[PATCH] [MIPS] Add smp_call_function_single.

[pwatkins@sicortex.com]

From: Peter Watkins <pwatkins@gsrv020.sicortex.com>

Signed-off-by: Peter Watkins <pwatkins@gsrv020.sicortex.com>
---
 arch/mips/kernel/smp.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/asm-mips/smp.h |    2 ++
 2 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 67edfa7..26f0f55 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -203,6 +203,56 @@ void smp_call_function_interrupt(void)
        }
 }
 
+int smp_call_function_single (int cpu, void (*func) (void *info), void *info, 
int retry,
+                             int wait)
+{
+       struct call_data_struct data;
+       int me = smp_processor_id();
+
+       /*
+        * Can die spectacularly if this CPU isn't yet marked online
+        */
+       BUG_ON(!cpu_online(me));
+
+       if (cpu == me) {
+               WARN_ON(1);
+               return -EBUSY;
+       }
+
+       if (!cpu_online(cpu))
+               return 0;
+
+       /* Can deadlock when called with interrupts disabled */
+       WARN_ON(irqs_disabled());
+
+       data.func = func;
+       data.info = info;
+       atomic_set(&data.started, 0);
+       data.wait = wait;
+       if (wait)
+               atomic_set(&data.finished, 0);
+
+       spin_lock(&smp_call_lock);
+       call_data = &data;
+       smp_mb();
+
+       /* Send a message to the other CPU */
+       core_send_ipi(cpu, SMP_CALL_FUNCTION);
+
+       /* Wait for response */
+       /* FIXME: lock-up detection, backtrace on lock-up */
+       while (atomic_read(&data.started) != 1)
+               barrier();
+
+       if (wait)
+               while (atomic_read(&data.finished) != 1)
+                       barrier();
+       call_data = NULL;
+       spin_unlock(&smp_call_lock);
+
+       return 0;
+}
+
 static void stop_this_cpu(void *dummy)
 {
        /*
diff --git a/include/asm-mips/smp.h b/include/asm-mips/smp.h
index 1608fd7..1aa6bb4 100644
--- a/include/asm-mips/smp.h
+++ b/include/asm-mips/smp.h
@@ -109,6 +109,8 @@ static inline void smp_send_reschedule(i
        core_send_ipi(cpu, SMP_RESCHEDULE_YOURSELF);
 }
 
+extern int smp_call_function_single(int cpuid, void (*func) (void *info),
+                               void *info, int retry, int wait);
 extern asmlinkage void smp_call_function_interrupt(void);
 
 #endif /* CONFIG_SMP */
-- 
1.4.2.4