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powerpc: Remove call sites of MSG_ALL_BUT_SELF

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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>
This commit is contained in:
Milton Miller 2011-05-10 19:29:06 +00:00 committed by Benjamin Herrenschmidt
parent 2a116f3dd0
commit e047637132
4 changed files with 16 additions and 9 deletions
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2
arch/powerpc/include/asm/smp.h
View file

@ -35,7 +35,7 @@ extern void cpu_die(void);
#ifdef CONFIG_SMP
extern void smp_send_debugger_break(int cpu);
extern void smp_send_debugger_break(void);
extern void smp_message_recv(int);
extern void start_secondary_resume(void);

2
arch/powerpc/kernel/kgdb.c
View file

@ -109,7 +109,7 @@ static int kgdb_call_nmi_hook(struct pt_regs *regs)
#ifdef CONFIG_SMP
void kgdb_roundup_cpus(unsigned long flags)
{
smp_send_debugger_break(MSG_ALL_BUT_SELF);
smp_send_debugger_break();
}
#endif

19
arch/powerpc/kernel/smp.c
View file

@ -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

2
arch/powerpc/xmon/xmon.c
View file

@ -437,7 +437,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
xmon_owner = cpu;
mb();
if (ncpus > 1) {
smp_send_debugger_break(MSG_ALL_BUT_SELF);
smp_send_debugger_break();
/* wait for other cpus to come in */
for (timeout = 100000000; timeout != 0; --timeout) {
if (cpumask_weight(&cpus_in_xmon) >= ncpus)