Re: [PATCH v5 3/5] arm64: smp: Allocate and setup IPI as NMI

On Mon, 19 Oct 2020 at 17:29, Marc Zyngier [off-list ref] wrote:

On 2020-10-14 12:12, Sumit Garg wrote:

quoted

Allocate an unused IPI that can be turned as NMI using ipi_nmi
framework.

This doesn't do any allocation, as far as I can see. It relies on
the initial grant from the interrupt controller to be larger than
what the kernel currently uses.

Okay, will update the commit message as s/Allocate/Assign/.

-Sumit

quoted

Also, invoke corresponding NMI setup/teardown APIs.

Signed-off-by: Sumit Garg <redacted>
---
 arch/arm64/kernel/smp.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 82e75fc..129ebfb 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c

@@ -43,6 +43,7 @@
 #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>

@@ -962,6 +963,8 @@ static void ipi_setup(int cpu)

      for (i = 0; i < nr_ipi; i++)
              enable_percpu_irq(ipi_irq_base + i, 0);
+
+     ipi_nmi_setup(cpu);
 }

 #ifdef CONFIG_HOTPLUG_CPU

@@ -974,6 +977,8 @@ static void ipi_teardown(int cpu)

      for (i = 0; i < nr_ipi; i++)
              disable_percpu_irq(ipi_irq_base + i);
+
+     ipi_nmi_teardown(cpu);
 }
 #endif

@@ -995,6 +1000,9 @@ 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_ipi_nmi(ipi_base + nr_ipi);
+
      ipi_irq_base = ipi_base;

      /* Setup the boot CPU immediately */

Thanks,

         M.
--
Jazz is not dead. It just smells funny...

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