Re: [PATCH v5 2/5] irqchip/gic-v3: Enable support for SGIs to act as NMIs

On Mon, 19 Oct 2020 at 17:37, Marc Zyngier [off-list ref] wrote:

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

quoted

Add support to handle SGIs as regular NMIs. As SGIs or IPIs defaults to
a

There is nothing "regular" about NMIs.

Okay, will do s/regular/pseudo/.

Drop "or IPIs".
s/defaults/default/

Ack.

quoted

special flow handler: handle_percpu_devid_fasteoi_ipi(), so skip NMI
handler update in case of SGIs.

Also, enable NMI support prior to gic_smp_init() as allocation of SGIs
as IRQs/NMIs happen as part of this routine.

Signed-off-by: Sumit Garg <redacted>
---
 drivers/irqchip/irq-gic-v3.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c

b/drivers/irqchip/irq-gic-v3.c
index 16fecc0..5efc865 100644

--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c

@@ -477,6 +477,11 @@ static int gic_irq_nmi_setup(struct irq_data *d)
      if (WARN_ON(gic_irq(d) >= 8192))
              return -EINVAL;

+     if (get_intid_range(d) == SGI_RANGE) {
+             gic_irq_set_prio(d, GICD_INT_NMI_PRI);
+             return 0;
+     }
+

Please follow the existing control flow, or rework it to be organised by
range.

Okay.

quoted

      /* desc lock should already be held */
      if (gic_irq_in_rdist(d)) {
              u32 idx = gic_get_ppi_index(d);

@@ -514,6 +519,11 @@ static void gic_irq_nmi_teardown(struct irq_data

*d)
      if (WARN_ON(gic_irq(d) >= 8192))
              return;

+     if (get_intid_range(d) == SGI_RANGE) {
+             gic_irq_set_prio(d, GICD_INT_DEF_PRI);
+             return;
+     }

Same here.

Okay.

-Sumit

quoted

+
      /* desc lock should already be held */
      if (gic_irq_in_rdist(d)) {
              u32 idx = gic_get_ppi_index(d);

@@ -1708,6 +1718,7 @@ static int __init gic_init_bases(void __iomem

*dist_base,

      gic_dist_init();
      gic_cpu_init();
+     gic_enable_nmi_support();
      gic_smp_init();
      gic_cpu_pm_init();

@@ -1719,8 +1730,6 @@ static int __init gic_init_bases(void __iomem

*dist_base,
                      gicv2m_init(handle, gic_data.domain);
      }

-     gic_enable_nmi_support();
-
      return 0;

 out_free:

Thanks,

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

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