[PATCH v3 07/13] genirq, irq-gic-v3: Make NMI flow handlers use ->irq_ack() if available

Valentin Schneider
2021-06-29T12:51:30Z

Subsequent patches will make the gic-v3 irqchip use an ->irq_ack()
callback. As a preparation, make the NMI flow handlers call said callback
if it is available.

Since this departs from the fasteoi scheme of only issuing a suffix
->eoi(), rename the NMI flow handlers.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
---
drivers/irqchip/irq-gic-v3.c | 4 ++--
include/linux/irq.h | 4 ++--
kernel/irq/chip.c | 25 ++++++++++++++-----------
3 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 37a23aa6de37..af11396996e3 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -484,10 +484,10 @@ static int gic_irq_nmi_setup(struct irq_data *d)
/* Setting up PPI as NMI, only switch handler for first NMI */
if (!refcount_inc_not_zero(&ppi_nmi_refs[idx])) {
refcount_set(&ppi_nmi_refs[idx], 1);
- desc->handle_irq = handle_percpu_devid_fasteoi_nmi;
+ desc->handle_irq = handle_percpu_devid_nmi;
}
} else {
- desc->handle_irq = handle_fasteoi_nmi;
+ desc->handle_irq = handle_nmi;
}

gic_irq_set_prio(d, GICD_INT_NMI_PRI);
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 37075929e329..0b45e42812d6 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -669,8 +669,8 @@ extern void handle_percpu_devid_irq(struct irq_desc *desc);
extern void handle_bad_irq(struct irq_desc *desc);
extern void handle_nested_irq(unsigned int irq);

-extern void handle_fasteoi_nmi(struct irq_desc *desc);
-extern void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc);
+extern void handle_nmi(struct irq_desc *desc);
+extern void handle_percpu_devid_nmi(struct irq_desc *desc);

extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg);
extern int irq_chip_pm_get(struct irq_data *data);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c2ca6b748987..099bc7e13d1b 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -748,18 +748,16 @@ void handle_fasteoi_irq(struct irq_desc *desc)
EXPORT_SYMBOL_GPL(handle_fasteoi_irq);

/**
- * handle_fasteoi_nmi - irq handler for NMI interrupt lines
+ * handle_nmi - irq handler for NMI interrupt lines
* @desc: the interrupt description structure for this irq
*
* A simple NMI-safe handler, considering the restrictions
* from request_nmi.
*
- * Only a single callback will be issued to the chip: an ->eoi()
- * call when the interrupt has been serviced. This enables support
- * for modern forms of interrupt handlers, which handle the flow
- * details in hardware, transparently.
+ * An ->ack() callback will be issued before servicing the interrupt,
+ * followed by an ->eoi() call.
*/
-void handle_fasteoi_nmi(struct irq_desc *desc)
+void handle_nmi(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
@@ -768,6 +766,9 @@ void handle_fasteoi_nmi(struct irq_desc *desc)

__kstat_incr_irqs_this_cpu(desc);

+ if (chip->irq_ack)
+ chip->irq_ack(&desc->irq_data);
+
trace_irq_handler_entry(irq, action);
/*
* NMIs cannot be shared, there is only one action.
@@ -778,7 +779,7 @@ void handle_fasteoi_nmi(struct irq_desc *desc)
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
-EXPORT_SYMBOL_GPL(handle_fasteoi_nmi);
+EXPORT_SYMBOL_GPL(handle_nmi);

/**
* handle_edge_irq - edge type IRQ handler
@@ -1032,14 +1033,13 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
}

/**
- * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
+ * handle_percpu_devid_nmi - Per CPU local NMI handler with per cpu
* dev ids
* @desc: the interrupt description structure for this irq
*
- * Similar to handle_fasteoi_nmi, but handling the dev_id cookie
- * as a percpu pointer.
+ * Similar to handle_nmi, but handling the dev_id cookie as a percpu pointer.
*/
-void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)
+void handle_percpu_devid_nmi(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
@@ -1048,6 +1048,9 @@ void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)

__kstat_incr_irqs_this_cpu(desc);

+ if (chip->irq_ack)
+ chip->irq_ack(&desc->irq_data);
+
trace_irq_handler_entry(irq, action);
res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
trace_irq_handler_exit(irq, action, res);
--
2.25.1