[PATCH v2 05/11] genirq: Introduce kconfig option GENERIC_PENDING_IRQ_CHIPFLAGS

Anup Patel
2024-12-14T17:32:54Z

From: Thomas Gleixner <tglx@linutronix.de>

Introduce kconfig option GENERIC_PENDING_IRQ_CHIPFLAGS which allows
irq core to set IRQD_MOVE_PCNTXT flag based on IRQCHIP_MOVE_DEFERRED
flag.

This kconfig option will help architectures such as x86 and RISC-V
to mark top-level irqchip instances where irqs can't be moved in
the process context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
include/linux/irq.h | 10 ++++++++++
kernel/irq/Kconfig | 4 ++++
kernel/irq/chip.c | 39 ++++++++++++++++++++++++++++++++++++---
kernel/irq/irqdomain.c | 1 +
4 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index fa711f80957b..b689c8fe8d60 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -567,6 +567,7 @@ struct irq_chip {
* in the suspend path if they are in disabled state
* IRQCHIP_AFFINITY_PRE_STARTUP: Default affinity update before startup
* IRQCHIP_IMMUTABLE: Don't ever change anything in this chip
+ * IRQCHIP_MOVE_DEFERRED: Move the interrupt in actual interrupt context
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
@@ -581,6 +582,7 @@ enum {
IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND = (1 << 9),
IRQCHIP_AFFINITY_PRE_STARTUP = (1 << 10),
IRQCHIP_IMMUTABLE = (1 << 11),
+ IRQCHIP_MOVE_DEFERRED = (1 << 12),
};

#include <linux/irqdesc.h>
@@ -634,6 +636,14 @@ static inline void irq_move_masked_irq(struct irq_data *data) { }
static inline void irq_force_complete_move(struct irq_desc *desc) { }
#endif

+#if defined(CONFIG_GENERIC_PENDING_IRQ_CHIPFLAGS)
+void irq_update_pcntxt_flag(unsigned int irq, const struct irq_chip *chip);
+#else
+static inline void irq_update_pcntxt_flag(unsigned int irq, const struct irq_chip *chip)
+{
+}
+#endif
+
extern int no_irq_affinity;

#ifdef CONFIG_HARDIRQS_SW_RESEND
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 529adb1f5859..6d85a47fbf41 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -31,6 +31,10 @@ config GENERIC_IRQ_EFFECTIVE_AFF_MASK
config GENERIC_PENDING_IRQ
bool

+# Deduce delayed migration from top-level interrupt chip flags
+config GENERIC_PENDING_IRQ_CHIPFLAGS
+ bool
+
# Support for generic irq migrating off cpu before the cpu is offline.
config GENERIC_IRQ_MIGRATION
bool
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 271e9139de77..623959a24464 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -33,6 +33,33 @@ struct irqaction chained_action = {
.handler = bad_chained_irq,
};

+#ifdef CONFIG_GENERIC_PENDING_IRQ_CHIPFLAGS
+static void __irq_update_pcntxt_flag(struct irq_desc *desc,
+ const struct irq_chip *chip)
+{
+ if (chip) {
+ if (chip->flags & IRQCHIP_MOVE_DEFERRED)
+ irqd_clear(&desc->irq_data, IRQD_MOVE_PCNTXT);
+ else
+ irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
+ }
+}
+
+void irq_update_pcntxt_flag(unsigned int irq, const struct irq_chip *chip)
+{
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
+
+ __irq_update_pcntxt_flag(desc, chip);
+ irq_put_desc_unlock(desc, flags);
+}
+#else
+static inline void __irq_update_pcntxt_flag(struct irq_desc *desc,
+ const struct irq_chip *chip)
+{
+}
+#endif
+
/**
* irq_set_chip - set the irq chip for an irq
* @irq: irq number
@@ -47,6 +74,7 @@ int irq_set_chip(unsigned int irq, const struct irq_chip *chip)
return -EINVAL;

desc->irq_data.chip = (struct irq_chip *)(chip ?: &no_irq_chip);
+ __irq_update_pcntxt_flag(desc, chip);
irq_put_desc_unlock(desc, flags);
/*
* For !CONFIG_SPARSE_IRQ make the irq show up in
@@ -1114,16 +1142,21 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
trigger = irqd_get_trigger_type(&desc->irq_data);

irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
- IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
+ IRQD_TRIGGER_MASK | IRQD_LEVEL);
if (irq_settings_has_no_balance_set(desc))
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
if (irq_settings_is_per_cpu(desc))
irqd_set(&desc->irq_data, IRQD_PER_CPU);
- if (irq_settings_can_move_pcntxt(desc))
- irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
if (irq_settings_is_level(desc))
irqd_set(&desc->irq_data, IRQD_LEVEL);

+ /* Keep this around until x86 is converted over */
+ if (!IS_ENABLED(CONFIG_GENERIC_PENDING_IRQ_CHIPFLAGS)) {
+ irqd_clear(&desc->irq_data, IRQD_MOVE_PCNTXT);
+ if (irq_settings_can_move_pcntxt(desc))
+ irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
+ }
+
tmp = irq_settings_get_trigger_mask(desc);
if (tmp != IRQ_TYPE_NONE)
trigger = tmp;
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index ec6d8e72d980..ec5fc1d8cebe 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1508,6 +1508,7 @@ int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
irq_data->hwirq = hwirq;
irq_data->chip = (struct irq_chip *)(chip ? chip : &no_irq_chip);
irq_data->chip_data = chip_data;
+ irq_update_pcntxt_flag(virq, chip);

return 0;