigned long old,
   switch (size) {
  #ifndef CONFIG_CPU_V6/* min ARCH = ARMv6K */
   case 1:
 - do {
 - asm volatile(@ __cmpxchg1\n
 -ldrexb  %1, [%2]\n
 -mov %0, #0\n
 -teq %1, %3\n
 -strexbeq %0, %4, [%2]\n
 - : =r (res), =r (oldval)
 - : r (ptr), Ir (old), r (new)
 - : memory, cc);
 - } while (res);
 + oldval = __cmpxchg8(ptr, old, new);
   break;
   case 2:
 - do {
 - asm volatile(@ __cmpxchg1\n
 -ldrexh  %1, [%2]\n
 -mov %0, #0\n
 -teq %1, %3\n
 -strexheq %0, %4, [%2]\n
 - : =r (res), =r (oldval)
 - : r (ptr), Ir (old), r (new)
 - : memory, cc);
 - } while (res);
 + oldval = __cmpxchg16(ptr, old, new);
   break;
  #endif
   case 4:
 diff --git a/arch/arm/include/asm/sync_bitops.h 
 b/arch/arm/include/asm/sync_bitops.h
 index 63479ee..942659a 100644
 --- a/arch/arm/include/asm/sync_bitops.h
 +++ b/arch/arm/include/asm/sync_bitops.h
 @@ -21,7 +21,29 @@
  #define sync_test_and_clear_bit(nr, p)   _test_and_clear_bit(nr, p)
  #define sync_test_and_change_bit(nr, p)  _test_and_change_bit(nr, p)
 

Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-31 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
> On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
> > Remove !GENERIC_ATOMIC64 build dependency:
> > - introduce xen_atomic64_xchg
> > - use it to implement xchg_xen_ulong
> > 
> > Remove !CPU_V6 build dependency:
> > - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
> >   CONFIG_CPU_V6
> > - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> > 
> > Signed-off-by: Stefano Stabellini 
> > CC: a...@arndb.de
> > CC: li...@arm.linux.org.uk
> > CC: will.dea...@arm.com
> > CC: catalin.mari...@arm.com
> > CC: linux-arm-ker...@lists.infradead.org
> > CC: linux-kernel@vger.kernel.org
> > CC: xen-de...@lists.xenproject.org
> 
>   Reviewed-by: Will Deacon 
> 
> Cheers Stefano,

Do you think it is acceptable to have this in 3.14?
Maybe we should aim at 3.15?
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Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-31 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
 On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
  Remove !GENERIC_ATOMIC64 build dependency:
  - introduce xen_atomic64_xchg
  - use it to implement xchg_xen_ulong
  
  Remove !CPU_V6 build dependency:
  - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
CONFIG_CPU_V6
  - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
  
  Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
  CC: a...@arndb.de
  CC: li...@arm.linux.org.uk
  CC: will.dea...@arm.com
  CC: catalin.mari...@arm.com
  CC: linux-arm-ker...@lists.infradead.org
  CC: linux-kernel@vger.kernel.org
  CC: xen-de...@lists.xenproject.org
 
   Reviewed-by: Will Deacon will.dea...@arm.com
 
 Cheers Stefano,

Do you think it is acceptable to have this in 3.14?
Maybe we should aim at 3.15?
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Re: [Xen-devel] [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-22 Thread Ian Campbell
On Tue, 2014-01-21 at 13:44 +, Stefano Stabellini wrote:
> Remove !GENERIC_ATOMIC64 build dependency:
> - introduce xen_atomic64_xchg
> - use it to implement xchg_xen_ulong
> 
> Remove !CPU_V6 build dependency:
> - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
>   CONFIG_CPU_V6
> - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> 
> Signed-off-by: Stefano Stabellini 

Acked-by: Ian Campbell 


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Re: [Xen-devel] [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-22 Thread Ian Campbell
On Tue, 2014-01-21 at 13:44 +, Stefano Stabellini wrote:
 Remove !GENERIC_ATOMIC64 build dependency:
 - introduce xen_atomic64_xchg
 - use it to implement xchg_xen_ulong
 
 Remove !CPU_V6 build dependency:
 - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
   CONFIG_CPU_V6
 - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
 
 Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com

Acked-by: Ian Campbell ian.campb...@citrix.com


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Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
> On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
> > Remove !GENERIC_ATOMIC64 build dependency:
> > - introduce xen_atomic64_xchg
> > - use it to implement xchg_xen_ulong
> > 
> > Remove !CPU_V6 build dependency:
> > - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
> >   CONFIG_CPU_V6
> > - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> > 
> > Signed-off-by: Stefano Stabellini 
> > CC: a...@arndb.de
> > CC: li...@arm.linux.org.uk
> > CC: will.dea...@arm.com
> > CC: catalin.mari...@arm.com
> > CC: linux-arm-ker...@lists.infradead.org
> > CC: linux-kernel@vger.kernel.org
> > CC: xen-de...@lists.xenproject.org
> 
>   Reviewed-by: Will Deacon 
> 
> Cheers Stefano,

Thanks!!
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Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Will Deacon
On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
> Remove !GENERIC_ATOMIC64 build dependency:
> - introduce xen_atomic64_xchg
> - use it to implement xchg_xen_ulong
> 
> Remove !CPU_V6 build dependency:
> - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
>   CONFIG_CPU_V6
> - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
> 
> Signed-off-by: Stefano Stabellini 
> CC: a...@arndb.de
> CC: li...@arm.linux.org.uk
> CC: will.dea...@arm.com
> CC: catalin.mari...@arm.com
> CC: linux-arm-ker...@lists.infradead.org
> CC: linux-kernel@vger.kernel.org
> CC: xen-de...@lists.xenproject.org

  Reviewed-by: Will Deacon 

Cheers Stefano,

Will
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[PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Stefano Stabellini
Remove !GENERIC_ATOMIC64 build dependency:
- introduce xen_atomic64_xchg
- use it to implement xchg_xen_ulong

Remove !CPU_V6 build dependency:
- introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
  CONFIG_CPU_V6
- implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16

Signed-off-by: Stefano Stabellini 
CC: a...@arndb.de
CC: li...@arm.linux.org.uk
CC: will.dea...@arm.com
CC: catalin.mari...@arm.com
CC: linux-arm-ker...@lists.infradead.org
CC: linux-kernel@vger.kernel.org
CC: xen-de...@lists.xenproject.org

---

Changes in v4:
- avoid moving and renaming atomic64_xchg
- introduce xen_atomic64_xchg
- fix asm comment in __cmpxchg8 and __cmpxchg16.

---
 arch/arm/Kconfig   |3 +-
 arch/arm/include/asm/cmpxchg.h |   60 
 arch/arm/include/asm/sync_bitops.h |   24 ++-
 arch/arm/include/asm/xen/events.h  |   32 ++-
 4 files changed, 95 insertions(+), 24 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c1f1a7e..ae54ae0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1881,8 +1881,7 @@ config XEN_DOM0
 config XEN
bool "Xen guest support on ARM (EXPERIMENTAL)"
depends on ARM && AEABI && OF
-   depends on CPU_V7 && !CPU_V6
-   depends on !GENERIC_ATOMIC64
+   depends on CPU_V7
select ARM_PSCI
select SWIOTLB_XEN
help
diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
index df2fbba..a17cff1 100644
--- a/arch/arm/include/asm/cmpxchg.h
+++ b/arch/arm/include/asm/cmpxchg.h
@@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size);
  * cmpxchg only support 32-bits operands on ARMv6.
  */
 
