arm64: smp: Assign and setup an IPI as NMI

maillist inclusion
category: feature
bugzilla: 49593
CVE: NA
Reference: https://www.spinics.net/lists/arm-kernel/msg851005.html

-------------------------------------------------

Assign an unused IPI which can be turned as NMI using ipi_nmi framework.
Also, invoke corresponding dynamic IPI setup/teardown APIs.
Signed-off-by: NSumit Garg <sumit.garg@linaro.org>
Signed-off-by: NWei Li <liwei391@huawei.com>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/kernel/smp.c

@@ -46,6 +46,7 @@
 #include <asm/daifflags.h>
 #include <asm/kvm_mmu.h>
 #include <asm/mmu_context.h>
+#include <asm/nmi.h>
 #include <asm/numa.h>
 #include <asm/processor.h>
 #include <asm/smp_plat.h>
@@ -1159,6 +1160,8 @@ static void ipi_setup(int cpu)
 
 	for (i = 0; i < nr_ipi; i++)
 		enable_percpu_irq(ipi_irq_base + i, 0);
+
+	dynamic_ipi_setup(cpu);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -1171,6 +1174,8 @@ static void ipi_teardown(int cpu)
 
 	for (i = 0; i < nr_ipi; i++)
 		disable_percpu_irq(ipi_irq_base + i);
+
+	dynamic_ipi_teardown(cpu);
 }
 #endif
 
@@ -1192,6 +1197,9 @@ void __init set_smp_ipi_range(int ipi_base, int n)
 		irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
 	}
 
+	if (n > nr_ipi)
+		set_smp_dynamic_ipi(ipi_base + nr_ipi);
+
 	ipi_irq_base = ipi_base;
 
 	/* Setup the boot CPU immediately */