Add generic helpers for arch IPI function calls

This adds kernel/smp.c which contains helpers for IPI function calls. In addition to supporting the existing smp_call_function() in a more efficient manner, it also adds a more scalable variant called smp_call_function_single() for calling a given function on a single CPU only. The core of this is based on the x86-64 patch from Nick Piggin, lots of changes since then. "Alan D. Brunelle" <[email protected]> has contributed lots of fixes and suggestions as well. Also thanks to Paul E. McKenney <[email protected]> for reviewing RCU usage and getting rid of the data allocation fallback deadlock. Acked-by: Ingo Molnar <[email protected]> Reviewed-by: Paul E. McKenney <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
faux123 · Jun 26, 2008 · 3d44223 · 3d44223
1 parent 543cf4c
commit 3d44223
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Showing 6 changed files with 428 additions and 7 deletions.
diff --git a/arch/Kconfig b/arch/Kconfig
@@ -39,3 +39,6 @@ config HAVE_KRETPROBES
 
 config HAVE_DMA_ATTRS
 	def_bool n
+
+config USE_GENERIC_SMP_HELPERS
+	def_bool n
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
@@ -816,8 +816,9 @@ extern unsigned long xcall_call_function;
  * You must not call this function with disabled interrupts or from a
  * hardware interrupt handler or from a bottom half handler.
  */
-static int smp_call_function_mask(void (*func)(void *info), void *info,
-				  int nonatomic, int wait, cpumask_t mask)
+static int sparc64_smp_call_function_mask(void (*func)(void *info), void *info,
+					  int nonatomic, int wait,
+					  cpumask_t mask)
 {
 	struct call_data_struct data;
 	int cpus;
@@ -855,8 +856,8 @@ static int smp_call_function_mask(void (*func)(void *info), void *info,
 int smp_call_function(void (*func)(void *info), void *info,
 		      int nonatomic, int wait)
 {
-	return smp_call_function_mask(func, info, nonatomic, wait,
-				      cpu_online_map);
+	return sparc64_smp_call_function_mask(func, info, nonatomic, wait,
+						cpu_online_map);
 }
 
 void smp_call_function_client(int irq, struct pt_regs *regs)
@@ -893,7 +894,7 @@ static void tsb_sync(void *info)
 
 void smp_tsb_sync(struct mm_struct *mm)
 {
-	smp_call_function_mask(tsb_sync, mm, 0, 1, mm->cpu_vm_mask);
+	sparc64_smp_call_function_mask(tsb_sync, mm, 0, 1, mm->cpu_vm_mask);
 }
 
 extern unsigned long xcall_flush_tlb_mm;

diff --git a/include/linux/smp.h b/include/linux/smp.h
@@ -7,9 +7,19 @@
  */
 
 #include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
 
 extern void cpu_idle(void);
 
+struct call_single_data {
+	struct list_head list;
+	void (*func) (void *info);
+	void *info;
+	unsigned int flags;
+};
+
 #ifdef CONFIG_SMP
 
 #include <linux/preempt.h>
@@ -53,9 +63,28 @@ extern void smp_cpus_done(unsigned int max_cpus);
  * Call a function on all other processors
  */
 int smp_call_function(void(*func)(void *info), void *info, int retry, int wait);
-
+int smp_call_function_mask(cpumask_t mask, void(*func)(void *info), void *info,
+				int wait);
 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 				int retry, int wait);
+void __smp_call_function_single(int cpuid, struct call_single_data *data);
+
+/*
+ * Generic and arch helpers
+ */
+#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
+void generic_smp_call_function_single_interrupt(void);
+void generic_smp_call_function_interrupt(void);
+void init_call_single_data(void);
+void ipi_call_lock(void);
+void ipi_call_unlock(void);
+void ipi_call_lock_irq(void);
+void ipi_call_unlock_irq(void);
+#else
+static inline void init_call_single_data(void)
+{
+}
+#endif
 
 /*
  * Call a function on all processors
@@ -112,7 +141,9 @@ static inline void smp_send_reschedule(int cpu) { }
 })
 #define smp_call_function_mask(mask, func, info, wait) \
 			(up_smp_call_function(func, info))
-
+static inline void init_call_single_data(void)
+{
+}
 #endif /* !SMP */
 
 /*

diff --git a/init/main.c b/init/main.c
@@ -31,6 +31,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/start_kernel.h>
 #include <linux/security.h>
+#include <linux/smp.h>
 #include <linux/workqueue.h>
 #include <linux/profile.h>
 #include <linux/rcupdate.h>
@@ -779,6 +780,7 @@ static void __init do_pre_smp_initcalls(void)
 {
 	extern int spawn_ksoftirqd(void);
 
+	init_call_single_data();
 	migration_init();
 	spawn_ksoftirqd();
 	if (!nosoftlockup)

diff --git a/kernel/Makefile b/kernel/Makefile
@@ -28,6 +28,7 @@ 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_SMP) += cpu.o spinlock.o
+obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_UID16) += uid16.o