+static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old,
+ unsigned long new)
+{
+   unsigned long oldval, res;
+
+   do {
+   asm volatile("@ __cmpxchg8\n"
+   "   ldrexb  %1, [%2]\n"
+   "   mov %0, #0\n"
+   "   teq %1, %3\n"
+   "   strexbeq %0, %4, [%2]\n"
+   : "=" (res), "=" (oldval)
+   : "r" (ptr), "Ir" (old), "r" (new)
+   : "memory", "cc");
+   } while (res);
+
+   return oldval;
+}
+
+static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long old,
+ unsigned long new)
+{
+   unsigned long oldval, res;
+
+   do {
+   asm volatile("@ __cmpxchg16\n"
+   "   ldrexh  %1, [%2]\n"
+   "   mov %0, #0\n"
+   "   teq %1, %3\n"
+   "   strexheq %0, %4, [%2]\n"
+   : "=" (res), "=" (oldval)
+   : "r" (ptr), "Ir" (old), "r" (new)
+   : "memory", "cc");
+   } while (res);
+
+   return oldval;
+}
+
 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  unsigned long new, int size)
 {
@@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, 
unsigned long old,
switch (size) {
 #ifndef CONFIG_CPU_V6  /* min ARCH >= ARMv6K */
case 1:
-   do {
-   asm volatile("@ __cmpxchg1\n"
-   "   ldrexb  %1, [%2]\n"
-   "   mov %0, #0\n"
-   "   teq %1, %3\n"
-   "   strexbeq %0, %4, [%2]\n"
-   : "=" (res), "=" (oldval)
-   : "r" (ptr), "Ir" (old), "r" (new)
-   : "memory", "cc");
-   } while (res);
+   oldval = __cmpxchg8(ptr, old, new);
break;
case 2:
-   do {
-   asm volatile("@ __cmpxchg1\n"
-   "   ldrexh  %1, [%2]\n"
-   "   mov %0, #0\n"
-   "   teq %1, %3\n"
-   "   strexheq %0, %4, [%2]\n"
-   : "=" (res), "=" (oldval)
-   : "r" (ptr), "Ir" (old), "r" (new)
-   : "memory", "cc");
-   } while (res);
+   oldval = __cmpxchg16(ptr, old, new);
break;
 #endif
case 4:
diff --git a/arch/arm/include/asm/sync_bitops.h 
b/arch/arm/include/asm/sync_bitops.h
index 63479ee..942659a 100644
--- a/arch/arm/include/asm/sync_bitops.h
+++ b/arch/arm/include/asm/sync_bitops.h
@@ -21,7 +21,29 @@
 #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p)
 #define sync_test_and_change_bit(nr, p)_test_and_change_bit(nr, p)
 #define sync_test_bit(nr, addr)test_bit(nr, addr)
-#define sync_cmpxchg   cmpxchg
 
+static inline unsigned long sync_cmpxchg(volatile void 

[PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Stefano Stabellini
Remove !GENERIC_ATOMIC64 build dependency:
- introduce xen_atomic64_xchg
- use it to implement xchg_xen_ulong

Remove !CPU_V6 build dependency:
- introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
  CONFIG_CPU_V6
- implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16

Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
CC: a...@arndb.de
CC: li...@arm.linux.org.uk
CC: will.dea...@arm.com
CC: catalin.mari...@arm.com
CC: linux-arm-ker...@lists.infradead.org
CC: linux-kernel@vger.kernel.org
CC: xen-de...@lists.xenproject.org

---

Changes in v4:
- avoid moving and renaming atomic64_xchg
- introduce xen_atomic64_xchg
- fix asm comment in __cmpxchg8 and __cmpxchg16.

---
 arch/arm/Kconfig   |3 +-
 arch/arm/include/asm/cmpxchg.h |   60 
 arch/arm/include/asm/sync_bitops.h |   24 ++-
 arch/arm/include/asm/xen/events.h  |   32 ++-
 4 files changed, 95 insertions(+), 24 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c1f1a7e..ae54ae0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1881,8 +1881,7 @@ config XEN_DOM0
 config XEN
bool Xen guest support on ARM (EXPERIMENTAL)
depends on ARM  AEABI  OF
-   depends on CPU_V7  !CPU_V6
-   depends on !GENERIC_ATOMIC64
+   depends on CPU_V7
select ARM_PSCI
select SWIOTLB_XEN
help
diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
index df2fbba..a17cff1 100644
--- a/arch/arm/include/asm/cmpxchg.h
+++ b/arch/arm/include/asm/cmpxchg.h
@@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size);
  * cmpxchg only support 32-bits operands on ARMv6.
  */
 
