From 539da7877275edb21a76aa02fb2c147eff02c559 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 4 Nov 2015 22:57:00 +0000 Subject: [PATCH] x86/apic: Add a single-target IPI function to the apic We still fall back on the "send mask" versions if an apic definition doesn't have the single-target version, but at least this allows the (trivial) case for the common clustered x2apic case. Signed-off-by: Linus Torvalds Reviewed-by: Ingo Molnar Cc: Borislav Petkov Cc: Peter Zijlstra Cc: Mike Travis Cc: Daniel J Blueman Link: http://lkml.kernel.org/r/20151104220848.737120838@linutronix.de Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/apic.h | 1 + arch/x86/kernel/smp.c | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index a30316bf801a..7f62ad47d7e4 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -303,6 +303,7 @@ struct apic { unsigned int *apicid); /* ipi */ + void (*send_IPI)(int cpu, int vector); void (*send_IPI_mask)(const struct cpumask *mask, int vector); void (*send_IPI_mask_allbutself)(const struct cpumask *mask, int vector); diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 12c8286206ce..1dbf590cdd89 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -114,6 +114,18 @@ static atomic_t stopping_cpu = ATOMIC_INIT(-1); static bool smp_no_nmi_ipi = false; +/* + * Helper wrapper: not all apic definitions support sending to + * a single CPU, so we fall back to sending to a mask. + */ +static void send_IPI_cpu(int cpu, int vector) +{ + if (apic->send_IPI) + apic->send_IPI(cpu, vector); + else + apic->send_IPI_mask(cpumask_of(cpu), vector); +} + /* * this function sends a 'reschedule' IPI to another CPU. * it goes straight through and wastes no time serializing @@ -125,12 +137,12 @@ static void native_smp_send_reschedule(int cpu) WARN_ON(1); return; } - apic->send_IPI_mask(cpumask_of(cpu), RESCHEDULE_VECTOR); + send_IPI_cpu(cpu, RESCHEDULE_VECTOR); } void native_send_call_func_single_ipi(int cpu) { - apic->send_IPI_mask(cpumask_of(cpu), CALL_FUNCTION_SINGLE_VECTOR); + send_IPI_cpu(cpu, CALL_FUNCTION_SINGLE_VECTOR); } void native_send_call_func_ipi(const struct cpumask *mask)