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authorAndrew Morton <akpm@linux-foundation.org>2009-01-09 12:27:08 -0800
committerIngo Molnar <mingo@elte.hu>2009-01-11 03:41:58 +0100
commit53ce3d9564908794ae7dd32969089b57df5fc098 (patch)
treed0eb540d9743155eff6d3c454db3493bf75c9023
parentabede81c4fb2e3b85d8760f25e3da39d2c69a134 (diff)
downloadlinux-sh-53ce3d9564908794ae7dd32969089b57df5fc098.tar.gz
smp_call_function_single(): be slightly less stupid
If you do smp_call_function_single(expression-with-side-effects, ...) then expression-with-side-effects never gets evaluated on UP builds. As always, implementing it in C is the correct thing to do. While we're there, uninline it for size and possible header dependency reasons. And create a new kernel/up.c, as a place in which to put uniprocessor-specific code and storage. It should mirror kernel/smp.c. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/smp.h13
-rw-r--r--kernel/Makefile6
-rw-r--r--kernel/up.c18
3 files changed, 26 insertions, 11 deletions
diff --git a/include/linux/smp.h b/include/linux/smp.h
index b82466968101..715196b09d67 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -24,6 +24,9 @@ struct call_single_data {
/* total number of cpus in this system (may exceed NR_CPUS) */
extern unsigned int total_cpus;
+int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
+ int wait);
+
#ifdef CONFIG_SMP
#include <linux/preempt.h>
@@ -79,8 +82,6 @@ smp_call_function_mask(cpumask_t mask, void(*func)(void *info), void *info,
return 0;
}
-int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
- int wait);
void __smp_call_function_single(int cpuid, struct call_single_data *data);
/*
@@ -140,14 +141,6 @@ static inline int up_smp_call_function(void (*func)(void *), void *info)
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
#define smp_prepare_boot_cpu() do {} while (0)
-#define smp_call_function_single(cpuid, func, info, wait) \
-({ \
- WARN_ON(cpuid != 0); \
- local_irq_disable(); \
- (func)(info); \
- local_irq_enable(); \
- 0; \
-})
#define smp_call_function_mask(mask, func, info, wait) \
(up_smp_call_function(func, info))
#define smp_call_function_many(mask, func, info, wait) \
diff --git a/kernel/Makefile b/kernel/Makefile
index 2921d90ce32f..2aebc4cd7878 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -40,7 +40,11 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
-obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o
+ifeq ($(CONFIG_USE_GENERIC_SMP_HELPERS),y)
+obj-y += smp.o
+else
+obj-y += up.o
+endif
obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
diff --git a/kernel/up.c b/kernel/up.c
new file mode 100644
index 000000000000..ce62cc9e9f71
--- /dev/null
+++ b/kernel/up.c
@@ -0,0 +1,18 @@
+/*
+ * Uniprocessor-only support functions. The counterpart to kernel/smp.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+ int wait)
+{
+ WARN_ON(cpuid != 0);
+ local_irq_disable();
+ (func)(info);
+ local_irq_enable();
+ return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single);