+static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old,
+ unsigned long new)
+{
+   unsigned long oldval, res;
+
+   do {
+   asm volatile(@ __cmpxchg8\n
+  ldrexb  %1, [%2]\n
+  mov %0, #0\n
+  teq %1, %3\n
+  strexbeq %0, %4, [%2]\n
+   : =r (res), =r (oldval)
+   : r (ptr), Ir (old), r (new)
+   : memory, cc);
+   } while (res);
+
+   return oldval;
+}
+
+static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long old,
+ unsigned long new)
+{
+   unsigned long oldval, res;
+
+   do {
+   asm volatile(@ __cmpxchg16\n
+  ldrexh  %1, [%2]\n
+  mov %0, #0\n
+  teq %1, %3\n
+  strexheq %0, %4, [%2]\n
+   : =r (res), =r (oldval)
+   : r (ptr), Ir (old), r (new)
+   : memory, cc);
+   } while (res);
+
+   return oldval;
+}
+
 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  unsigned long new, int size)
 {
@@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, 
unsigned long old,
switch (size) {
 #ifndef CONFIG_CPU_V6  /* min ARCH = ARMv6K */
case 1:
-   do {
-   asm volatile(@ __cmpxchg1\n
-  ldrexb  %1, [%2]\n
-  mov %0, #0\n
-  teq %1, %3\n
-  strexbeq %0, %4, [%2]\n
-   : =r (res), =r (oldval)
-   : r (ptr), Ir (old), r (new)
-   : memory, cc);
-   } while (res);
+   oldval = __cmpxchg8(ptr, old, new);
break;
case 2:
-   do {
-   asm volatile(@ __cmpxchg1\n
-  ldrexh  %1, [%2]\n
-  mov %0, #0\n
-  teq %1, %3\n
-  strexheq %0, %4, [%2]\n
-   : =r (res), =r (oldval)
-   : r (ptr), Ir (old), r (new)
-   : memory, cc);
-   } while (res);
+   oldval = __cmpxchg16(ptr, old, new);
break;
 #endif
case 4:
diff --git a/arch/arm/include/asm/sync_bitops.h 
b/arch/arm/include/asm/sync_bitops.h
index 63479ee..942659a 100644
--- a/arch/arm/include/asm/sync_bitops.h
+++ b/arch/arm/include/asm/sync_bitops.h
@@ -21,7 +21,29 @@
 #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p)
 #define sync_test_and_change_bit(nr, p)_test_and_change_bit(nr, p)
 #define sync_test_bit(nr, addr)test_bit(nr, addr)
-#define sync_cmpxchg   cmpxchg
 
+static inline unsigned long sync_cmpxchg(volatile void *ptr,
+

Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Will Deacon
On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
 Remove !GENERIC_ATOMIC64 build dependency:
 - introduce xen_atomic64_xchg
 - use it to implement xchg_xen_ulong
 
 Remove !CPU_V6 build dependency:
 - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
   CONFIG_CPU_V6
 - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
 
 Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
 CC: a...@arndb.de
 CC: li...@arm.linux.org.uk
 CC: will.dea...@arm.com
 CC: catalin.mari...@arm.com
 CC: linux-arm-ker...@lists.infradead.org
 CC: linux-kernel@vger.kernel.org
 CC: xen-de...@lists.xenproject.org

  Reviewed-by: Will Deacon will.dea...@arm.com

Cheers Stefano,

Will
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Re: [PATCH v4] arm: remove !CPU_V6 and !GENERIC_ATOMIC64 build dependencies for XEN

2014-01-21 Thread Stefano Stabellini
On Tue, 21 Jan 2014, Will Deacon wrote:
 On Tue, Jan 21, 2014 at 01:44:24PM +, Stefano Stabellini wrote:
  Remove !GENERIC_ATOMIC64 build dependency:
  - introduce xen_atomic64_xchg
  - use it to implement xchg_xen_ulong
  
  Remove !CPU_V6 build dependency:
  - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef
CONFIG_CPU_V6
  - implement sync_cmpxchg using __cmpxchg8 and __cmpxchg16
  
  Signed-off-by: Stefano Stabellini stefano.stabell...@eu.citrix.com
  CC: a...@arndb.de
  CC: li...@arm.linux.org.uk
  CC: will.dea...@arm.com
  CC: catalin.mari...@arm.com
  CC: linux-arm-ker...@lists.infradead.org
  CC: linux-kernel@vger.kernel.org
  CC: xen-de...@lists.xenproject.org
 
   Reviewed-by: Will Deacon will.dea...@arm.com
 
 Cheers Stefano,

Thanks!!
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