[PATCH] sched: add cacheflush() asm

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 <[e-mail]>
Cc: Nick Piggin <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/ia64/kernel/setup.c

···
 #include <asm/smp.h>
 #include <asm/system.h>
 #include <asm/unistd.h>
+#include <asm/system.h>
 
 #if defined(CONFIG_SMP) && (IA64_CPU_SIZE > PAGE_SIZE)
 # error "struct cpuinfo_ia64 too big!"
···
 	__get_cpu_var(ia64_phys_stacked_size_p8) = num_phys_stacked*8 + 8;
 	platform_cpu_init();
 	pm_idle = default_idle;
+}
+
+/*
+ * 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.
+ */
+void sched_cacheflush(void)
+{
+	ia64_sal_cache_flush(3);
 }
 
 void

include/asm-alpha/system.h

···
 struct task_struct;
 extern struct task_struct *alpha_switch_to(unsigned long, struct task_struct*);
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 #define imb() \
 __asm__ __volatile__ ("call_pal %0 #imb" : : "i" (PAL_imb) : "memory")
 

include/asm-arm/system.h

···
 } while (0)
 
 /*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
+/*
  * CPU interrupt mask handling.
  */
 #if __LINUX_ARM_ARCH__ >= 6

include/asm-arm26/system.h

···
 } while (0)
 
 /*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
+/*
  * Save the current interrupt enable state & disable IRQs
  */
 #define local_irq_save(x)                               \

include/asm-i386/system.h

···
 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

include/asm-ia64/system.h

···
 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)
 
 void cpu_idle_wait(void);
+void sched_cacheflush(void);
 
 #define arch_align_stack(x) (x)
 

include/asm-m32r/system.h

···
 	last = __last; \
 } while(0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 /* Interrupt Control */
 #if !defined(CONFIG_CHIP_M32102) && !defined(CONFIG_CHIP_M32104)
 #define local_irq_enable() \

include/asm-mips/system.h

···
 		__restore_dsp(current);					\
 } while(0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
 {
 	__u32 retval;

include/asm-parisc/system.h

···
 	(last) = _switch_to(prev, next);			\
 } while(0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
 
 
 /* interrupt control */

include/asm-powerpc/system.h

···
 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 extern unsigned int rtas_data;
 extern int mem_init_done;	/* set on boot once kmalloc can be called */
 extern unsigned long memory_limit;

include/asm-ppc/system.h

···
 	struct task_struct *);
 #define switch_to(prev, next, last)	((last) = __switch_to((prev), (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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 struct thread_struct;
 extern struct task_struct *_switch(struct thread_struct *prev,
 				   struct thread_struct *next);

include/asm-s390/system.h

···
 	prev = __switch_to(prev,next);					     \
 } while (0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 extern void account_user_vtime(struct task_struct *);
 extern void account_system_vtime(struct task_struct *);

include/asm-sh/system.h

···
 	last = __last;							\
 } while (0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 #define nop() __asm__ __volatile__ ("nop")
 
 

include/asm-sparc/system.h

···
 	} while(0)
 
 /*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
+/*
  * Changing the IRQ level on the Sparc.
  */
 extern void local_irq_restore(unsigned long);

include/asm-sparc64/system.h

···
 	}								\
 } while(0)
 
+/*
+ * 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: fill this in!
+ */
+static inline void sched_cacheflush(void)
+{
+}
+
 static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
 {
 	unsigned long tmp1, tmp2;

include/asm-x86_64/system.h

···
 #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")