[RFC Patch v1 2/4] irqchip/gic-v3: Add support to handle SGI as pseudo NMI

[Sumit Garg <sumit.garg@linaro.org>]

With pseudo NMIs enabled, interrupt controller can be configured to
deliver SGI as a pseudo NMI. So add corresponding handling for SGIs.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 drivers/irqchip/irq-gic-v3.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index d7006ef..be361bf 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -609,17 +609,29 @@ static inline void gic_handle_nmi(u32 irqnr, struct pt_regs *regs)
 	if (irqs_enabled)
 		nmi_enter();
 
-	if (static_branch_likely(&supports_deactivate_key))
-		gic_write_eoir(irqnr);
 	/*
 	 * Leave the PSR.I bit set to prevent other NMIs to be
 	 * received while handling this one.
 	 * PSR.I will be restored when we ERET to the
 	 * interrupted context.
 	 */
-	err = handle_domain_nmi(gic_data.domain, irqnr, regs);
-	if (err)
-		gic_deactivate_unhandled(irqnr);
+	if (likely(irqnr > 15)) {
+		if (static_branch_likely(&supports_deactivate_key))
+			gic_write_eoir(irqnr);
+
+		err = handle_domain_nmi(gic_data.domain, irqnr, regs);
+		if (err)
+			gic_deactivate_unhandled(irqnr);
+	} else {
+		gic_write_eoir(irqnr);
+		if (static_branch_likely(&supports_deactivate_key))
+			gic_write_dir(irqnr);
+#ifdef CONFIG_SMP
+		handle_IPI(irqnr, regs);
+#else
+		WARN_ONCE(true, "Unexpected SGI received!\n");
+#endif
+	}
 
 	if (irqs_enabled)
 		nmi_exit();
-- 
2.7.4