From: Ingo Molnar <mingo@elte.hu>

add per-arch sched_cacheflush() which is a write-back cacheflush used by
the migration-cost calibration code at bootup time.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 include/asm-i386/system.h   |    9 +++++++++
 include/asm-ia64/system.h   |    9 +++++++++
 include/asm-ppc64/system.h  |    9 +++++++++
 include/asm-x86_64/system.h |    9 +++++++++
 kernel/sched.c              |   17 -----------------
 5 files changed, 36 insertions(+), 17 deletions(-)

diff -puN include/asm-i386/system.h~sched-add-cacheflush-asm include/asm-i386/system.h
--- 25/include/asm-i386/system.h~sched-add-cacheflush-asm	2005-06-25 01:17:14.000000000 -0700
+++ 25-akpm/include/asm-i386/system.h	2005-06-25 01:17:14.000000000 -0700
@@ -469,6 +469,15 @@ void enable_hlt(void);
 extern int es7000_plat;
 void cpu_idle_wait(void);
 
+/*
+ * On SMP systems, when the scheduler does migration-cost autodetection,
+ * it needs a way to flush as much of the CPU's caches as possible:
+ */
+static inline void sched_cacheflush(void)
+{
+	wbinvd();
+}
+
 extern unsigned long arch_align_stack(unsigned long sp);
 
 #endif
diff -puN include/asm-ia64/system.h~sched-add-cacheflush-asm include/asm-ia64/system.h
--- 25/include/asm-ia64/system.h~sched-add-cacheflush-asm	2005-06-25 01:17:14.000000000 -0700
+++ 25-akpm/include/asm-ia64/system.h	2005-06-25 01:17:14.000000000 -0700
@@ -278,6 +278,15 @@ extern void ia64_load_extra (struct task
 
 void cpu_idle_wait(void);
 
+/*
+ * On SMP systems, when the scheduler does migration-cost autodetection,
+ * it needs a way to flush as much of the CPU's caches as possible.
+ */
+static inline void sched_cacheflush(void)
+{
+	ia64_sal_cache_flush(1);
+}
+
 #define arch_align_stack(x) (x)
 
 #endif /* __KERNEL__ */
diff -puN include/asm-ppc64/system.h~sched-add-cacheflush-asm include/asm-ppc64/system.h
--- 25/include/asm-ppc64/system.h~sched-add-cacheflush-asm	2005-06-25 01:17:14.000000000 -0700
+++ 25-akpm/include/asm-ppc64/system.h	2005-06-25 01:17:14.000000000 -0700
@@ -141,6 +141,15 @@ struct thread_struct;
 extern struct task_struct * _switch(struct thread_struct *prev,
 				    struct thread_struct *next);
 
+/*
+ * On SMP systems, when the scheduler does migration-cost autodetection,
+ * it needs a way to flush as much of the CPU's caches as possible.
+ * TODO: how do you cacheflush on ppc64?
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 static inline int __is_processor(unsigned long pv)
 {
 	unsigned long pvr;
diff -puN include/asm-x86_64/system.h~sched-add-cacheflush-asm include/asm-x86_64/system.h
--- 25/include/asm-x86_64/system.h~sched-add-cacheflush-asm	2005-06-25 01:17:14.000000000 -0700
+++ 25-akpm/include/asm-x86_64/system.h	2005-06-25 01:17:14.000000000 -0700
@@ -180,6 +180,15 @@ static inline void write_cr4(unsigned lo
 #define wbinvd() \
 	__asm__ __volatile__ ("wbinvd": : :"memory");
 
+/*
+ * On SMP systems, when the scheduler does migration-cost autodetection,
+ * it needs a way to flush as much of the CPU's caches as possible.
+ */
+static inline void sched_cacheflush(void)
+{
+	wbinvd();
+}
+
 #endif	/* __KERNEL__ */
 
 #define nop() __asm__ __volatile__ ("nop")
diff -puN kernel/sched.c~sched-add-cacheflush-asm kernel/sched.c
--- 25/kernel/sched.c~sched-add-cacheflush-asm	2005-06-25 01:17:14.000000000 -0700
+++ 25-akpm/kernel/sched.c	2005-06-25 01:17:14.000000000 -0700
@@ -5089,23 +5089,6 @@ __init static void touch_cache(void *__c
 	}
 }
 
-// FIXME: move sched_cacheflush into arch include files:
-
-#ifdef CONFIG_IA64
-# include <asm/sal.h>
-#endif
-
-__init static void sched_cacheflush(void)
-{
-#ifdef CONFIG_X86
-	asm ("wbinvd");
-#elif defined(CONFIG_IA64)
-	ia64_sal_cache_flush(1); // what argument does d/cache flush?
-#else
-# warning implement sched_cacheflush()! Calibration results may be unreliable.
-#endif
-}
-
 /*
  * Measure the cache-cost of one task migration. Returns in units of nsec.
  */
_