powerpc: Remove call sites of MSG_ALL_BUT_SELF

The only user of MSG_ALL_BUT_SELF in the whole kernel tree is powerpc,
and it only uses it to start the debugger. Both debuggers always call
smp_send_debugger_break with MSG_ALL_BUT_SELF, and only mpic can do
anything more optimal than a loop over all online cpus, but all message
passing implementations have to code for this special delivery target.

Convert smp_send_debugger_break to take void and loop calling the smp_ops
message_pass function for each of the other cpus in the online cpumask.

Use raw_smp_processor_id() because we are either entering the debugger
or trying to start kdump and the additional warning it not useful were
it to trigger.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 13 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 87517ab6d36..b7441144692 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -218,11 +218,18 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask)
                 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 }
 
-#ifdef CONFIG_DEBUGGER
-void smp_send_debugger_break(int cpu)
+#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
+void smp_send_debugger_break(void)
 {
-        if (likely(smp_ops))
-                smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
+        int cpu;
+        int me = raw_smp_processor_id();
+
+        if (unlikely(!smp_ops))
+                return;
+
+        for_each_online_cpu(cpu)
+                if (cpu != me)
+                        smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 }
 #endif
 
@@ -230,9 +237,9 @@ void smp_send_debugger_break(int cpu)
 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 {
         crash_ipi_function_ptr = crash_ipi_callback;
-        if (crash_ipi_callback && smp_ops) {
+        if (crash_ipi_callback) {
                 mb();
-                smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
+                smp_send_debugger_break();
         }
 }
 #endif