2007-11-28 21:17:57

by Christoph Lameter

Subject: [patch 06/10] s390: Use generic percpu

s390 has a special way to determine the pointer to a per cpu area
plus there is a way to access the base of the per cpu area of the
currently executing processor.

Note: I had to do a minor change to ASM code. Please check that
this was done right.

Cc: [email protected]
Signed-off-by: Christoph Lameter <[email protected]>

---
include/asm-s390/percpu.h | 33 +++++++++------------------------
1 file changed, 9 insertions(+), 24 deletions(-)

Index: linux-2.6.24-rc3-mm2/include/asm-s390/percpu.h
===================================================================
--- linux-2.6.24-rc3-mm2.orig/include/asm-s390/percpu.h 2007-11-28 12:51:42.448213150 -0800
+++ linux-2.6.24-rc3-mm2/include/asm-s390/percpu.h 2007-11-28 12:51:53.193400115 -0800
@@ -13,40 +13,25 @@
*/
#if defined(__s390x__) && defined(MODULE)

-#define __reloc_hide(var,offset) (*({ \
+#define SHIFT_PTR(ptr,offset) (({ \
extern int simple_identifier_##var(void); \
unsigned long *__ptr; \
- asm ( "larl %0,per_cpu__"#var"@GOTENT" \
- : "=a" (__ptr) : "X" (per_cpu__##var) ); \
- (typeof(&per_cpu__##var))((*__ptr) + (offset)); }))
+ asm ( "larl %0, %1@GOTENT" \
+ : "=a" (__ptr) : "X" (ptr) ); \
+ (typeof(ptr))((*__ptr) + (offset)); }))

#else

-#define __reloc_hide(var, offset) (*({ \
+#define SHIFT_PTR(ptr, offset) (({ \
extern int simple_identifier_##var(void); \
unsigned long __ptr; \
- asm ( "" : "=a" (__ptr) : "0" (&per_cpu__##var) ); \
- (typeof(&per_cpu__##var)) (__ptr + (offset)); }))
+ asm ( "" : "=a" (__ptr) : "0" (ptr) ); \
+ (typeof(ptr)) (__ptr + (offset)); }))

#endif

-#ifdef CONFIG_SMP
+#define __my_cpu_offset S390_lowcore.percpu_offset

-extern unsigned long __per_cpu_offset[NR_CPUS];
-
-#define __get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
-#define __raw_get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
-#define per_cpu(var,cpu) __reloc_hide(var,__per_cpu_offset[cpu])
-#define per_cpu_offset(x) (__per_cpu_offset[x])
-
-#else /* ! SMP */
-
-#define __get_cpu_var(var) __reloc_hide(var,0)
-#define __raw_get_cpu_var(var) __reloc_hide(var,0)
-#define per_cpu(var,cpu) __reloc_hide(var,0)
-
-#endif /* SMP */
-
-#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
+#include <asm-generic/percpu.h>

#endif /* __ARCH_S390_PERCPU__ */

--

2007-11-29 15:56:22

by Martin Schwidefsky

Subject: Re: [patch 06/10] s390: Use generic percpu

On Wed, 2007-11-28 at 13:09 -0800, Christoph Lameter wrote:
> s390 has a special way to determine the pointer to a per cpu area
> plus there is a way to access the base of the per cpu area of the
> currently executing processor.
>
> Note: I had to do a minor change to ASM code. Please check that
> this was done right.

Hi Christoph,

after fixing the trainwreck with Gregs kset changes I've got rc3-mm2
compiled with your percpu patches. The new s390 percpu code works fine:

Acked-by: Martin Schwidefsky <[email protected]>

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

2007-11-29 18:16:40

by Christoph Lameter

Subject: Re: [patch 06/10] s390: Use generic percpu

On Thu, 29 Nov 2007, Martin Schwidefsky wrote:

> On Wed, 2007-11-28 at 13:09 -0800, Christoph Lameter wrote:
> > s390 has a special way to determine the pointer to a per cpu area
> > plus there is a way to access the base of the per cpu area of the
> > currently executing processor.
> >
> > Note: I had to do a minor change to ASM code. Please check that
> > this was done right.
>
> Hi Christoph,
>
> after fixing the trainwreck with Gregs kset changes I've got rc3-mm2
> compiled with your percpu patches. The new s390 percpu code works fine:
>
> Acked-by: Martin Schwidefsky <[email protected]>

Thank you.