MIPS: SMP-CPS: Add support for irq migration when CPU offline

Currently we won't migrate irqs when offline CPUs, which has been
implemented on most architectures. That will lead to some devices work
incorrectly if the bound cores are offline.

While that can be easily supported by enabling GENERIC_IRQ_MIGRATION.
But i don't pretty known the reason it was not supported on all MIPS
platforms.

This patch add the support for irq migration on MIPS CPS platform, and
it's tested on the interAptiv processor.

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b99498958b5c7a752cf85958fdbc6995eddf5855..b49a390df1cb7eebd3e67fca5a2f9c5c24ae5d6f 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2488,6 +2488,7 @@ config MIPS_CPS
        select SYS_SUPPORTS_SCHED_SMT if CPU_MIPSR6
        select SYS_SUPPORTS_SMP
        select WEAK_ORDERING
+       select GENERIC_IRQ_MIGRATION if HOTPLUG_CPU
        help
          Select this if you wish to run an SMP kernel across multiple cores
          within a MIPS Coherent Processing System. When this option is

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index dbb3f1fc71ab602a7da797816584b148eaea143a..8b027c72b8ef26beae20f94d432ce994b415c5ff 100644 (file)
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/smp.h>
 #include <linux/types.h>
+#include <linux/irq.h>
 
 #include <asm/bcache.h>
 #include <asm/mips-cps.h>
@@ -461,6 +462,7 @@ static int cps_cpu_disable(void)
        smp_mb__after_atomic();
        set_cpu_online(cpu, false);
        calculate_cpu_foreign_map();
+       irq_migrate_all_off_this_cpu();
 
        return 0;
 }